Self-assembling Bletilla polysaccharide nanogels facilitate healing of acute and infected wounds via inflammation control and antibacterial activity

Wound healing is one of the fundamental problems faced by the medical profession. Thus, there is a need for the development of biomaterials that are safe, economically viable, possess anti-inflammatory and antibacterial characteristics, and enhance wound healing. In this study, we designed a nanomicelle of Bletilla striata polysaccharide (BSP) self-loaded with Azithromycin (AZI). The properties are improved by physically blending Carbomer 940 (CBM) with Gelatin (GEL) to serve as the hydrogel matrix. The preparation was made by combining the nanomicelle, used as the precursor solution, with the gel matrix. It was designed to treat wound infections and promote healing. Relevant experiments indicate its excellent biocompatibility. The hydrogel not only promotes cell migration, proliferation, angiogenesis, and collagen deposition associated with skin healing, but also regulates the polarization of macrophages from the M1 to M2 phenotype, as well as the expression of related factors. Additionally, in vitro experiments demonstrate its good antibacterial activity. In addition, we demonstrated the gel's anti-inflammatory, antibacterial, and pro-healing effects in acute wounds and methicillin-resistant Staphylococcus aureus (MRSA) wounds. Therefore, the nanomicellar gel enhances antibacterial activity and related immune regulation, offering a new direction in the treatment of acute and chronic wounds.