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Periodontitis suffer from inflammation-induced destruction of periodontal tissues, resulting in the serious loss of alveolar bone. Controlling inflammation and promoting bone regeneration are two crucial aspects for periodontitis-related alveolar bone defect treatment. Herein, we developed a hierarchically structured nanofibrous scaffold with a nano-embossed sheath and a bone morphogenetic protein 2-loaded core to match the periodontitis-specific features that spatiotemporally modulated the osteoimmune environment and promoted periodontal bone regeneration. We investigated the potential of this unique scaffold to treat periodontitis-related alveolar bone defects in vivo and in vitro. The results demonstrated that the hierarchically structured scaffold effectively reduced the inflammatory levels in macrophages and enhanced the osteogenic potential of bone mesenchymal stem cells in an inflammatory microenvironment. Moreover, in vivo experiments revealed that the hierarchically structured scaffold significantly ameliorated inflammation in the periodontium and inhibited alveolar bone resorption. Notably, the hierarchically structured scaffold also exhibited a prolonged effect on promoting alveolar bone regeneration. These findings highlight the significant therapeutic potential of hierarchically structured nanofibrous scaffolds for the treatment of periodontitis, and their promising role in the field of periodontal tissue regeneration. STATEMENT OF SIGNIFICANCE: We present a novel hierarchically structured nanofibrous scaffold of coupling topological and biomolecular signals for precise spatiotemporal modulation of the osteoimmune micro-environment. Specifically, the scaffold was engineered via coaxial electrospinning of the poly(ε-caprolactone) sheath and a BMP-2/polyvinyl alcohol core, followed by surface-directed epitaxial crystallization to generate cyclic nano-lamellar embossment on the sheath. With this unique hierarchical structure, the cyclic nano-lamellar sheath provided a direct nano-topographical cue to alleviate the osteoimmune environment, and the stepwise release of BMP-2 from the core provided a biological cue for bone regeneration. This research underscores the potential of hierarchically structured nanofibrous scaffolds as a promising therapeutic approach for periodontal tissue regeneration and highlights their role in advancing periodontal tissue engineering., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2024 Acta Materialia Inc. Published by Elsevier Ltd. All rights reserved.)

The distinctive composition and functions of osteochondral structures result in constrained regeneration. Insufficient healing processes may precipitate the emergence of tissue growth disorders or excessive subchondral bone formation, which can culminate in the deterioration and failure of osteochondral tissue repair. To overcome these limitations, materials designed for osteochondral repair must provide region-specific modulation of the microenvironment and mechanical compatibility. To address these challenges, we propose a method to create continuous hydrogels with distinct structural and functional properties by a precise cross-linking method. We have developed an innovative polyurethane enriched with dimethylglyoxime, facilitating the coordinated loading and precise release of Zn 2+ . This strategy enables the meticulous control of alginate cross-linking, resulting in an elastic gradient hydrogel that closely resembles the osteochondral interface. The SeSe within the hydrogel effectively modulates the inflammatory microenvironment and fosters the M2 polarization of macrophages. The hydrogel's lower layer is designed to rapidly release Zn 2+ , thereby enhancing bone regeneration. The upper layer is intended to prevent bone overgrowth and stimulate chondrogenic differentiation. This dual-layer strategy allows targeted stimuli to each region, promoting the seamless integration of neoosteochondral tissue. Our study demonstrates the potential of this stratified hydrogel in achieving uniform and smooth osteochondral tissue regeneration., Competing Interests: Declaration of competing interest No potential conflict of interest was reported by the authors., (Copyright © 2024 Elsevier B.V. All rights reserved.)

Macrophages play a central role in orchestrating the inflammatory response to implanted biomaterials and are sensitive to changes in the chemical and physical characteristics of the implant. Macrophages respond to biological, chemical, and physical cues by polarizing into pro-inflammatory (M1) or anti-inflammatory (M2) states. We previously showed that rough-hydrophilic titanium (Ti) implants skew macrophage polarization towards an anti-inflammatory phenotype and increase mesenchymal stem cell (MSC) recruitment and bone formation around the implant. In the present study, we aimed to investigate whether the adoptive transfer of macrophages in different polarization states would alter the inflammatory microenvironment and improve biomaterial integration in macrophage-competent and macrophage-ablated mice. We found that ablating macrophages increased the presence of neutrophils, reduced T cells and MSCs, and compromised the healing and biomaterial integration process. These effects could not be rescued with adoptive transfer of naïve or polarized macrophages. Adoptive transfer of M1 macrophages into macrophage-competent mice increased inflammatory cells and inflammatory microenvironment, resulting in decreased bone-to-implant contact. Adoptive transfer of M2 macrophages into macrophage-competent mice reduced the pro-inflammatory environment in the peri‑implant tissue and increased bone-to-implant contact. Taken together, our results show the importance of macrophages in controlling and modulating the inflammatory process in response to implanted biomaterials and suggest they can be used to improve outcomes following biomaterial implantation. STATEMENT OF SIGNIFICANCE: Macrophages are central in orchestrating the inflammatory response to implanted biomaterials and are sensitive to biomaterial chemical and physical characteristics. Our study shows that a deficiency of macrophages results in prolonged inflammation and abolishes bone-biomaterial integration. Adoptive transfer of immunomodulatory macrophages into macrophage-competent mice reduced the inflammatory environment and increased bone-implant contact., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2024 Acta Materialia Inc. Published by Elsevier Ltd. All rights reserved.)

Drug-Induced Liver Injury (DILI) and herb Induced Liver Injury (HILI) continues to pose a substantial challenge in both clinical practice and drug development, representing a grave threat to patient well-being. This comprehensive review introduces a novel perspective on DILI and HILI by thoroughly exploring the intricate microenvironment of the liver. The dynamic interplay among hepatocytes, sinusoidal endothelial cells, Kupffer cells, hepatic stellate cells, cholangiocytes, and the intricate vascular network assumes a central role in drug metabolism and detoxification. Significantly, this microenvironment is emerging as a critical determinant of susceptibility to DILI and HILI. The review delves into the multifaceted interactions within the liver microenvironment, providing valuable insights into the complex mechanisms that underlie DILI and HILI. Furthermore, we discuss potential strategies for mitigating drug-induced liver injury by targeting these influential factors, emphasizing their clinical relevance. By highlighting recent advances and future prospects, our aim is to shed light on the promising avenue of leveraging the liver microenvironment for the prevention and mitigation of DILI and HILI. This deeper understanding is crucial for advancing clinical practices and ensuring patient safety in the realm of DILI and HILI., Competing Interests: Declaration of Competing Interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2024 Elsevier B.V. All rights reserved.)

Decellularized extracellular matrix (dECM) hydrogels provide tissue-specific microenvironments which accommodate physiological cellular phenotypes in 3D in vitro cell cultures. However, their formation hinges on collagen fibrillogenesis, a complex process which limits regulation of physicochemical properties. Hence, achieving reproducible results with dECM hydrogels poses as a challenge. Here, we demonstrate that thiolation of solubilized liver dECM enables rapid formation of covalently crosslinked hydrogels via Michael-type addition, allowing for precise control over mechanical properties and superior organotypic biological activity. Investigation of various decellularization methodologies revealed that treatment of liver tissue with Triton X-100 and ammonium hydroxide resulted in near complete DNA removal with significant retention of the native liver proteome. Chemical functionalization of pepsin-solubilized liver dECMs via 1-ethyl-3(3-dimethylamino)propyl carbodiimide (EDC)/N-hydroxysuccinimide (NHS) coupling of l-Cysteine created thiolated liver dECM (dECM-SH), which rapidly reacted with 4-arm polyethylene glycol (PEG)-maleimide to form optically clear hydrogels under controlled conditions. Importantly, Young's moduli could be precisely tuned between 1 - 7 kPa by varying polymer concentrations, enabling close replication of healthy and fibrotic liver conditions in in vitro cell cultures. Click dECM-SH hydrogels were cytocompatible, supported growth of HepG2 and HepaRG liver cells, and promoted liver-specific functional phenotypes as evidenced by increased metabolic activity, as well CYP1A2 and CYP3A4 activity and excretory function when compared to monolayer culture and collagen-based hydrogels. Our findings demonstrate that click-functionalized dECM hydrogels offer a highly controlled, reproducible alternative to conventional tissue-derived hydrogels for in vitro cell culture applications. STATEMENT OF SIGNIFICANCE: Traditional dECM hydrogels face challenges in reproducibility and mechanical property control due to variable crosslinking processes. We introduce a click hydrogel based on porcine liver decellularized extracellular matrix (dECM) that circumnavigates these challenges. After optimizing liver decellularization for ECM retention, we integrated thiol-functionalized liver dECM with polyethylene-glycol derivatives through Michael-type addition click chemistry, enabling rapid, room-temperature gelation. This offers enhanced control over the hydrogel's mechanical and biochemical properties. The resultant click dECM hydrogels mimic the liver's natural ECM and exhibit greater mechanical tunability and handling ease, facilitating their application in high-throughput and industrial settings. Moreover, these hydrogels significantly improve the function of HepaRG-derived hepatocytes in 3D culture, presenting an advancement for liver tissue cell culture models for drug testing applications., Competing Interests: Declaration of competing interest The authors declare the following financial interests/personal relationships which may be considered as potential competing interests: Christoph Meinert reports a relationship with Gelomics Pty Ltd that includes: board membership, employment, and equity or stocks. Dietmar W. Hutmacher reports a relationship with Gelomics Pty Ltd that includes: equity or stocks. Jordan W. Davern reports a relationship with Gelomics Pty Ltd that includes: employment. If there are other authors, they declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2024 The Author(s). Published by Elsevier Ltd.. All rights reserved.)

Mesenchymal stem cells (MCSs) secretome provide MSC-like therapeutic effects in preclinical models of lung injury, circumventing safety concerns with the use of live cells. Secretome consists of Extracellular Vesicles (EVs), including populations of nano- to micro-sized particles (exosomes and microvesicles) delimited by a phospholipidic bilayer. However, its poor stability and bioavailability severely limit its application. The role of Hyaluronic acid (HA) as potential carrier in biomedical applications has been widely demonstrated. Here, we investigated the interplay between HA and MSCs- secretome blends and their ability to exert a bioactive effect on pulmonary differentiation in a 3D microenvironment mimicking lung niche. To this aim, the physical-chemical properties of HA/Secre blends have been characterized at low, medium and high HA Molecular Weights (MWs), by means of SEM/TEM, DLS, confocal microscopy and FTIR. Collectively physical-chemical properties highlight the interplay between the HA and the EVs. In 3D matrices, HA/Secre blends showed to promote differentiation in pulmonary lineage, improved as the MW of the HA in the blends decreased. Finally, HA/Secre blends' ability to cross an artificial mucus has been demonstrated. Overall, this work provides new insights for the development of future devices for the therapy of respiratory diseases that are still unmet., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2024 The Authors. Published by Elsevier B.V. All rights reserved.)

Myocardial infarction (MI) is a serious cardiovascular disease with complex complications and high lethality. Currently, exosome (Exo) therapy has emerged as a promising treatment of ischemic MI due to its antioxidant, anti-inflammatory, and vascular abilities. However, traditional Exo delivery lacks spatiotemporal precision and targeting of microenvironment modulation, making it difficult to localize the lesion site for sustained effects. In this study, an injectable oxidized hyaluronic acid-polylysine (OHA-PL) hydrogel was developed to conveniently load adipose-derived mesenchymal stem cell exosomes (ADSC-Exos) and improve their retention under physiological conditions. The OHA-PL@Exo hydrogel with high spatiotemporal precision is transplanted minimally invasively into the ischemic myocardium to scavenge intracellular and extracellular reactive oxygen species, regulate macrophage polarization, and attenuate inflammation in the early phase of MI. In addition, this synergistic microenvironment modulation can effectively reduce myocardial fibrosis and ventricular remodeling, promote angiogenesis, and restore electrophysiological function in the late stage of MI. Therefore, this hyaluronic acid-polylysine to deliver exosomes has become a promising therapeutic strategy for myocardial repair., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2024 Elsevier B.V. All rights reserved.)

Antimicrobial drug development faces challenges from bacterial resistance, biofilms, and excessive inflammation. Here, we design an intelligent nanoplatform utilizing mesoporous silica nanoparticles doped with copper ions for loading copper sulfide (DM/Cu 2+ -CuS). The mesoporous silica doped with tetrasulfide bonds responds to the biofilm microenvironment (BME), releasing Cu 2+ ions, CuS along with hydrogen sulfide (H 2 S) gas. The release of hydrogen sulfide within 72 h reached 793.5 µM, significantly higher than that observed with conventional small molecule donors. H 2 S induces macrophages polarization towards the M2 phenotype, reducing inflammation and synergistically accelerating endothelial cell proliferation and migration with Cu 2+ ions. In addition, H 2 S disrupts extracellular DNA within biofilms, synergistically photothermal enhanced peroxidase-like activity of CuS to effectively eradicate biofilms. Remarkably, DM-mediated consumption of endogenous glutathione enhances the anti-biofilm activity of H 2 S and improves oxygen species (ROS) destruction efficiency. The combination of photothermal therapy (PTT), chemodynamic therapy (CDT), and gas treatment achieves sterilization rates of 99.3 % and 99.6 % against Staphylococcus aureus (S. aureus) and Escherichia coli (E. coli), respectively, in vitro under 808 nm laser irradiation. Additionally, in vivo experiments demonstrate a significant biosafety and antibacterial potential. In summary, the H 2 S donor developed in this study exhibits enhanced biocompatibility and controlled release properties. By integrating BME-responsive gas therapy with antibacterial ions, PTT and CDT, a synergistic multimodal strategy is proposed to offer new therapeutic approaches for wound healing. STATEMENT OF SIGNIFICANCE: The advanced DMOS/Cu 2+ -CuS (DMCC) multimodal therapeutic nanoplatform has been developed for the treatment of drug-resistant bacterial wound infections and has exhibited enhanced therapeutic efficacy through the synergistic effects of photothermal therapy, chemodynamic therapy, Cu 2+ ions, and H 2 S. The DMCC exhibited exceptional biocompatibility and could release CuS, Cu 2+ , and H 2 S in response to elevated concentrations of glutathione within the biofilm microenvironment. H 2 S effectively disrupted the biofilm structure. Meanwhile, peroxidase activity of CuS combined with GSH-mediated reduction of Cu 2+ to Cu + generated abundant hydroxyl radicals under acidic conditions, leading to efficient eradication of pathogenic bacteria. Furthermore, both H 2 S and Cu 2+ could modulate M2 macrophages polarization and regulate immune microenvironment dynamics. These strategies collectively provided a novel approach for developing antibacterial nanomedical platforms., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2024 Acta Materialia Inc. Published by Elsevier Ltd. All rights reserved.)

Diabetic wound healing is a great clinical challenge due to the microenvironment of hyperglycemia and high pH value, bacterial infection and persistent inflammation. Here, we develop a cascade nanoreactor hydrogel (Arg@Zn-MOF-GOx Gel, AZG-Gel) with arginine (Arg) loaded Zinc metal organic framework (Zn-MOF) and glucose oxidase (GOx) based on chondroitin sulfate (CS) and Pluronic (F127) to accelerate diabetic infected wound healing. GOx in AZG-Gel was triggered by hyperglycemic environment to reduce local glucose and pH, and simultaneously produced hydrogen peroxide (H 2 O 2 ) to enable Arg-to release nitric oxide (NO) for inflammation regulation, providing a suitable microenvironment for wound healing. Zinc ions (Zn 2+ ) released from acid-responsive Zn-MOF significantly inhibited the proliferation and biofilm formation of S.aureus and E.coli. AZG-Gel significantly accelerated diabetic infected wound healing by down-regulating pro-inflammatory tumor necrosis factor (TNF)-α and interleukin (IL)-6, up-regulating anti-inflammatory factor IL-4, promoting angiogenesis and collagen deposition in vivo. Collectively, our nanoreactor cascade strategy combining "endogenous improvement (reducing glucose and pH)" with "exogenous resistance (anti-bacterial and anti-inflammatory)" provides a new idea for promoting diabetic infected wound healing by addressing both symptoms and root causes. STATEMENT OF SIGNIFICANCE: A cascade nanoreactor (AZG-Gel) is constructed to solve three key problems in diabetic wound healing, namely, hyperglycemia and high pH microenvironment, bacterial infection and persistent inflammation. Local glucose and pH levels are reduced by GOx to provide a suitable microenvironment for wound healing. The release of Zn 2+ significantly inhibits bacterial proliferation and biofilm formation, and NO reduces wound inflammation and promotes angiogenesis. The pH change when AZG-Gel is applied to wounds is expected to enable the visualization of wound healing to guide the treatment of diabetic wound. Our strategy of "endogenous improvement (reducing glucose and pH)" combined with "exogenous resistance (anti-bacterial and anti-inflammatory)" provides a new way for promoting diabetic wound healing., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2024 Acta Materialia Inc. Published by Elsevier Ltd. All rights reserved.)

The impairment of phenotype switching of pro-inflammatory M1 to pro-healing M2 macrophage induced by hyperglycemic microenvironment often elevates oxidative stress, impairs angiogenesis, and leads to chronic non-healing wounds in diabetic patients. Administration of M2 macrophage-derived exosomes (M2Exo) at wound site is known to polarize M1 to M2 macrophage and can accelerate wound healing by enhancing collagen deposition, angiogenesis, and re-epithelialization. In the present study, M2Exo were conjugated with oxidized hyaluronic acid and mixed with PEGylated silk fibroin to develop self-healing Exo-gel to achieve an efficient therapy for diabetic wounds. Exo-gel depicted porous networked morphology with self-healing and excellent water retention behaviour. Fibroblast cells treated with Exo-gel showed significant uptake of M2Exo that increased their proliferation and migration in vitro. Interestingly, in a diabetic wound model of wistar rats, Exo-gel treatment induced 75 % wound closure within 7 days with complete epithelial layer regeneration by modulating cytokine levels, stimulating fibroblast-keratinocyte interaction and migration, angiogenesis, and organized collagen deposition. Taken together, this study suggests that Exo-gel depict properties of an excellent wound healing matrix and can be used as a therapeutic alternative to treat chronic non-healing diabetic wounds., Competing Interests: Declaration of competing interest The authors describe no conflict of interest., (Copyright © 2024 Elsevier B.V. All rights reserved.)

Excessive inflammation leads to periodontitis, which inhibits the osteogenic differentiation of human dental pulp stem cells (hDPSCs), irreversibly injured and difficultly repaired for the important dental pulp. Hence, it is necessary to study the functional gene to enhance the osteogenic differentiation of hDPSCs. Previous found that SNHG7 expression was increased in the osteogenic differentiation of hDPSCs. However, the regulatory functions of SNHG7 on osteogenic differentiation of hDPSCs in the inflammatory microenvironment still remains unknown. In this study, hDPSCs treatment with 50 ng/mL TNF-α to mimic the inflammatory microenvironment, then cultured in osteoblast differentiation medium for 14 days. SNHG7, miR-6512-3p, BSP, DSPP, DMP-1, RUNX2 and OPN in hDPSCs were detect by RT-qPCR. We found that SNHG7 expression was reduced during the osteogenic differentiation of hDPSCs after different concentrations TNF-α treatment. SNHG7 overexpression improved the TNF-α-induced suppression of calcium deposition, ALP activity, and the expression of BSP, DSPP, DMP-1, RUNX2 and OPN. Furthermore, SNHG7 can sponge with miR-6512-3p. miR-6512-3p expression was increased during the osteogenic differentiation of hDPSCs after different concentrations TNF-α treatment while inhibited after SNHG7 overexpression. knockdown of miR-6512-3p improved the TNF-α-induced suppression of calcium deposition, ALP activity, and the expression of BSP, DSPP, DMP-1, RUNX2 and OPN. Finally, miR-6512-3p overexpression reversed the effect of SNHG7 on the osteo/dentinogenic differentiation of TNF-α-treated hDPSCs. In conclusions, SNHG7 improves the osteogenic differentiation of hDPSCs by inhibiting miR-6512-3p expression under 50 ng/mL TNF-α-induced inflammatory environment, which provided potential targets for the treatment of periodontitis., (Copyright © 2021 Elsevier Inc. All rights reserved.)

Achieving chondrogenic differentiation of bone marrow mesenchymal stem cells (BMSCs) successfully is crucial for cartilage regeneration. To date, various hydrogels with different chemical microenvironment have been used to modulate chondrogenic differentiation of BMSCs, especially collagen and hyaluronic acid hydrogel. However, the chondro-inductive ability of collagen and hyaluronic acid hydrogel has not been evaluated yet and the different chemical and physical microenvironment of these two hydrogels increase the difficulty of comparison. In this study, three different hydrogels based on collagen and hyaluronic acid (self-assembled collagen hydrogel (Col), self-assembled collagen hydrogel cross-linked with genipin (Cgp), and methacrylated hyaluronic acid hydrogel (HA)) were prepared and their chondro-inductive ability on the encapsulated BMSCs was evaluated. Col and Cgp have the same chemical composition and similar microstructure, but are different from HA, while Cgp and HA hydrogels have the same mechanical strength. It was found that chemical and physical microenvironments of the hydrogels combined to influence cell condensation. Thanks to cell condensation was more likely to occur in collagen hydrogels in the early stage, the cartilage-induced ability was in the order of Col > Cgp > HA. However, the severe shrinkage of Col and Cgp resulted in no enough space for cell proliferation within hydrogels in the later stage. In contrast, relatively stable physical microenvironment of HA helped to maintain continuous production of cartilage-related matrix in the later stage. Overall, these results revealed that the chondro-inductive ability of collagen and hyaluronic acid hydrogel with different chemical and physical microenvironment cannot be evaluated by a particular time period. However, it provided important information for optimization and design of the future hydrogels towards successful repair of articular cartilage., (Copyright © 2021 Elsevier B.V. All rights reserved.)

Ghrelin has been identified as a multifunctional peptide that has a potential application for treating Parkinson's disease (PD). The objective of this study was to assess the effects of subcutaneous administration of low-dose ghrelin via miniosmotic pumps on PD progression. The decreased levels of total and active ghrelin in plasma were rescued by ghrelin administration in PD mice. Interestingly, ghrelin did not affect weight gain in wild-type mice but improved weight loss in PD mice. We observed the attenuation of dopaminergic neuron loss in substantia nigra and a low level of dopamine content in the striatum in PD mice with ghrelin treatment. Ghrelin administration could improve the microenvironment of dopaminergic neurons by inhibiting microglial proliferation and proinflammatory cytokine expression and could enhance cell survival by upregulating Bcl-2/Bax ratio and superoxide dismutase1 protein level in the substantia nigra of PD mice. Subcutaneous administration of low-dose ghrelin could prevent the onset of the progression of PD and also provide a possible method for ghrelin application to cure PD., (Copyright © 2021 Elsevier Inc. All rights reserved.)

Oleuropein (Ole) is the main bioactive phenolic compound present in olive leaves, fruits and olive oil. This molecule has been shown to exert beneficial effects on several human pathological conditions. In particular, recent preclinical and observational studies have provided evidence that Ole exhibits chemo-preventive effects on different types of human tumors. Studies undertaken to elucidate the specific mechanisms underlying these effects have shown that this molecule may thwart several key steps of malignant progression, including tumor cell proliferation, survival, angiogenesis, invasion and metastasis, by modulating the expression and activity of several growth factors, cytokines, adhesion molecules and enzymes involved in these processes. Interestingly, experimental observations have highlighted the fact that most of these signalling molecules also appear to be actively involved in the homing and growth of disseminating cancer cells in bones and, ultimately, in the development of metastatic bone diseases. These findings, and the experimental and clinical data reporting the preventive activity of Ole on various pathological conditions associated with a bone loss, are indicative of a potential therapeutic role of this molecule in the prevention and treatment of cancer-related bone diseases. This paper provides a current overview regarding the molecular mechanisms and the experimental findings underpinning a possible clinical role of Ole in the prevention and development of cancer-related bone diseases., (Copyright © 2020 Elsevier Inc. All rights reserved.)

Cytokines are key factors affecting the fate of intestinal stem cells (ISCs) and effective reagents to manipulate ISCs for research purpose. Tumor necrosis factor alpha (TNFα) is a cytokine produced primarily by monocytes and macrophages. It can induce apoptotic cell death and inflammation, and to inhibit tumorigenesis and viral replication. Additionally, TNFα has been shown to play a critical role in the pathogenesis of inflammatory bowel disease (IBD). It is therefore important to identify the mechanism by which individual cytokines affect particular cell types. For this purpose, we used both conventional (CONV) and altered Schaedler flora (ASF) C3H/HeN mice to elucidate the effect of different microbial populations (complex versus defined) on growth of miniguts derived from two different intestinal environments. Furthermore, we studied the effects of different concentrations of TNFα extracted from the lymph and spleen on the growth and viability of ISCs recovered from mice bearing the ASF or CONV microbiota. The effect of TNFα on miniguts growth depends not only on the source and concentration, but also on the intestinal microenvironment from which the ISCs were derived. The findings suggest that TNFα influences the proliferation of miniguts derived from ISCs and, therefore, modulates mucosal homeostasis of the host., Competing Interests: Declaration of competing interest The authors declare no competing interests., (Copyright © 2020 Elsevier B.V. All rights reserved.)

Click chemistry is fundamentally important to medicinal chemistry and chemical biology. It represents a powerful and versatile tool, which can be exploited to develop novel Pt-based anticancer drugs and to better understand the biological effects of Pt-based anticancer drugs at a cellular level. Innovative azide-alkyne cycloaddition-based approaches are being used to functionalise Pt-based complexes with biomolecules to enhance tumour targeting. Valuable information in relation to the mechanisms of action and resistance of Pt-based drugs is also being revealed through click-based detection, isolation and tracking of Pt drug surrogates in biological and cellular environments. Although less well-explored, inorganic Pt-click reactions enable synthesis of novel (potentially multimetallic) Pt complexes and provide plausible routes to introduce functional groups and monitoring Pt-azido drug localisation., Competing Interests: Conflict of interest statement Nothing declared., (Copyright © 2019 The Author(s). Published by Elsevier Ltd.. All rights reserved.)

Cytokines mediate and control immune and inflammatory responses. Complex interactions exist among cytokines, inflammation, and the innate and adaptive immune responses in maintaining homeostasis, health, and well-being. On-demand, local delivery of anti-inflammatory drugs to target tissues provides an approach for more effective drug dosing while reducing the adverse effects of systemic drug delivery. This work demonstrates a proof-of-concept theranostic approach for inflammation based on analyte-kissing induced signaling, whereby a drug (in this report, aspirin) can be released upon the detection of a target level of a proinflammatory cytokine (i.e., interferon-γ (IFN-γ)) in real time. The structure-switching aptamer-based biosensor described here is capable of quantitatively and dynamically detecting IFN-γ both in vitro and in vivo with a sensitivity of 10 pg mL -1 . Moreover, the released aspirin triggered by the immunoregulatory cytokine IFN-γ is able to inhibit inflammation in a rat model, and the release of aspirin can be quantitatively controlled. The data reported here provide a new and promising strategy for the in vivo detection of proinflammatory cytokines and the subsequent therapeutic delivery of anti-inflammatory molecules. This universal theranostic platform is expected to have great potential for patient-specific personalized medicine. STATEMENT OF SIGNIFICANCE: We developed an adaptive in vivo sensing device whereby a drug, aspirin, can be released upon the detection of a proinflammatory cytokine, interferon-γ (IFN-γ), in real time with a sensitivity of 10 pg mL -1 . Moreover, the aspirin triggered by IFN-γ depressed inflammation in the rat model and was delivered indirectly through blood and cerebrospinal fluid or directly to the inflammation tissue or organ without adverse gastrointestinal effects observed in the liver and kidney. We envision that, for the first time, patients with chronic inflammatory disease can receive the right intervention and treatment at the right time. Additionally, this technology may empower patients to monitor their personalized health and disease management program, allowing real-time diagnostics, disease monitoring, and precise and effective treatments., (Copyright © 2019 Acta Materialia Inc. Published by Elsevier Ltd. All rights reserved.)

In the field of orthopaedics, inflammation-modulatory biomaterials are receiving increasing attentions due to their abilities to regulate innate immune response and mediate wound healing. In the current work, a Cu-containing micro/nano-topographical bio-ceramic surface (Cu-Hier-Ti surface) was employed as material model to explore the role played by Cu 2+ release or material surface in regulating macrophage polarization as well as macrophage-mediated osteogenic and bactericidal effect. A Cu-free micro-topographical surface (Micro-Ti surface) generated by micro-arc oxidation was employed as control. The results showed that Cu 2+ supplemented directly into the culture medium or released from Cu-Hier-Ti surface could polarize macrophages to pro-inflammatory M1 phenotype by activating Cu-transport signaling (copper transporter 1 (CTR1) and ATP7A) in macrophages, while the material characteristics exhibited anti-inflammatory effect to some extent by regulating integrin (α5, αM, β1 and β2) and TLR (TLR-3, TLR-4, Myd88 and Ticam-1/2) signaling. Macrophages grown on Cu-Hier-Ti surface or treated by Cu 2+ could create a favorable inflammatory microenvironment for osteoblast-like SaOS-2 cell proliferation and differentiation. Moreover, Cu-Hier-Ti surface promoted macrophage capacity to engulf and kill bacteria, even though it did not show direct bactericidal effect against Staphylococcus aureus. In vivo results showed that Cu-Hier-Ti surface could lead to promoted osteointegraion and enhanced expression levels of M1 surface marker CD11c, growth factor BMP-6 and osteogenic makers including osteocalcin (OCN) and Runx-2 at the biomaterial/bone tissue interface in a rat model. The results indicate that Cu could be employed as a promising inflammation-modulatory agent to activate macrophages for enhanced osteogenic and bactericidal effect. STATEMENT OF SIGNIFICANCE: The next generation of bone biomaterials should be active to regulate the local inflammatory environment such that it favors bone regeneration. For the design and development of Cu-containing inflammation-modulatory biomaterials, it is of great importance to recognize the exact role played by Cu 2+ release or material surface characteristics. So far, relatively little is known about the regulatory role of Cu 2+ or micro/nano-topographical surface on macrophages. The results in the current work suggest that Cu 2+ release and material surface characteristics of Cu-containing micro/nano-topographical coating could activate distinct signaling pathways in macrophages. The activated M1 macrophages exhibited stimulatory effect on osteoblast maturation and enhanced bactericidal capacity against Staphylococcus aureus. This study might provide new thoughts for the development of multi-functional Cu-containing biomaterials., (Copyright © 2019 Acta Materialia Inc. Published by Elsevier Ltd. All rights reserved.)

Vitamin K antagonists (VKAs) have been used in 1% of the world's population for prophylaxis or treatment of thromboembolic events for 64 years. Impairment of osteoblast function and osteoporosis has been described in patients receiving VKAs. Given the involvement of cells of the bone marrow microenvironment (BMM), such as mesenchymal stem cells (MSCs) and macrophages, as well as other factors such as the extracellular matrix for the maintenance of normal hematopoietic stem cells (HSCs), we investigated a possible effect of VKAs on hematopoiesis via the BMM. Using various transplantation and in vitro assays, we show here that VKAs alter parameters of bone physiology and reduce functional HSCs 8-fold. We implicate impairment of the functional, secreted, vitamin K-dependent, γ-carboxylated form of periostin by macrophages and, to a lesser extent, MSCs of the BMM and integrin β3-AKT signaling in HSCs as at least partly causative of this effect, with VKAs not being directly toxic to HSCs. In patients, VKA use associates with modestly reduced leukocyte and monocyte counts, albeit within the normal reference range. VKAs decrease human HSC engraftment in immunosuppressed mice. Following published examples that alteration of the BMM can lead to hematological malignancies in mice, we describe, without providing a causal link, that the odds of VKA use are higher in patients with vs without a diagnosis of myelodysplastic syndrome (MDS). These results demonstrate that VKA treatment impairs HSC function via impairment of the BMM and the periostin/integrin β3 axis, possibly associating with increased MDS risk., (© 2019 by The American Society of Hematology.)

The extracellular matrix (ECM) of the lung provides physical support and key mechanical signals to pulmonary cells. Although lung ECM is continuously subjected to different stretch levels, detailed mechanics of the ECM at the scale of the cell is poorly understood. Here, we developed a new polydimethylsiloxane (PDMS) chip to probe nonlinear mechanics of tissue samples with atomic force microscopy (AFM). Using this chip, we performed AFM measurements in decellularized rat lung slices at controlled stretch levels. The AFM revealed highly nonlinear ECM elasticity with the microscale stiffness increasing with tissue strain. To correlate micro- and macroscale ECM mechanics, we also assessed macromechanics of decellularized rat lung strips under uniaxial tensile testing. The lung strips exhibited exponential macromechanical behavior but with stiffness values one order of magnitude lower than at the microscale. To interpret the relationship between micro- and macromechanical properties, we carried out a finite element (FE) analysis which revealed that the stiffness of the alveolar cell microenvironment is regulated by the global strain of the lung scaffold. The FE modeling also indicates that the scale dependence of stiffness is mainly due to the porous architecture of the lung parenchyma. We conclude that changes in tissue strain during breathing result in marked changes in the ECM stiffness sensed by alveolar cells providing tissue-specific mechanical signals to the cells. STATEMENT OF SIGNIFICANCE: The micromechanical properties of the extracellular matrix (ECM) are a major determinant of cell behavior. The ECM is exposed to mechanical stretching in the lung and other organs during physiological function. Therefore, a thorough knowledge of the nonlinear micromechanical properties of the ECM at the length scale that cells probe is required to advance our understanding of cell-matrix interplay. We designed a novel PDMS chip to perform atomic force microscopy measurements of ECM micromechanics on decellularized rat lung slices at different macroscopic strain levels. For the first time, our results reveal that the microscale stiffness of lung ECM markedly increases with macroscopic tissue strain. Therefore, changes in tissue strain during breathing result in variations in ECM stiffness providing tissue-specific mechanical signals to lung cells., (Copyright © 2019 Acta Materialia Inc. Published by Elsevier Ltd. All rights reserved.)

Engineered skin coverings have been adopted clinically to support extensive and deep wounds that result in fewer healthy skin remaining and therefore take longer to heal. Nonetheless, these biomaterials demand intensive labor and an expensive final cost. In comparison to conventional bandages, which do not meet all the requirements of wound care, electrospun fiber mats could potentially provide an excellent environment for healing. In this work, we developed two nanostructured scaffolds based on polyamide-6 (PA-6) to be tested as a wound covering in a rat model of full-thickness incisional wound healing. The central idea was to create a bioconstruct that is simple to implement and biologically safe, with a high survival rate, which provides physical support and biological recognition for new functional tissues. An unmodified PA-6 and a soybean-modified PA-6 were employed as nanofibrillar matrices in this study. The biomaterials showed a dimensional homology to natural extracellular matrix components and neither in vitro toxicity nor in vivo side effects. Both polymeric scaffolds were resistant to the sterilization process and could promote the attachment of 3T3 fibroblast cells, besides successfully incorporating the growth factor PDGF-BB, which had its bioactivity extended for up to 12 h under simulated conditions. The modification of PA-6 chains with a fatty acid derivative increased the scaffold's surface free energy, favoring cell proliferation, collagen formation, and ECM secretion. These results confirm the potential of these materials as a topical dermal covering for skin regeneration., (Copyright © 2019 Elsevier B.V. All rights reserved.)

It is becoming increasingly clear that metabolic reprogramming plays a critical role in T cell activation, differentiation and function. To this end, cellular metabolism not only meets the energetic demands of T cells but also provides critical substrates for their growth and function. Furthermore, metabolites themselves are emerging as key regulators of immune responses. As the details of how metabolic reprogramming regulates immune function are revealed, new potential targets for modulating immune responses have emerged. Indeed, the distinct metabolic demands of different T cell subsets make them exquisitely sensitive to pharmacologic inhibitors of metabolism. In this review, we will describe the emerging strategies whereby targeting metabolism can shape the T cell response., (Copyright © 2017 Elsevier Ltd. All rights reserved.)

In this study, we report a facile method to construct a bioactive (poly(phenylalanine)-b-poly(l-histidine)-b-poly(ethylene glycol) polypeptide nanoconstruct to co-load doxorubicin (DOX) and quercetin (QUR) (DQ-NV). The smart pH-sensitive nanovehicle was fabricated with precisely tailored drug-to-carrier ratio that resulted in accelerated, sequential drug release. As a result of ratiometric loading, QUR could significantly enhance the cytotoxic potential of DOX, induced marked cell apoptosis; change cell cycle patterns, inhibit the migratory capacity of sensitive and resistant cancer cells. In particular, pro-oxidant QUR from DQ-NV remarkably reduced the GSH/GSSG ratio, indicating high oxidative stress and damage to cellular components. DQ-NV induced tumor shrinkage more effectively than the single drugs in mice carrying subcutaneous SCC-7 xenografts. DQ-NV consistently induced high expression of caspase-3 and PARP and low expression of Ki67 and CD31 immunomarkers. In summary, we demonstrate the development of a robust polypeptide-based intracellular nanovehicle for synergistic delivery of DOX/QUR in cancer chemotherapy., Statement of Significance: In this study, we report a facile method to construct bioactive and biodegradable polypeptide nanovehicles as an advanced platform technology for application in cancer therapy. We designed a robust (poly(phenylalanine)-b-poly(l-histidine)-b-poly(ethylene glycol) nanoconstruct to co-load doxorubicin (DOX) and quercetin (QUR) (DQ-NV). The conformational changes of the histidine block at tumor pH resulted in accelerated, sequential drug release. QUR could significantly enhance the cytotoxic potential of DOX, induce marked cell apoptosis, change cell cycle patterns, and inhibit the migratory capacity of sensitive and resistant cancer cells. DQ-NV induced tumor shrinkage more effectively than the single drugs and the 2-drug cocktail in tumor xenografts. In summary, we demonstrate the development of an intracellular nanovehicle for synergistic delivery of DOX/QUR in cancer chemotherapy., (Copyright © 2016 Acta Materialia Inc. Published by Elsevier Ltd. All rights reserved.)

Enhancing vascularization of cell-transplantation devices is necessary for maintaining cell viability and integration within the host, but it also increases the risk of allograft rejection. Here, we investigated the feasibility of generating an immunoregulatory environment in a highly vascularized macroporous alginate scaffold by affinity-binding of the transforming growth factor-β (TGF-β) in a manner mimicking its binding to heparan sulfate. Using this device to transplant allofibroblasts under the kidney capsule resulted in the induction of local and peripheral TGF-β-dependent immunotolerance, characterized by higher frequency of immature dendritic cells and regulatory T cells within the device and by markedly reduced allofibroblast-specific T-cell response in the spleen, thereby increasing the viability of the transplanted cells. Culturing whole splenocytes in the TGF-β-bound scaffold indicated that the regulatory function of TGF-β is IL-10-dependent. We thus demonstrate a novel platform for transplantation devices, designed to promote an immunoregulatory microenvironment suitable for cell transplantation and autoimmune regulation., Statement of Significance: Allogeneic cell graft transplantation is a potentially optimal treatment for many clinical deficiencies. It is yet challenging to overcome chronic rejection without compromising host immunity to pathogens. We present the features and function of a cell transplantation device designed based on the principle of affinity binding of angiogenic and immunoregulatory factors to extracellular matrix in aim to achieve sustained release of these factors. We show that presentation of these factors in such manner generates the infrastructure for device vascularization and induces profound local allocell-specific tolerance, which then evokes peripheral T-cell tolerance. The tolerance is antigen specific, does not cause immune deficits and may thus serve to improve allocell survival as well as a platform to mitigate pathogenic autoimmunity., (Copyright © 2016 Acta Materialia Inc. Published by Elsevier Ltd. All rights reserved.)

Unlabelled: Mesenchymal stem cells (MSCs) can differentiate into multiple lineages through guidance from the biophysical and biochemical properties of the extracellular matrix. In this work we conduct a combinatorial study of matrix properties that influence adipogenesis and neurogenesis including: adhesion proteins, stiffness, and cell geometry, for mesenchymal stem cells derived from adipose tissue (AT-MSCs) and bone marrow (BM-MSCs). We uncover distinct differences in integrin expression, the magnitude of traction stress, and lineage specification to adipocytes and neuron-like cells between cell sources. In the absence of media supplements, adipogenesis in AT-MSCs is not significantly influenced by matrix properties, while the converse is true in BM-MSCs. Both cell types show changes in the expression of neurogenesis markers as matrix cues are varied. When cultured on laminin conjugated microislands of the same adhesive area, BM-MSCs display elevated adipogenesis markers, while AT-MSCs display elevated neurogenesis markers; integrin analysis suggests neurogenesis in AT-MSCs is guided by adhesion through integrin αvβ3. Overall, the properties of the extracellular matrix guides MSC adhesion and lineage specification to different degrees and outcomes, in spite of their similarities in general characteristics. This work will help guide the selection of MSCs and matrix components for applications where high fidelity of differentiation outcome is desired., Statement of Significance: Mesenchymal stem cells (MSCs) are an attractive cell type for stem cell therapies; however, in order for these cells to be useful in medicine, we need to understand how they respond to the physical and chemical environments of tissue. Here, we explore how two promising sources of MSCs-those derived from bone marrow and from adipose tissue-respond to the compliance and composition of tissue using model extracellular matrices. Our results demonstrate a source-specific propensity to undergo adipogenesis and neurogenesis, and uncover a role for adhesion, and the degree of traction force exerted on the substrate in guiding these lineage outcomes., (Copyright © 2016 Acta Materialia Inc. Published by Elsevier Ltd. All rights reserved.)

Sixteen training compounds selected in the IMI MIP-DILI consortium, 12 drug-induced liver injury (DILI) positive compounds and 4 non-DILI compounds, were assessed in cryopreserved primary human hepatocytes. When a ten-fold safety margin threshold was applied, the non-DILI-compounds were correctly identified 2h following a single exposure to pooled human hepatocytes (n=13 donors) in suspension and 14-days following repeat dose exposure (3 treatments) to an established 3D-microtissue co-culture (3D-MT co-culture, n=1 donor) consisting of human hepatocytes co-cultured with non-parenchymal cells (NPC). In contrast, only 5/12 DILI-compounds were correctly identified 2h following a single exposure to pooled human hepatocytes in suspension. Exposure of the 2D-sandwich culture human hepatocyte monocultures (2D-sw) for 3days resulted in the correct identification of 11/12 DILI-positive compounds, whereas exposure of the human 3D-MT co-cultures for 14days resulted in identification of 9/12 DILI-compounds; in addition to ximelagatran (also not identified by 2D-sw monocultures, Sison-Young et al., 2016), the 3D-MT co-cultures failed to detect amiodarone and bosentan. The sensitivity of the 2D human hepatocytes co-cultured with NPC to ximelagatran was increased in the presence of lipopolysaccharide (LPS), but only at high concentrations, therefore preventing its classification as a DILI positive compound. In conclusion (1) despite suspension human hepatocytes having the greatest metabolic capacity in the short term, they are the least predictive of clinical DILI across the MIP-DILI test compounds, (2) longer exposure periods than 72h of human hepatocytes do not allow to increase DILI-prediction rate, (3) co-cultures of human hepatocytes with NPC, in the presence of LPS during the 72h exposure period allow the assessment of innate immune system involvement of a given drug., (Copyright © 2016 Elsevier Ireland Ltd. All rights reserved.)

Novel agents such as the Bcl-2 inhibitor venetoclax (ABT-199) are changing treatment paradigms for chronic lymphocytic leukemia (CLL) but important problems remain. Although some patients exhibit deep and durable responses to venetoclax as a single agent, other patients harbor subpopulations of resistant leukemia cells that mediate disease recurrence. One hypothesis for the origin of resistance to venetoclax is by kinase-mediated survival signals encountered in proliferation centers that may be unique for individual patients. An in vitro microenvironment model was developed with primary CLL cells that could be incorporated into an automated high-content microscopy-based screen of kinase inhibitors (KIs) to identify agents that may improve venetoclax therapy in a personalized manner. Marked interpatient variability was noted for which KIs were effective; nevertheless, sunitinib was identified as the most common clinically available KI effective in overcoming venetoclax resistance. Examination of the underlying mechanisms indicated that venetoclax resistance may be induced by microenvironmental signals that upregulate antiapoptotic Bcl-xl, Mcl-1, and A1, which can be counteracted more efficiently by sunitinib than by ibrutinib or idelalisib. Although patient-specific drug responses are common, for many patients, combination therapy with sunitinib may significantly improve the therapeutic efficacy of venetoclax., (© 2016 by The American Society of Hematology.)

Change in cellular pH due to onset of certain malfunctions needs to be tracked quickly so that treatment to cure such incidents may be started immediately. For example, microenvironment of a developing tumor is acidic due to high metabolic rate as well as low oxygen supply. Hence biomarkers that can sharply sense transition in pH could be of great use in the early detection of tumor formation. In the present work, a unique pH sensitive non-cytotoxic gold nanocluster based probe has been synthesized to precisely detect sharp change in biological pH. The gold nanoclusters were coated with dihydrolipoic acid incorporated γ-cyclodextrins. Measurements with steady state fluorometric changes reveal the sensibility of the probes through obvious wavelength shift depending on the changes in the microenvironment. The nanocluster based probe has been successfully applied to detect cancer cells with high precision., From the Clinical Editor: Biomarkers sensitive to physiological environment have extensive uses in nanomedicines. pH sensitive ultrasmall gold nanoclusters coated with dihydrolipoic acid incorporated γ-cyclodextrins indicate Changes in cellular pH, therefore certain malfunctions. The new biomarker could be useful to detect tumor calls., (Copyright © 2016 Elsevier Inc. All rights reserved.)

To mimic extracellular microenvironment of endothelial cell, a bioactive multilayered structure of gelatin/chitosan pair, embedding with vascular endothelial growth factor (VEGF), was constructed onto NiTi alloy substrate surface via a layer-by-layer assembly technique. The successful fabrication of the multilayered structure was demonstrated by scanning electron microscopy, atomic force microscopy, contact angle measurement, attenuated total reflection-fourier transform infrared spectroscopy and X-ray photoelectron spectroscopy, respectively. The growth behaviors of endothelial cells on various NiTi alloy substrates were investigated in vitro. Cytoskeleton observation, MTT assay, and wound healing assay proved that the VEGF-embedded multilayer structure positively stimulated adhesion, proliferation and motogenic responses of endothelial cells. More importantly, the present system promoted the nitric oxide production of endothelial cells. The approach affords an alternative to construct extracellular microenvironment for improving surface endothelialization of a cardiovascular implant., (Copyright © 2015 Elsevier B.V. All rights reserved.)

Introduction: Intrauterine growth restriction complicates 5-10% of pregnancies. This study aims to test the hypothesis that Chinese herbal formula, JLFC01, affects pregnancy and fetal development by modulating the pro-inflammatory decidual micro-environment., Methods: Human decidua from gestational age-matched elective terminations or incomplete/missed abortion was immunostained using anti-CD68 + anti-CD86 or anti-CD163 antibodies. qRT-PCR and Luminex assay measured the effects of JLFC01 on IL-1β- or TNF-α-induced cytokine expression in first trimester decidual cells and on an established spontaneous abortion/intrauterine growth restriction (SA/IUGR)-prone mouse placentae. The effect of JLFC01 on human endometrial endothelial cell angiogenesis was evaluated by average area, length and numbers of branching points of tube formation. Food intake, litter size, fetal weight, placental weight and resorption rate were recorded in SA/IUGR-prone mouse treated with JLFC01. qRT-PCR, Western blot and immunohistochemistry assessed the expression of mouse placental IGF-I and IGF-IR., Results: In spontaneous abortion, numbers of decidual macrophages expressing CD86 and CD163 are increased and decreased, respectively. JLFC01 reduces IL-1β- or TNF-α-induced GM-CSF, M-CSF, C-C motif ligand 2 (CCL2), interferon-γ-inducible protein-10 (IP-10), CCL5 and IL-8 production in first trimester decidual cells. JLFC01 suppresses the activity of IL-1β- or TNF-α-treated first trimester decidual cells in enhancing macrophage-inhibited angiogenesis. In SA/IUGR-prone mice, JLFC01 increases maternal food intake, litter size, fetal and placental weight, and reduces fetal resorption rate. JLFC01 induces IGF-I and IGF-IR expression and inhibits M-CSF, CCL2, CCL5, CCL11, CCL3 and G-CSF expression in the placentae., Discussion: JLFC01 improves gestation by inhibiting decidual inflammation, enhancing angiogenesis and promoting fetal growth., (Copyright © 2015 The Authors. Published by Elsevier Ltd.. All rights reserved.)

The reconstruction of soft tissue, such as that which is found in the nervous system, is governed by the mechanical cues of the growth microenvironment. The complexity of the nervous system, particularly in cases of nerve repair and reconstruction, necessitates the development of facile high-throughput investigational tools. This study assesses the hypothesis that a mechanically tunable photoreactive interpenetrating network (IPN) of hyaluronic acid and Puramatrix can be manipulated in order to demonstrate that 3-D environmental stiffness influences neurite growth and proliferation. For these studies we employed photocrosslinkable glycidyl methacrylate hyaluronic acid (GMHA) and Puramatrix, a self-assembling peptide scaffold, leading to a structurally adjustable IPN system. Our in vitro model provides us with a simple, reproducible environment to generate different properties in a single specimen. Mechanically manipulated IPN systems with different degrees of methacrylation were fabricated using a dynamic mask projection photolithography apparatus and characterized. To gauge the impact of IPN stiffness on neurite outgrowth, dorsal root ganglia (DRG) explants were cultured in the hydrogels. We found that neurite outgrowth in 3-D was more likely to happen in an environment with a lesser degree of methacrylation, which corresponded to structures that were more compliant and more porous. Overall, tuning the mechanical behavior of our IPN systems led to statistically significant (p<0.05) differences in cellular growth and extension that warrants further investigations., (Copyright © 2015 Acta Materialia Inc. Published by Elsevier Ltd. All rights reserved.)

Herein, the micelles based on histidine modified dextran-g-cholesterol (HDC) were successfully prepared which exhibited excellent pH-responsive behavior in acidic aqueous solution (pH<6, within the range of malignant cellular endosome). Taking advantage of this pH-sensitivity in acidic conditions, doxorubicin (DOX), a model anticancer drug, was effectively loaded into the micelles via hydrophobic interactions. The DOX release from all DOX-loaded micelles was accelerated in acid conditions mimicking the endosomal/lysosomal compartments. The enhanced intracellular DOX release was also observed in MCF-7 cells. DOX-loaded pH-sensitive micelles showed higher cellular proliferation inhibition toward MCF-7 cells than that of pH-insensitive micelles. These features suggested that the micelles could efficiently load and deliver DOX into tumor cells, which can enhance the inhibition of cellular proliferation in vitro, providing a powerful mean for delivering and releasing cargoes at the tumor sites., (Copyright © 2014 Elsevier B.V. All rights reserved.)

Around birth, hematopoietic stem cells (HSCs) expanding in the fetal liver migrate to the developing bone marrow (BM) to mature and expand. To identify the molecular processes associated with HSCs located in the 2 different microenvironments, we compared the expression profiles of HSCs present in the liver and BM of perinatal mice. This revealed the higher expression of a cluster of extracellular matrix-related genes in BM HSCs, with secreted protein acidic and rich in cysteine (SPARC) being one of the most significant ones. This extracellular matrix protein has been described to be involved in tissue development, repair, and remodeling, as well as metastasis formation. Here we demonstrate that SPARC-deficient mice display higher resistance to serial treatment with the chemotherapeutic agent 5-fluorouracil (5-FU). Using straight and reverse chimeras, we further show that this protective effect is not due to a role of SPARC in HSCs, but rather is due to its function in the BM niche. Although the kinetics of recovery of the hematopoietic system is normal, HSCs in a SPARC-deficient niche show an accelerated return to quiescence, protecting them from the lethal effects of serial 5-FU treatment. This may become clinically relevant, as SPARC inhibition and its protective effect on HSCs could be used to optimize chemotherapy schemes., (© 2014 by The American Society of Hematology.)

Aims: The aim of this study was to evaluate the structural and molecular effects of antiangiogenic therapies and finasteride on the ventral prostate of senile mice., Main Methods: 90 male FVB mice were divided into: Young (18 weeks old) and senile (52 weeks old) groups; finasteride group: finasteride (20mg/kg); SU5416 group: SU5416 (6 mg/kg); TNP-470 group: TNP-470 (15 mg/kg,) and SU5416+TNP-470 group: similar to the SU5416 and TNP-470 groups. After 21 days, prostate ventral lobes were collected for morphological, immunohistochemical and Western blotting analyses., Key Findings: The results demonstrated atrophy, occasional proliferative lesions and inflammatory cells in the prostate during senescence, which were interrupted and/or blocked by treatment with antiangiogenic drugs and finasteride. Decreased AR and endostatin reactivities, and an increase for ER-α, ER-β and VEGF, were seen in the senile group. Decreased VEGF and ER-α reactivities and increased ER-β reactivity were verified in the finasteride, SU5416 groups and especially in SU5416+TNP-470 group. The TNP-470 group showed reduced AR and ER-β protein levels., Significance: The senescence favored the occurrence of structural and/or molecular alterations suggesting the onset of malignant lesions, due to the imbalance in the signaling between the epithelium and stroma. The SU5416+TNP-470 treatment was more effective in maintaining the structural, hormonal and angiogenic factor balance in the prostate during senescence, highlighting the signaling of antiproliferation via ER-β., (Copyright © 2014 Elsevier Inc. All rights reserved.)

Introduction: Dental pulp is particularly susceptible to ischemic conditions (hypoxia and serum deprived) because it is commonly exposed to trauma, inflammation, chronic caries injury, and pulpitis. We investigated the apoptotic response of human dental pulp cells (HDPCs) to varying levels of oxygen and serum to mimic different degrees of ischemia, tested whether lysophosphatidic acid (LPA) could reverse ischemia-induced apoptosis, and investigated the possible mechanisms of LPA., Methods: HDPCs were cultured under conditions mimicking serum deprivation and ischemia for 2 days with or without LPA at 25 μg/mL. Flow cytometry and JC-1 fluorescence were used to detect any apoptotic change. Western blotting was used to measure the expression of the apoptosis regulators B-cell lymphoma 2 (Bcl-2) and Bax, focal adhesion kinase (FAK), Src, extracellular signal-regulated kinase (ERK), and Akt., Results: Flow cytometry and JC-1 immunofluorescence showed that ischemia could induce apoptosis of HDPCs in 2 days and treatment with LPA could reduce cell death significantly. To clarify the molecular mechanisms, Western blot results showed up-regulation of both proapoptotic Bax and antiapoptotic Bcl-2 during apoptosis. LPA functioned as an antiapoptotic cytokine by activation of the phosphorylation of FAK and ERK. No statistically significant difference was found in the activation levels of p-Src or p-Akt., Conclusions: A self-defense mechanism functioned during cell apoptosis. LPA could effectively rescue HDPCs from ischemia-induced apoptosis via regulation of Bax and Bcl-2 and the activation of phosphorylated FAK and phosphorylated ERK. LPA is a potent candidate for biological therapy of chronic pulpal inflammatory diseases., (Copyright © 2014 American Association of Endodontists. Published by Elsevier Inc. All rights reserved.)

Therapy-related myeloid neoplasms (t-MN) are a late complication of the successful use of cytotoxic therapy for patients with cancer. A heterozygous deletions of the long arm of chromosome 5 [del(5q)], observed in 40% of patients, is associated with prior exposure to alkylating agents, and a high frequency of TP53 loss or mutation. In previous studies, we demonstrated that haploinsufficiency of 2 del(5q) genes, Egr1, and Apc, individually play a role in the pathogenesis of hematologic disease in mice. We now show that loss of one copy of Egr1 or Tp53 in an Apc haploinsufficient background (Apc (del/+)) accelerated the development of a macrocytic anemia with monocytosis, early features of t-MN. The development of anemia was significantly accelerated by treatment of mice with the alkylating agent, N-ethyl-N-nitrosourea (ENU), regardless of the levels of expression of Egr1 and Tp53. Transplantation of either wild type; Egr1(+/-); Tp53(+/-); Apc(del/+); or Egr1(+/-), Apc(del/+) bone marrow cells into lethally irradiated Apc(del/+) recipients resulted in rapid development of anemia that was further accelerated by administration of ENU to recipients, demonstrating that the Apc(del/+)-induced anemia was cell extrinsic and potentiated by ENU mutagenesis. These data emphasize the synergistic role of cell intrinsic and cell extrinsic (microenvironment) factors in the pathogenesis of t-MN, and raise awareness of the deleterious effects of cytotoxic therapy on the stromal microenvironment.

Dental-derived mesenchymal stem cells (MSCs) are promising candidates for cartilage regeneration, with a high capacity for chondrogenic differentiation. This property helps make dental MSCs an advantageous therapeutic option compared to current treatment modalities. The MSC delivery vehicle is the principal determinant for the success of MSC-mediated cartilage regeneration therapies. The objectives of this study were to: (1) develop a novel co-delivery system based on TGF-β1 loaded RGD-coupled alginate microspheres encapsulating periodontal ligament stem cells (PDLSCs) or gingival mesenchymal stem cells (GMSCs); and (2) investigate dental MSC viability and chondrogenic differentiation in alginate microspheres. The results revealed the sustained release of TGF-β1 from the alginate microspheres. After 4 weeks of chondrogenic differentiation in vitro, PDLSCs and GMSCs as well as human bone marrow mesenchymal stem cells (hBMMSCs) (as positive control) revealed chondrogenic gene expression markers (Col II and Sox-9) via qPCR, as well as matrix positively stained by Toluidine Blue and Safranin-O. In animal studies, ectopic cartilage tissue regeneration was observed inside and around the transplanted microspheres, confirmed by histochemical and immunofluorescent staining. Interestingly, PDLSCs showed more chondrogenesis than GMSCs and hBMMSCs (p<0.05). Taken together, these results suggest that RGD-modified alginate microencapsulating dental MSCs make a promising candidate for cartilage regeneration. Our results highlight the vital role played by the microenvironment, as well as value of presenting inductive signals for viability and differentiation of MSCs., (Copyright © 2013 Acta Materialia Inc. All rights reserved.)

Integrin-mediated cell adhesion plays a central role in cell behavior on biomaterial surfaces and influences various cell functions. Photoactivatable RGD adhesive peptides were used to investigate the effect of the density and time point of bioadhesive ligand presentation on cell adhesion, proliferation and differentiation. PEGylated self-assembled monolayers were functionalized with RGD and caged RGD ligands and seeded with C2C12 myoblasts. The cultures were irradiated at various time points between 1 and 48 h after cell seeding in order to increase RGD surface concentration at defined time points. Attachment, spreading and myogenic differentiation of C2C12 myoblasts strongly varied with the density of RGD at the surface. Proliferation and myogenesis were further regulated by the time point at which RGD was presented to the cell, reaching highest levels when RGD exposure occurred≤6 h after cell seeding. These results provide fundamental insights in cell-biomaterial interactions of C2C12 myoblasts in terms of temporal integrin-mediated cell responses., (Copyright © 2013 Acta Materialia Inc. Published by Elsevier Ltd. All rights reserved.)

The physiological mechanisms of decreased NK activity of β-Thalassemia major (BTM) patients are unknown. To assess in vitro effects of mononuclear cells and their cytokine secretion on NK activity, we compared activator receptor levels and cytotoxic activity of purified NK cells and NK cells in mononuclear cells (MNC) pools. We collected cell supernatant from unincubated and incubated MNC with K562 cells and measured their secreted cytokines levels. CD16 was lower on the surface of NK cells in MNC pools from BTM patients compared to healthy volunteers. This inhibition does not appear when NK cells were purified. NKp30 levels in NK cells decreased both as purified cells and as part of a pool of MNC in BTM patients. After incubation of MNC pools with K562 target cells, we found that supernatant levels of IL10, TGFβ1 and IL15 cytokines were also significantly higher in BTM patients compared to healthy volunteers., (Copyright © 2013 Elsevier Inc. All rights reserved.)

Endothelial to mesenchymal transition (EndMT) contributes to fibrotic diseases. The main inducer of EndMT is TGFβ signaling. TGFβ2 is the dominant isoform in the physiological embryonic EndMT, but its role in the pathological EndMT in the context of inflammatory co-stimulation is not known. The aim of this study was to investigate TGFβ2-induced EndMT in the context of inflammatory IL-1β signaling. Co-stimulation with IL-1β and TGFβ2, but not TGFβ1, caused synergistic induction of EndMT. Also, TGFβ2 was the only TGFβ isoform that was progressively upregulated during EndMT. External IL-1β stimulation was dispensable once EndMT was induced. The inflammatory transcription factor NFκB was upregulated in an additive manner by IL-1β and TGFβ2 co-stimulation. Co-stimulation also led to the nuclear translocation of NFκB which was sustained over long-term treatment. Activation of NFκB was indispensable for the co-induction of EndMT. Our data suggest that the microenvironment at the verge between inflammation (IL-1β) and tissue remodeling (TGFβ2) can strongly promote the process of EndMT. Therefore our findings provide new insights into the mechanisms of pathological EndMT., (Copyright © 2012 Elsevier GmbH. All rights reserved.)

The chemokine CCL3/MIP-1α is a risk factor in the outcome of multiple myeloma (MM), particularly in the development of osteolytic bone disease. This chemokine, highly overexpressed by MM cells, can signal mainly through 2 receptors, CCR1 and CCR5, only 1 of which (CCR1) is responsive to CCL3 in human and mouse osteoclast precursors. CCR1 activation leads to the formation of osteolytic lesions and facilitates tumor growth. Here we show that formation of mature osteoclasts is blocked by the highly potent and selective CCR1 antagonist CCX721, an analog of the clinical compound CCX354. We also show that doses of CCX721 selected to completely inhibit CCR1 produce a profound decrease in tumor burden and osteolytic damage in the murine 5TGM1 model of MM bone disease. Similar effects were observed when the antagonist was used prophylactically or therapeutically, with comparable efficacy to that of zoledronic acid. 5TGM1 cells were shown to express minimal levels of CCR1 while secreting high levels of CCL3, suggesting that the therapeutic effects of CCX721 result from CCR1 inhibition on non-MM cells, most likely osteoclasts and osteoclast precursors. These results provide a strong rationale for further development of CCR1 antagonists for the treatment of MM and associated osteolytic bone disease.

Culturing multipotent adult mesenchymal stem cells as 3D aggregates augments their differentiation potential and paracrine activity. One caveat of stem cell spheroids, though, can be the limited diffusional transport barriers posed by the inherent 3D structure of the multicellular aggregates. In order to circumvent such limitations, polymeric microparticles have been incorporated into stem cell aggregates as a means to locally control the biochemical and physical properties of the 3D microenvironment. However, the introduction of biomaterials to the 3D stem cell microenvironment could alter the mechanical forces sensed by cells within aggregates, which in turn could impact various cell behaviors and overall spheroid mechanics. Therefore, the objective of this study was to determine the acute effects of biomaterial incorporation within mesenchymal stem cell spheroids on aggregate structure and mechanical properties. The results of this study demonstrate that although gelatin microparticle incorporation results in similar multi-cellular organization within human mesenchymal stem cell spheroids, the introduction of gelatin materials significantly impacts spheroid mechanical properties. The marked differences in spheroid mechanics induced by microparticle incorporation may hold major implications for in vitro directed differentiation strategies and offer a novel route to engineer the mechanical properties of tissue constructs ex vivo., (Copyright © 2012 Elsevier Ltd. All rights reserved.)

Secretory granules of pancreatic β-cells contain high concentrations of Ca2+ ions that are co-released with insulin in the extracellular milieu upon activation of exocytosis. As a consequence, an increase in the extracellular Ca2+ concentration ([Ca2+]ext) in the microenvironment immediately surrounding β-cells should be expected following the exocytotic event. Using Ca2+-selective microelectrodes we show here that both high glucose and non-nutrient insulinotropic agents elicit a reversible increase of [Ca2+]ext within rat insulinoma (INS-1E) β-cells pseudoislets. The glucose-induced increases in [Ca2+]ext are blocked by pretreatment with different Ca2+ channel blockers. Physiological agonists acting as positive or negative modulators of the insulin secretion and drugs known to intersect the secretory machinery at different levels also induce [Ca2+]ext changes as predicted on the basis of their described action on insulin secretion. Finally, the glucose-induced [Ca2+]ext increase is strongly inhibited after disruption of the actin web, indicating that the dynamic [Ca2+]ext changes recorded in INS-1E pseudoislets by Ca2+-selective microelectrodes occur mainly as a consequence of exocytosis of Ca2+-rich granules. In conclusion, our data directly demonstrate that the extracellular spaces surrounding β-cells constitute a restricted domain where Ca2+ is co-released during insulin exocytosis, creating the basis for an autocrine/paracrine cell-to-cell communication system via extracellular Ca2+ sensors., (Copyright © 2012 Elsevier Ltd. All rights reserved.)

GS-1101 (CAL-101) is an oral PI3Kδ-specific inhibitor that has shown preclinical and clinical activity in non-Hodgkin lymphoma and chronic lymphocytic leukemia. To investigate the potential role of PI3Kδ in Hodgkin lymphoma (HL), we screened 5 HL cell lines and primary samples from patients with HL for PI3Kδ isoform expression and constitutive PI3K pathway activation. Inhibition of PI3Kδ by GS-1101 resulted in the inhibition of Akt phosphorylation. Cocultures with stroma cells induced Akt activation in HL cells, and this effect was blocked by GS-1101. Conversely, production of the stroma-stimulating chemokine, CCL5, by HL cells was reduced by GS-1101. GS-1101 also induced dose-dependent apoptosis of HL cells at 48 hours. Reductions in cell viability and apoptosis were enhanced when combining GS-1101 with the mTOR inhibitor everolimus. Our findings suggest that excessive PI3Kδ activity is characteristic in HL and support clinical evaluation of GS-1101, alone and in combination, as targeted therapy for HL.

Fibroblast activation protein-α (FAP) is a serine protease that can provide target specificity to therapeutic agents because in adults its expression is restricted to pathologic sites, including cancer, fibrosis, arthritis, wounding, or inflammation. It is not expressed in most normal tissues. The majority of FAP is expressed by activated fibroblasts responding to the pathologic situations. FAP is typically found as a type II transmembrane protein physically attached to cells and with the bulk of the protein, including the catalytic domain, exposed to the extracellular space and accessible to small molecules. In this chapter, we review the structure, substrate specificities, signaling functions, and current design of FAP inhibitors. Evidence indicating the presence of FAP in multiple cancers, arthritis, fibrosis, keloids, and other pathologies is described and indicates possible roles for FAP in facilitating cell invasion and growth. Separate sections are devoted to the role of FAP in coordinating the stromal response to cancer, including a role in angiogenesis and a potential role in modulation of the antitumor immune response. Finally studies attempting to demonstrate the clinical potential of FAP are discussed, as well as some novel applications employing FAP in therapy or diagnosis. Throughout this review, effort is made to highlight areas where information is lacking and to highlight important questions that require further investigation., (Copyright © 2012 Elsevier Inc. All rights reserved.)

Rational design of biomaterials requires understanding how cells interrogate their microenvironment. In this study, human umbilical vein endothelial cells are cultured on combinations of extracellular matrix (ECM) components (collagen I, collagen IV, vitronectin, fibronectin, laminin, heparan sulfate proteoglycan, chondroitin sulfate proteoglycan), and the phosphorylation of four intracellular signaling kinases (Erk1/2, JNK, Akt1, and NFκB) is quantified. These combinations of ECM components elicit different temporal patterns of Erk1/2 phosphorylation. Collagen I-containing substrates cause Erk1/2 phosphorylation to reach maximal levels at 30 min and remain near maximal levels until 90 min. Collagen IV/laminin substrates elicit maximal phosphorylation at 30-45 min, and then phosphorylation decreases substantially at 60-90 min. All other combinations studied (collagen IV and vitronectin-based combinations) cause an increase in phosphorylation at 30-45 min, but not to maximal levels; maximal phosphorylation is reached by 60-90 min. These temporal patterns of phosphorylation may explain how a limited number of intracellular signaling pathways can distinguish among thousands of possible combinations of microenvironmental cues by adding to the information contained in each cell signaling pathway., (Copyright © 2011 Acta Materialia Inc. Published by Elsevier Ltd. All rights reserved.)

In a previous report, we observed that the phytol-derived immunostimulant, PHIS-01 (phytanol), is a nontoxic oil-in-water adjuvant which is superior to most commercial adjuvants. In contrast, the parent diterpene alcohol phytol, though highly effective as an adjuvant, is relatively toxic. To assess the importance of the polar functional group in PHIS-01, we prepared two new compounds PHIS-02 (phytanyl amine) and PHIS-03 (phytanyl mannose). All three phytol derivatives proved to be excellent adjuvants, but differed in solubility and mode of action. To delineate their molecular signatures in the local microenvironment, we performed inflammasome and cytokine microarray analyses with the peritoneal fluid of mice treated with alum or the phytol compounds above, in the presence or absence of soluble protein antigens. We report here that the phytol derivatives had a significant time-dependent impact on the host chemokine-cytokine microenvironment and subsequently on specific humoral responses. Moreover, the inclusion of protein immunogens induced further changes in host microenvironments, including rapid (<2h) expression of cytokines and chemotactic factors (IL-6, MCP-1, KC, MIP-1, and LIX), implying mobilization and activation of neutrophils, and monocytes. PHIS-01 proved to be the most effective in this regard. Inflammatory cytokine cascades were dominant even after 24h possibly to facilitate involvement of the acquired immune system with the release of B-lymphocyte chemo-attractant BLC, T-cell activation-3 chemokines TCA, IL-4, IL-12, and TIMP-1. We also noted enhanced expression of NLRP genes including NLRP3 with both alum and phytol derivatives (particularly PHIS-01)., (Copyright © 2011 Elsevier Inc. All rights reserved.)