Camel Milk Extracellular Vesicles as Engineered Biogenic Particles: Thermosensitive Hydrogel Integration for Optimized Wound Delivery and Tissue Regeneration.

Objective

This study aimed to enhance wound healing by developing a delivery platform that combines camel milk-derived extracellular vesicles (CM-EVs) with a thermosensitive chitosan/Poloxamer 407 hydrogel (CM-EVs-Gel), addressing the challenges of instability, poor skin penetration, and burst release associated with EVs.

Methods

CM-EVs were isolated and analyzed for size, markers, and protein content. A thermosensitive hydrogel was created and infused with CM-EVs. Its gelation, injectability, and release kinetics (using the Higuchi model) were tested. Safety was evaluated through ocular irritation and 28-day skin toxicity in rabbits. Wound healing effectiveness was tested in rats with full-thickness wounds, comparing CM-EVs-Gel, a blank hydrogel, and untreated controls.

Results

CM-EVs had an average size of 108.5 nm and expressed CD63, CD81, and Alix. The hydrogel solidified at 37 °C within 10 min and followed the Higuchi model for diffusion-controlled release (R2 = 0.974), releasing 81.7% of EVs over 48 h without toxicity. In rats, CM-EVs-Gel achieved 76.31% wound closure by day 6 and 94.7% by day 15, outperforming blank hydrogel (48.77% and 82.1%) and untreated controls (43.14% and 72.3%) (p < 0.01). Histology showed improved re-epithelialization, collagen deposition, and angiogenesis.

Conclusions

This study shows that integrating biogenic particle engineering with optimized hydrogel systems allows for controlled release, safety, and enhanced wound healing. Despite missing free EV controls, full rheological data, and mechanistic insights, it highlights comprehensive delivery strategies from particle design to system performance, aligning with the Special Issue's focus.