Electrospraying micro-nano structures on chitosan composite coatings for enhanced antibacterial effect

Abstract

In this work, chitosan-functionalized nanosilica was electrosprayed on the spin-coated base layer to form a composite coating with a micro-nano protruding surface, which has good antibacterial properties and sustained release effect. Nanosilica with uniform size was prepared by sol-gel method and coated with quaternized chitosan, and its structure, morphology and antibacterial properties were characterized. Antibacterial functional nanosilica was electrosprayed on spin-coated chitosan and quaternized chitosan base layers. During the electrospray process, functional nanosilica and sodium hyaluronate were atomized into tiny droplets, which were then assembled on spin-coated substrates to form micro-nano protruding structures. The unique micro-nano surface structure of the composite coating and the contact sterilization of chitosan quaternary ammonium salt play a synergistic effect, showing a good sterilization effect on drug-resistant Staphylococcus aureus, and also controlling the sustained release of quaternized chitosan. The prepared composite coatings also exhibited good scratch resistance and simulated bodily fluid immersion stability.