Salvianolic Acid B

Diabetic foot ulcer (DFU) is a prevalent and challenging clinical condition characterized by impaired microcirculation, chronic wound infections, and a hyperglycemic, high-reactive oxygen species (ROS) environment. These factors make treatment particularly complex, often requiring a multidisciplinary approach that yields suboptimal results. In this study, a novel therapeutic strategy was developed using metal-polyphenol nanoparticles synthesized from (-)-Epigallocatechin-3-gallate (EGCG) and ferric ions (Fe³⁺). These nanoparticles were further loaded with salvianolic acid B (SAB) and glucose oxidase (GOx) to enhance their multifunctional biological properties. Complementing these nanoparticles, a polysaccharide hydrogel was engineered using quaternized chitosan (QCS) and oxidized fucoidan (OFu), forming a robust and stable network through Schiff base linkages. This innovative platform demonstrated strong antibacterial activity against DFU-associated pathogens. Within the ulcer's hostile microenvironment, the hydrogel degraded via dynamic bond cleavage, releasing nanoparticles that boosted mitochondrial metabolism, induced M2 macrophage polarization, promoted angiogenesis and reduced ROS levels. These combined effects accelerated tissue regeneration and wound healing. The results suggest that this advanced hydrogel system holds significant promise as a therapeutic option for improving DFU management and addressing its multifaceted challenges.

Hypertrophic scar (HS) represents a natural consequence of abnormal fibroproliferation occurring during wound healing, which not only leads to tissue dysfunction but also causes psychological issues for patients. Up to now, no completely effective therapy for HS has been found. Salvianolic acid B (SalB), one of the natural plant-derived compounds, has the capacity to suppress the fibrosis process in scarring treatment. Nevertheless, due to its poor skin-penetration ability and unsatisfactory stability in existing formulations, its current clinical applicability is restricted. In this study, inspired by the separation behavior of the thorns on the trunks of the silk floss tree, we developed a hyaluronic acid (HA) dissolving microneedle (MN) platform loaded with SalB. This platform can enhance the sustainable delivery of Sal-B directly into scar tissue in a minimally invasive manner, thereby enhancing the efficacy of HS therapy and improving the stability of SalB. To evaluate the therapeutic efficacy of Sal-B MN, we established a rabbit ear HS model. After being administered five times, Sal-B MN significantly reduced the scar elevation index (SEI) and down-regulated the expressions of collagen I, transforming growth factor beta 1 (TGF-β1), Signal Transducer and Activator of Transcription 3 (STAT3), and alpha-smooth muscle actin (α-SMA). Notably, these effects were still evident even after six months of storage at room temperature. This indicates that tree-inspired Sal-B MN holds great potential as a highly effective tool for HS treatment with a long shelf-life. This makes the system suitable for clinical application and storage under various conditions.