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Advanced wound scaffolds that integrate active substances to treat chronic wounds have gained significant recent attention. While wound scaffolds and advanced functionalities have previously been incorporated into one medical device, the wirelessly triggered release of active substances has remained the focus of many research endeavors. To combine multiple functions including light-triggered activation, anti-septic, angiogenic, and moisturizing properties, we have developed a 3D printed hydrogel patch encapsulating vascular endothelial growth factor (VEGF) decorated with photoactive and antibacterial tetrapodal zinc oxide (t-ZnO) microparticles. To achieve the smart release of VEGF, t-ZnO was modified by chemical treatment and activated through UV/visible light exposure. This process would also make the surface rough and improve protein adhesion. The elastic modulus and degradation behavior of the composite hydrogels, which must match the wound healing process, were adjusted by changing t-ZnO concentrations. The t-ZnO-laden composite hydrogels can be printed with any desired micropattern to potentially create a modular elution of various growth factors. The VEGF decorated t-ZnO-laden hydrogel patches showed low cytotoxicity and improved angiogenic properties while maintaining antibacterial functions in vitro. In vivo tests showed promising results for the printed wound patches, with less immunogenicity and enhanced wound healing.
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OBJECTIVE: University students who experience more discrimination typically report more negative consequences from alcohol use. The study aimed to assess whether drinking to cope and protective behavioral strategies for alcohol use would help explain the relationship between everyday discrimination and alcohol-related consequences among university student drinkers. METHOD: Data were collected in Fall 2020 and the sample included 707 undergraduate and graduate students from a large public institution in the northeast who reported consuming alcohol in the past month. Participants identified predominantly as women (71.7%; 24.6% men) and White (65.1%; 7.9% Black/African American; 7.2% Asian/Asian American; 7.1% Hispanic/Latinx). A cross-sectional serial mediation analysis using structural equation modeling was conducted using Mplus. RESULTS: Controlling for alcohol use, results supported a serial partial mediation model. More experiences of discrimination predicted a significant increase in alcohol-related consequences, above and beyond the increase attributed to drinking to cope. More frequent use of protective behavioral strategies significantly increased the odds of reporting no alcohol-related consequences. CONCLUSIONS: Drinking to cope and protective behavioral strategies for alcohol use may help explain why university students who report frequent discrimination are more likely to experience alcohol-related consequences, independent of how much alcohol they consume. Findings can inform clinical and prevention practice, advocacy, and training.
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Objective: Drinking more and drinking to cope increase undergraduates' likelihood of experiencing alcohol-related problems (ARP; e.g., driving intoxicated). In accordance with stress-coping models of addiction, anxiety about COVID-19 may motivate undergraduates to drink to cope, leading them to experience more ARP. However, this hypothesis has not been tested. Participants and methods: During fall 2020, 358 undergraduate drinkers (Mage = 21.18; 69.80% cis-women; 62.30% White) provided data regarding COVID-anxiety, alcohol consumption, drinking to cope, and ARP during an annual student survey. Results: Mediation analysis controlling for alcohol consumption revealed greater COVID-anxiety predicted higher levels of drinking to cope; in turn, higher levels of drinking to cope were associated with more ARP. Additionally, the positive relationship between greater COVID-anxiety and experiencing more ARP was explained entirely by higher levels of drinking to cope. Conclusion: During the pandemic and beyond, university prevention and intervention initiatives should target coping motives for alcohol use to help students avoid ARP.
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A combination of hydrogel materials, and therapeutic agents have been actively reported to facilitate bone defect healing. However, conventionally hydrogels using cross-linker would result in low stability of the hydrogel itself, loss of agents during cross-linking, and complexity of use. In this study, alendronate was tethered to an AlA to improve its bone healing and drug-loading stability. AlA was further functionalized with Ca2+ (AlACa). A mixture of AlACa and alginate formed AlAA hydrogel. The gelation time of AlAA was sufficient for injecting into the defect site. The hydrogel stiffness was controlled, while the stress-relaxation time was fixed. In vitro cell tests demonstrated that the AlAA promoted proliferation and differentiation behaviors. In particular, AlAA showed the best mechanical stiffness with appropriate stress-relaxation and cellular behavior, indicating that it would be beneficial as a scaffold in the bone tissue engineering field.
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Hidrogeles , Osteogénesis , Hidrogeles/farmacología , Andamios del Tejido , Alendronato/farmacología , Calcio , Ingeniería de Tejidos , Alginatos/farmacologíaRESUMEN
Introduction: Astrocytes play crucial role in modulating immune response in the damaged central nervous system. Numerous studies have investigated the relationship between immune responses in astrocytes and brain diseases. However, the potential application of nanomaterials for alleviating neuroinflammation induced by astrocytes remains unexplored. Method: In this study, we utilized electrophoretic deposition (EPD) to coat graphene oxide (GO) onto titanium (Ti) to enhance the bioactivity of Ti. Results: We confirmed that GO-Ti could improve cell adhesion and proliferation of astrocytes with upregulated integrins and glial fibrillary acidic protein (GFAP) expression. Moreover, we observed that astrocytes on GO-Ti exhibited a heightened immune response when exposed to lipopolysaccharide (LPS). Although pro-inflammatory cytokines increased, anti-inflammatory cytokines and brain-derived neurotrophic factors involved in neuroprotective effects were also augmented through nuclear localization of the yes-associated protein (YAP) and nuclear factor kappa B (NF-κB). Discussion: Taken together, GO-Ti could enhance the neuroprotective function of astrocytes by upregulating the expression of anti-inflammatory cytokines and neuroprotective factors with improved cell adhesion and viability. Consequently, our findings suggest that GO-Ti has the potential to induce neuroprotective effects by regulating cell activity.
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Jeong-Sun Park was not included as an author in the original publication [...].
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Statin derivatives traditionally have been used for the treatment of hyperlipidemia, but recent studies have shown their ability to regulate bone metabolism and promote bone growth. In this study, simvastatin (Sim), a new therapeutic candidate for bone regeneration, was combined with graphene oxide (GO), which has recently attracted much interest as a drug delivery method, to produce a compound substance effective for bone regeneration. To create a stable and homogenous complex with Sim, GO was modified with polyethylenimine, and the effect of modification was analyzed using Fourier transform infrared spectroscopy, zeta potential, and cytotoxicity testing. More specifically, the osteogenic differentiation potential expected by the combination of the two effective materials for osteogenic differentiation, GO and Sim, was evaluated in mesenchymal stem cells. Compared with control groups with GO and Sim used separately, the GO/Sim complex showed excellent osteogenic differentiation properties, with especially enhanced effects in the complex containing < 1 µM Sim.
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Biological dressings composed of multi-components including extracellular matrix (ECM) materials and therapeutic agents for facilitating wound healing have been actively reported. To improve the wound healing ability of chitosan dressing, sol-gel derived silica was incorporated with chitosan and this chitosan-silica hybrid dressing was combined with keratinocyte growth factor (KGF) in this study. Such hybrid dressing showed higher efficacy of KGF adsorption than pure chitosan dressing due to its porous structure and hydrophilic character. The hybrid dressing showed sustainable release profile for KGF. The delivered-KGF improved keratinocyte activities such as attachment and proliferation. In vivo animal test using excisional wound model revealed that such dressing could facilitate skin regeneration. However, the tissue regeneration process was different depending on combinatorial components in the dressing. Chitosan dressing incorporated with KGF improved the wound healing process compared to chitosan dressing without KGF. The chitosan-silica hybrid dressing combined with KGF showed the best wound healing process.
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Vendajes , Sistemas de Liberación de Medicamentos/métodos , Factor 7 de Crecimiento de Fibroblastos/administración & dosificación , Nanocompuestos/química , Cicatrización de Heridas/efectos de los fármacos , Animales , Células Cultivadas , Quitosano/química , Relación Dosis-Respuesta a Droga , Liberación de Fármacos , Factor 7 de Crecimiento de Fibroblastos/farmacocinética , Factor 7 de Crecimiento de Fibroblastos/farmacología , Queratinocitos/efectos de los fármacos , Masculino , Ratones Pelados , Dióxido de Silicio/químicaRESUMEN
Development of bioactive hydrogel as extracellular matrix (ECM) is a very important field for cell-based therapy. In this study, we provided a facile method based on sol-gel process for fabricating bioactive composite hydrogels. The composite hydrogels were composed of sol-gel derived silica and biopolymer. Different amounts of silica solution (20-80wt%) were mixed with 2% polymer sol (alginate) followed by aging and gelation to form a network so that the alginate-silica hybrid mixture could form a gel without any additional crosslinking process. The self-gelation time of the hybrid hydrogel measured by rheometer was reduced as the content of silica was increased. Such hydrogels had highly porous and interconnected structures. Their strut showed uniform surface texture. Under physiological conditions (PBS, 37°C), these hybrid hydrogels exhibited long-term stability compared to alginate hydrogels as control. The mechanical properties of these hydrogels such as compressive strength, compressive modulus, and work of fracture were significantly enhanced by hybridization with sol-gel derived silica. In vitro cell tests revealed that these hybrid hydrogels exhibited improved cell adhesion and proliferation behaviors compared to pure alginate hydrogel cross-linked by CaCl2 solution. Furthermore, cell encapsulation within these hydrogels revealed that their alginate-silica composite provided suitable microenvironment for cell survival.