Gelatin-based hydrogel, which mimics the natural dermal extracellular matrix, is a promising tissue engineering material. However, insufficient and uncontrollable mechanical and degradation properties remain the major obstacles for its application in medical bone regeneration material. Herein, we develop a facile but efficient strategy for a novel hydrogel as guided bone regeneration (GBR) material. In this study, methacrylic anhydride (MA) has been used to modify gelatin to obtain photo-crosslinkable methacrylated gelatin (GelMA). Moreover, the GelMA/PEGDA hydrogel was prepared by photo-crosslinking GelMA and PEGDA with photoinitiator I2959 under UV treatment. Compared with the GelMA hydrogel, the GelMA/PEGDA hydrogel exhibits several times stronger mechanical properties than pure GelMA hydrogel. The GelMA/PEGDA hydrogel shows a suitable degradation rate of more than 4 weeks, which is beneficial to implant in body. In vitro cell culture showed that osteoblast can adhere and proliferate on the surface of the hydrogel, indicating that the GelMA/PEGDA hydrogel had good cell viability and biocompatibility. Furthermore, by changing the quantities of GelMA, I2959, and PEGDA, the gelation time can be controlled easily to meet the requirement of its applications. In short, this study demonstrated that PEGDA enhanced the performance and extended the applications of GelMA hydrogels, turning the GelMA/PEGDA hydrogel into an excellent GBR material.

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Steam Alkali catalyst Hydrogen Hydrothermal carbonization a b s t r a c tHydrothermal carbonization is an effective pretreatment for further thermal conversion of high moisture biomass without a high cost of a dehydration process. The current paper concerns the properties of hydrochar derived from hydrothermal carbonization of sewage sludge, and the feasibility of steam gasification of hydrochar for hydrogen-rich gas production was investigated. Sewage sludge derived hydrochar was characterized using scanning electron microscopy, Fourier transform infrared spectroscopy, and inductively coupled plasma atomic emission spectroscopy to evaluate its feasibility for gasification application. The effect of reaction temperature, steam to biomass mass ratio, and addition of alkali catalysts on steam gasification characteristics of raw sewage sludge and corresponding hydrochar were evaluated, in terms of major composition of the produced gas, gas yield, gasification efficiency and energy density. The results showed that sewage sludge derived hydrochar was rich in hydrophilic functional groups and increased Fe, Ni, alkali and alkaline earth metals (i.e. K, Na, Ca, Mg), resulting in a higher hydrogen yield and energy efficiency than direct steam gasification of sewage sludge under identical conditions. In addition, hydrogen-rich gas production was also favored with the presence of alkali catalysts, especially for the hydrochar. The present study demonstrates that hydrothermal carbonization provides an effective pretreatment of sewage sludge for production of hydrogen-rich gas via steam gasification.

ObjectiveCollagen peptides (CP) compounds, as bone health supplements, are known to play a role in the treatment of osteoporosis. However, the molecular mechanisms of this process remain unclear. This study aimed to investigate the effects of bovine CP compounds on the proliferation and differentiation of MC3T3-E1 cells.MethodsMouse pre-osteoblast cell line MC3T3-E1 subclone 4 cells were treated with bovine CP compounds. Cell proliferation was analyzed by MTT assays and the cell cycle was evaluated by flow cytometry scanning. Furthermore, MC3T3-E1 cell differentiation was analyzed at the RNA level by real-time PCR and at the protein level by western blot analysis for runt-related transcription factor 2 (Runx2), a colorimetric p-nitrophenyl phosphate assay for alkaline phosphatase (ALP), and ELISA for osteocalcin (OC). Finally, alizarin red staining for mineralization was measured using Image Software Pro Plus 6.0.ResultsCell proliferation was very efficient after treatment with different concentrations of bovine CP compounds, and the best concentration was 3 mg/mL. Bovine CP compounds significantly increased the percentage of MC3T3-E1 cells in G2/S phase. Runx2 expression, ALP activity, and OC production were significantly increased after treatment with bovine CP compounds for 7 or 14 days. Quantitative analyses with alizarin red staining showed significantly increased mineralization of MC3T3-E1 cells after treatment with bovine CP compounds for 14 or 21 days.ConclusionsBovine CP compounds increased osteoblast proliferation, and played positive roles in osteoblast differentiation and mineralized bone matrix formation. Taking all the experiments together, our study indicates a molecular mechanism for the potential treatment of osteoarthritis and osteoporosis.

Clear cell renal cell carcinomas (RCC), the major histologic subtype of RCC accounting for more than 80% of cases, are typified by biallelic inactivation of the von Hippel-Lindau (VHL) tumor suppressor gene. Although accumulation of hypoxia-inducible factor alpha (HIF-a) is the most well-studied effect of VHL inactivation, direct inhibition of HIFa or restoration of wild-type pVHL protein expression has not proved readily feasible, given the limitations associated with pharmacologic targeting of transcription factors (i.e

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Flexible sensors based on conductive hydrogel show great potential in electronic skin and human–machine interface. However, pure water in hydrogel inevitably freezes or rapidly evaporates under extreme temperatures, leading to inadequate fulfillment of sensor performances. Herein, a well-designed strategy is reported for fabricating extreme temperature-tolerant gel-based sensors. By immersing a gelatin/polyacrylamide (PAAm)–clay composite (GC) hydrogel into a ZnCl2/water/glycerol system, a phase-transition-tunable gel (PTTGC gel) is obtained with outstanding antifreezing (−82 °C) and long-lasting moisture (70 °C, more than 40 days) properties. Meanwhile, the gel also presents good antibacterial activity and biocompatibility attributing to Zn2+ and gelatin, respectively. Then, a dual-response sensor with a wide operating temperature (−60 to 60 °C) is proposed, presenting high stress and temperature sensitivities and long-term stability. The sensor will meet the needs of the human–machine interface for scientific investigation and data monitoring in polar, desert, etc.

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