石墨烯改性硅橡胶功能复合材料的制备及应用

综合性能优异的石墨烯改性硅橡胶复合材料在航天航空、电子电器以及医药卫生等领域展现出广泛的应用前景。总结石墨烯改性硅橡胶复合材料的主要制备方法及其优缺点,重点介绍具有特殊润湿性、导热性能和导电性能的石墨烯改性硅橡胶功能复合材料的研究进展。提高石墨烯的功能改性效率及石墨烯在复合材料中的含量和均匀分散性、实现复合材料的多功能化等是未来研究的难点和重点。     

Effects of Puerarin-Loaded Tetrahedral Framework Nucleic Acids on Osteonecrosis of the Femoral Head

Osteonecrosis of the femoral head (ONFH) is recognized as a common refractory orthopedic disease that causes severe pain and poor quality of life in patients. Puerarin (Pue), a natural isoflavone glycoside, can promote osteogenesis and inhibit apoptosis of bone mesenchymal stem cells (BMSCs), demonstrating its great potential in the treatment of osteonecrosis. However, its low aqueous solubility, fast degradation in vivo, and inadequate bioavailability, limit its clinical application and therapeutic efficacy. Tetrahedral framework nucleic acids (tFNAs) are promising novel DNA nanomaterials in drug delivery. In this study, tFNAs as Pue carriers is used and synthesized a tFNA/Pue complex (TPC) that exhibited better stability, biocompatibility, and tissue utilization than free Pue. A dexamethasone (DEX)-treated BMSC model in vitro and a methylprednisolone (MPS)-induced ONFH model in vivo is also established, to explore the regulatory effects of TPC on osteogenesis and apoptosis of BMSCs. This findings showed that TPC can restore osteogenesis dysfunction and attenuated BMSC apoptosis induced by high-dose glucocorticoids (GCs) through the hedgehog and Akt/Bcl-2 pathways, contributing to the prevention of GC-induced ONFH in rats. Thus, TPC is a promising drug for the treatment of ONFH and other osteogenesis-related diseases.