Inhibition of methicillin-resistant (MRSA) biofilm by cationic poly (D, L-lactide-co-glycolide) nanoparticles.

The emergent need for new treatment methods for multi-drug resistant pathogens such as methicillin-resistant (MRSA) has focused attention on novel potential tools like nanoparticles (NPs). In the present study, a drug-free cationic nanoparticles (CNPs) system was developed and its anti-MRSA effects were firstly investigated. The results showed that CNPs (261.7 nm, 26.1 mv) showed time- and concentration-dependent activity against MRSA growth, killing ∼ 90% of planktonic bacterial cells in 3 h at 400 μg ml, and completely inhibiting biofilm formation at 1000 μg ml. Moreover, CNPs at 400 μg ml reduced the minimum inhibitory concentration (MIC) of vancomycin on inhibition of planktonic MRSA growth (∼ 25%) and biofilm formation (∼ 50%). The CNPs-bacteria interaction force was up to 22 nN. Overall, these data suggest that CNPs have a good potential in clinical applications for the prevention and treatment of MRSA infection.