Antimicrobial nanocomposite gellan gum-based hydrogels as injectable and 3D-printable platforms for infected wound treatment

A quaternized derivative of gellan gum (GG-EDA-GTMAC) was synthesized and employed to develop injectable and printable nanocomposite hydrogels incorporating silver nanoparticles (AgNPs). The specific physicochemical properties of the GG-EDA-GTMAC derivative enabled efficient synthesis and stabilization of AgNPs within the hydrogel matrix. The hydrogels demonstrated remarkable stability, resisting hydrolytic degradation with only ∼20 % weight loss over 14 days of incubation, and exhibited controlled silver release. A comprehensive study of the properties of nanocomposite hydrogels was conducted to evaluate their ease of formulation, injectability, safety, and broad-spectrum antimicrobial effectiveness. Rheological characterization highlighted shear-thinning and self-healing behavior, as well as sensitivity to ionic strength, ensuring good injectability and shape maintenance after injection. These properties enabled the successful 3D printing of the hydrogels into structures with various shapes and sizes, demonstrating excellent model fidelity and structural stability. Biological and microbiological evaluations confirmed cytocompatibility, hemocompatibility, and strong antimicrobial activity against Gram-positive and Gram-negative bacteria, Candida albicans, and protozoa, highlighting the multifunctional antimicrobial potential of the system. Collectively, these findings suggest the developed hydrogels as promising candidates for the treatment of wounds infected by a wide range of pathogens, including both bacterial and protozoan agents.