109 results on '"Markus Mezger"'
Search Results
2. Free Standing Dry and Stable Nanoporous Polymer Films Made through Mechanical Deformation
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Hsiao‐Ping Hsu, Manjesh K. Singh, Yu Cang, Héloïse Thérien‐Aubin, Markus Mezger, Rüdiger Berger, Ingo Lieberwirth, George Fytas, and Kurt Kremer
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free‐standing polymer film ,mechanical deformation ,polymer glass ,porosity ,Science - Abstract
Abstract A new straight forward approach to create nanoporous polymer membranes with well defined average pore diameters is presented. The method is based on fast mechanical deformation of highly entangled polymer films at high temperatures and a subsequent quench far below the glass transition temperature Tg. The process is first designed generally by simulation and then verified for the example of polystyrene films. The methodology does not need any chemical processing, supporting substrate, or self assembly process and is solely based on polymer inherent entanglement effects. Pore diameters are of the order of ten polymer reptation tube diameters. The resulting membranes are stable over months at ambient conditions and display remarkable elastic properties.
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- 2023
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3. Generation of a heterozygous and a homozygous CSF1R knockout line from iPSC using CRISPR/Cas9
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Anne S. Schmitz, Milena Korneck, Janani Raju, Andrés Lamsfus-Calle, Alberto Daniel-Moreno, Justin S. Antony, Markus Mezger, Ludger Schöls, Stefan Hauser, and Stefanie N. Hayer
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Biology (General) ,QH301-705.5 - Abstract
Mutations in Colony-stimulating factor 1 receptor (CSF1R) lead to CSF1R-related leukoencephalopathy, also known as Adult-onset leukoencephalopathy with axonal spheroids and pigmented glia (ALSP), a rapidly progressing neurodegenerative disease with severe cognitive and motor impairment. In this study, a homozygous and a heterozygous CSF1R knockout induced pluripotent stem cell (iPSC) line were generated by CRISPR/Cas9-based gene editing. These in vitro models will provide a helpful tool for investigating the still largely unknown pathophysiology of CSF1R-related leukoencephalopathy.
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- 2023
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4. A combination of metformin and epigallocatechin gallate potentiates glioma chemotherapy in vivo
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Shreyas S. Kuduvalli, Precilla S. Daisy, Anandraj Vaithy, Mugilarasi Purushothaman, Arumugam Ramachandran Muralidharan, Kumar B. Agiesh, Markus Mezger, Justin S. Antony, Madhu Subramani, Biswajit Dubashi, Indrani Biswas, K. P. Guruprasad, and T. S. Anitha
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glioma ,metformin ,epigallocatechin gallate (EGCG) ,molecular docking ,quantum mechanics (QM) ,ROS-reactive oxygen species ,Therapeutics. Pharmacology ,RM1-950 - Abstract
Glioma is the most devastating high-grade tumor of the central nervous system, with dismal prognosis. Existing treatment modality does not provide substantial benefit to patients and demands novel strategies. One of the first-line treatments for glioma, temozolomide, provides marginal benefit to glioma patients. Repurposing of existing non-cancer drugs to treat oncology patients is gaining momentum in recent years. In this study, we investigated the therapeutic benefits of combining three repurposed drugs, namely, metformin (anti-diabetic) and epigallocatechin gallate (green tea-derived antioxidant) together with temozolomide in a glioma-induced xenograft rat model. Our triple-drug combination therapy significantly inhibited tumor growth in vivo and increased the survival rate (50%) of rats when compared with individual or dual treatments. Molecular and cellular analyses revealed that our triple-drug cocktail treatment inhibited glioma tumor growth in rat model through ROS-mediated inactivation of PI3K/AKT/mTOR pathway, arrest of the cell cycle at G1 phase and induction of molecular mechanisms of caspases-dependent apoptosis.In addition, the docking analysis and quantum mechanics studies performed here hypothesize that the effect of triple-drug combination could have been attributed by their difference in molecular interactions, that maybe due to varying electrostatic potential. Thus, repurposing metformin and epigallocatechin gallate and concurrent administration with temozolomide would serve as a prospective therapy in glioma patients.
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- 2023
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5. Haploidentical hematopoietic stem cell transplantation as individual treatment option in pediatric patients with very high-risk sarcomas
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Thomas Eichholz, Michaela Döring, Stefano Giardino, Bernd Gruhn, Christian Seitz, Tim Flaadt, Wolfgang Schwinger, Martin Ebinger, Ursula Holzer, Markus Mezger, Heiko-Manuel Teltschik, Monika Sparber-Sauer, Ewa Koscielniak, Michael Abele, Rupert Handgretinger, and Peter Lang
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haploidentical hematopoietic stem cell transplantation ,pediatric sarcoma ,Ewing sarcoma ,soft tissue sarcoma ,rhabdomyosarcoma ,Neoplasms. Tumors. Oncology. Including cancer and carcinogens ,RC254-282 - Abstract
BackgroundPrognosis of children with primary disseminated or metastatic relapsed sarcomas remains dismal despite intensification of conventional therapies including high-dose chemotherapy. Since haploidentical hematopoietic stem cell transplantation (haplo-HSCT) is effective in the treatment of hematological malignancies by mediating a graft versus leukemia effect, we evaluated this approach in pediatric sarcomas as well.MethodsPatients with bone Ewing sarcoma or soft tissue sarcoma who received haplo-HSCT as part of clinical trials using CD3+ or TCRα/β+ and CD19+ depletion respectively were evaluated regarding feasibility of treatment and survival.ResultsWe identified 15 patients with primary disseminated disease and 14 with metastatic relapse who were transplanted from a haploidentical donor to improve prognosis. Three-year event-free survival (EFS) was 18,1% and predominantly determined by disease relapse. Survival depended on response to pre-transplant therapy (3y-EFS of patients in complete or very good partial response: 36,4%). However, no patient with metastatic relapse could be rescued.ConclusionHaplo-HSCT for consolidation after conventional therapy seems to be of interest for some, but not for the majority of patients with high-risk pediatric sarcomas. Evaluation of its future use as basis for subsequent humoral or cellular immunotherapies is necessary.
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- 2023
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6. CRISPR medicine for blood disorders: Progress and challenges in delivery
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Tahereh Mohammadian Gol, Guillermo Ureña-Bailén, Yujuan Hou, Ralph Sinn, Justin S. Antony, Rupert Handgretinger, and Markus Mezger
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CRISPR/Cas ,blood disorder ,physical delivery ,viral vectors ,non-viral vectors ,Biotechnology ,TP248.13-248.65 ,Genetics ,QH426-470 - Abstract
Blood disorders are a group of diseases including hematological neoplasms, clotting disorders and orphan immune deficiency diseases that affects human health. Current improvements in genome editing based therapeutics demonstrated preclinical and clinical proof to treat different blood disorders. Genome editing components such as Cas nucleases, guide RNAs and base editors are supplied in the form of either a plasmid, an mRNA, or a ribonucleoprotein complex. The most common delivery vehicles for such components include viral vectors (e.g., AAVs and RV), non-viral vectors (e.g., LNPs and polymers) and physical delivery methods (e.g., electroporation and microinjection). Each of the delivery vehicles specified above has its own advantages and disadvantages and the development of a safe transferring method for ex vivo and in vivo application of genome editing components is still a big challenge. Moreover, the delivery of genome editing payload to the target blood cells possess key challenges to provide a possible cure for patients with inherited monogenic blood diseases and hematological neoplastic tumors. Here, we critically review and summarize the progress and challenges related to the delivery of genome editing elements to relevant blood cells in an ex vivo or in vivo setting. In addition, we have attempted to provide a future clinical perspective of genome editing to treat blood disorders with possible clinical grade improvements in delivery methods.
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- 2023
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7. Complex coacervation of food grade antimicrobial lauric arginate with lambda carrageenan
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Trivikram Nallamilli, Markus Ketomaeki, Domenik Prozeller, Julian Mars, Svenja Morsbach, Markus Mezger, and Thomas Vilgis
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Isothermal titration calorimetry ,Small angle X ray scattering ,Turbidity ,Catanionic micelles ,Foam ,Zetapotential ,Nutrition. Foods and food supply ,TX341-641 ,Food processing and manufacture ,TP368-456 - Abstract
In this study, the complex coacervation mechanism of Lauric arginate ester (LAE) with λ-carrageenan was studied using turbidimetry, light scattering and electrophoresis. The complexes formed were found to have a bilayer-like structure using small angle X-ray scattering (SAXS) and cryo-TEM (transmission electron microscopy). It was observed that mixing LAE with Sodium dodecyl sulfate (SDS) could significantly reduce the interactions between mixed micelles and λ-carrageenan. The interactions between LAE/SDS and λ-carrageenan were found to be predominantly entropy driven. Mixed micelles of LAE/Tween 20 and LAE/SDS showed significantly less interactions with carrageenan compared to pure LAE micelles. Interfacial properties of complexes were measured using surface tension measurements. It was observed that pure LAE showed good foaming behavior and when mixed with increasing amounts of carrageenan the foaming capacity decreased. Reduction in foam volume was due to reduced availability of free LAE molecules for foam stabilization and due to hydrophilic nature of complexes.
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- 2021
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8. Immunomonitoring of Stage IV Relapsed Neuroblastoma Patients Undergoing Haploidentical Hematopoietic Stem Cell Transplantation and Subsequent GD2 (ch14.18/CHO) Antibody Treatment
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Christian Martin Seitz, Tim Flaadt, Markus Mezger, Anne-Marie Lang, Sebastian Michaelis, Marie Katz, Desireé Syring, Alexander Joechner, Armin Rabsteyn, Nikolai Siebert, Sascha Troschke-Meurer, Maxi Zumpe, Holger N. Lode, Sile F. Yang, Daniel Atar, Anna-Sophia Mast, Sophia Scheuermann, Florian Heubach, Rupert Handgretinger, Peter Lang, and Patrick Schlegel
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neuroblastoma ,immunomonitoring immunotherapy ,GD2 antibody therapy ,haploidentical allogeneic stem cell transplantation ,antibody-dependent cellular cytotoxicity ,complement-dependent cytotoxicity ,Immunologic diseases. Allergy ,RC581-607 - Abstract
Haploidentical stem cell transplantation (haplo SCT) in Stage IV neuroblastoma relapsed patients has been proven efficacious, while immunotherapy utilizing the anti-GD2 antibody dinutuximab beta has become a standard treatment for neuroblastoma. The combinatorial therapy of haplo SCT and dinutuximab may potentiate the efficacy of the immunotherapy. To gain further understanding of the synergistic effects, functional immunomonitoring was assessed during the clinical trial CH14.18 1021 Antibody and IL2 After haplo SCT in Children with Relapsed Neuroblastoma (NCT02258815). Rapid immune reconstitution of the lymphoid compartment was confirmed, with clinically relevant dinutuximab serum levels found in all patients over the course of treatment. Only one patient developed human anti-chimeric antibodies (HACAs). In-patient monitoring revealed highly functional NK cell posttransplant capable of antibody-dependent cellular cytotoxicity (ADCC). Degranulation of NK cell subsets revealed a significant response increased by dinutuximab. This was irrespective of the KIR receptor–ligand constellation within the NK subsets, defined by the major KIR receptors CD158a, CD158b, and CD158e. Moreover, complement-dependent cytotoxicity (CDC) was shown to be an extremely potent effector-cell independent mechanism of tumor cell lysis, with a clear positive correlation to GD2 expression on the cancer cells as well as to the dinutuximab concentrations. The ex vivo testing of patient-derived effector cells and the sera collected during dinutuximab therapy demonstrated both high functionality of the newly established lymphoid immune compartment and provided confidence that the antibody dosing regimen was sufficient over the duration of the dinutuximab therapy (up to nine cycles in a 9-month period). During the course of the dinutuximab therapy, proinflammatory cytokines and markers (sIL2R, TNFa, IL6, and C reactive protein) were significantly elevated indicating a strong anti-GD2 immune response. No impact of FcGR polymorphism on event-free and overall survival was found. Collectively, this study has shown that in-patient functional immunomonitoring is feasible and valuable in contributing to the understanding of anti-cancer combinatorial treatments such as haplo SCT and antibody immunotherapy.
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- 2021
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9. RNA ImmunoGenic Assay: A Method to Detect Immunogenicity of in vitro Transcribed mRNA in Human Whole Blood
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AKM Haque, Petra Weinmann, Sumit Biswas, Rupert Handgretinger, Markus Mezger, Michael Kormann, and Justin Antony
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Biology (General) ,QH301-705.5 - Abstract
The mRNA therapeutics is a new class of medicine to treat many various diseases. However, in vitro transcribed (IVT) mRNA triggers immune responses due to recognition by human endosomal and cytoplasmic RNA sensors, but incorporation of modified nucleosides have been shown to reduce such responses. Therefore, an assay signifying important aspects of the human immune system is still required. Here, we present a simple ex vivo method called ‘RNA ImmunoGenic Assay’ to measure immunogenicity of IVT-mRNAs in human whole blood. Chemically modified and unmodified mRNA are complexed with a transfection reagent (TransIT), and co-incubated in human whole blood. Specific cytokines are measured (TNF-α, INF-α, INF-γ, IL-6 and IL-12p70) using ELISAs. The qPCR analysis is performed to reveal the activation of specific immune pathways. The RNA ImmunoGenic Assay provides a simple and fast method to detect donor specific - immune response against mRNA therapeutics.Graphic abstract:Schematic representation of RNA ImmunoGenic Assay
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- 2020
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10. In Vitro Evaluation of CD276-CAR NK-92 Functionality, Migration and Invasion Potential in the Presence of Immune Inhibitory Factors of the Tumor Microenvironment
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Stefan Grote, Guillermo Ureña-Bailén, Kenneth Chun-Ho Chan, Caroline Baden, Markus Mezger, Rupert Handgretinger, and Sabine Schleicher
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CD276 ,B7-H3 ,chimeric antigen receptor ,NK-92 ,immune therapy ,melanoma ,Cytology ,QH573-671 - Abstract
Background: Melanoma is the most lethal of all skin-related cancers with incidences continuously rising. Novel therapeutic approaches are urgently needed, especially for the treatment of metastasizing or therapy-resistant melanoma. CAR-modified immune cells have shown excellent results in treating hematological malignancies and might represent a new treatment strategy for refractory melanoma. However, solid tumors pose some obstacles for cellular immunotherapy, including the identification of tumor-specific target antigens, insufficient homing and infiltration of immune cells as well as immune cell dysfunction in the immunosuppressive tumor microenvironment (TME). Methods: In order to investigate whether CAR NK cell-based immunotherapy can overcome the obstacles posed by the TME in melanoma, we generated CAR NK-92 cells targeting CD276 (B7-H3) which is abundantly expressed in solid tumors, including melanoma, and tested their effectivity in vitro in the presence of low pH, hypoxia and other known factors of the TME influencing anti-tumor responses. Moreover, the CRISPR/Cas9-induced disruption of the inhibitory receptor NKG2A was assessed for its potential enhancement of NK-92-mediated anti-tumor activity. Results: CD276-CAR NK-92 cells induced specific cytolysis of melanoma cell lines while being able to overcome a variety of the immunosuppressive effects normally exerted by the TME. NKG2A knock-out did not further improve CAR NK-92 cell-mediated cytotoxicity. Conclusions: The strong cytotoxic effect of a CD276-specific CAR in combination with an “off-the-shelf” NK-92 cell line not being impaired by some of the most prominent negative factors of the TME make CD276-CAR NK-92 cells a promising cellular product for the treatment of melanoma and beyond.
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- 2021
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11. Impact of Surface Chemistry and Doping Concentrations on Biofunctionalization of GaN/Ga‒In‒N Quantum Wells
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Nilanjon Naskar, Martin F. Schneidereit, Florian Huber, Sabyasachi Chakrabortty, Lothar Veith, Markus Mezger, Lutz Kirste, Theo Fuchs, Thomas Diemant, Tanja Weil, R. Jürgen Behm, Klaus Thonke, and Ferdinand Scholz
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n-type GaN ,p-type GaN ,biosensor ,chemical functionalization ,protein adsorption ,self-assembled monolayer ,Chemical technology ,TP1-1185 - Abstract
The development of sensitive biosensors, such as gallium nitride (GaN)-based quantum wells, transistors, etc., often makes it necessary to functionalize GaN surfaces with small molecules or even biomolecules, such as proteins. As a first step in surface functionalization, we have investigated silane adsorption, as well as the formation of very thin silane layers. In the next step, the immobilization of the tetrameric protein streptavidin (as well as the attachment of chemically modified iron transport protein ferritin (ferritin-biotin-rhodamine complex)) was realized on these films. The degree of functionalization of the GaN surfaces was determined by fluorescence measurements with fluorescent-labeled proteins; silane film thickness and surface roughness were estimated, and also other surface sensitive techniques were applied. The formation of a monolayer consisting of adsorbed organosilanes was accomplished on Mg-doped GaN surfaces, and also functionalization with proteins was achieved. We found that very high Mg doping reduced the amount of surface functionalized proteins. Most likely, this finding was a consequence of the lower concentration of ionizable Mg atoms in highly Mg-doped layers as a consequence of self-compensation effects. In summary, we could demonstrate the necessity of Mg doping for achieving reasonable bio-functionalization of GaN surfaces.
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- 2020
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12. Safety and Tolerance of Donor-Derived Mesenchymal Stem Cells in Pediatric Living-Donor Liver Transplantation: The MYSTEP1 Study
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Steffen Hartleif, Michael Schumm, Michaela Döring, Markus Mezger, Peter Lang, Marc H. Dahlke, Joachim Riethmüller, Alfred Königsrainer, Rupert Handgretinger, Silvio Nadalin, and Ekkehard Sturm
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Internal medicine ,RC31-1245 - Abstract
Background. Calcineurin inhibitors (CNI) have significantly improved patient and graft survival in pediatric liver transplantation (pLT). However, CNI toxicity leads to significant morbidity. Moreover, CNIs cannot prevent long-term allograft injury. Mesenchymal stem (stromal) cells (MSC) have potent immunomodulatory properties, which may promote allograft tolerance and ameliorate toxicity of high-dose CNI. The MYSTEP1 trial aims to investigate safety and feasibility of donor-derived MSCs in pLT. Methods/Design. 7 to 10 children undergoing living-donor pLT will be included in this open-label, prospective pilot trial. A dose of 1 × 106 MSCs/kg body weight will be given at two time points: first by intraportal infusion intraoperatively and second by intravenous infusion on postoperative day 2. In addition, participants will receive standard immunosuppressive treatment. Our primary objective is to assess the safety of intraportal and intravenous MSC infusion in pLT recipients. Our secondary objective is to evaluate efficacy of MSC treatment as measured by the individual need for immunosuppression and the incidence of biopsy-proven acute rejection. We will perform detailed immune monitoring to investigate immunomodulatory effects. Discussion. Our study will provide information on the safety of donor-derived MSCs in pediatric living-donor liver transplantation and their effect on immunomodulation and graft survival.
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- 2017
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13. NKG2D Signaling Leads to NK Cell Mediated Lysis of Childhood AML
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Patrick Schlegel, Kerstin Ditthard, Peter Lang, Markus Mezger, Sebastian Michaelis, Rupert Handgretinger, and Matthias Pfeiffer
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Immunologic diseases. Allergy ,RC581-607 - Abstract
Natural killer cells have been shown to be relevant in the recognition and lysis of acute myeloid leukemia. In childhood acute lymphoblastic leukemia, it was shown that HLA I expression and KIR receptor-ligand mismatch significantly impact ALL cytolysis. We characterized 14 different primary childhood AML blasts by flow cytometry including NKG2D ligands. Further HLA I typing of blasts was performed and HLA I on the AML blasts was quantified. In two healthy volunteer NK cell donors HLA I typing and KIR genotyping were done. Blasts with high NKG2D ligand expression had significantly higher lysis by isolated NK cells. Grouping the blasts by NKG2D ligand expression led to a significant inverse correlation of HLA I expression and cytolysis in NKG2D low blasts. Furthermore, a significant positive correlation of NKG2D ligand expression and blast cytolysis was shown. No impact of KIR ligand-ligand mismatch was found but a significantly increased lysis of homozygous C2 blasts by KIR2DL1 negative NK cells (donor B) was revealed. In conclusion, NKG2D signaling leads to NK cell mediated lysis of childhood AML despite high HLA I expression.
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- 2015
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14. Eradication of Pulmonary Aspergillosis in an Adolescent Patient Undergoing Three Allogeneic Stem Cell Transplantations for Acute Lymphoblastic Leukemia
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Michaela Döring, Angelika Zierl, Markus Mezger, Peter Lang, Rupert Handgretinger, and Ingo Müller
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Surgery ,RD1-811 - Abstract
Systemic fungal infections are a major cause of infection-related mortality in patients with hematologic malignancies. This report addresses the case of an adolescent patient with acute lymphoblastic leukemia who underwent three allogeneic hematopoietic stem cell transplantations and developed pulmonary aspergillosis. Combination therapy with liposomal amphotericin B (L-AmB, 3 mg/kg bw/day) and caspofungin (CAS, 50 mg/day) during the first allogeneic hematopoietic stem cell transplantation (HSCT) improved the pulmonary situation. After shifting the antifungal combination therapy to oral voriconazole (2 × 200 mg/day) and CAS, a new pulmonal lesion occurred alongside the improvements in the existing pulmonary aspergillosis. An antifungal combination during a second HSCT with L-AmB (3 mg/kg bw/day) and CAS showed an improvement in the pulmonary aspergillosis. A combination therapy with CAS and L-AmB (1 mg/kg bw/day) during the third HSCT led once again to progress the pulmonary aspergillosis, after increasing the L-AMB to 3 mg/kg bw/day for recovery. The presented case provides an example of how, despite severe immunosuppression, a combination of antifungal drugs administered intravenously at therapeutic dosages may be more efficient than either intravenous monotherapy or combinations of intravenous and oral antifungals in selecting pediatric and adolescent patients with proven fungal infections.
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- 2012
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15. The temporal dynamics of differential gene expression in Aspergillus fumigatus interacting with human immature dendritic cells in vitro.
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Charles O Morton, John J Varga, Anke Hornbach, Markus Mezger, Helga Sennefelder, Susanne Kneitz, Oliver Kurzai, Sven Krappmann, Hermann Einsele, William C Nierman, Thomas R Rogers, and Juergen Loeffler
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Medicine ,Science - Abstract
Dendritic cells (DC) are the most important antigen presenting cells and play a pivotal role in host immunity to infectious agents by acting as a bridge between the innate and adaptive immune systems. Monocyte-derived immature DCs (iDC) were infected with viable resting conidia of Aspergillus fumigatus (Af293) for 12 hours at an MOI of 5; cells were sampled every three hours. RNA was extracted from both organisms at each time point and hybridised to microarrays. iDC cell death increased at 6 h in the presence of A. fumigatus which coincided with fungal germ tube emergence; >80% of conidia were associated with iDC. Over the time course A. fumigatus differentially regulated 210 genes, FunCat analysis indicated significant up-regulation of genes involved in fermentation, drug transport, pathogenesis and response to oxidative stress. Genes related to cytotoxicity were differentially regulated but the gliotoxin biosynthesis genes were down regulated over the time course, while Aspf1 was up-regulated at 9 h and 12 h. There was an up-regulation of genes in the subtelomeric regions of the genome as the interaction progressed. The genes up-regulated by iDC in the presence of A. fumigatus indicated that they were producing a pro-inflammatory response which was consistent with previous transcriptome studies of iDC interacting with A. fumigatus germ tubes. This study shows that A. fumigatus adapts to phagocytosis by iDCs by utilising genes that allow it to survive the interaction rather than just up-regulation of specific virulence genes.
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- 2011
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16. Automated Good Manufacturing Practice-Compatible CRISPR-Cas9 Editing of Hematopoietic Stem and Progenitor Cells for Clinical Treatment of β-Hemoglobinopathies
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Guillermo Ureña-Bailén, Milena Block, Tommaso Grandi, Faidra Aivazidou, Jona Quednau, Dariusz Krenz, Alberto Daniel-Moreno, Andrés Lamsfus-Calle, Thomas Epting, Rupert Handgretinger, Stefan Wild, and Markus Mezger
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Genetics ,Original Research ,Biotechnology - Abstract
Cellular therapies hold enormous potential for the cure of severe hematological and oncological disorders. The forefront of innovative gene therapy approaches including therapeutic gene editing and hematopoietic stem cell transplantation needs to be processed by good manufacturing practice to ensure safe application in patients. In the present study, an effective transfection protocol for automated clinical-scale production of genetically modified hematopoietic stem and progenitor cells (HSPCs) using the CliniMACS Prodigy(®) system including the CliniMACS Electroporator (Miltenyi Biotec) was established. As a proof-of-concept, the enhancer of the BCL11A gene, clustered regularly interspaced short palindromic repeat (CRISPR) target in ongoing clinical trials for β-thalassemia and sickle-cell disease treatment, was disrupted by the CRISPR-Cas9 system simulating a large-scale clinical scenario, yielding 100 million HSPCs with high editing efficiency. In vitro erythroid differentiation and high-performance liquid chromatography analyses corroborated fetal hemoglobin resurgence in edited samples, supporting the feasibility of running the complete process of HSPC gene editing in an automated closed system.
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- 2023
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17. Cohesion Gain Induced by Nanosilica Consolidants for Monumental Stone Restoration
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Joanna Dziadkowiec, Hsiu-Wei Cheng, Michael Ludwig, Matea Ban, Timon Pascal Tausendpfund, Regine von Klitzing, Markus Mezger, and Markus Valtiner
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Electrochemistry ,General Materials Science ,Surfaces and Interfaces ,Condensed Matter Physics ,Spectroscopy - Abstract
Mineral nanoparticle suspensions with consolidating properties have been successfully applied in the restoration of weathered architectural surfaces. However, the design of these consolidants is usually stone-specific and based on trial and error, which prevents their robust operation for a wide range of highly heterogeneous monumental stone materials. In this work, we develop a facile and versatile method to systematically study the consolidating mechanisms in action using a surface forces apparatus (SFA) with real-time force sensing and an X-ray surface forces apparatus (X-SFA). We directly assess the mechanical tensile strength of nanosilica-treated single mineral contacts and show a sharp increase in their cohesion. The smallest used nanoparticles provide an order of magnitude stronger contacts. We further resolve the microstructures and forces acting during evaporation-driven, capillary-force-induced nanoparticle aggregation processes, highlighting the importance of the interactions between the nanoparticles and the confining mineral walls. Our novel SFA-based approach offers insight into nano- and microscale mechanisms of consolidating silica treatments, and it can aid the design of nanomaterials used in stone consolidation.
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- 2022
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18. Transferring measurable residual disease measurement in pediatric acute lymphoblastic leukemia from quantitative real‐time <scp>PCR</scp> to digital droplet <scp>PCR</scp>
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Luise Luib, Hermann Kreyenberg, Sebastian Michaelis, Rupert Handgretinger, and Markus Mezger
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Transplantation ,Pediatrics, Perinatology and Child Health - Published
- 2023
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19. Time‐dependent analysis of adoptive immunotherapy following sequential FLAMSA‐reduced intensity conditioning and allogeneic hematopoietic stem cell transplantation in patients with high‐risk myeloid neoplasia
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Jan Frederic Weller, Markus Mezger, Leon Louis Seifert, Wichard Vogel, Dominik Schneidawind, Christoph Faul, Wolfgang Bethge, Claudia Lengerke, and Maximilian Christopeit
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Leukemia, Myeloid, Acute ,Transplantation Conditioning ,Hematopoietic Stem Cell Transplantation ,Graft vs Host Disease ,Humans ,Hematology ,General Medicine ,Neoplasm Recurrence, Local ,Immunotherapy, Adoptive ,Retrospective Studies - Abstract
Prophylactic donor lymphocyte infusions (DLI) are part of the sequential FLAMSA-reduced intensity conditioning (RIC) regimen to cure high risk myeloid neoplasia with allogeneic hematopoietic stem cell transplantation (HSCT). Although DLI themselves carry significant risks, their prophylactic use has not been analyzed in a time-dependent manner. One hundred and fourteen patients underwent FLAMSA-RIC HSCT between 2013 and 2020. Next to Kaplan-Meier estimation of overall, disease-free, and graft-versus-host relapse-free survival (OS, DFS, GRFS), cumulative incidences of relapse and death in remission were calculated in a competing risk model. Additionally, the contribution of prophylactic and preemptive DLI as time-dependent covariates was assessed using a time-varying model toward DFS (Simon-Makuch method, Mantel-Byar test). At 2 years, OS was 45.2% [95% CI 36.7-55.7%], DFS 31.8% [95% CI 24-42.2%] and GRFS 11.3 [95% CI 6.5-19.8]. Neither prophylactic nor preemptive DLI showed a significant influence on DFS when considered time-dependent covariates (Mantel-Byar, p = .3). This was further corroborated in competing risk analysis with DLI as time-dependent covariates. Both prophylactic and preemptive DLI miss significance in their impact on survival within a high-risk cohort in a time-varying model. Controlled trials to address the impact of postgrafting immunotherapy approaches are needed.
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- 2021
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20. Somatic Reversion of a Novel IL2RG Mutation Resulting in Atypical X-Linked Combined Immunodeficiency
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Yujuan Hou, Hans Peter Gratz, Guillermo Ureña-Bailén, Paul G. Gratz, Karin Schilbach-Stückle, Tina Renno, Derya Güngör, Daniel A. Mader, Elke Malenke, Justin S. Antony, Rupert Handgretinger, and Markus Mezger
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atypical X-SCID ,Genetics ,hypomorphic mutation ,somatic reversion ,IL-2RG ,QH426-470 ,immunodeficiency ,γC - Abstract
Mutations of the IL2RG gene, which encodes for the interleukin-2 receptor common gamma chain (γC, CD132), can lead to X-linked severe combined immunodeficiency (X-SCID) associated with a T−B+NK− phenotype as a result of dysfunctional γC-JAK3-STAT5 signaling. Lately, hypomorphic mutations of the IL2RG gene have been described causing atypical SCID with a milder phenotype. Here, we report three brothers with low-normal lymphocyte counts and susceptibility to recurrent respiratory infections and cutaneous warts. The clinical presentation combined with dysgammaglobulinemia suspected an inherited immunity disorder, which has been proven by Next Generation Sequencing as a novel c.458T > C; p.Ile153Thr IL2RG missense-mutation. Subsequent functional characterization revealed impaired T-cell proliferation, low TREC levels and a skewed TCR Vβ repertoire in all three patients. Interestingly, investigation of various subpopulations showed normal expression of CD132 but with partially impaired STAT5 phosphorylation compared to healthy controls. Additionally, we performed precise genetic analysis of subpopulations revealing spontaneous somatic reversion, predominately in lymphoid derived CD3+, CD4+ and CD8+ T cells. Our data demonstrate that the atypical SCID phenotype noticed in these three brothers is due to the combination of hypomorphic IL-2RG function and somatic reversion.
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- 2022
21. Challenges in Gene Therapy for Somatic Reverted Mosaicism in X-Linked Combined Immunodeficiency by CRISPR/Cas9 and Prime Editing
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Yujuan, Hou, Guillermo, Ureña-Bailén, Tahereh, Mohammadian Gol, Paul Gerhard, Gratz, Hans Peter, Gratz, Alicia, Roig-Merino, Justin S, Antony, Andrés, Lamsfus-Calle, Alberto, Daniel-Moreno, Rupert, Handgretinger, and Markus, Mezger
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Gene Editing ,Mosaicism ,Humans ,Genetic Therapy ,CRISPR-Cas Systems ,X-Linked Combined Immunodeficiency Diseases - Abstract
X-linked severe combined immunodeficiency (X-SCID) is a primary immunodeficiency that is caused by mutations in the interleukin-2 receptor gamma
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- 2022
22. Preclinical Evaluation of CRISPR-Edited CAR-NK-92 Cells for Off-the-Shelf Treatment of AML and B-ALL
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Guillermo, Ureña-Bailén, Jérôme-Maurice, Dobrowolski, Yujuan, Hou, Alicia, Dirlam, Alicia, Roig-Merino, Sabine, Schleicher, Daniel, Atar, Christian, Seitz, Judith, Feucht, Justin S, Antony, Tahereh, Mohammadian Gol, Rupert, Handgretinger, and Markus, Mezger
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Cytotoxicity, Immunologic ,Killer Cells, Natural ,Leukemia, Myeloid, Acute ,B7 Antigens ,Lymphoma, B-Cell ,Receptors, Chimeric Antigen ,Cell Line, Tumor ,Antigens, CD19 ,Humans ,Precursor Cell Lymphoblastic Leukemia-Lymphoma ,Immunotherapy, Adoptive - Abstract
Acute myeloid leukemia (AML) and B-cell acute lymphocytic leukemia (B-ALL) are severe blood malignancies affecting both adults and children. Chimeric antigen receptor (CAR)-based immunotherapies have proven highly efficacious in the treatment of leukemia. However, the challenge of the immune escape of cancer cells remains. The development of more affordable and ready-to-use therapies is essential in view of the costly and time-consuming preparation of primary cell-based treatments. In order to promote the antitumor function against AML and B-ALL, we transduced NK-92 cells with CD276-CAR or CD19-CAR constructs. We also attempted to enhance cytotoxicity by a gene knockout of three different inhibitory checkpoints in NK cell function (CBLB, NKG2A, TIGIT) with CRISPR-Cas9 technology. The antileukemic activity of the generated cell lines was tested with calcein and luciferase-based cytotoxicity assays in various leukemia cell lines. Both CAR-NK-92 exhibited targeted cytotoxicity and a significant boost in antileukemic function in comparison to parental NK-92. CRISPR-Cas9 knock-outs did not improve B-ALL cytotoxicity. However, triple knock-out CD276-CAR-NK-92 cells, as well as CBLB or TIGIT knock-out NK-92 cells, showed significantly enhanced cytotoxicity against U-937 or U-937 CD19/tag AML cell lines. These results indicate that the CD19-CAR and CD276-CAR-NK-92 cell lines' cytotoxic performance is suitable for leukemia killing, making them promising off-the-shelf therapeutic candidates. The knock-out of CBLB and TIGIT in NK-92 and CD276-CAR-NK-92 should be further investigated for the treatment of AML.
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- 2022
23. Universal Gene Correction Approaches for β-hemoglobinopathies Using CRISPR-Cas9 and Adeno-Associated Virus Serotype 6 Donor Templates
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Justin S. Antony, Markus Mezger, Alberto Daniel-Moreno, Praveen Baskaran, Rupert Handgretinger, Jennifer Rottenberger, Andrés Lamsfus-Calle, Sabina Marciano, Janani Raju, Thomas Epting, Lukas Heumos, and Guillermo Ureña-Bailén
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Gene Editing ,Transgene ,beta-Thalassemia ,KLF1 ,Genetic Therapy ,beta-Globins ,Dependovirus ,Biology ,Hematopoietic Stem Cells ,medicine.disease_cause ,Hemoglobinopathies ,Insertional mutagenesis ,Homology directed repair ,Fetal hemoglobin ,Genetics ,medicine ,Cancer research ,Humans ,Clustered Regularly Interspaced Short Palindromic Repeats ,CRISPR-Cas Systems ,Enhancer ,Adeno-associated virus ,Gene ,Fetal Hemoglobin ,Biotechnology - Abstract
Mutations in the human β-globin gene are the cause of β-hemoglobinopathies, one of the most common inherited single-gene blood disorders in the world. Novel therapeutic approaches are based on lentiviral vectors (LVs) or CRISPR-Cas9-mediated gene disruption to express adult hemoglobin (HbA), or to reactivate the completely functional fetal hemoglobin, respectively. Nonetheless, LVs present a risk of insertional mutagenesis, while gene-disrupting transcription factors (BCL11A, KLF1) involved in the fetal-to-adult hemoglobin switch might generate dysregulation of other cellular processes. Therefore, universal gene addition/correction approaches combining CRISPR-Cas9 and homology directed repair (HDR) by delivering a DNA repair template through adeno-associated virus could mitigate the limitations of both lentiviral gene transfer and gene disruption strategies, ensuring targeted integration and controlled transgene expression. In this study, we attained high rates of gene addition (up to 12%) and gene correction (up to 38%) in hematopoietic stem and progenitor cells from healthy donors without any cell sorting/enrichment or the application of HDR enhancers. Furthermore, these approaches were tested in heterozygous (β0/β+) and homozygous (β0/β0, β+/β+) β-thalassemia patients, achieving a significant increase in HbA and demonstrating the universal therapeutic potential of this study for the treatment of β-hemoglobinopathies.
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- 2021
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24. Wassermobilität in der grenzflächeninduzierten Schmelzschicht von Eis/Tonmineral‐Nanokompositen
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Hans-Jürgen Butt, Julian Mars, Wiebke Lohstroh, Markus Mezger, Hailong Li, and Michael Marek Koza
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General Medicine - Published
- 2021
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25. Complex coacervation of food grade antimicrobial lauric arginate with lambda carrageenan
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Markus Ketomaeki, Markus Mezger, Thomas A. Vilgis, Julian Mars, Trivikram Nallamilli, Svenja Morsbach, and Domenik Prozeller
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Catanionic micelles ,Applied Microbiology and Biotechnology ,Micelle ,Food processing and manufacture ,Teubner-strey structure factor model ,Turbidity ,chemistry.chemical_compound ,TX341-641 ,Sodium dodecyl sulfate ,Zetapotential ,Coacervate ,Small angle X ray scattering ,Nutrition. Foods and food supply ,Small-angle X-ray scattering ,Isothermal titration calorimetry ,TP368-456 ,Foam ,Surfactant bilayers ,Carrageenan ,Electrophoresis ,chemistry ,Articles from the special issue: Edible Soft Matter, edited by Ashok R.Patel ,Turbidimetry ,Food Science ,Biotechnology ,Nuclear chemistry - Abstract
In this study, the complex coacervation mechanism of Lauric arginate ester (LAE) with λ-carrageenan was studied using turbidimetry, light scattering and electrophoresis. The complexes formed were found to have a bilayer-like structure using small angle X-ray scattering (SAXS) and cryo-TEM (transmission electron microscopy). It was observed that mixing LAE with Sodium dodecyl sulfate (SDS) could significantly reduce the interactions between mixed micelles and λ-carrageenan. The interactions between LAE/SDS and λ-carrageenan were found to be predominantly entropy driven. Mixed micelles of LAE/Tween 20 and LAE/SDS showed significantly less interactions with carrageenan compared to pure LAE micelles. Interfacial properties of complexes were measured using surface tension measurements. It was observed that pure LAE showed good foaming behavior and when mixed with increasing amounts of carrageenan the foaming capacity decreased. Reduction in foam volume was due to reduced availability of free LAE molecules for foam stabilization and due to hydrophilic nature of complexes., Graphical abstract Image 1, Highlights • Lauric arginate forms complex coacervates with Lambda carrageenan due to combination of electrostatic and hydrophobic interactions. • Coacervation leads to both soluble and insoluble coacervates depending on the mixing ratio. • The complex coacervates show a lamellar microstructure with certain degree of disorder in the lamellar layers. • Interactions of Lauric arginate with Lambda carrageenan decrease when it is mixed with either non ionic or anionic surfactant due to formation of mixed micelles.
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- 2021
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26. Naturally occurring polyphenols as building blocks for supramolecular liquid crystals – substitution pattern dominates mesomorphism
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Christoph Wölper, Michael Giese, Jan Balszuweit, Markus Mezger, Jens Voskuhl, Marco Saccone, Meik Blanke, Constantin G. Daniliuc, Balszuweit J., Blanke M., Saccone M., Mezger M., Daniliuc C.G., Wolper C., Giese M., and Voskuhl J.
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Chemistry ,Hydrogen bond ,Liquid crystalline ,Process Chemistry and Technology ,Chemie ,Biomedical Engineering ,Supramolecular chemistry ,Energy Engineering and Power Technology ,02 engineering and technology ,010402 general chemistry ,021001 nanoscience & nanotechnology ,01 natural sciences ,Industrial and Manufacturing Engineering ,0104 chemical sciences ,Crystallography ,Chemistry (miscellaneous) ,Liquid crystal ,Supramolecular Chemistry, Liquid Crystals, Crystal Engineering, Hydrogen Bonding ,Materials Chemistry ,Chemical Engineering (miscellaneous) ,Settore CHIM/07 - Fondamenti Chimici Delle Tecnologie ,0210 nano-technology - Abstract
A modular supramolecular approach towards hydrogen-bonded liquid crystalline assemblies based on naturally occurring polyphenols is reported. The combination of experimental observations, crystallographic studies and semi-empirical analyses of the assemblies provides insight into the structure–property relationships of these materials. Here a direct correlation of the number of donor OH-groups as well as their orientation with the mesomorphic behavior is reported. We discovered that the number and orientation of the OH-groups have a stronger influence on the mesomorphic behavior of the supramolecular assemblies than the connectivity (e.g. stilbenoid or chalconoid) of the hydrogen bond donors. Furthermore, the photo-switching behavior of selected complexes containing azopyridine ligands was investigated. This study will help future scientists to gain a deeper understanding of the underlying mechanisms and structure–property relationships of supramolecular assemblies with mesomorphic behavior, which is still one of the major challenges in current science.
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- 2021
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27. Outstanding Charge Mobility by Band Transport in Two-Dimensional Semiconducting Covalent Organic Frameworks
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Shuai Fu, Enquan Jin, Hiroki Hanayama, Wenhao Zheng, Heng Zhang, Lucia Di Virgilio, Matthew A. Addicoat, Markus Mezger, Akimitsu Narita, Mischa Bonn, Klaus Müllen, and Hai I. Wang
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Colloid and Surface Chemistry ,General Chemistry ,Biochemistry ,Catalysis - Abstract
Two-dimensional covalent organic frameworks (2D COFs) represent a family of crystalline porous polymers with a long-range order and well-defined open nanochannels that hold great promise for electronics, catalysis, sensing, and energy storage. To date, the development of highly conductive 2D COFs has remained challenging due to the finite π-conjugation along the 2D lattice and charge localization at grain boundaries. Furthermore, the charge transport mechanism within the crystalline framework remains elusive. Here, time- and frequency-resolved terahertz spectroscopy reveals intrinsically Drude-type band transport of charge carriers in semiconducting 2D COF thin films condensed by 1,3,5-tris(4-aminophenyl)benzene (TPB) and 1,3,5-triformylbenzene (TFB). The TPB-TFB COF thin films demonstrate high photoconductivity with a long charge scattering time exceeding 70 fs at room temperature which resembles crystalline inorganic materials. This corresponds to a record charge carrier mobility of 165 ± 10 cm
- Published
- 2022
28. Comparative targeting analysis of KLF1, BCL11A, and HBG1/2 in CD34+ HSPCs by CRISPR/Cas9 for the induction of fetal hemoglobin
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Andrés Lamsfus-Calle, Alberto Daniel-Moreno, Justin S. Antony, Thomas Epting, Lukas Heumos, Praveen Baskaran, Jakob Admard, Nicolas Casadei, Ngadhnjim Latifi, Darina M. Siegmund, Michael S. D. Kormann, Rupert Handgretinger, and Markus Mezger
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hemic and lymphatic diseases ,lcsh:R ,lcsh:Medicine ,lcsh:Q ,lcsh:Science - Abstract
β-hemoglobinopathies are caused by abnormal or absent production of hemoglobin in the blood due to mutations in the β-globin gene (HBB). Imbalanced expression of adult hemoglobin (HbA) induces strong anemia in patients suffering from the disease. However, individuals with natural-occurring mutations in the HBB cluster or related genes, compensate this disparity through γ-globin expression and subsequent fetal hemoglobin (HbF) production. Several preclinical and clinical studies have been performed in order to induce HbF by knocking-down genes involved in HbF repression (KLF1 and BCL11A) or disrupting the binding sites of several transcription factors in the γ-globin gene (HBG1/2). In this study, we thoroughly compared the different CRISPR/Cas9 gene-disruption strategies by gene editing analysis and assessed their safety profile by RNA-seq and GUIDE-seq. All approaches reached therapeutic levels of HbF after gene editing and showed similar gene expression to the control sample, while no significant off-targets were detected by GUIDE-seq. Likewise, all three gene editing platforms were established in the GMP-grade CliniMACS Prodigy, achieving similar outcome to preclinical devices. Based on this gene editing comparative analysis, we concluded that BCL11A is the most clinically relevant approach while HBG1/2 could represent a promising alternative for the treatment of β-hemoglobinopathies.
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- 2020
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29. Vitamin C Loaded Polyethylene: Synthesis and Properties of Precise Polyethylene with Vitamin C Defects via Acyclic Diene Metathesis Polycondensation
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Henning Weiss, Markus Mezger, Volker Mailänder, Rüdiger Berger, Katharina Landfester, Ingo Lieberwirth, Carole Champanhac, Frederik R. Wurm, and Oksana Suraeva
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chemistry.chemical_classification ,Condensation polymer ,Polymers and Plastics ,Vitamin C ,Olefin metathesis ,Organic Chemistry ,02 engineering and technology ,Polymer ,Polyethylene ,010402 general chemistry ,021001 nanoscience & nanotechnology ,01 natural sciences ,Article ,0104 chemical sciences ,Inorganic Chemistry ,chemistry.chemical_compound ,chemistry ,Polymerization ,Materials Chemistry ,Organic chemistry ,0210 nano-technology ,Acyclic diene metathesis - Abstract
A polyethylene-like polymer with an in-chain vitamin C group was synthesized by olefin metathesis polymerization. Here, we describe both the synthesis and a comprehensive physical characterization. Because of the olefin metathesis synthesis, the vitamin C groups are equidistantly arranged in the polyethylene (PE) main chain. Their separation was adjusted to 20 CH2 units. After hydrogenation, a semicrystalline polymer is obtained that is soluble in polar solvents. Because of its size and steric effect, the vitamin C acts as a chain defect, which is expelled from the crystal lattice, yielding a lamellar crystal with a homogeneous thickness corresponding to the interdefect distance. The physical properties were examined by various methods including differential scanning calorimetry, X-ray scattering, and transmission electron microscopy. We show that vitamin C retains its radical scavenger properties despite being incorporated into a polyethylene chain. Furthermore, we demonstrate that it is degrading in alkaline conditions. To complete its suitability as a biocompatible material, cytotoxicity and cell uptake experiments were performed. We show that the polymer is nontoxic and that it is taken up in nanoparticular form via endocytosis processes into the cytoplasm of cells.
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- 2020
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30. Anisotropic carrier diffusion in single MAPbI(3) grains correlates to their twin domains
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Markus Mezger, Julian Mars, Ilka M. Hermes, Hans-Jürgen Butt, Kaloian Koynov, Liam Collins, Stefan A. L. Weber, Sarah M. Vorpahl, David S. Ginger, Andreas Best, and Leonard Elias Winkelmann
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Phase transition ,Materials science ,Condensed matter physics ,Renewable Energy, Sustainability and the Environment ,02 engineering and technology ,010402 general chemistry ,021001 nanoscience & nanotechnology ,01 natural sciences ,7. Clean energy ,Pollution ,Diffusion Anisotropy ,0104 chemical sciences ,Piezoresponse force microscopy ,Strain engineering ,Nuclear Energy and Engineering ,Environmental Chemistry ,Charge carrier ,Grain boundary ,Diffusion (business) ,0210 nano-technology ,Anisotropy - Abstract
Polycrystalline thin films and single crystals of hybrid perovskites – a material group successfully used for photovoltaic and optoelectronic applications – reportedly display heterogeneous charge carrier dynamics often attributed to grain boundaries or crystalline strain. Here, we locally resolved the carrier diffusion in large, isolated methylammonium lead iodide (MAPbI3) grains via spatial- and time-resolved photoluminescence microscopy. We found that the anisotropic carrier dynamics directly correlate with the arrangement of ferroelastic twin domains. Comparing diffusion constants parallel and perpendicular to the domains showed carriers diffuse around 50–60% faster along the parallel direction. Extensive piezoresponse force microscopy experiments on the nature of the domain pattern suggest that the diffusion anisotropy most likely originates from structural and electrical anomalies at ferroelastic domain walls. We believe that the domain walls act as shallow energetic barriers, which delay the transversal diffusion of carriers. Furthermore, we demonstrate a rearrangement of the domains via heat treatment above the cubic-tetragnal phase transition. Together with the previously reported strain engineering via external stress, our findings promise additional routes to tailor the directionality of the charge carrier diffusion in MAPbI3-based photovoltaics and optoelectronics as well as other ferroelastic materials for optoelectronic applications.
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- 2020
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31. Somatic Reversion of a Novel
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Yujuan, Hou, Hans Peter, Gratz, Guillermo, Ureña-Bailén, Paul G, Gratz, Karin, Schilbach-Stückle, Tina, Renno, Derya, Güngör, Daniel A, Mader, Elke, Malenke, Justin S, Antony, Rupert, Handgretinger, and Markus, Mezger
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Adult ,Male ,atypical X-SCID ,somatic reversion ,CD8-Positive T-Lymphocytes ,IL-2RG ,X-Linked Combined Immunodeficiency Diseases ,Article ,Young Adult ,Phenotype ,Mutation ,Humans ,hypomorphic mutation ,γC ,immunodeficiency ,Cell Proliferation ,Interleukin Receptor Common gamma Subunit - Abstract
Mutations of the IL2RG gene, which encodes for the interleukin-2 receptor common gamma chain (γC, CD132), can lead to X-linked severe combined immunodeficiency (X-SCID) associated with a T−B+NK− phenotype as a result of dysfunctional γC-JAK3-STAT5 signaling. Lately, hypomorphic mutations of the IL2RG gene have been described causing atypical SCID with a milder phenotype. Here, we report three brothers with low-normal lymphocyte counts and susceptibility to recurrent respiratory infections and cutaneous warts. The clinical presentation combined with dysgammaglobulinemia suspected an inherited immunity disorder, which has been proven by Next Generation Sequencing as a novel c.458T > C; p.Ile153Thr IL2RG missense-mutation. Subsequent functional characterization revealed impaired T-cell proliferation, low TREC levels and a skewed TCR Vβ repertoire in all three patients. Interestingly, investigation of various subpopulations showed normal expression of CD132 but with partially impaired STAT5 phosphorylation compared to healthy controls. Additionally, we performed precise genetic analysis of subpopulations revealing spontaneous somatic reversion, predominately in lymphoid derived CD3+, CD4+ and CD8+ T cells. Our data demonstrate that the atypical SCID phenotype noticed in these three brothers is due to the combination of hypomorphic IL-2RG function and somatic reversion.
- Published
- 2021
32. Expression of KIR2DS1 does not significantly contribute to NK cell cytotoxicity in HLA-C1/C2 heterozygous haplotype B donors
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Ayline Kübler, Monika Balvočiūte, Markus Mezger, Maya C. André, Karla Baltner, Marina Pal, and Rupert Handgretinger
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Cytotoxicity, Immunologic ,0301 basic medicine ,Heterozygote ,Genotype ,medicine.medical_treatment ,Immunology ,Graft vs Leukemia Effect ,HLA-C Antigens ,Human leukocyte antigen ,Hematopoietic stem cell transplantation ,Biology ,Cell Line ,Natural killer cell ,03 medical and health sciences ,0302 clinical medicine ,Receptors, KIR ,medicine ,Humans ,Immunology and Allergy ,Cytotoxicity ,Receptor ,Leukemia ,Haplotype ,Hematopoietic Stem Cell Transplantation ,Heterozygote advantage ,General Medicine ,medicine.disease ,Coculture Techniques ,Tissue Donors ,Killer Cells, Natural ,030104 developmental biology ,medicine.anatomical_structure ,Haplotypes ,030215 immunology - Abstract
NK cells are functionally controlled by the killer immunoglobulin-like receptor (KIR) family that comprises inhibitory (iKIR) and activating (aKIR) members. Genetic association studies suggest that donors expressing aKIRs next to iKIRs will be superior donors in the setting of hematopoietic stem cell transplantation of patients with leukemia. However, contrary evidence states that aKIR expression may be irrelevant or even detrimental. Using a complex methodology incorporating KIR-Q-PCR, double fluorescence and viSNE analysis, we characterized subset distribution patterns and functionality in haplotype A donors which lack aKIRs and haplotype B donors that express a variety of B-specific genes. Here, we show that the alloreactive KIR2DS1+ NK cell subset in HLA-C1/C2 donors is highly responsive towards C2-expressing targets but quantitatively small and as such does not significantly contribute to cytotoxicity. Thus, we fail to find a direct link between haplotype allocation status and NK cell cytotoxicity at least in HLA-C1/C2 heterozygous donors.
- Published
- 2021
33. CRISPR/Cas9 technology: towards a new generation of improved CAR-T cells for anticancer therapies
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Christian Seitz, Daniel Atar, Justin S. Antony, Patrick Schlegel, Alberto Daniel-Moreno, Markus Mezger, Rupert Handgretinger, Guillermo Ureña-Bailén, Andrés Lamsfus-Calle, and Janani Raju
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Gene Editing ,0303 health sciences ,medicine.medical_treatment ,Cell ,Cancer ,Computational biology ,Immunotherapy ,Biology ,medicine.disease ,Chimeric antigen receptor ,Clinical trial ,03 medical and health sciences ,0302 clinical medicine ,medicine.anatomical_structure ,Genome editing ,030220 oncology & carcinogenesis ,medicine ,Humans ,CRISPR ,CRISPR-Cas Systems ,Car t cells ,030304 developmental biology - Abstract
Chimeric antigen receptor (CAR)-modified T cells have raised among other immunotherapies for cancer treatment, being implemented against B-cell malignancies. Despite the promising outcomes of this innovative technology, CAR-T cells are not exempt from limitations that must yet to be overcome in order to provide reliable and more efficient treatments against other types of cancer. The purpose of this review is to shed light on the field of CAR-T cell gene editing for therapy universalization and further enhancement of antitumor function. Several studies have proven that the disruption of certain key genes is essential to boost immunosuppressive resistance, prevention of fratricide, and clinical safety. Due to its unparalleled simplicity, feasibility to edit multiple gene targets simultaneously, and affordability, CRISPR/CRISPR-associated protein 9 system has been proposed in different clinical trials for such CAR-T cell improvement. The combination of such powerful technologies is expected to provide a new generation of CAR-T cell-based immunotherapies for clinical application.
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- 2019
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34. Synthesis of Precision Poly(1,3-adamantylene alkylene)s via Acyclic Diene Metathesis Polycondensation
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Markus Mezger, Christopher P. Ender, Tanja Weil, Jonas Friebel, Jasper J. Michels, Kenneth B. Wagener, and Manfred Wagner
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chemistry.chemical_classification ,Condensation polymer ,Polymers and Plastics ,Adamantane ,Organic Chemistry ,02 engineering and technology ,Polymer ,Polyethylene ,010402 general chemistry ,021001 nanoscience & nanotechnology ,Ring (chemistry) ,01 natural sciences ,0104 chemical sciences ,Inorganic Chemistry ,chemistry.chemical_compound ,Crystallinity ,chemistry ,Polymer chemistry ,Materials Chemistry ,Thermal stability ,0210 nano-technology ,Acyclic diene metathesis - Abstract
[Image: see text] Fully saturated, aliphatic polymers containing adamantane moieties evenly distributed along the polymer backbone are of great interest due to their exceptional thermal stability, yet more synthetic strategies toward these polymers would be desirable. Herein, we report for the first time the synthesis of poly(1,3-adamantylene alkylene)s based on α,ω-dienes containing bulky 1,3-adamantylene defects precisely located on every 11th, 17th, 19th, and 21st chain carbon via acyclic diene metathesis polycondensation. All saturated polymers revealed excellent thermal stabilities (452–456 °C) that were significantly higher compared to those of structurally similar polyolefins with aliphatic or aromatic ring systems in the backbone of polyethylene (PE). Their crystallinity increases successively from shorter to longer CH(2) chains between the adamantane defects. The adamantanes were located in the PE crystals distorting the PE unit cell by the incorporation of the adamantane defect at the kinks of a terrace arrangement. Precise positioning of structural defects within the polymeric backbone provides various opportunities to customize material properties by “defect engineering” in soft polymeric materials.
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- 2019
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35. Presence of centromeric but absence of telomeric group B KIR haplotypes in stem cell donors improve leukaemia control after HSCT for childhood ALL
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Peter Bader, Brigitte Strahm, Joannis Mytilineos, Lena Oevermann, Ulrike Pötschger, Martin Sauer, Cornelia Eckert, Florian Babor, Christina Peters, Roland Meisel, Martin Schrappe, Martin Zimmermann, Friedhelm R. Schuster, Nadine Scherenschlich, Bernd Gruhn, Bernhard Kremens, Tobias Feuchtinger, Markus Uhrberg, Gabriele Escherich, Wilhelm Wössmann, Martina Ahlmann, Peter Lang, Meinolf Siepermann, Daniel Stachel, Herbert Pichler, Arndt Borkhardt, Tayfun Güngör, Peter A. Horn, Evgenia Glogova, Markus Mezger, Angela R. Manser, Gunnar Cario, and Ingo Müller
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Adult ,Male ,Oncology ,medicine.medical_specialty ,Transplantation Conditioning ,Adolescent ,Medizin ,chemical and pharmacologic phenomena ,Disease-Free Survival ,Donor Selection ,03 medical and health sciences ,0302 clinical medicine ,Receptors, KIR ,immune system diseases ,Internal medicine ,Genotype ,medicine ,Humans ,Child ,Transplantation ,Polymorphism, Genetic ,business.industry ,Donor selection ,Incidence (epidemiology) ,Haplotype ,Hazard ratio ,Hematopoietic Stem Cell Transplantation ,Infant ,Hematology ,Precursor Cell Lymphoblastic Leukemia-Lymphoma ,Telomere ,Survival Rate ,Leukemia, Myeloid, Acute ,Haematopoiesis ,Haplotypes ,Child, Preschool ,030220 oncology & carcinogenesis ,Female ,Gene polymorphism ,business ,030215 immunology - Abstract
Although allogeneic hematopoietic stem-cell transplantation (HSCT) provides high cure rates for children with high-risk acute lymphoblastic leukaemia (ALL), relapses remain the main cause of treatment failure. Whereas donor killer cell immunoglobulin-like receptor (KIR) genotype was shown to impact on relapse incidence in adult myeloid leukaemia similar studies in paediatric ALL are largely missing. Effect of donor KIR genotype on transplant outcome was evaluated in 317 children receiving a first myeloablative HSCT from an HLA-matched unrelated donor or sibling within the prospective ALL-SCT-BFM-2003 trial. Analysis of donor KIR gene polymorphism revealed that centromeric presence and telomeric absence of KIR B haplotypes was associated with reduced relapse risk. A centromeric/telomeric KIR score (ct-KIR score) integrating these observations correlated with relapse risk (hazard ratio (HR) 0.58; P = 0.002) while it had no impact on graft-versus-host disease or non-relapse mortality. In multivariable analyses ct-KIR score was associated with reduced relapse risk (HR 0.58; P = 0.003) and a trend towards improved event-free survival (HR 0.76; P = 0.059). This effect proved independent of MRD level prior to HSCT. Our data suggest that in children with ALL undergoing HSCT after myeloablative conditioning, donor selection based on KIR genotyping holds promise to improve clinical outcome by decreasing relapse risk and prolonged event-free survival.
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- 2019
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36. The Surface of Ice under Equilibrium and Nonequilibrium Conditions
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Gen Sazaki, Yuki Nagata, Markus Mezger, Mischa Bonn, Daniel Bonn, Ellen H. G. Backus, Tetsuya Hama, IoP (FNWI), and Soft Matter (WZI, IoP, FNWI)
- Subjects
Materials science ,010405 organic chemistry ,Hydrogen bond ,Non-equilibrium thermodynamics ,General Medicine ,General Chemistry ,010402 general chemistry ,01 natural sciences ,Article ,0104 chemical sciences ,Molecular dynamics ,Macroscopic scale ,Chemical physics ,Lubrication ,Molecule ,Spectroscopy ,Layer (electronics) - Abstract
ConspectusThe ice premelt, often called the quasi-liquid layer (QLL), is key for the lubrication of ice, gas uptake by ice, and growth of aerosols. Despite its apparent importance, in-depth understanding of the ice premelt from the microscopic to the macroscopic scale has not been gained. By reviewing data obtained using molecular dynamics (MD) simulations, sum-frequency generation (SFG) spectroscopy, and laser confocal differential interference contrast microscopy (LCM-DIM), we provide a unified view of the experimentally observed variation in quasi-liquid (QL) states. In particular, we disentangle three distinct types of QL states of disordered layers, QL-droplet, and QL-film and discuss their nature.The topmost ice layer is energetically unstable, as the topmost interfacial H2O molecules lose a hydrogen bonding partner, generating a disordered layer at the ice-air interface. This disordered layer is homogeneously distributed over the ice surface. The nature of the disordered layer changes over a wide temperature range from -90 °C to the bulk melting point. Combined MD simulations and SFG measurements reveal that the topmost ice surface starts to be disordered around -90 °C through a process that the topmost water molecules with three hydrogen bonds convert to a doubly hydrogen-bonded species. When the temperature is further increased, the second layer starts to become disordered at around -16 °C. This disordering occurs not in a gradual manner, but in a bilayer-by-bilayer manner.When the temperature reaches -2 °C, more complicated structures, QL-droplet and QL-film, emerge on the top of the ice surface. These QL-droplets and QL-films are inhomogeneously distributed, in contrast to the disordered layer. We show that these QL-droplet and QL-film emerge only under supersaturated/undersaturated vapor pressure conditions, as partial and pseudopartial wetting states, respectively. Experiments with precisely controlled pressure show that, near the water vapor pressure at the vapor-ice equilibrium condition, no QL-droplet and QL-film can be observed, implying that the QL-droplet and QL-film emerge exclusively under nonequilibrium conditions, as opposed to the disordered layers formed under equilibrium conditions.These findings are connected with many phenomena related to the ice surface. For example, we explain how the disordering of the topmost ice surface governs the slipperiness of the ice surface, allowing for ice skating. Further focus is on the gas uptake mechanism on the ice surface. Finally, we note the unresolved questions and future challenges regarding the ice premelt.
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- 2019
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37. CRISPR/Cas9-modified hematopoietic stem cells—present and future perspectives for stem cell transplantation
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Justin S. Antony, Janani Raju, Rupert Handgretinger, Andrés Lamsfus-Calle, Markus Mezger, and Alberto Daniel-Moreno
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Transplantation Conditioning ,medicine.medical_treatment ,Genetic enhancement ,Disease ,Hematopoietic stem cell transplantation ,Bioinformatics ,Viral vector ,03 medical and health sciences ,0302 clinical medicine ,Humans ,Transplantation, Homologous ,Medicine ,CRISPR ,Transplantation ,business.industry ,Hematopoietic Stem Cell Transplantation ,Hematology ,Haematopoiesis ,surgical procedures, operative ,030220 oncology & carcinogenesis ,CRISPR-Cas Systems ,Stem cell ,business ,Stem Cell Transplantation ,030215 immunology - Abstract
Allogeneic hematopoietic stem cell transplantation (HSCT) is a standard therapeutic intervention for hematological malignancies and several monogenic diseases. However, this approach has limitations related to lack of a suitable donor, graft-versus-host disease and infectious complications due to immune suppression. On the contrary, autologous HSCT diminishes the negative effects of allogeneic HSCT. Despite the good efficacy, earlier gene therapy trials with autologous HSCs and viral vectors have raised serious safety concerns. However, the CRISPR/Cas9-edited autologous HSCs have been proposed to be an alternative option with a high safety profile. In this review, we summarized the possibility of CRISPR/Cas9-mediated autologous HSCT as a potential treatment option for various diseases supported by preclinical gene-editing studies. Furthermore, we discussed future clinical perspectives and possible clinical grade improvements of CRISPR/cas9-mediated autologous HSCT.
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- 2019
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38. Improving the mesomorphic behaviour of supramolecular liquid crystals by resonance-assisted hydrogen bonding
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Christoph Wölper, Sven Kather, Michael Pfletscher, Markus Mezger, Michael Giese, Constantin G. Daniliuc, Marco Saccone, Saccone M., Pfletscher M., Kather S., Wolper C., Daniliuc C., Mezger M., and Giese M.
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Materials science ,Liquid crystalline ,Hydrogen bond ,Chemie ,Supramolecular chemistry ,02 engineering and technology ,General Chemistry ,Atmospheric temperature range ,010402 general chemistry ,021001 nanoscience & nanotechnology ,Ring (chemistry) ,Resonance (chemistry) ,01 natural sciences ,0104 chemical sciences ,Crystallography ,Liquid Crystals, Hydrogen Bonding, Structure-Property, Supramolecular Chemistry, intramolecular ,Liquid crystal ,Intramolecular force ,Materials Chemistry ,Settore CHIM/07 - Fondamenti Chimici Delle Tecnologie ,0210 nano-technology - Abstract
A systematic structure-property relationship study on hydrogen-bonded liquid crystals was performed, revealing the impact of resonance-assisted hydrogen bonds (RAHBs) on the self-assembling behavior of the supramolecular architecture. The creation of a six-membered intramolecular hydrogen-bonded ring acts as a counterpart to the self-organization between hydrogen bond donators and acceptors and determines thus the suprastructure. Variation of the hydrogen-bonding pattern allowed us to significantly improve the temperature range of the reported liquid crystalline assemblies.
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- 2019
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39. In Vitro Evaluation of CD276-CAR NK-92 Functionality, Migration and Invasion Potential in the Presence of Immune Inhibitory Factors of the Tumor Microenvironment
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Kenneth Chun-Ho Chan, Rupert Handgretinger, Sabine Schleicher, Caroline Baden, Guillermo Ureña-Bailén, Stefan Grote, and Markus Mezger
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Cytotoxicity, Immunologic ,B7 Antigens ,Skin Neoplasms ,QH301-705.5 ,medicine.medical_treatment ,In Vitro Techniques ,Immunotherapy, Adoptive ,Article ,Immune system ,NK-92 ,Antigen ,Antigens, Neoplasm ,Cell Movement ,Cell Line, Tumor ,immune therapy ,medicine ,Tumor Microenvironment ,melanoma ,Cytotoxic T cell ,Humans ,Neoplasm Invasiveness ,Lactic Acid ,CD276 ,Biology (General) ,Hypoxia ,CRISPR/Cas9 ,Immunosuppression Therapy ,Tumor microenvironment ,Receptors, Chimeric Antigen ,chimeric antigen receptor ,business.industry ,Melanoma ,Lentivirus ,General Medicine ,Immunotherapy ,Fibroblasts ,Hydrogen-Ion Concentration ,medicine.disease ,Chimeric antigen receptor ,Gene Expression Regulation, Neoplastic ,Killer Cells, Natural ,B7-H3 ,Immune System ,Cancer research ,CRISPR-Cas Systems ,business ,Immunosuppressive Agents - Abstract
Background: Melanoma is the most lethal of all skin-related cancers with incidences continuously rising. Novel therapeutic approaches are urgently needed, especially for the treatment of metastasizing or therapy-resistant melanoma. CAR-modified immune cells have shown excellent results in treating hematological malignancies and might represent a new treatment strategy for refractory melanoma. However, solid tumors pose some obstacles for cellular immunotherapy, including the identification of tumor-specific target antigens, insufficient homing and infiltration of immune cells as well as immune cell dysfunction in the immunosuppressive tumor microenvironment (TME). Methods: In order to investigate whether CAR NK cell-based immunotherapy can overcome the obstacles posed by the TME in melanoma, we generated CAR NK-92 cells targeting CD276 (B7-H3) which is abundantly expressed in solid tumors, including melanoma, and tested their effectivity in vitro in the presence of low pH, hypoxia and other known factors of the TME influencing anti-tumor responses. Moreover, the CRISPR/Cas9-induced disruption of the inhibitory receptor NKG2A was assessed for its potential enhancement of NK-92-mediated anti-tumor activity. Results: CD276-CAR NK-92 cells induced specific cytolysis of melanoma cell lines while being able to overcome a variety of the immunosuppressive effects normally exerted by the TME. NKG2A knock-out did not further improve CAR NK-92 cell-mediated cytotoxicity. Conclusions: The strong cytotoxic effect of a CD276-specific CAR in combination with an “off-the-shelf” NK-92 cell line not being impaired by some of the most prominent negative factors of the TME make CD276-CAR NK-92 cells a promising cellular product for the treatment of melanoma and beyond.
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- 2021
40. Water Mobility in the Interfacial Liquid Layer of Ice/Clay Nanocomposites
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Markus Mezger, Wiebke Lohstroh, Julian Mars, Michael Marek Koza, Hailong Li, and Hans-Jürgen Butt
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Nanocomposite ,Materials science ,Diffusion ,General Chemistry ,Water Mobility ,Vermiculite ,Neutron scattering ,Talc ,Catalysis ,ddc ,Premelting ,quasi-elastic neutron scattering ,Chemical engineering ,medicine ,Melting point ,interfacial premelting ,Supercooling ,Research Articles ,Research Article ,permafrost ,medicine.drug - Abstract
At solid/ice interfaces, a premelting layer is formed at temperatures below the melting point of bulk water. However, the structural and dynamic properties within the premelting layer have been a topic of intense debate. Herein, we determined the translational diffusion coefficient Dt of water in ice/clay nanocomposites serving as model systems for permafrost by quasi‐elastic neutron scattering. Below the bulk melting point, a rapid decrease of Dt is found for charged hydrophilic vermiculite, uncharged hydrophilic kaolin, and more hydrophobic talc, reaching plateau values below −4 °C. At this temperature, Dt in the premelting layer is reduced up to a factor of two compared to supercooled bulk water. Adjacent to charged vermiculite the lowest water mobility was observed, followed by kaolin and the more hydrophobic talc. Results are explained by the intermolecular water interactions with different clay surfaces and interfacial segregation of the low‐density liquid water (LDL) component., Using quasi‐elastic neutron scattering (QENS), the mobility of water molecules confined in the premelting layer of three different ice/clay nanocomposites is quantified. Layers of low‐density liquid water are formed adjacent to ice Ih and clay mineral interfaces. This leads to a reduction of the translational diffusion coefficient within the premelting layer.
- Published
- 2021
41. Controlling the crystal structure of precisely spaced polyethylene-like polyphosphoesters
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Tobias Haider, Frederik R. Wurm, Julian Mars, Markus Mezger, Oksana Suraeva, Miriam L. O’Duill, and Ingo Lieberwirth
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chemistry.chemical_classification ,Materials science ,Polymers and Plastics ,Small-angle X-ray scattering ,Crystallization of polymers ,Organic Chemistry ,Bioengineering ,02 engineering and technology ,Polymer ,010402 general chemistry ,021001 nanoscience & nanotechnology ,01 natural sciences ,Biochemistry ,0104 chemical sciences ,law.invention ,Differential scanning calorimetry ,Polymerization ,chemistry ,Chemical engineering ,law ,Lamellar structure ,Orthorhombic crystal system ,Crystallization ,0210 nano-technology - Abstract
Understanding polymer crystallization is important for polyethylene-like materials. A small fraction of monomers with functional groups within the polyethylene chain can act as crystallization “defects”. Such defects can be used to control the crystallization behavior in bulk and to generate functional anisotropic polymer crystals if crystallized from a dilute solution. Due to their geometry, phosphate groups cannot be incorporated in the polyethylene lamellae and thus control chain folding and crystal morphology. Herein, the synthesis and crystallization behavior for three different long-chain polyphosphates with a precise spacing of 20, 30, and 40 CH2-groups between each phosphate group are reported. Monomers were prepared by esterification of ethyl dichlorophosphate with respective tailor-made unsaturated alcohols. Acyclic diene metathesis (ADMET) polymerization and subsequent hydrogenation were used to receive polyethylene-like polyphosphoesters with molecular weights up 23 100 g mol−1. Polymer crystallization was studied from the melt and dilute solution. Samples were characterized by differential scanning calorimetry (DSC), small-angle X-ray scattering (SAXS), wide-angle X-ray scattering (WAXS), transmission electron microscopy (TEM), and atomic force microscopy (AFM). A change in crystal structure from pseudo-hexagonal to orthorhombic was observed from the “C20” to the “C40” polymer. Melting points and lamellar thicknesses increased with the length of the aliphatic spacer from 51 °C (“C20”) to 62 °C (“C30”) and 91 °C (“C40”). Values for the long periods in bulk (3.1 nm for C20, 4.8 nm for C30, and 7.2 nm for C40) obtained by SAXS and TEM are in qualitative agreement. The thickness of the crystalline part obtained by AFM and TEM increased from about 1.0 nm (C20) to 2.0 nm (C30) to 2.9 nm (C40). Our systematic library of long-chain polyphosphates will allow designing anisotropic polymer colloids by crystallization from solution as functional and versatile colloid platform.
- Published
- 2020
42. Photo-switching and -cyclisation of hydrogen bonded liquid crystals based on resveratrol
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David Doblas Jiménez, Michael Giese, Jens Voskuhl, Marco Saccone, Jan Balszuweit, Markus Mezger, Christoph Wölper, Meik Blanke, Blanke M., Balszuweit J., Saccone M., Wolper C., Doblas Jimenez D., Mezger M., Voskuhl J., and Giese M.
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Materials science ,Hydrogen ,Metals and Alloys ,Chemie ,chemistry.chemical_element ,General Chemistry ,Resveratrol ,Photochemistry ,Catalysis ,Surfaces, Coatings and Films ,Electronic, Optical and Magnetic Materials ,chemistry.chemical_compound ,chemistry ,Liquid crystal ,Materials Chemistry ,Ceramics and Composites ,Settore CHIM/07 - Fondamenti Chimici Delle Tecnologie ,Photoswitching, Liquid Crystals, Hydrogen Bonding, Packing Analysis - Abstract
A series of hydrogen-bonded liquid crystals based on resveratrol and resveratrone is reported and investigated with respect to their photo-switchability (at 405 nm) and photo-cyclisation (at 300 nm).
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- 2020
43. On the impact of linking groups in hydrogen-bonded liquid crystals – a case study
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Michael Giese, Markus Mezger, and Michael Pfletscher
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Materials science ,Hydrogen ,Chemie ,chemistry.chemical_element ,02 engineering and technology ,General Chemistry ,010402 general chemistry ,021001 nanoscience & nanotechnology ,Condensed Matter Physics ,01 natural sciences ,0104 chemical sciences ,Crystallography ,chemistry ,Group (periodic table) ,Liquid crystal ,Side chain ,0210 nano-technology - Abstract
The impact of the linking group in hydrogen-bonded liquid crystals is systematically studied by a modular approach. POM and DSC results exhibited tremendous differences in the mesomorphic behaviour of the assemblies, due to the versatile linkages of the side chains, which were correlated with structural features and the elctronical nature of the side chains.
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- 2018
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44. Single-crystal I h ice surfaces unveil connection between macroscopic and molecular structure
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Alexandra Brumberg, Kevin Hammonds, Ellen H. G. Backus, Markus Mezger, Charles P. Daghlian, Mischa Bonn, Patrick J. Bisson, Ian Baker, and Mary Jane Shultz
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Hexagonal prism ,Multidisciplinary ,Materials science ,genetic structures ,010504 meteorology & atmospheric sciences ,Ice crystals ,business.industry ,Ice Ih ,Geometry ,02 engineering and technology ,021001 nanoscience & nanotechnology ,Corrections ,01 natural sciences ,Crystal ,Optics ,Physical Sciences ,Prism ,Snowflake ,0210 nano-technology ,business ,Single crystal ,0105 earth and related environmental sciences ,Electron backscatter diffraction - Abstract
Physics and chemistry of ice surfaces are not only of fundamental interest but also have important impacts on biological and environmental processes. As ice surfaces—particularly the two prism faces—come under greater scrutiny, it is increasingly important to connect the macroscopic faces with the molecular-level structure. The microscopic structure of the ubiquitous ice Ih crystal is well-known. It consists of stacked layers of chair-form hexagonal rings referred to as molecular hexagons. Crystallographic unit cells can be assembled into a regular right hexagonal prism. The bases are labeled crystallographic hexagons. The two hexagons are rotated 30° with respect to each other. The linkage between the familiar macroscopic shape of hexagonal snowflakes and either hexagon is not obvious per se. This report presents experimental data directly connecting the macroscopic shape of ice crystals and the microscopic hexagons. Large ice single crystals were used to fabricate samples with the basal, primary prism, or secondary prism faces exposed at the surface. In each case, the same sample was used to capture both a macroscopic etch pit image and an electron backscatter diffraction (EBSD) orientation density function (ODF) plot. Direct comparison of the etch pit image and the ODF plot compellingly connects the macroscopic etch pit hexagonal profile to the crystallographic hexagon. The most stable face at the ice–water interface is the smallest area face at the ice–vapor interface. A model based on the molecular structure of the prism faces accounts for this switch.
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- 2017
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45. Comparative targeting analysis of KLF1, BCL11A, and HBG1/2 in CD34
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Andrés, Lamsfus-Calle, Alberto, Daniel-Moreno, Justin S, Antony, Thomas, Epting, Lukas, Heumos, Praveen, Baskaran, Jakob, Admard, Nicolas, Casadei, Ngadhnjim, Latifi, Darina M, Siegmund, Michael S D, Kormann, Rupert, Handgretinger, and Markus, Mezger
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Gene Editing ,Kruppel-Like Transcription Factors ,Gene Expression ,Antigens, CD34 ,Anemia, Sickle Cell ,Translational research ,Article ,Stem-cell research ,Repressor Proteins ,Gene therapy ,hemic and lymphatic diseases ,Mutation ,Humans ,gamma-Globins ,Molecular Targeted Therapy ,CRISPR-Cas Systems ,Cells, Cultured ,Fetal Hemoglobin - Abstract
β-hemoglobinopathies are caused by abnormal or absent production of hemoglobin in the blood due to mutations in the β-globin gene (HBB). Imbalanced expression of adult hemoglobin (HbA) induces strong anemia in patients suffering from the disease. However, individuals with natural-occurring mutations in the HBB cluster or related genes, compensate this disparity through γ-globin expression and subsequent fetal hemoglobin (HbF) production. Several preclinical and clinical studies have been performed in order to induce HbF by knocking-down genes involved in HbF repression (KLF1 and BCL11A) or disrupting the binding sites of several transcription factors in the γ-globin gene (HBG1/2). In this study, we thoroughly compared the different CRISPR/Cas9 gene-disruption strategies by gene editing analysis and assessed their safety profile by RNA-seq and GUIDE-seq. All approaches reached therapeutic levels of HbF after gene editing and showed similar gene expression to the control sample, while no significant off-targets were detected by GUIDE-seq. Likewise, all three gene editing platforms were established in the GMP-grade CliniMACS Prodigy, achieving similar outcome to preclinical devices. Based on this gene editing comparative analysis, we concluded that BCL11A is the most clinically relevant approach while HBG1/2 could represent a promising alternative for the treatment of β-hemoglobinopathies.
- Published
- 2019
46. Interfacial premelting of ice in nano composite materials
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Ann-Christin Dippel, Hailong Li, Markus Mezger, Markus Bier, Olof Gutowski, Veijo Honkimäki, Henning Weiss, and Julian Mars
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Materials science ,General Physics and Astronomy ,Thermodynamics ,02 engineering and technology ,Atmospheric temperature range ,Vermiculite ,010402 general chemistry ,021001 nanoscience & nanotechnology ,Permafrost ,01 natural sciences ,0104 chemical sciences ,Premelting ,Soil water ,ddc:540 ,Melting point ,Ice nucleus ,Physical and Theoretical Chemistry ,0210 nano-technology ,Clay minerals - Abstract
Physical chemistry, chemical physics 21, 3734 - 3741 (2019). doi:10.1039/C8CP05604H, The interfacial premelting in ice/clay nano composites was studied by high energy X-ray diffraction. Below the melting point of bulk water, the formation of liquid water was observed for the ice/ vermiculite and ice/kaolin systems. The liquid fraction is gradually increasing with temperature. For both minerals, similar effective premelting layer thicknesses of 2–3 nm are reached 3 K below the bulk melting point. For the quantitative description of the molten water fraction in wet clay minerals we developed a continuum model for short range interactions and arbitrary pore size distributions. This model quantitatively describes the experimental data over the entire temperature range. Model parameters were obtained by fitting using a maximum entropy (MaxEnt) approach. Pronounced differences in the deviation from Antonow’s rule relating interfacial free energy between ice, water, and clay are observed for the charged vermiculite and uncharged kaolin minerals. The resultant parameters are discussed in terms of their ice nucleation efficiency. Using well defined and characterized ice/clay nano composite samples, this work bridges the gap between studies on single crystalline ice/solid model interfaces and naturally occurring soils and permafrost., Published by RSC Publ., Cambridge
- Published
- 2019
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47. Experimental and theoretical evidence for bilayer-by-bilayer surface melting of crystalline ice
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Mara Jochum, Tatsuya Ishiyama, Jenée D. Cyran, Wilbert J. Smit, M. Alejandra Sánchez, Mischa Bonn, Tanja Kling, Marc Jan Van Zadel, Akihiro Morita, Huib J. Bakker, Markus Mezger, Patrick J. Bisson, Yuki Nagata, Mary Jane Shultz, Ellen H. G. Backus, and Davide Donadio
- Subjects
Multidisciplinary ,Sum-frequency generation ,Materials science ,Bilayer ,Transition temperature ,Sum frequency generation ,Surface melting ,Water ,Nanotechnology ,02 engineering and technology ,010402 general chemistry ,021001 nanoscience & nanotechnology ,01 natural sciences ,Spectral line ,0104 chemical sciences ,Molecular dynamics ,Chemical physics ,Commentaries ,Melting point ,Stepwise ,0210 nano-technology ,Spectroscopy ,Crystalline ice ,Layer (electronics) - Abstract
On the surface of water ice, a quasi-liquid layer (QLL) has been extensively reported at temperatures below its bulk melting point at 273 K. Approaching the bulk melting temperature from below, the thickness of the QLL is known to increase. To elucidate the precise temperature variation of the QLL, and its nature, we investigate the surface melting of hexagonal ice by combining noncontact, surface-specific vibrational sum frequency generation (SFG) spectroscopy and spectra calculated from molecular dynamics simulations. Using SFG, we probe the outermost water layers of distinct single crystalline ice faces at different temperatures. For the basal face, a stepwise, sudden weakening of the hydrogen-bonded structure of the outermost water layers occurs at 257 K. The spectral calculations from the molecular dynamics simulations reproduce the experimental findings; this allows us to interpret our experimental findings in terms of a stepwise change from one to two molten bilayers at the transition temperature.
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- 2016
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48. Collagen VII Half-Life at the Dermal-Epidermal Junction Zone: Implications for Mechanisms and Therapy of Genodermatoses
- Author
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Tobias Kühl, Ingrid Hausser, Leena Bruckner-Tuderman, Alexander Nyström, Markus Mezger, Lin T. Guey, and Rupert Handgretinger
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Male ,0301 basic medicine ,Pathology ,medicine.medical_specialty ,Collagen Type VII ,Blotting, Western ,Cell ,Cell- and Tissue-Based Therapy ,Dermatology ,Mesenchymal Stem Cell Transplantation ,Biochemistry ,Mice ,Random Allocation ,03 medical and health sciences ,Dermis ,medicine ,Animals ,Humans ,Molecular Biology ,Cells, Cultured ,Dermoepidermal junction ,Mice, Knockout ,integumentary system ,Epidermis (botany) ,Chemistry ,Mesenchymal stem cell ,Epidermolysis bullosa dystrophica ,Skin Diseases, Genetic ,Genetic Therapy ,Cell Biology ,Fibroblasts ,medicine.disease ,Epidermolysis Bullosa Dystrophica ,Cell biology ,Blot ,Disease Models, Animal ,Dystrophic epidermolysis bullosa ,030104 developmental biology ,medicine.anatomical_structure ,Epidermis ,Half-Life - Abstract
The tissue half-life of proteins largely determines treatment frequency of non-gene-editing-based therapies targeting the cause of genodermatoses. Surprisingly, such knowledge is missing for a vast number of proteins involved in pathologies. The dermal-epidermal junction zone is believed to be a rather static structure, but to our knowledge no detailed analysis of the stability of proteins within this zone has been performed. Here, we addressed the in vivo half-life of collagen type VII using genetic ablation of its expression and therapeutic introduction of exogenous collagen VII in a preclinical model. A similar in vivo stability of collagen VII was observed in the skin, tongue, and esophagus, with a half-life of about 1 month. Collagen VII expressed by intradermally injected mesenchymal stromal cells also exhibited a similar half-life. Our study provides key information needed for the development of protein replacement or cell-based therapies for dystrophic epidermolysis bullosa caused by genetic deficiency of collagen VII. Moreover, by showing what we define as an intermediate half-life of collagen VII, our study challenges the view of the dermal-epidermal junction zone as a static structure with very slow turnover.
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- 2016
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49. Ferroelastic Fingerprints in Methylammonium Lead Iodide Perovskite
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Simon A. Bretschneider, Alexander Klasen, Rüdiger Berger, Ilka M. Hermes, Victor W. Bergmann, Frédéric Laquai, Julian Mars, Dan Li, Markus Mezger, Wolfgang Tremel, Brian J. Rodriguez, Stefan A. L. Weber, and Hans-Jürgen Butt
- Subjects
Diffraction ,chemistry.chemical_classification ,Phase transition ,Materials science ,Ferroelasticity ,Iodide ,02 engineering and technology ,010402 general chemistry ,021001 nanoscience & nanotechnology ,01 natural sciences ,0104 chemical sciences ,Surfaces, Coatings and Films ,Electronic, Optical and Magnetic Materials ,Crystallography ,General Energy ,Piezoresponse force microscopy ,chemistry ,Chemical physics ,Texture (crystalline) ,Physical and Theoretical Chemistry ,0210 nano-technology ,Nanoscopic scale ,Perovskite (structure) - Abstract
Methylammonium lead iodide (MAPbI3) perovskite shows an outstanding performance in photovoltaic devices. However, certain material properties, especially the possible ferroic behavior, remain unclear. We observed distinct nanoscale periodic domains in the piezoresponse of MAPbI3(Cl) grains. The structure and the orientation of these striped domains indicate ferroelasticity as their origin. By correlating vertical and lateral piezoresponse force microscopy experiments performed at different sample orientations with X-ray diffraction, the preferred domain orientation is suggested to be the a1–a2-phase. The observation of these ferroelastic fingerprints appears to strongly depend on the film texture and thus the preparation route. The ferroelastic twin domains could form due to the introduction of strain during the cubic−tetragonal phase transition.
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- 2016
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50. Gene correction of HBB mutations in CD34
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Justin S, Antony, Ngadhnjim, Latifi, A K M Ashiqul, Haque, Andrés, Lamsfus-Calle, Alberto, Daniel-Moreno, Sebastian, Graeter, Praveen, Baskaran, Petra, Weinmann, Markus, Mezger, Rupert, Handgretinger, and Michael S D, Kormann
- Subjects
Short Communication ,Gene correction ,IVS1–110 ,HBB ,Beta-thalassemia ,CRISPR/Cas9 ,Cas9 mRNA - Abstract
Background β-Thalassemia is an inherited hematological disorder caused by mutations in the human hemoglobin beta (HBB) gene that reduce or abrogate β-globin expression. Although lentiviral-mediated expression of β-globin and autologous transplantation is a promising therapeutic approach, the risk of insertional mutagenesis or low transgene expression is apparent. However, targeted gene correction of HBB mutations with programmable nucleases such as CRISPR/Cas9, TALENs, and ZFNs with non-viral repair templates ensures a higher safety profile and endogenous expression control. Methods We have compared three different gene-editing tools (CRISPR/Cas9, TALENs, and ZFNs) for their targeting efficiency of the HBB gene locus. As a proof of concept, we studied the personalized gene-correction therapy for a common β-thalassemia splicing variant HBBIVS1–110 using Cas9 mRNA and several optimally designed single-stranded oligonucleotide (ssODN) donors in K562 and CD34+ hematopoietic stem cells (HSCs). Results Our results exhibited that indel frequency of CRISPR/Cas9 was superior to TALENs and ZFNs (P
- Published
- 2018
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