Tailoring the Surface of Polylactide/Poly(itaconate derivative) Fibers: A Path to Antibacterial Enhancement

Polylactide (PLA) is a biodegradable polymer with satisfactory mechanical properties but lacks antimicrobial activity. In this work, PLA fibers were functionalized with a cationic derivative of poly-(itaconic acid) (PTTIBuI) and treated using supercritical carbon dioxide (scCO₂). Electrospun PLA and PLA + PTTIBuI fibers were subjected to scCO₂ treatment at 200 bar and 60 °C for 3 and 6 h and subsequently characterized. Surface analysis revealed wrinkling, crystallization, increased crystallinity, and reduced hydrophobicity after treatment. Antimicrobial testing showed that PLA + PTTIBuI fibers significantly inhibited biofilm formation, with stronger effects against Acinetobacter baumannii (50-60%) than against methicillin-resistant Staphylococcus aureus (43-55%). Long-term scCO₂ exposure increased antibacterial activity, likely due to increased surface accessibility of cationic groups. These results demonstrate that the combination of poly-(itaconic acid)-based antimicrobial agents with supercritical fluid treatment is an effective strategy for tailoring PLA fibers with improved antimicrobial activity. The modified materials show strong potential for biomedical applications such as wound dressings and infection prevention agents.