硅酸盐生物陶瓷对内皮细胞与成骨细胞间相互作用的影响及机制研究

The facts that biomaterials affect the behavior of single type of cells have been widely accepted. However, during tissue renegeration, there is not only biomaterial-cell interactions but also cell-cell intereactions, which plays an important rile.Therefore, we assumed that biomaterials may affect tissue regeneration throughing affecting the interactions between cells. However, the effects of biomaterials on cell-cell interactions have rarely been reported.Bone tissue engineering involves osteoblastic cells (OCs), endothelial cells (ECs) and the interactions between OCs and ECs.We have observed that silicate biomaterials can not only stimulate osteogenic differentiation of OCs and vascularization of ECs, but also affect the interactions between ECs and OCs for enhancing vascularization and osteogenesis.However, the mechanism needs to be further investigated. Therefore,the aim of this project is to investigate the interactions between human umbilical vein endothelail cells (HUVECs) and human bone marrow stromal cells (HBMSCs) with the involvement of silicate bioceramics doped with diffferent elements doped. Our investigations will focus on determining the effective silicate bioceramics ion products,ion concentrations and the synergistic effects between the different ions for stimulating interactions between HUVECs and HBMSCs and finally angiogenesis and osteogenesis. Based on the results, a silicate bioceramic with optimal ability to enhance vascularization and osteogenesis will be designed and a composite three dimensional scaffolds containing different content of that silicate bioceramic and polylactic acid (PLA) will be fabricated. The behavior of ion release from the composite scaffolds will be studied and the effects of the composite scaffolds on the osteogenesis and angiogenesis will be studied. Furthermore, the effects of bioceramics on the interactions between HUVECs and HBMSCs with or without the involvement of silicate bioceramics, especially on the cell-cell junction molecules and extracellular cell matrix secreted growth factors that affect angiogenesis and osteogenesis will be investigated. Then, the critical signal pathways for osteogenesis and angiogenesis will be studied in order to elucidate the mechanism through which the interactions between HUVEC and HBMSC influence the HUVEC's angiogenesis and HBMSC's osteogenesis with or without silicate cereamics.

生物材料能够影响单独细胞的行为进而影响组织再生，而细胞与细胞间的相互交流在组织再生过程中也非常关键。我们假设，生物材料对组织再生的影响可能与其对细胞间相互作用影响有关，进而影响组织再生。然而，生物材料对细胞间相互作用的影响至今鲜有报道。我们预实验结果证实：硅酸钙能促进内皮细胞与骨髓间充质干细胞相互作用进而促进成骨分化和血管化。但是，其中的机制仍有待研究。因此，本项目将重点研究含有不同元素的硅酸盐生物陶瓷对成骨细胞与内皮细胞相互作用的影响及各离子的作用、有效浓度范围和离子间协同作用，优化硅酸盐陶瓷组成并通过硅酸盐陶瓷/聚合物复合支架调控离子释放行为，获得能促进血管化组织工程骨再生的支架材料。同时，从分子生物学角度探讨在硅酸盐陶瓷影响成骨细胞与内皮细胞相互作用过程中，材料对细胞中成骨和成血管关键分子以及相关信号通道状态的影响，阐明硅酸盐陶瓷影响两种细胞间相互作用进而促进成血管和成骨的分子机制。

生物材料能够影响单独细胞的行为进而影响组织再生，而细胞与细胞间的相互交流在组织再生过程中也非常关键。为了进一步阐明硅酸盐材料促进组织再生的材料学机制以及分子生物学机制，本项目重点研究了以硅酸钙以及生物活性玻璃为主的硅酸盐生物陶瓷对干细胞与内皮细胞相互作用的影响及硅离子在此过程中产生的重要作用，并且研究了硅酸盐生物活性陶瓷离子产物的化学信号与电纺丝材料的纳米结构信号组合使用时对成骨细胞与内皮细胞相互作用的影响。在此基础上，本项目还开发了含有镁黄长石的可注射海藻酸钠水凝胶材料，通过水凝胶的结构调控镁黄长石的离子释放行为，并且研究了该材料对炎症细胞与内皮细胞以及成骨细胞的相互作用的影响。此外，本项目还从分子生物学角度探讨在硅酸盐陶瓷影响成骨细胞与内皮细胞相互作用过程中，材料对细胞中成骨和成血管关键分子以及相关信号通道状态的影响，阐明硅酸盐陶瓷影响两种细胞间相互作用进而促进成血管和成骨的分子机制。. 本项目主要有以下发现；（1）硅酸钙离子产物能通过激活Wnt/beta-catenin信号通道促进尿液来源干细胞朝成骨分化，在体内还能促进血管长入聚乳酸/硅酸钙多孔支架材料内部。主要是硅离子的生物学效应起作用，其有效离子浓度在0.8-1.7微克/毫升。（2）生物活性玻璃的离子产物能在缺氧状态下支持内皮细胞存活，迁移并通过促进Cx43的表达促进细胞-细胞之间的交流从而促进内皮细胞形成血管，最终促进组织修复（皮肤创面为例），该结果阐明了生物活性玻璃促进内皮细胞成血管以及促进创面修复的部分分子机理。（3）可通过将生物材料中不同种类的材料信号以及小分子药物与生物材料活性信号进行组合，研究各种信号对细胞-细胞相互交流的影响以及各自扮演的角色，获得材料活性信号间的相互作用，发掘具有协同作用的材料活性信号，并组合使用具有协同作用的材料活性信号刺激细胞-细胞间相互作用，获得性能优良的组织工程产品。