LCM3负载BMSCs调控巨噬细胞M2极化促进成骨成血管的机理研究

Regulation of the immune microenvironment created by bone repair scaffold materials is critical for enhancing osteogenic efficiency. In our previous studies, implantation of BMSCs-laden hydrogel scaffold by two-photon polymerization (LCM3) into animal models could improve the immune microenvironment and promote angiogenesis and osteogenesis. Studies have shown self-renewal of BMSCs is closely related to the adhesion molecule E-cadherin and cells adhering to the surface of scaffolds are mainly mononuclear macrophages post-implantation, and macrophages play a key role in inflammation response. The project intends to construct a co-culture model of BMSCs-laden LCM3 with macrophages to study the role of E-cadherin/EGFR/PI3K/Akt signaling pathway in M2 macrophage polarization; and to study pro-angiogenesis and pro-osteogenesis effect of BMSCs-laden LCM3 via M2 macrophage polarization by means of molecular experiments in vitro and animal experiments in vivo. It aims to clarify the mechanism of the pro-angiogenesis and pro-osteogenesis effect of BMSCs-laden LCM3 via M2 macrophage polarization, to provide a experimental and theoretical basis for enhancing osteogenic efficiency.

调控骨生物材料植入局部的免疫微环境是解决提高成骨效能的关键问题。项目组前期研究发现双光子聚合加工的水凝胶支架LCM3负载骨髓间充质干细胞BMSCs可改善植入局部的炎性微环境，促进BMSCs成骨成血管分化。鉴于BMSCs的自我更新与E-cadherin密切相关，黏附植入材料表面的主要为单核巨噬细胞，且巨噬细胞是炎症反应的关键调节者，其不同极化类型功能各异。本项目拟建立LCM3/BMSCs/巨噬细胞共培养模型，研究E-cadherin/EGFR/PI3K/Akt信号通路调控巨噬细胞M2极化的机制；通过体外细胞分子实验和体内动物实验研究巨噬细胞M2极化对BMSCs成骨成血管分化的分子机制，从而阐明LCM3负载的BMSCs调控巨噬细胞M2极化，继而改善免疫微环境促进BMSCs成骨成血管分化的机理，为临床上提高骨生物材料的成骨效能提供实验及理论依据。

本项目拟运用现代分子生物学和免疫学技术，以双光子聚合加 工而成的水凝胶生物支架材料 3D GelMA ICC为平台，从以下几个方面进行深入研究： ①负载 BMSCs 的生物材料体外实验，探讨巨噬细胞 M2 型释放的抗炎因子 和活性物质对 BMSCs 成骨成血管分化的影响；②负载 BMSCs 的生物材料，在动物颅骨植入实验中，能够促进骨形成；③本研究将首次从 材料与细胞复合物结合，这个新观点探讨 BMSCs 调控巨噬细胞 M2 极化，继而促进 BMSCs 成骨成血管分化的机制，为临床上提高骨生物材料成骨效能提供坚实的实验及理论依。