粉碎骨折、肿瘤或骨髓炎病灶清除后大段骨缺损是骨科医生面临的挑战之一。现今的骨修复材料多存在生物活性不足、修复效果不佳及无法抵御外界细菌感染等缺陷。作为修复骨缺损的生物材料应具有诱导骨形成、促进骨折端血管化和抗菌能力强等特性。课题组前期利用3D打印技术成功构建三维框架生物活性骨组织工程支架，并证实PDGF-BB可明显促进骨组织微血管形成。如何使PDGF-BB缓慢释放，长期诱导BMSCs成血管化，建立骨组织微血管是我们迫切需要解决的问题。利用载银介孔氧化硅（AG-MSN）携载并逐步释放PDGF-BB，长期诱导BMSCs成血管化是实现组织工程骨微血管形成的一个新的策略。本研究的主要目的是探讨携载PDGF-BB的AG-MSN多功能混合物（P-AG-MSN）对BMSCs的成血管化作用及其抗菌效应，以期结合3D打印技术构建出全新的兼有诱导BMSCs成骨化、血管化及抗菌作用的活性生物支架。

Large-segmental bone defect after comminuted fracture, tumor or osteomyelitis lesions clearing is one of challenges for orthopedists. Current bone repair materials often have insufficient bioactivity, poor repair effect and incapability to defend external bacterial infection and other defects. Biomaterials repairing bone defect should possess such properties as osteoinductive, vascularization promotion at fracture end and strong antibacterial ability. The research group has successfully constructed 3-dimensional framework bioactive bone tissue engineering scaffold using 3D print technology in preliminary study stage, and has verified that PDGF-BB can significantly promote the formation of bone tissue microvascular. How to induce long-term BMSCs vascularization by enhancing PDGF-BB sustained-release so as to establish bone tissue microvascular is a pressing problem to address. Using silver-loaded mesoporous silica (AG-MSN）to load and gradually release PDGF-BB for long-term induction of BMSCs vascularization represents a new strategy to realize the formation of tissue engineering bone microvascular. The main objective of the study is to explore the vascularization and antibacterial effect of AG-MSN multifunctional mixture （P-AG-MSN）loaded with PDGF-BB on BMSCs, so as to construct a completely-new active biological scaffold in possession of BMSCs ossification and vascularization induction and antibacterial effecting 3D print technology.