摘要Treating bone defects complicated by bacterial infections remains a significant clinical challenge.Drawing inspiration from the human body's bone repair mechanisms,the use of biomimetic methods to design tissue engineering scaffolds is of great significance for bone repair.This study synthesized copper(Cu)-doped mesoporous silica nanoparticles(Cu@MSN)modified with hydroxyethyl methacrylate to obtain methacrylated Cu@MSN(Cu@MSNMA).Furtheremore,bio-mimetic nanocomposite hydrogels were prepared by adding Cu@MSNMA to a GelMA/gelatin solution.This hydrogel achieves multi-modal bone tissue biomimicry:(ⅰ)GelMA/gelatin mimics the matrix components in bone ECM,ensuring biocompatibility while promoting cellular behavior(such as adhesion,proliferation,and differentiation);(ⅱ)GelMA/gela-tin and the crosslinking sites introduced by Cu@MSNMA form a stable porous network structure,achieving structural and mechanical biomimicry to provide necessary support for bone defects;(ⅲ)The elemental biomimicry of Si and Cu in Cu@MSNMA achieves efficient osteogenic induction.The effect of different proportions of Cu@MSNMA on the physi-cal properties of the composite hydrogels was investigated to determine the optimal proportion.The results indicated that the mechanical properties of hydrogel were enhanced with the increasing Cu@MSNMA mass ratio.Notably,5％NPs/GelMA/gelatin hydrogel exhibited excellent mechanical property compared to the GelMA/gelatin hydrogel.In vitro and vivo cellular experiments demonstrated a significant enhancement in antibacterial and osteogenic induction with Cu@MSNMA addition.In conclusion,the proposed nanocomposite hydrogel with biomimetic components and ion-regulating properties can serve as a multifunctional scaffold,offering antimicrobial properties for infected bone regeneration,and guide for future research in bone regeneration and three-dimensional printing.