In situ deposition of nano CuO on electrospun chitosan nanofibrous scaffolds and their antimicrobial properties.

In order to obtain a synergistic antimicrobial effect of cuprous oxide nanoparticles (CuO NPs) and chitosan (CS) nanofibers, the nano CuO/CS nanofibrous scaffolds were synthesized in situ via two subsequent steps of chelation and reduction. The Cu were stably chelated on CS nanofibrous scaffolds through the coordination of amino group (-NH) and hydroxyl group (-OH) on CS with Cu, and then the chelated Cu were reduced to nano CuO by Vitamin C under alkaline conditions. And by the measurements of XRD, XPS and FTIR-ATR, the results showed that CuO NPs were successfully deposited on the CS nanofibrous scaffolds. SEM clarified that the particle size of CuO gradually decreased and the shape changed from cubic to irregular with the increase of CuSO concentration. With the CuSO concentration of 0.02 and 0.04 mol·L, the CuO/CS nanofibrous scaffolds presented outstanding hydrophilicity and antibacterial activity against Gram-negative Escherichia coli (E. coli) and Gram-positive Staphylococcus aureus (S. aureus) comparing to the CS nanofibrous scaffolds, meanwhile, they possessed good biocompatibility. This kind of nanofibrous scaffolds deposited with nano CuO would have broad application prospects in the field of antibacterial biomaterials.