Antifungal Coating Based on Pyocyanin Nanoparticles (Np-Pyo)

Abstract

Pyocyanin is a pigment produced by 95% of Pseudomonas aeruginosa strains and exhibits antimicrobial properties that can be used for different purposes. In this work, PMMA-based nanoparticles that were encapsulated into 200 µg/mL of pyocyanin (Np-Pyo) were produced by the nanoprecipitation method. They were evaluated with respect to antifouling activity against Aspergillus sp. and Penicillium sp. With an encapsulation efficiency of 56%, the NpPyo remained stable for 90 days. Their characteristics were satisfactory for the following parameters: average size (616.90±38.30 nm; blank: 282.58±22.89 nm), polydispersion index (0.51±0.01; blank: 0.45±0.78), zeta potential (-5.13±0.41 mV; blank: -6.44±1.12 mV) and pH (6.18±0.03; blank: 6.42±0.01). The in vitro biofilm formation assay was performed on dolomite coupons measuring 1 cm2, on which the formulation was applied. There were tested conditions with and without immersion for 72h at 30 ºC. In the tests with the immersed coupons, there was fungal colonization; this was, however, lower than that observed in the control. A. niger decreased by 3 log units. No growth was observed on the coupons that were not immersed. The results were promising and demonstrated viability as a means of antifouling protection, particularly on dry surfaces.