Encapsulation of Red Propolis in Polymer Nanoparticles for the Destruction of Pathogenic Biofilms

Microbial biofilms, structured communities of microorganisms, have been often associated to the infection and bacterial multiresistance problem. Conventional treatment of infection involves the use of antibiotics, being an alternative approach is the use of red propolis, a natural product, to prepare polymer nanoparticles. The aim of the present study was to encapsulate red propolis extract in poly(lactic-co-glycolic acid) (PLGA) nanoparticles for destruction in vitro of pathogenic biofilms. Poly(lactic-co-glycolic acid) nanoparticles (PLGA NPs) containing red propolis hydroethanolic extract (2 mg/mL) were produced by emulsification solvent diffusion method. The extract and developed nanoparticles were analyzed for antimicrobial activity and inhibition of bacterial biofilm formation in vitro against Staphylococcus aureus and Pseudomonas aeruginosa. Transmission electron microscopy images confirmed spherical nanoparticles in the range size from 42.4 nm (PLGA NPs) to 69.2 nm (HERP PLGA NPs), with encapsulation efficiencies of 96.99%. The free extract and encapsulated in polymer nanoparticle presented antimicrobial potential, with a minimum inhibitory concentration from 15.6 to 125 μg mL^-1 and from 100 to 1560 μg mL^-1 to inhibit biofilm formation for the Staphylococcus aureus and Pseudomonas aeruginosa, respectively.