A multifunctional nanocomposite spray dressing of Kappa-carrageenan-polydopamine modified ZnO/L-glutamic acid for diabetic wounds.

Sprayable bioadhesives with exceptional properties were developed for application in wound healing. In this study, a visible light-crosslinkable nanocomposite bioadhesive hydrogel with multifunctional properties was proposed. While methacrylated Kappa-carrageenan (KaMA), mimicking the natural glycosaminoglycan was applied as the hydrogel matrix, various concentrations of polydopamine modified ZnO (ZnO/PD) nanoparticles (0, 0.5, 1 and 2 wt%) was loaded in it to improve its mechanical, antibacterial and cellular properties. Moreover, L-glutamic acid was incorporated in the nanocomposite hydrogel network to accelerate wound healing. The nanocomposite hydrogels revealed significant mechanical property and recovery ability, comparable elasticity with human skin and great adhesiveness. For instance, the tensile strength of KaMA hydrogel enhanced from 64.1 ± 10 to 80.3 ± 8 kPa and elongation jumped from 20 ± 4% to 61 ± 5% after incorporation of 1 wt% ZnO/PD nanoparticles. The nanocomposite hydrogels demonstrated effectual blood clotting ability and biocompatibility, >95% cell viability after 3 days of incubation. In vivo experiments also suggested that L-glutamic acid loaded nanocomposite hydrogel considerably accelerated wound healing with superior granulation tissue thickness than control in a full-thickness skin defect model. Taken together, this visible-light crosslinking nanocomposite hydrogel with significant properties could be used to spray on a wound area to eliminate wound infection and accelerate wound healing process.