Fabrication and evaluation of nanoencapsulated quercetin for wound healing application

Nanotechnology based platforms have gained new insights into the development of effective modes of drug delivery systems for addressing wounds and related pathologies. Drugs encapsulated in nanodimensioned materials or nanoparticles are becoming a dermatologically attractive and versatile strategy for the development of optimized pharmaceutical formulations. In the current study, we developed gel formulations of Quercetin (Q) loaded alginate (ALG)/chitosan nanoparticle (CSNP) with concentrations 0.01% and 0.075% incorporated into carbopol encoded as Q-ALG/CSNP-G1, Q-ALG/CSNP-G2, respectively, and assessed their wound healing potential when topically applied to open excision wounds on adult Wistar rats. The characterization tests confirmed Q-ALG/CSNP-G2 featured pH, spreadability, extrudability and consistency. The in vitro release profile showed that the optimized Q-ALG/CSNP-G2 released quercetin in a sustained manner of 62.51 +/- 0.72% over the period of 24 h as optimally needed for the wound healing onrush covering the inflammatory and proliferative phases. The in vivo acute dermal toxicity study did not produce any overt indications of toxicity as compared with control rats. The healing time for wounds treated with quercetin was even longer than those treated with Q-ALG/CSNP-G2. Antioxidant assays (SOD, CAT, LPO, and NO) revealed enhanced free radical scavenging ability of Q-ALG/CSNP-G2 gel receiving rats, thus improving healing quality. Furthermore, the restoration of biomarkers hydroxyproline and hexosamine content significantly proved increased re-epithelialization and collagen formation. The histopathological investigations on wounds treated with drug-loaded gel demonstrated efficient healing, as evidenced by the deficit of inflammation, established fibrous tissues, well-organized fibroblasts, and blood capillaries. Combining the unique properties of controlled drug release, enhanced antioxidant and antibacterial effects, the developed Q-ALG/CSNP-G2 were topically effective and showed synergistic wound healing capabilities compared with free quercetin in Wistar albino rats.