Polyphenol derived bioactive carbon quantum dot-incorporated multifunctional hydrogels as an oxidative stress attenuator for antiaging and in vivo wound-healing applications

Upregulation of certain enzymes, such as collagenase, tyrosinase, and elastase, is triggered by several extrinsic environmental factors, such as temperature, UV radiation, humidity, and stress, and leads to elasticity loss and skin pigmentation. Herein, dual-emissive polyaromatic carbon quantum dots (CQDs) with abundant phenolic moieties, that is green and yellow CQDs (G-CQDs and Y-CQDs, respectively), were prepared using a three-fold symmetric molecule, 1,3,5-trihydroxybenzene. The significant inhibition efficacy of the fabricated CQDs against collagenase, elastase, and tyrosinase, which play important roles in skin aging, revealed their excellent antiaging potential. Y-CQDs with large polyphenolic-polyaromatic domains and abundant -OH groups exhibited high enzyme inhibitory efficacy against skin aging, and their collagenase, elastase, and tyrosinase inhibitory efficacies were ∼75 ± 4.2%, ∼52 ± 3.1%, and ∼35.3 ± 4.2%, respectively, at a concentration of 100 μg mL^-1. The most critical factor that delays wound healing is oxidative stress, which is caused by the overproduction of free radicals around inflamed tissue. CQDs were effective in suppressing UV-induced reactive oxygen species at the cellular level and improved the cell viability. Subsequently, CQD-incorporated dual-emissive biocompatible gelatin-methacryloyl hydrogels were constructed as wound dressing materials to promote wound healing via inducing the proliferation of fibroblasts, enhancing cell migration and alleviating inflammation and to provide antiaging benefits. Our results demonstrated that the fabricated CQDs with remarkable optical features, low cytotoxicity, and excellent antioxidant and antiaging properties can be used as bio-imaging probes, antiaging agents, and wound dressing materials for oxidative stress-related diseases in the nanomedicine and cosmetics industries.