Cationized Decalcified Bone Matrix for Infected Bone Defect Treatment

Objective: We aim to develop a dual-functional bone regeneration scaffold (Qx-D) with antibacterial and osteogenic properties for infected bone defect treatment. Impact Statement: This study provides insights into antibacterial components that could be combined with naturally derived materials through a facile Schiff base reaction, offering a potential strategy to enhance antibacterial properties. Introduction: Naturally derived decalcified bone matrix (DBM) has been reported to be porous and biodegradable. DBM can induce various cell differentiations and participate in immune regulation, making it an ideal bone regeneration scaffold for bone defects. However, DBM does not exhibit antimicrobial properties. Therefore, it is essential to develop antibacterial functionalization method for DBM. Methods: DBM was modified with a macromolecular quaternary ammonium salt (QPEI). A series of Qx-D with tunable feeding ratios were synthesized through Schiff base reaction. The morphology, chemical property, in vitro antibacterial efficiency, in vitro biocompatibility, osteogenic property, and in vivo anti-infection performances were characterized. Results: All Qx-D exhibited marked antibacterial properties. Small adjustments in feed concentration could not induce changes in antibacterial properties. However, cell viability slightly decreased with increasing feed concentration. Q10-D demonstrated significant antibacterial properties and could promote recovery of infected bone defect in an animal model. Conclusion: Qx-D shows marked antibacterial properties and good biocompatibility. Moreover, Q10-D could be a potential choice for infected bone defects.