Rare-Earth-Functionalized Carbon Dot Hydrogels as Mechanically Robust Antibacterial Wound Dressings

Hydrogel-based wound dressings have attracted sustained interest due to their ability to support fibroblast proliferation and maintain a moist healing environment; however, achieving simultaneous antibacterial efficacy, mechanical robustness, and biocompatibility. In response to these limitations, we report a multifunctional antibacterial hydrogel incorporating blue-emissive lanthanum-functionalized nitrogen-doped carbon dots (La, N-CDs), synthesized via a green and cost-effective hydrothermal route using citric acid, urea, and lanthanum nitrate. Lanthanum coordination with surface oxygen- and nitrogen-containing groups enhances the antibacterial activity of N-CDs by promoting stronger interactions with bacterial cell envelope, by strengthening coordination-associated antibacterial mechanism that surpasses undoped counterparts. The La, N-CDs were integrated into a poly(vinyl alcohol)-borax hydrogel network, further reinforced with dipotassium glycyrrhizinate as a multifunctional cross-linker. Abundant hydrophilic functional groups from both dipotassium glycyrrhizinate (DPG) and La, N-CDs impart high surface wettability (contact angle <20°) and rapid swelling (>180%), facilitating efficient wound exudate absorption and sustained moisture retention. The resulting hydrogel exhibits acceptable cytocompatibility (cell viability >80%) alongside pronounced antibacterial activity against Escherichia coli (E. Coli) and Staphylococcus aureus (S. aureus). Collectively, this work establishes for rare-earth-functionalized carbon dot hydrogels for antibacterial performance, structural integrity, and biological compatibility.