Photodynamic Chitosan Nano-Assemblyas a Potent Alternative Candidate for Combating Antibiotic-ResistantBacteria

The facts that increasing antibiotic resistance of pathogenic bacteria and lack of new potent broad-spectrum antibiotics call for the development of alternative approaches for treating infectious diseases. With the merits of great efficacy, safety and facile implementation, antibacterial photodynamic therapy (APDT) represents an attractive modality for this purpose. Here we report the newly fabricated photodynamic chitosan nano-assembly, designated CS-Ce6, could synergistically kill antibiotic-resistant bacteria with superior potency to vancomycin. CS-Ce6 nano-assembly, obtained from covalent conjugate of chlorin e6 (Ce6) with chitosan, exhibited strong association with bacteria, thus altering their morphologies and mediating great delivery efficiency of Ce6. Upon light irradiation, localized generation of singlet oxygen by CS-Ce6 nano-assembly empower remarkable bactericidal effect toward both drug-resistance Gram-positive methicillin-resistant S. aureus (MRSA) and Gram-negative Acinetobacter baumannii (...