Antibacterial and Wound-Healing Efficacy of 12-Hydroxylauric Acid-Conjugated Heterochiral Diphenylalanines: Insights From In Vitro and In Vivo Investigations.

To overcome the limitations of microbial infections in modern medicine, we developed compound I incorporating the amphiphile 12-hydroxy lauric acid (12-HDA) at the N-terminus linked to a heterochiral diphenylalanine motif (D- and L-Phe) at the C-terminus guided by the principle of chiral orchestration (R. Ahuja, M. Singh, and A. Dutt Konar, ACS Appl. Biomater. 2025, 8, 1108). Although preliminary minimum inhibitory concentration (MIC) data indicated encouraging antimicrobial activity against the Gram-positive pathogens Staphylococcus aureus and Bacillus subtilis, these results alone were insufficient to consider the molecule a viable therapeutic lead. Consequently, comprehensive in vitro evaluation revealed a pronounced, organism-dependent response: Compound I reduced B. subtilis colony formation by 98%, compared to only 22% for S. aureus. Flow cytometric Live/Dead analyses corroborated these findings, showing increased cellular granularity, enhanced PI uptake, and 59.6% non-viable B. subtilis cells, whereas S. aureus exhibited limited susceptibility. Motivated by this selectivity, we evaluated Compound I in a B. subtilis-infected excisional wound model, where treated animals achieved complete wound closure, robust hair regrowth, and scar-free healing within 14 days, comparable to that of the standard drug. Overall, these findings establish compound I as a strong therapeutic candidate for future wound dressing.