Chronic wound infection poses a clinical threat, as bacterial presence and a prolonged inflammatory phase hinder the normal wound healing process. Photodynamic therapy (PDT) emerges as an effective strategy, demonstrating potent antibacterial activity and healing efficacy compared with conventional strategies. In the present study, carbon quantum dots (CQDs) are prepared as photosensitizers via a hydrothermal approach. The therapeutic efficiency is further improved by incorporating CQDs into an injectable hydrogel (OG) composed of oxidized sodium alginate and gelatin. SEM morphological analysis and FTIR functional group characterization validate the successful incorporation of CQDs into the hydrogel matrix. In vitro cytotoxicity evaluation and scratch assay reveal minimal cytotoxicity, enhanced fibroblast cell proliferation and migration in the CQD-OG hydrogel group under light irradiation. This activity is mediated by photoactivation of CQDs, which upregulates ERK signaling and promotes re-epithelization. Further, in vivo studies confirm that CQD-OG hydrogel shows accelerated wound closure, accompanied by significant collagen deposition and epithelial regeneration. The hydrogel not only promotes tissue regeneration but also mitigates the inflammatory response, as demonstrated by immunofluorescence staining for IL-6 and TNF-α. Therefore, the CQD-OG hydrogel, with excellent antibacterial activity and wound healing properties, represents a potent therapeutic material for chronic wound management.
A very first time the tunability of environmentally friendly Ethyl-Cellulose (EC)/Phosphate Graphene (PG) nanocomposites is explored by modulating the concentration of functionalized PG nanofillers. The work reported aims to understand the mechanisms of influencing the structural, optical, mechanical, and biological properties of EC-based nanocomposites for potential multifunctional applications via PG incorporation. Structural investigations by XRD reveal that increasing wt.% of PG nanofiller enhances crystallite size while reducing dislocation density and micro-strain. Simultaneously, energy density and mechanical flexibility reduce, as evidenced by increase in Young's modulus. Optical measurements indicate a notable narrowing of direct bandgap (5.02 eV-3.85 eV), accompanied by an increase in Urbach energy and refractive index. Enhancements in optical dielectric constants and optical conductivity with increasing the PG loading suggest intensified interfacial polarization and dipole interactions. Surface morphology and structural evolution are explored by FESEM along with EDAX and Raman spectroscopy, respectively, which is consistent with XRD findings. Furthermore, the nanocomposites exhibited concentration-dependent antioxidant and enzyme inhibition activities, with optimal biological performance observed at 5 wt.% PG. They also demonstrated stronger inhibition of alpha-glucosidase and alpha-amylase, suggesting improved interaction with enzymes. Thus, phosphate-functionalized graphene enhanced surface reactivity, validating EC/PG nanocomposites for flexible optoelectronics and eco-friendly packaging.
