Composite Scaffold Containing Asiaticoside Polymeric Nanoparticles and Neurotensin Porous Microparticles Demonstrates Accelerated Diabetic Wound Healing

Diabetic wounds are characterized by multiple anomalies in the four overlapping phases of wound healing. Therefore, targeting multiple factors is considered ideal for more promising therapeutic outcome. We came across two potent molecules, asiaticoside (AST) and neurotensin (NT), which promote wound healing during different phases. However, AST shows poor physicochemical properties and has high molecular weight, poor solubility, and permeability. NT, on the other hand, is rapidly degraded by proteases present at the wound site, limiting its effectiveness. This study focuses on developing asiaticoside-loaded polymeric nanoparticles (AST PNPs) and neurotensin-conjugated porous microparticles (NT-PMPs), followed by their incorporation into a gelatin-based hydrogel. This codelivery system aims to explore their synergism and hence improve therapeutic outcomes. AST PNPs with a size of 168.4 nm (0.09 PDI) were prepared. NT-PMPs were prepared within a size range of 60-200 μm. Application of the AST PNP&NT-PMP-loaded gelatin gel on wounds of diabetic rats resulted in accelerated healing with completely re-epithelialized epidermis, migrating fibroblasts, and regeneration of hair follicles in the treated group. An organized collagen matrix and significant upregulation of NT (∼4-fold) and COL-1 (∼2.5-fold) levels compared to untreated animals were noted. Additionally, relative mRNA expression of key healing markers eNOS increased by 6.97-fold and MMP-9 decreased by 4.83-fold in the AST PNP&NT-PMP hydrogel-treated group compared to the untreated animals. Altogether, AST encapsulated into polymeric nanoparticles and NT conjugated to PMP, both loaded in gelatin gel, depicted significant improvement due to their synergistic behavior in therapeutic response compared to individual molecules and untreated groups.