A tissue-adhesive, mechanically enhanced, natural Aloe Vera-based injectable hydrogel for wound healing: Macrophage mediation and collagen proliferation

Macromolecule hydrogels made from natural extracts have received much attention because of their favorable biocompatibility and wound healing properties. However, their clinical applications are limited by their insufficient mechanical strength and low adhesion properties. To overcome these limitations, we developed a novel injectable Aloe vera hydrogel (PDMA-GelMA@AV). By integrating gelatin methacrylate (GelMA) and polydopamine methacrylamide (PDMA), we significantly improved the mechanical and adhesion properties of the hydrogel. The PDMA-GelMA@AV hydrogel degraded in a simulated wound environment, which was synchronized with the sustained release of the bioactive components of A. vera . In vitro and in vivo analyses revealed that this hydrogel has good biocompatibility. In vitro studies also revealed that the sustained release of the active ingredients of A. vera promoted fibroblast proliferation and migration and increased the expression of key proteins and mRNAs required for wound healing. In addition, it modulated LPS-stimulated macrophages and decreased the expression of TNF-α, IL-1β and iNOS while increasing the expression of TGF-β and ARG. In vivo experiments further confirmed the efficacy of hydrogels in wound healing applications. These findings offer a novel perspective on the application of natural macromolecules as hydrogel-based delivery vehicles in wound care.