Overcoming Resistance Mechanisms via Membrane Disruption with newly Developed Antimicrobial Peptides

The rising threat of antimicrobial resistance makes novel therapeutics necessary. In this study, we designed nature-inspired antimicrobial peptides (AMPs) and evaluated their biological potency and safety profile. The synthesized peptides exhibited exceptional antibacterial and antifungal activity, characterized by low minimum inhibitory concentration (MIC range: 0.5-2 µg/mL), values across all standard ATCC strains tested (E. coli, S. aureus, P. aureginosa and C.albicans). Meanwhile, cytotoxicity assays confirmed their selectivity as they displayed no significant toxic effects on mammalian cells. Building on this favorable safety index, the peptides also demonstrated high stability against proteolytic degradation, overcoming a common limitation of natural AMPs. To elucidate their mode of action, we employed molecular modelling to predict peptide-membrane interactions. These studies confirmed that the peptides compromise bacterial membrane integrity alongside membrane permeability assays. This finding was visually corroborated by scanning and transmission electron microscopy (SEM/TEM), which revealed irreversible structural damage and cell lysis. Furthermore, we evaluated kinetics of resistance development by exposing E. coli to serial passages of the peptides versus gentamicin. While the bacteria rapidly developed high-level resistance to gentamicin, no resistance was observed against our peptide candidates. These results show that the designed AMPs are potent and safe and offer a robust solution to resistance development. Their unique membrane-targeting mechanism, combined with a high safety profile and an inability to induce rapid resistance, positions them as promising candidates for future clinical development against multidrug-resistant infections.