Combating Bacterial Drug Resistance via Dual-Mechanism Drive Penetration and Triple-Approach Metabolic Disruption.

The emergence of multidrug-resistant (MDR) bacteria poses a serious threat to global public health. Enhancing the permeability across the physical barriers, including lipopolysaccharide (LPS) and extracellular polymeric substances (EPS), while simultaneously preventing drug resistance, remains a major challenge. To address this issue, we developed a novel biotin-conjugated cationic photosensitizer (PS), ACR-DM-Bio. It not only effectively binds to the bacterial outer membrane and EPS via electrostatic interactions but also facilitates active uptake through the biotin transport system. This dual mechanism promotes penetration through the physical barriers and destroys the outer membrane. Moreover, ACR-DM-Bio competitively disrupts biotin-dependent metabolism and inhibits fatty acid biosynthesis, thereby compromising outer membrane integrity. Besides, this metabolic interference further hinders the tricarboxylic acid (TCA) cycle, severely disrupting energy metabolism and biosynthetic precursor supply. This three-pronged strategy could efficiently overcome bacterial resistance evolution and prevent biofilm recurrence. In a murine biofilm infection model, ACR-DM-Bio-mediated photodynamic therapy (PDT) not only completely cleared biofilms but also promoted tissue repair by modulating inflammation and angiogenesis, outperforming the conventional antibiotic polymyxin B. This work not only presents a highly promising candidate for treating MDR bacterial infections, but also provides theoretical guidance for the rational design of next-generation antimicrobial PS.