On-chip engineering of EDC-crosslinked antimicrobial peptide hydrogels for enhanced eradication of MRSA infections

This study developed a controlled slow-release antimicrobial peptide (AMP) hydrogel to address the hemolytic side effects that limit AMP clinical application. Innovatively employing microfluidic-assisted 1-ethyl-3-(3-dimethylaminopropyl) carbodiimide (EDC) coupling, the antimicrobial peptide (HfAMP) was covalently conjugated within a sodium alginate hydrogel network. This approach overcame the critical efficiency bottleneck of conventional EDC bioconjugation: laminar flow mixing resolved diffusion limitations in the high-viscosity system, drastically reducing the carboxylate activation time from 12 h to merely 20 minutes. This engineering strategy enhanced biosafety via a dual mechanism-reducing electrostatic adsorption onto red blood cell membranes and preventing a sudden drug concentration spike through sustained gel release. At the highest tested HfAMP-equivalent concentration (100 µg mL^-1), the hemolysis rate was reduced from 72.4% for free HfAMP to 2.4% for HfAMP@Alginate. In vivo, the system accelerated the healing of MRSA-infected wounds (7.2 ± 0.8 days) while maintaining potent antibacterial efficacy (96.3 ± 2.7% bacterial inhibition). The proposed chemical coupling strategy successfully resolves the paradox between high antimicrobial activity and biosafety, offering a scalable engineering paradigm for developing ready-to-use antimicrobial formulations.