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Scarless wound management remains a clinical challenge worldwide because of its complicated and overlapping phases of inflammation, clearing, and regeneration. Among the currently available dressing materials, hydrogels have attracted emerging attention as potential wound dressing materials because of their specific properties, such as porosity, tissue-mimicking architecture, softness, and improved mechanical, biological as well as physicochemical properties. However, naturally driven hydrogels have shown several advantages over conventional hydrogels because of their biodegradability, biocompatibility, high mechanical strength, and functionality. Recently, nanoparticle (NPs) integrated polymeric hydrogels (metals, non-metals, metal oxides, and polymeric moieties) have been established as analogous to these naturally driven hydrogels because of the synergistic effects of the NPs and polymers in the three-dimensional composite material. Over the years, researchers have reported the synthesis and potential applications of diverse inorganic and organic nanocomposite gels with antioxidant or antibacterial properties where they have exploited the intelligent incorporation of biomolecules into the NP-polymeric network that are beneficial for wound healing. Among various natural polymers as hydrogel matrix, chitosan-mediated hydrogel dressings have received extensive interest resulting in improved mechanical, biological, and physicochemical properties due to the well-reported antibacterial, antitumor, antioxidant, and tissue regeneration efficacies of chitosan polymer. This review is intended to summarize the recent developments of inorganic nanoparticle-incorporated chitosan-based hydrogels as wound dressing materials where various synthetic methodologies of these nanocomposite gels are extensively discussed via incorporating nanoparticles, active biomolecules, and other substances into the intrinsic structure of the gels. In addition, the future and prospects of chitosan-based nanocomposite hydrogels as a novel wound dressing as well as tissue engineering materials are also highlighted.

Scarless healing of injury remains a clinical challenge because of its complicated and overlapping phases of inflammation, clearing, and regeneration. Curcumin has been already established as a potential wound healing agent for normal and diabetic-impaired wounds. Herein, the question has been addressed whether a well-known antioxidant cerium oxide nanoparticle (CNP) can potentiate the activity of curcumin to promote a cellular program for scarless healing. In this study, we have developed a biocompatible poly (acrylamide) hydrogel (PAGE)-based dressing material comprising of CNP and curcumin (ACC) and tested its wound healing activity in an animal model of acute wound. Characterization of the CNP- and curcumin-entrapped hydrogel dressing (ACC) demonstrated high loading efficiency and sustained release of curcumin. In a full-thickness acute wound healing model of rat, a single application of ACC dressing demonstrated higher wound healing efficacy (78%) and negligible scarring compared to dressings containing only curcumin or CNP in 7 days. Enhanced cell proliferation, higher collagen content, advanced wound maturity, re-epithelialization, and granulation tissue formation were observed using the combination of curcumin and CNP (ACC). Study of cellular mechanisms identified MCP-1 and TGF-β as the key drivers of differential and accelerated healing observed in the ACC group. These, coupled with the upregulation of growth-related signaling pathways (HER2/ErbB2, TGF-β-Smad2/3, MAPK/ERK, AKT, and VEGF), promoted almost scarless healing in animals treated with ACC. The optimized combination of curcumin and CNP used in our study shows distinct advantage and can be a better agent for complete wound healing.

A simple strategy to fabricate carbon dots (CDs) incorporated organically modified silica (ORMOSIL) films exhibiting tunable tricolor emission has been accomplished. First, the green-emitting CDs with excitation-independent nature and high quantum yield were prepared from o-phenylenediamine in ethanol by solvothermal method. These CDs after purification were dispersed in ORMOSIL sol, and their photoluminescence wavelengths were tuned to three intense luminescent colors (orange, yellow, and green) by adjusting the pH of the sol. It was observed that with pH tuning the functional groups residing on surface-passivated CDs are undergoing chemical modifications, and accordingly the PL emission of CDs in ORMOSIL sol systematically changes to orange, yellow, and green emissions, respectively. Interestingly, the structure of such surface-modified CDs can be well-preserved in the ORMOSIL film-matrix with substantial concentration to obtain the above tricolor luminescent films on glass. A systematic X-ray photoelectron spectroscopy study revealed that the blue shifting in triluminous films (from 560 to 510 nm) with pH increment was originated due to the deprotonation of the surface groups (−CONH– → −CO(N–)–; −NH3+→ −NH2) associated with the CDs. The plausible mechanism behind the rationalization of pH-triggered engineering of surface-passivated CD-ORMOSIL sols and their confinement in films has been explored.