Enhancing wound healing: incorporating carotenoid pigments from Kocuria Sp. bacteria in alginate/Chitosan/PVA...

Chronic wounds represent a significant clinical challenge, necessitating the development of multifunctional dressings with bioactive compounds to accelerate healing. Carotenoids-natural pigments with potent antioxidant and anti-inflammatory properties-are emerging as promising agents for tissue repair. This study explores the therapeutic potential of carotenoid pigments biosynthesized by Kocuria sp. and their integration into a chitosan/alginate/polyvinyl alcohol (Cs/Alg/PVA) nanocomposite for wound healing applications. Carotenoids were extracted and optimized under varying conditions of temperature, salinity, pH, and culture media. The pigments were incorporated into a Cs/Alg/PVA matrix and characterized using Fourier transform infrared spectroscopy, scanning electron microscopy, differential scanning calorimetry (DSC), andin vitrorelease studies. Antioxidant capacity was evaluated via DPPH assay, and anti-inflammatory properties were assessed using hemolysis assays. Cell viability and proliferation were analyzed on L929 and human dermal fibroblast cells using MTT assay.In vivowound healing efficacy was evaluated in a murine excisional wound model with histological and morphometric analyses. The carotenoid-enriched composite exhibited strong antioxidant activity, significant anti-hemolytic effects, and enhanced biocompatibility with fibroblasts. Release kinetics revealed sustained and pH-responsive delivery of carotenoids.In vivo, the composite significantly accelerated wound contraction and epithelialization compared to controls, with histopathological analysis confirming increased fibroblast presence, collagen deposition, and reduced inflammation. This study highlights the therapeutic potential of microbial carotenoids embedded in Cs/Alg/PVA dressings as a biocompatible, antioxidant-rich platform for enhanced wound healing. The approach offers a sustainable, natural alternative to synthetic additives in wound care biomaterials.