Preparation and antibiofilm studies of curcumin loaded chitosan nanoparticles against polymicrobial biofilms of Candida albicans and Staphylococcus aureus.

Polymicrobial biofilms related infections are an important clinical problem with classical antibiotics being not sufficient in therapy. Here, curcumin (Cur) was loaded on positively charged chitosan nanoparticles (CSNP). The antibiofilm activities against mono- and polymicrobial biofilms of Candida albicans and Staphylococcus aureus were evaluated. The average diameter of CSNP-Cur was 134.37 ± 1.99 nm and its surface charge was +18.10 ± 0.82 mV. Cur released from NPs was slower at pH 7.4 than at pH 5.4. Scanning electron microscopy (SEM) and confocal laser scanning microscopy (CLSM) were used to observe biofilm architecture and live/dead organisms within biofilm on medical silicone surface. CSNP-Cur exhibited excellent antibiofilm activity against planktonic bacteria or fungi, mono- and polymicrobial biofilm formations and preformed biofilms. SEM and CLSM showed that CSNP-Cur was able to reduce biofilm thickness as well as kill microbial cells embedded in biofilm on silicone surfaces.