Homotypic Membrane Vesicle-Formulated VAN@ ^Δagr MVs for Methicillin-Resistant Staphylococcus aureus Biofilm Clearance

Multidrug-resistant (MDR) pathogens such as methicillin-resistant Staphylococcus aureus (MRSA) pose a substantial challenge to global public health, particularly because of chronic and persistent infections associated with bacterial biofilms, which call for safe and innovative therapeutic strategies. Here, we present a novel antibiofilm system inspired by the preferential uptake properties of isogenous bacterial membrane vesicles (MVs). This system employs vancomycin (VAN) for bacterial killing, while MVs act as delivery vehicles to increase VAN penetration into biofilms. VAN@ ^Δagr MVs demonstrated sustained drug release and improved VAN accessibility within biofilms. Treatment with VAN@ ^Δagr MVs considerably reduced the number of planktonic MRSA strain USA300 cells and effectively eradicated MRSA biofilms in vitro. RNA sequencing revealed substantial alterations in genes associated with bacterial cell wall biosynthesis, global regulators, virulence factors, and biofilm formation. Treatment with VAN@ ^Δagr MVs substantially reduced the MRSA burden within biofilms in vivo. Safety evaluation demonstrated the avirulent properties of the VAN@ ^Δagr MVs, highlighting its potential for clinical application. Overall, this study offers a promising alternative for MRSA biofilm eradication, providing a viable strategy to combat chronic infections caused by MDR biofilm-forming pathogens.