Biological effect of Zn-loaded polysuccinimide nanofibers on cells and bacteria

Antimicrobial resistance (AMR) poses a serious threat to modern medicine by reducing the effectiveness of current treatments. This makes it harder to manage infections, such as those in wound healing, as standard antibacterial agents become less effective. To address this, new treatments, like metal salts and nanoparticles, are needed, which can be incorporated into polymer-based wound dressings. In this study, we developed nanofibrous meshes based on biocompatible and biodegradable polysuccinimide (PSI) incorporating varying compositions of zinc-oxide (ZnO) nanoparticles and zinc-chloride, aimed at localized treatment of bacterial infections. ZnO nanoparticles were synthesized in situ in organic solvents, enabling their direct mixing with PSI solutions for electrospinning into nanofiber-based meshes. Comprehensive physicochemical analyses of the different meshes were performed, and their antibacterial efficacy was evaluated against two Gram-positive and two Gram-negative bacterial strains relevant to wound healing. Additionally, a detailed concentration-dependent cytotoxicity assay was performed using a human cell line to establish the effective concentration range. Zn-loaded PSI meshes are effective against Gram-positive bacteria but less so against Gram-negative strains, suggesting their potential use as wound dressing materials.