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Ethylene-vinyl alcohol copolymer (EVOH)/clay nanocomposites were prepared via a dynamic melt-intercalation process using a Brabender Plastograph or extruder. The phase morphology and the crystallization behavior of the nanocomposites were investigated, using differential scanning calorimetry (DSC). X-ray diffraction (XRD), and transmission electron microscopy (TEM). Mechanical properties were determined using an Instron machine. It was found that the viscosity of EVOH/clay mixtures increases with processing time. Thermal analysis of the EVOH/clay nanocomposites showed that the melting temperature, crystallization temperature, and heat of fusion of the EVOH matrix sharply decrease when clay is added. XRD verified an increased gallery height for the clay in the composites. Maleic anhydride-grafted ethylene vinyl acetate (EVA-g-MA) or maleic anhydride-grafted linear low-density polyethylene (LLDPE-g-MA) were added as compatibilizers of EVOH with clay, in various concentrations (1, 5 and 10 wt%). Significantly higher viscosity levels were obtained for the compatibilized systems as the torque dramatically increased when processed in the Brabender machine. Enhanced intercalation within the galleries was obtained. EVOH crystallinity decreased with increasing compatibilizer content, until at a certain content no crystallization took place. EVOH/clay composites were also processed in an extruder, showing improved mechanical properties for as low as 1 wt% clay. The strong EVOH/clay interactions are responsible for the unique behavior of their nanocomposites. Polym. Eng. Sci. 44:1019-1026, 2004., INTRODUCTION Polymer melt intercalation is a promising new approach for fabricating polymer-layered silicate nanocomposites, apparently by using a conventional melt-mixing technology. The absence of solvents makes direct intercalation an environmentally [...]

Introduction: Over 6.8 million fractures occur annually in the US, with 10% experiencing delayed- or non-union. Anabolic therapeutics like PTH analogs stimulate fracture repair, and small molecule salt inducible kinase (SIK) inhibitors mimic PTH action. This study tests whether the SIK inhibitor YKL-05-099 accelerates fracture callus osteogenesis., Methods: 126 female mice underwent femoral shaft pinning and midshaft fracture, receiving daily injections of PBS, YKL-05-099, or PTH. Callus tissues were analyzed via RT-qPCR, histology, single-cell RNA-seq, and μCT imaging. Biomechanical testing evaluated tissue rigidity. A hydrogel-based delivery system for PTH and siRNAs targeting SIK2/SIK3 was developed and tested., Results: YKL-05-099 and PTH-treated mice showed higher mineralized callus volume fraction and improved structural rigidity. RNA-seq indicated YKL-05-099 increased osteoblast subsets and reduced chondrocyte precursors. Hydrogel-released siRNAs maintained target knockdown, accelerating callus mineralization., Discussion: YKL-05-099 enhances fracture repair, supporting selective SIK inhibitors' development for clinical use. Hydrogel-based siRNA delivery offers targeted localized treatment at fracture sites., Competing Interests: The authors declare that the research was conducted in the absence of any commercial or financial relationships that could be construed as a potential conflict of interest., (Copyright © 2024 Momenzadeh, Yeritsyan, Abbasian, Kheir, Hanna, Wang, Dosta, Papaioannou, Goldfarb, Tang, Amar-Lewis, Nicole Prado Larrea, Martinez Lozano, Yousef, Wixted, Wein, Artzi and Nazarian.)

Disorders in the regulatory arm of the adaptive immune system result in autoimmune-mediated diseases. While systemic immunosuppression is the prevailing approach to manage them, it fails to achieve long-lasting remission due to concomitant suppression of the regulatory arm and carries the risk of heightened susceptibility to infections and malignancies. Alopecia areata is a condition characterized by localized hair loss due to autoimmunity. The accessibility of the skin allows local rather than systemic intervention to avoid broad immunosuppression. It is hypothesized that the expansion of endogenous regulatory T cells (T regs ) at the site of antigen encounter can restore the immune balance and generate a long-lasting tolerogenic response. A hydrogel microneedle (MN) patch is therefore utilized for delivery of CCL22, a T reg -chemoattractant, and IL-2, a T reg  survival factor to amplify them. In an immune-mediated murine model of alopecia, local bolstering of T reg  numbers is shown, leading to sustained hair regrowth and attenuation of inflammatory pathways. In a humanized skin transplant mouse model, expansion of T regs within human skin is confirmed without engendering peripheral immunosuppression. The patch offers high-loading capacity and shelf-life stability for prospective clinical translation. By harmonizing immune responses locally, the aim is to reshape the landscape of autoimmune skin disease management., (© 2024 Wiley‐VCH GmbH.)

Glioblastoma (GBM) is a primary malignant brain tumor with limited therapeutic options. One promising approach is local drug delivery, but the efficacy is hindered by limited diffusion and retention. To address this, we synthesized and developed a dual-sensitive nanoparticle (Dual-NP) system, formed between a dendrimer and dextran NPs, bound by a dual-sensitive [matrix metalloproteinase (MMP) and pH] linker designed to disassemble rapidly in the tumor microenvironment. The disassembly prompts the in situ formation of nanogels via a Schiff base reaction, prolonging Dual-NP retention and releasing small doxorubicin (Dox)-conjugated dendrimer NPs over time. The Dual-NPs were able to penetrate deep into 3D spheroid models and detected at the tumor site up to 6 days after a single intratumoral injection in an orthotopic mouse model of GBM. The prolonged presence of Dual-NPs in the tumor tissue resulted in a significant delay in tumor growth and an overall increase in survival compared to untreated or Dox-conjugated dendrimer NPs alone. This Dual-NP system has the potential to deliver a range of therapeutics for efficiently treating GBM and other solid tumors.

In recent years, steady progress has been made in synthesizing and characterizing engineered nanoparticles, resulting in several approved drugs and multiple promising candidates in clinical trials. Regulatory agencies such as the Food and Drug Administration and the European Medicines Agency released important guidance documents facilitating nanoparticle-based drug product development, particularly in the context of liposomes and lipid-based carriers. Even with the progress achieved, it is clear that many barriers must still be overcome to accelerate translation into the clinic. At the recent conference workshop "Mechanisms and Barriers in Nanomedicine" in May 2023 in Colorado, U.S.A., leading experts discussed the formulation, physiological, immunological, regulatory, clinical, and educational barriers. This position paper invites open, unrestricted, nonproprietary discussion among senior faculty, young investigators, and students to trigger ideas and concepts to move the field forward.

Naturally occurring internal bleeding, such as in stomach ulcers, and complications following interventions, such as polyp resection post-colonoscopy, may result in delayed (5-7 days) post-operative adverse events-such as bleeding, intestinal wall perforation, and leakage. Current solutions for controlling intra- and post-procedural complications are limited in effectiveness. Hemostatic powders only provide a temporary solution due to their short-term adhesion to GI mucosal tissues (less than 48 h). In this study, a sprayable adhesive hydrogel for facile application and sustained adhesion to GI lesions is developed using clinically available endoscopes. Upon spraying, the biomaterial (based on polyethyleneimine-modified Pluronic micelles precursor and oxidized dextran) instantly gels upon contact with the tissue, forming an adhesive shield. In vitro and in vivo studies in guinea pigs, rabbits, and pig models confirm the safety and efficacy of this biomaterial in colonic and acidic stomach lesions. The authors' findings highlight that this family of hydrogels ensures prolonged tissue protection (3-7 days), facilitates wound healing, and minimizes the risk of delayed complications. Overall, this technology offers a readily adoptable approach for gastrointestinal wound management., (© 2024 The Authors. Advanced Materials published by Wiley‐VCH GmbH.)

Integrating multimodal neuro- and nanotechnology-enabled precision immunotherapies with extant systemic immunotherapies may finally provide a significant breakthrough for combatting glioblastoma (GBM). The potency of this approach lies in its ability to train the immune system to efficiently identify and eradicate cancer cells, thereby creating anti-tumor immune memory while minimizing multi-mechanistic immune suppression. A critical aspect of these therapies is the controlled, spatiotemporal delivery of structurally defined nanotherapeutics into the GBM tumor microenvironment (TME). Architectures such as spherical nucleic acids or poly(beta-amino ester)/dendrimer-based nanoparticles have shown promising results in preclinical models due to their multivalency and abilities to activate antigen-presenting cells and prime antigen-specific T cells. These nanostructures also permit systematic variation to optimize their distribution, TME accumulation, cellular uptake, and overall immunostimulatory effects. Delving deeper into the relationships between nanotherapeutic structures and their performance will accelerate nano-drug development and pave the way for the rapid clinical translation of advanced nanomedicines. In addition, the efficacy of nanotechnology-based immunotherapies may be enhanced when integrated with emerging precision surgical techniques, such as laser interstitial thermal therapy, and when combined with systemic immunotherapies, particularly inhibitors of immune-mediated checkpoints and immunosuppressive adenosine signaling. In this perspective, we highlight the potential of emerging treatment modalities, combining advances in biomedical engineering and neurotechnology development with existing immunotherapies to overcome treatment resistance and transform the management of GBM. We conclude with a call to action for researchers to leverage these technologies and accelerate their translation into the clinic., Competing Interests: Competing interests statement:A.B.H. serves on the advisory board of Caris Life Sciences and the WCG Oncology Advisory Board. She has received consulting fees from BlueRock Therapeutics and Novocure and been provided in-kind support for research from Moleculin, Takeda, ImmunoGenesis, and Carthera. A.H.K. is a consultant for Monteris Medical and has a received research grant from Stryker for a clinical outcomes study about a dural substitute, which has no direct relation to this study. A.H.S. is a shareholder of Exicure Inc., which develops SNA therapeutic platforms. A.H.S. and C.A.M. are inventors on patent US20150031745A1, which describes SNA nanoconjugates to cross the blood-brain barrier. A.B.H. receives royalty and milestone payments from DNAtrix for the licensing of the patent titled “Biomarkers and combination therapies using oncolytic virus and immunomodulation” (11,065,285). She additionally has active patents titled “miRNA for treating cancer and for use with adoptive immunotherapies” (9,675,633) and “Concurrent chemotherapy and immunotherapy” (9,399,662) “Low intensity ultrasound combination cancer therapies” (International applications PCT/US2022/019435 and US 63/158,642).

Intravenously administered cyclic dinucleotides and other STING agonists are hampered by low cellular uptake and poor circulatory half-life. Here we report the covalent conjugation of cyclic dinucleotides to poly(β-amino ester) nanoparticles through a cathepsin-sensitive linker. This is shown to increase stability and loading, thereby expanding the therapeutic window in multiple syngeneic tumour models, enabling the study of how the long-term fate of the nanoparticles affects the immune response. In a melanoma mouse model, primary tumour clearance depends on the STING signalling by host cells-rather than cancer cells-and immune memory depends on the spleen. The cancer cells act as a depot for the nanoparticles, releasing them over time to activate nearby immune cells to control tumour growth. Collectively, this work highlights the importance of nanoparticle structure and nano-biointeractions in controlling immunotherapy efficacy., (© 2023. The Author(s), under exclusive licence to Springer Nature Limited.)

Patients diagnosed with osteosarcoma undergo extensive surgical intervention and chemotherapy resulting in dismal prognosis and compromised quality of life owing to poor bone regeneration, which is further compromised with chemotherapy delivery. This study aims to investigate if localized delivery of miR-29b-which is shown to promote bone formation by inducing osteoblast differentiation and also to suppress prostate and cervical tumor growth-can suppress osteosarcoma tumors whilst simultaneously normalizing the dysregulation of bone homeostasis caused by osteosarcoma. Thus, the therapeutic potential of microRNA (miR)-29b is studied to promote bone remodeling in an orthotopic model of osteosarcoma (rather than in bone defect models using healthy mice), and in the context of chemotherapy, that is clinically relevant. A formulation of miR-29b:nanoparticles are developed that are delivered via a hyaluronic-based hydrogel to enable local and sustained release of the therapy and to study the potential of attenuating tumor growth whilst normalizing bone homeostasis. It is found that when miR-29b is delivered along with systemic chemotherapy, compared to chemotherapy alone, the therapy provided a significant decrease in tumor burden, an increase in mouse survival, and a significant decrease in osteolysis thereby normalizing the dysregulation of bone lysis activity caused by the tumor., (© 2023 The Authors. Advanced Materials published by Wiley-VCH GmbH.)

Nucleic acid vaccines have become a transformative technology to fight emerging infectious diseases and cancer. Delivery of such via the transdermal route could boost their efficacy given the complex immune cell reservoir present in the skin that is capable of engendering robust immune responses. We have generated a novel library of vectors derived from poly(β-amino ester)s (PBAEs) including oligopeptide-termini and a natural ligand, mannose, for targeted transfection of antigen presenting cells (APCs) such as Langerhans cells and macrophages in the dermal milieu. Our results reaffirmed terminal decoration of PBAEs with oligopeptide chains as a powerful tool to induce cell-specific transfection, identifying an outstanding candidate with a ten-fold increased transfection efficiency over commercial controls in vitro. The inclusion of mannose in the PBAE backbone rendered an additive effect and increased transfection levels, achieving superior gene expression in human monocyte-derived dendritic cells and other accessory antigen presenting cells. Moreover, top performing candidates were capable of mediating surface gene transfer when deposited as polyelectrolyte films onto transdermal devices such as microneedles, offering alternatives to conventional hypodermic administration. We predict that the use of highly efficient delivery vectors derived from PBAEs could advance clinical translation of nucleic acid vaccination over protein- and peptide-based strategies.

Background: Immune-modulating therapies impart positive outcomes in a subpopulation of cancer patients. Improved delivery strategies and non-invasive monitoring of anti-tumor effects can help enhance those outcomes and understand the mechanisms associated with the generation of anti-tumor immune responses following immunotherapy. Methods: We report on the design of a microneedle (MN) platform capable of simultaneous delivery of immune activators and collection of interstitial skin fluid (ISF) to monitor therapeutic responses. While either approach has shown promise, the integration of the therapy and diagnostic arms into one MN platform has hardly been explored before. MNs were synthesized out of crosslinked hyaluronic acid (HA) and loaded with a model immunomodulatory nanoparticle-containing drug, CpG oligodinucleotides (TLR9 agonist), for cancer therapy in melanoma and colon cancer models. The therapeutic response was monitored by longitudinal analysis of entrapped immune cells in the MNs following patch retrieval and digestion. Results: Transdermal delivery of CpG-containing NPs with MNs induced anti-tumor immune responses in multiple syngeneic mouse cancer models. CpG-loaded MNs stimulated innate immune cells and reduced tumor growth. Intravital microscopy showed deposition and spatiotemporal co-localization of CpG-NPs within the tumor microenvironment when delivered with MNs. Analysis of MN-sampled ISF revealed similar immune signatures to those seen in the bulk tumor homogenate, such as increased populations of macrophages and effector T cells following treatment. Conclusions: Our hydrogel-based MNs enable effective transdermal drug delivery into immune cells in the tumor microenvironment, and upon retrieval, enable studying the immune response to the therapy over time. This platform has the theranostic potential to deliver a range of combination therapies while detecting biomarkers., Competing Interests: Competing Interests: The authors have declared that no competing interest exists., (© The author(s).)

Bleeding-related complications following vascular surgeries occur in up to half of the patients-500 000 cases annually in the United States alone. This results in additional procedures, increased mortality rate, and prolonged hospitalization, posing a burden on the healthcare system. Commercially available materials rely, in large, on forming covalent bonds between the tissue and the biomaterial to achieve adhesion. Here, it is shown that a biomaterial based on oxidized alginate and oxidized dextran together with polyamidoamine (PAMAM) dendrimer amine provides simultaneous electrostatic and covalent interactions between the biomaterial and the tissue, maximizing adhesion. This study finds that the material withstands supraphysiological pressures (≈300 mmHg) and prevents bleeding in a rabbit aortic puncture model and in a pig carotid bilateral poly(tetrafluoroethylene) graft model-achieving superior performance to commercially available materials such as Tisseel and BioGlue. Material biocompatibility is validated in comprehensive in vitro and in vivo studies in accordance with the US Food and Drug Administration (FDA) guidelines, including in vitro neutral red uptake test, subcutaneous implantation in rabbits, ames genotoxicity, and guinea pig maximization test. This material has the potential to provide with adequate seal and reduced complications following complex vascular surgeries, including hard-to-seal tissue-graft interfaces., (© 2022 Wiley-VCH GmbH.)

Osteosarcoma is the most diagnosed bone tumor in children. The use of tissue engineering strategies after malignant tumor resection remains a subject of scientific controversy. As a result, there is limited research that focuses on bone regeneration postresection, which is further compromised following chemotherapy. This study aims to develop the first co-culture spheroid model for osteosarcoma, to understand the divergent relationship between tumor elimination and bone regeneration. By manipulating the ratio of stromal to osteosarcoma cells the modelled cancer state (early/late) is modified, as is evident by the increased tumor growth rates and an upregulation of a panel of well-established osteosarcoma prognostic genes. Validation of the authors' model is conducted by analyzing its ability to mimic the cytotoxic effects of the FDA-approved chemotherapeutic Doxorubicin. Next, the model is used to investigate what effect osteogenic supplements have, if any, on tumor growth. When their model is treated with osteogenic supplements, there is a stimulatory effect on the surrounding stromal cells. However, when treated with chemotherapeutics this stimulatory effect is significantly diminished. Together, the results of this study present a novel multicellular model of osteosarcoma and provide a unique platform for screening potential therapeutic options for osteosarcoma before conducting in vivo experiments., (© 2021 Wiley-VCH GmbH.)

Mining a large cohort of single-cell transcriptomics data, here we employ combinatorial optimization techniques to chart the landscape of optimal combination therapies in cancer. We assume that each individual therapy can target any one of 1269 genes encoding cell surface receptors, which may be targets of CAR-T, conjugated antibodies or coated nanoparticle therapies. We find that in most cancer types, personalized combinations composed of at most four targets are then sufficient for killing at least 80% of tumor cells while sparing at least 90% of nontumor cells in the tumor microenvironment. However, as more stringent and selective killing is required, the number of targets needed rises rapidly. Emerging individual targets include PTPRZ1 for brain and head and neck cancers and EGFR in multiple tumor types. In sum, this study provides a computational estimate of the identity and number of targets needed in combination to target cancers selectively and precisely., (© 2022. This is a U.S. Government work and not under copyright protection in the US; foreign copyright protection may apply.)

Thermal monitoring during focused ultrasound (FUS) transcranial procedures is mandatory and commonly performed by MRI. Transcranial ultrasonic thermal monitoring is an attractive alternative. Furthermore, using the therapeutic FUS transducer itself for this task is highly desirable. Nonetheless, such application is challenged by massive skull-induced signal attenuation and aberrations. This study examined the feasibility of implementing the Golay-coded excitations (CoE) for temperature monitoring in bovine brain samples in the range of 35 °C-43 °C (hyperthermia). Feasibility was assessed using computer simulations, water-based phantoms, and ex vivo bovine brain white-matter samples. The samples were gradually heated to about 45 °C and sonicated during cool down with a 1-MHz therapeutic FUS implementing Golay CoE. Initially, a calibration curve correlating the normalized time-of-flight (TOF) changes and the temperature was generated. Next, a bovine bone was positioned between the FUS and the brain samples, and the scanning process was repeated for different fresh samples. The calibration curve was then used as a mean for estimating the temperature, which was compared to thermocouple measurements. The simulations demonstrated a substantial improvement in signal-to-noise ratio (SNR) and suggested that the implementation of 4-bit sequences is advantageous. The experimental measurements with bone demonstrated good temperature estimation with an average absolute error for the water phantoms and brains of 1.46 °C ± 1.22 °C and 1.23 °C ± 0.99 °C, respectively. In conclusion, a novel noninvasive method utilizing the Golay CoE for ultrasonic thermal monitoring using a therapeutic FUS transducer is introduced. This method can lead to the development of an acoustic tool for brain thermal monitoring.

Microcarriers, including crosslinked porous gelatin beads (Cultispher G) are widely used as cell carriers for cell therapy applications. Microcarriers can support a range of adherent cell types in stirred tank bioreactor culture, which is scalable up to several thousands of liters. Cultispher G in particular is advantageous for cell therapy applications because it can be dissolved enzymatically, and thus cells can be harvested without the need to perform a large-scale cell-bead filtration step. This enzymatic dissolution, however, is challenged by the slow degradation of the carriers in the presence of enzymes as new extracellular matrix is being deposited by the proliferating cells. This extended dissolution timelimits the yield of cell recovery while compromising cellular viability. We report herein the development of crosslinked porous gelatin beads that afford rapid, stimuli-triggered dissolution for facile cell removal using human mesenchymal stem cells (hMSC) as a model system. We successfully fabricated redox-sensitive beads (RS beads) and studied their cell growth, dissolution time and cell yield, compared to regular gelatin-based beads (Reg beads). We have shown that RS beads allow for much faster dissolution compared to Reg beads, supporting better hMSC detachment and recovery following 8 days of culture in spinner flasks, or in 3L bioreactors. These newly synthesized RS beads show promise as cellular microcarriers and can be used for scale-up manufacturing of different cell types while providing on-demand degradation for facile cell retrieval., (© 2020 Wiley Periodicals, Inc.)

Cancer of mucosal tissues is a major cause of worldwide mortality for which only palliative treatments are available for patients with late-stage disease. Engineered cancer vaccines offer a promising approach for inducing antitumor immunity. The route of vaccination plays a major role in dictating the migratory pattern of lymphocytes, and thus vaccine efficacy in mucosal tissues. Parenteral immunization, specifically subcutaneous and intramuscular, is the most common vaccination route. However, this induces marginal mucosal protection in the absence of tissue-specific imprinting signals. To circumvent this, the mucosal route can be utilized, however degradative mucosal barriers must be overcome. Hence, vaccine administration route and selection of materials able to surmount transport barriers are important considerations in mucosal cancer vaccine design. Here, an overview of mucosal immunity in the context of cancer and mucosal cancer clinical trials is provided. Key considerations are described regarding the design of biomaterial-based vaccines that will afford antitumor immune protection at mucosal surfaces, despite limited knowledge surrounding mucosal vaccination, particularly aided by biomaterials and mechanistic immune-material interactions. Finally, an outlook is given of how future biomaterial-based mucosal cancer vaccines will be shaped by new discoveries in mucosal vaccinology, tumor immunology, immuno-therapeutic screens, and material-immune system interplay., (© 2019 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.)

Triple negative breast cancer patients remain with chemotherapy as their only viable therapeutic option. However, the toxicity of available anticancer drugs and their inefficient delivery have limited the development of effective chemotherapy administration protocols and combination therapies. Drug delivery devices that can properly target chemotherapy to the right cells with efficient cancer-cell killing may play a vital role in eliminating triple-negative breast cancer. While systemic delivery results in low drug accumulation at the tumor site and for a short period of time, local delivery enables sustained drug release. However, a system that is able to provide rapid, yet prolonged action, would enable efficient tumor elimination. Herein, the development of dual-sensitive nanogels is described that are designed to rapidly dislodge the chemotherapy drug, doxorubicin, inside cancer cells through dual-sensitive action-pH and redox sensitivities-enabling efficient cancer-cell killing while eliminating systemic side effects. Their embedding within a hydrogel injected next to a tumor in a triple-negative breast-cancer mouse model enables prolonged release of the drug with instantaneous action when inside the cells resulting in efficacious tumor elimination compared to sustained local delivery only. This technology can be used for the delivery of combination therapies and for the treatment of other solid tumors., (© 2020 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.)

The process of new bone formation following trauma requires the temporal recruitment of cells to the site, including mesenchymal stem cells, preosteoblasts, and osteoblasts, the latter of which deposit minerals. Hence, bone repair, a process that is assessed by the extent of mineralization within the defect, can take months before it is possible to determine if a treatment is successful. Here, a fluorescently tagged Osterix, an early key gene in the bone formation cascade, is used as a predictive measure of bone formation. Using a calvarial defect model in mice, the ability to noninvasively track the Osterix transcription factor in an Osterix-mCherry mouse model is evaluated as a measure for bone formation following treatment with recombinant human Bone-Morphogenetic-Protein 2 (rhBMP-2). Two distinct delivery materials are utilized, an injectable nanocomposite hydrogel and a collagen sponge, that afford distinct release kinetics and it is found that cherry-fluorescent protein can be detected as early as 2 weeks following treatment. Osterix intensity correlates with subsequent bone formation and hence can serve as a rapid screening tool for osteogenic drugs or for the evaluation and optimization of delivery platforms., (© 2019 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.)

Culture of endothelial cells (ECs) embedded in 3D scaffolds of denatured collagen has shown tremendous therapeutic potential in clinical trials of tissue repair. It is postulated that these matrix-embedded ECs (MEECs) attain a differential phenotype similar to early progenitor forms, which cannot be attained in 2D culture. MEECs are compared to 2D-ECs and endothelial progenitor cells (EPCs) by secretome, phenotype, and genetic fingerprint, and are found to be altered from 2D-ECs on all levels, adopting an EPC-like phenotype. This manifests in elevation of CD34 expression-a progenitor cell marker-and protein secretion and gene expression pro-files that are similar to EPCs. Even more striking is that EPCs in 2D lose their phenotype, evident by the loss of CD34 expression, but are able to regain expression over time when embedded in the same 3D matrices, suggesting that future in vitro EPC work should use ME-EPCs to recapitulate in vivo phenotype. These findings elucidate the relationship between EPCs and the substratum-dependent regulation imparted by ECs which is critical to understand in order to optimize MEEC therapy and propel it into the clinic., Competing Interests: Conflict of Interest The authors declare no conflict of interest.

Purpose: To evaluate the efficacy of topical apraclonidine in reducing pain and subconjunctival hemorrhage (SCH) after intravitreal injections (IViT)., Methods: A prospective, randomized, double-blinded study. Thirty-nine patients were examined twice, at each monthly IViT of 1.25 mg/0.05 mL bevacizumab. Patients were randomly assigned to receive either topical apraclonidine 0.5% or placebo to the treated eye, 30 minutes before the first IViT. At their second IViT, the intervention was switched. Thirty minutes after the injection, SCH size was measured by a slit lamp, and pain was assessed by the numerical rating scale (NRS-11)., Results: Mean pain score was 1.69 (SD ±1.44) in the apraclonidine group and 3.28 (SD ±2.27) in the control group (P < 0.001). Phakic patients had a greater pain reduction after topical apraclonidine (P < 0.001). Subconjunctival hemorrhage incidence was 41% in the apraclonidine group and 51.3% in the control group (P = 0.503). Mean SCH size was 1.71 mm (SD ±5.83) in the apraclonidine group and 3.25 mm (SD ±6.41) in the control group (P = 0.253). After topical apraclonidine, there was a smaller reduction in SCH size in patients with choroidal neovascularization or hypertension (P = 0.003 and 0.044, respectively), and a greater reduction in phakic patients (P = 0.048)., Conclusion: Topical apraclonidine 0.5%, administered 30 minutes before IViT, significantly decreased pain by a factor of 1.94. It did not decrease the incidence or size of SCH in the entire cohort, but only in several subpopulations.

Tertiary lymphoid structures (TLSs) have been identified in the parenchyma and/or in the peripheral margins of human solid tumors. Uncovering the functional nature of these structures is the subject of much intensive investigation. Studies have shown a direct correlation of the presence of human tumor-localized TLS and better patient outcome (e.g., increase in overall survival) in certain solid tumor histologies, but not all. We had identified a tumor-derived immune gene-expression signature, encoding 12 distinct chemokines, which could reliably identify the presence of TLSs, of different degrees, in various human solid tumors. We are focused on understanding the influence of TLSs on the tumor microenvironment and leveraging this understanding to both manipulate the antitumor immune response and potentially enhance immunotherapy applications. Moreover, as not all human solid tumors show the presence of these lymphoid structures, we are embarking on bioengineering approaches to design and build "designer" TLSs to address, and potentially overcome, an unmet medical need in cancer patients whose tumors lack such lymphoid structures.

Systemic administration of therapeutic agents has been the preferred approach to treat most pathological conditions, in particular for cancer therapy. This treatment modality is associated with side effects, off-target accumulation, toxicity, and rapid renal and hepatic clearance. Multiple efforts have focused on incorporating targeting moieties into systemic therapeutic vehicles to enhance retention and minimize clearance and side effects. However, only a small percentage of the nanoparticles administered systemically accumulate at the tumor site, leading to poor therapeutic efficacy. This has prompted researchers to call the status quo treatment regimen into question and to leverage new delivery materials and alternative administration routes to improve therapeutic outcomes. Recent approaches rely on the use of local delivery platforms that circumvent the hurdles of systemic delivery. Local administration allows delivery of higher "effective" doses while enhancing therapeutic molecules' stability, minimizing side effects, clearance, and accumulation in the liver and kidneys following systemic administration. Hydrogels have proven to be highly biocompatible materials that allow for versatile design to afford sensing and therapy at the same time. Hydrogels' chemical and physical versatility can be exploited to attain disease-triggered in situ assembly and hydrogel programmed degradation and consequent drug release, and hydrogels can also serve as a biocompatible depot for local delivery of stimuli-responsive therapeutic cargo. We will focus this Account on the hydrogel platform that we have developed in our lab, based on dendrimer amine and dextran aldehyde. This hydrogel is disease-responsive and capable of sensing the microenvironment and reacting in a graded manner to diverse pathologies to render different properties, including tissue adhesion, biocompatibility, hydrogel degradation, and embedded drug release profile. We also studied the degradation kinetics of our stimuli-responsive materials in vivo and analyzed the in vitro conditions under which in vitro-in vivo correlation is attained. Identifying key parameters in the in vivo microenvironment under healthy and disease conditions was key to attaining that correlation. The adhesive capacity of our dendrimer-dextran hydrogel makes it optimal for localized and sustained release of embedded drugs. We demonstrated that it affords the delivery of a range of therapeutics to combat cancer, including nucleic acids, small molecules, and antibody drugs. As a depot for local delivery, it allows a high dose of active biomolecules to be delivered directly at the tumor site. Immunotherapy, a recently blooming area in cancer therapy, may exploit stimuli-responsive hydrogels to impart systemic effects following localized therapy. Local delivery would enable release of the proper drug dose and improve drug bioavailability where needed at the same time creating memory and exerting the therapeutic effect systemically. This Account highlights our perspective on how local and systemic therapies provided by stimuli-responsive hydrogels should be used to impart more precise, long-lasting, and potent therapeutic outcomes.

Hydrogels are an attractive class of biomaterials for minimally invasive local drug delivery given their injectability, tunability, high water content, and biocompatibility. Broad applicability though is challenged: relatively modest mechanical properties restrict use to soft tissues, while flow properties necessary for injectability limit implantation to dried, enclosed tissues to minimize material migration during gelation. To address these dual concerns, we designed an injectable nanocomposite hydrogel based on dextran aldehyde and a poly(amido amine) dendrimer doped with phyllosilicate nanoplatelet fillers. Balance of components allows for exfoliation of nanoplatelets, significantly changing macromer solution flow, facilitating injection and manipulation in a wide variety of implantation contexts while enhancing compressive modulus of hydrogels at low loading. Importantly, rheological and mechanical effects were dependent on aspect ratio, with high aspect ratio nanoplatelets having much stronger effects on mechanics and low aspect ratio nanoplatelets having stronger effects on rheology, enabling nearly independent control of rheological and mechanical properties. Nanoplatelets enhanced hydrogel properties at a filler loading substantially lower than that of comparably sized nanoparticles. We present a model to explain the role that aspect ratio plays in control of rheology and mechanics in nanoplatelet-containing hydrogels, with lessons for further nanocomposite hydrogel development. This low-cost biocompatible material may be useful as a drug delivery platform in challenging implantation environments.

Hydrogels consisting of three-dimensional (3D) polymeric networks have found a wide range of applications in biotechnology due to their large water capacity, high biocompatibility, and facile functional versatility. The hydrogels with stimulus-responsive swelling properties have been particularly instrumental to realizing signal transduction in biosensors and bioelectronics. Graphenes are two-dimensional (2D) nanomaterials with unprecedented physical, optical, and electronic properties and have also found many applications in biosensors and bioelectronics. These two classes of materials present complementary strengths and limitations which, when effectively coupled, can result in significant synergism in their electrical, mechanical, and biocompatible properties. This report reviews recent advances made with hydrogel and graphene materials for the development of high-performance bioelectronics devices. The report focuses on the interesting intersection of these materials wherein 2D graphenes are hybridized with 3D hydrogels to develop the next generation biosensors and bioelectronics., (Copyright © 2016 Elsevier B.V. All rights reserved.)

Conventional cancer therapies involve the systemic delivery of anticancer agents that neither discriminate between cancer and normal cells nor eliminate the risk of cancer recurrence. Here, we demonstrate that the combination of gene, drug and phototherapy delivered through a prophylactic hydrogel patch leads, in a colon cancer mouse model, to complete tumour remission when applied to non-resected tumours and to the absence of tumour recurrence when applied following tumour resection. The adhesive hydrogel patch enhanced the stability and provided local delivery of embedded nanoparticles. Spherical gold nanoparticles were used as a first wave of treatment to deliver siRNAs against Kras, a key oncogene driver, and rod-shaped gold nanoparticles mediated the conversion of near-infrared radiation into heat, causing the release of a chemotherapeutic as well as thermally induced cell damage. This local, triple-combination therapy can be adapted to other cancer cell types and to molecular targets associated with disease progression.

Metastasis is the primary cause for mortality in breast cancer. MicroRNAs, gene expression master regulators, constitute an attractive candidate to control metastasis. Here we show that breast cancer metastasis can be prevented by miR-96 or miR-182 treatment, and decipher the mechanism of action. We found that miR-96/miR-182 downregulate Palladin protein levels, thereby reducing breast cancer cell migration and invasion. A common SNP, rs1071738, at the miR-96/miR-182-binding site within the Palladin 3'-UTR abolishes miRNA:mRNA binding, thus diminishing Palladin regulation by these miRNAs. Regulation is successfully restored by applying complimentary miRNAs. A hydrogel-embedded, gold-nanoparticle-based delivery vehicle provides efficient local, selective, and sustained release of miR-96/miR-182, markedly suppressing metastasis in a breast cancer mouse model. Combined delivery of the miRNAs with a chemotherapy drug, cisplatin, enables significant primary tumour shrinkage and metastasis prevention. Our data corroborate the role of miRNAs in metastasis, and suggest miR-96/miR-182 delivery as a potential anti-metastatic drug.

Herein lies the issue of how to best approach cancer metastasis therapeutics in a focused, directed and efficacious manner. The lack of standardized means to efficiently deliver therapeutic cargo to metastatic sites calls for a paradigm shift in the way we view and treat metastasis. It is crucial to leverage the potential of nanomedicine to differentially combat cancer spread at each stage of the disease (primary tumor growth and formation of metastases) while considering the optimal administration route. We propose to implement three possible strategies to treat cancer as a function of disease type and state, while leveraging the advancement in materials design and in particular nanotechnology: (1) local primary tumor abrogation; (2) primary tumor re-programming to prevent metastasis; and (3) combination (local and systemic) therapy when metastasis has already transpired. Herein, we highlight potential means to bridge the gap between basic and translational research as related to metastasis therapy., (© 2016 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.)

The promise of (nano)biomaterials for the treatment of cancer can only be realized following a comprehensive scrutiny of the tumor microenvironment. The generic use of 'inert' vehicles that deliver a specific cargo to treat a range of cancer types and disease states obeys the 'one material fits all' rule. However, this approach leads to suboptimal and unpredictable clinical outcomes. The key factors constructing the tumor milieu should guide the design of disease-responsive materials. Given the growing availability of nanomaterials for cancer therapy, a material that responds to each patient's needs and, hence, reacts in a graded manner based on disease cues, would pave the way to precision materials for cancer therapy., (Copyright © 2016 Elsevier Ltd. All rights reserved.)