Synthesis of a mace-like cellulose nanocrystal@Ag nanosystem via in-situ growth for antibacterial activities of poly-L-lactide scaffold

Antibacterial property for scaffolds is an urgent problem to prevent infections in bone repair. Ag nanoparticles possess excellent bactericidal activities, whereas their agglomeration restricts the full play of antibacterial property in scaffold. Herein, a mace-like nanosystem was constructed to improve their dispersion by in-situ growth of Ag nanoparticles on cellulose nanocrystal (CNC), which was labeled CNC@Ag nanosystem. Subsequently, the CNC@Ag nanosystem was introduced into poly-L-lactide (PLLA) scaffolds. Results demonstrated that the nanosystem uniformly dispersed in scaffold. The antibacterial tests demonstrated that the scaffolds possessed robust antibacterial activities against E. coli, with bacterial inhibition rate over 95%. Moreover, ion release behavior corroborated the scaffolds continuously released Ag+ for more than 28 days, which benefited from the immobilization effect of CNC on Ag. Encouragingly, the mechanical properties of the scaffolds were remarkably higher than that of PLLA/CNC scaffolds, owing to the mace-like CNC@Ag nanosystem improved the load transfer efficiency in the scaffold.