Dual-crosslinked nanocomposite hydrogels based on quaternized chitosan and clindamycin-loaded hyperbranched...

Bacterial infections caused by S. aureus are prevalent all over the world. Antibiotic-loaded hydrogel has been reported as a promising drug delivery system for the treatment. However, the direct incorporation of antibiotics into the hydrogel leads to quick initial burst release, which results in a sub-inhibition concentration of antibiotics in local environment and induces the antibiotic resistance of bacteria. In this work, a novel dual-crosslinked nanocomposite hydrogel (imine bond and nanoparticle crosslinking) was prepared based on quaternized chitosan and clindamycin-loaded hyperbranched nanoparticles. Dual-crosslinked nanocomposite structure endowed the hydrogel with considerable mechanical and injectable properties. Dual pH responses were introduced into the hydrogel, and a controlled clindamycin release was observed in the acidic environment, which might avoid inducing the antibiotic resistance of bacteria. What's more, the antibacterial results demonstrated an excellent antibacterial activity of the hydrogel for not only E. coli and S. aureus, but also Methicillin-resistant S. aureus (MRSA). Nearly 90% of bacteria was killed after contacting with the hydrogel. In addition, the in vitro cell cytotoxicity test results showed that the hydrogel owned good biocompatibility. The in vitro cell viability was >90%. Above all, this dual-crosslinked nanocomposite hydrogel owned possibility for potential antibacterial applications.