Spatiotemporally activated gelatin/unzipped carbon nanotubes/ chitosan-based conductive hydrogel via dual stimuli for robust methicillin-resistant Staphylococcus aureus biofilm eradication

초록

Antibiotic-resistant bacteria, especially methicillin-resistant Staphylococcus aureus (MRSA), pose a significant global health risk because they can form biofilms that are highly resistant to standard treatments. Even with considerable progress in antibacterial materials, reliance on passive antimicrobial agents may still lead to the emergence of resistance over time. We introduce a dual-action approach by developing a gelatin/glycerol/conductive chitosan (GGCC) hydrogel that demonstrates bactericidal properties both naturally and by external stimulation. We chemically modified chitosan with unzipped CNTs to impart conductivity (similar to 4.2 S/m) and NIR responsiveness, then blended it with gelatin to enhance its biocompatibility and skin regeneration capabilities. The antibacterial activity was enhanced via NIR (similar to 92.23 %) and electrical stimulation (similar to 99.85 %). Moreover, robust biofilm was also similar to 100 % eliminated upon electrical stimulation. To clarify the fundamental mechanisms, we performed RNA sequencing on MRSA treated with hydrogel, with and without electrical stimulation. Pathways in oxidative stress, replication, biofilm formation, and peptidoglycan synthesis were triggered, resulting in strong antibacterial and anti-biofilm properties. Electrical exposure restricts bacterial adaptability, reducing the likelihood of resistance development. Our findings indicate that integrating of conductive chitosan with electrical stimulation offers a potential, resistance-resistant approach for addressing chronic bacterial infections.

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