Construction of oxidized icariin functionalized collagen composite with promoting osteogenesis, vascularization and anti-inflammatory properties potential for bone repair application

Bone defects are mainly treated by transplanting bone scaffold, and lack of osteogenesis, vascularization and anti-inflammatory properties will reduce the ability of new bone tissue to grow into them, thus increasing the risk of bone repair failure. In this study, inspired by the composition of natural bone, COL-BG-MOF composite was first prepared (collagen (COL) as the organic component, aminated mesoporous bioactive glass (BG-NH₂) as the inorganic non-metallic component, and mesoporous silica shell-coated Mg-MOF-74 (Mg-MOF-74@MSiO₂) as the metallic trace element component). Subsequently, in order to further enhance the effectiveness of its bone repair application potential, COL-BG-MOF was functionalized by oxidized Icariin (OICA) as a “growth factor” component to endow it with simultaneous osteogenesis promoting, vascularization promoting, and anti-inflammatory properties. Notably, the –CHO of OICA can react with the –NH₂ in COL-BG-MOF by Schiff base reaction, which can cross-link the COL, thus improving the interfacial binding of BG-NH₂ to the COL and slowing down the release rate of OICA. The results showed that the obtained functionalized composite scaffold exhibited better compressive strength, anti-degradation and osteoconductivity, as well as sustained OICA release behavior. More importantly, the synergistic effect of OICA and Mg-MOF-74@MSiO₂ greatly promoted its osteogenic differentiation, HUVEC migration and anti-inflammatory properties. Therefore, this study provided a strategy to prepare functionalized composites by using modified Chinese medicine, which has great application potential in the field of bone regeneration.