Dual-loading naringin and chitosan to simultaneously enhance antibacterial property and osteogenic activity of zeolitic imidazolate framework-8 nanoparticles

A novel ZIF-8@Nar@CS nanocomposite was synthesized by a ternary co-assembly strategy. • ZIF-8@Nar@CS has pH-responsive drug release feature following first-order kinetics. • ZIF-8@Nar@CS revealed strong bactericidal effect against E. coli and S. aureus . • ZIF-8@Nar@CS enhanced cytocompatibility and osteogenic activity as compared to ZIF-8. • The designed drug-delivery platform shows potential to be used in orthopedics field. Development of functional nanocomposites for bone tissue repair is often hampered by their bioinertness and insufficient antibacterial performance. To overcome the limitation, this study developed a novel ZIF-8@Nar@CS composite nanoparticle system via a ternary co-assembly strategy. The microstructure of the ZIF-8@Nar@CS was explored by SEM, XRD, FTIR, UV–Vis, BET, and the interaction mechanism of the composite was elucidated via XPS and zeta potential analysis. In addition, the drug release behavior, antibacterial activity and osteogenic property of the composite were also evaluated in vitro. The results show that the ZIF-8@Nar@CS achieved a naringin (Nar) drug loading efficiency of 19.22% through the electrostatic interactions and exhibited a distinct pH-dependent drug release profile. Its cumulative release reached 98.89% at pH 5.5, in stark contrast to only 13.6% at pH 7.4, following first-order kinetics. Profiting from the concomitant release of Zn 2+ , Nar, and chitosan (CS), the ZIF-8@Nar@CS exerted a strong antibacterial activity of 99.99% against both S. aureus and E. coli . Critically, the ZIF-8@Nar@CS also exhibited favorable cytocompatibility and effectively enhanced the osteo-differentiation of MC3T3-E1 cells as compared to the ZIF-8 nanocarrier. This work might provide a new horizon for developing a safe nanoparticle delivery platform for bone repair and regeneration in clinic.