Bioadhesive, non-drug-loaded nanoparticles as modulators of candidal adherence to buccal epithelial cells: a potentially novel prophylaxis for candidosis

Adherence of microorganisms, such as Candida albicans, represents the initial step in the establishment of infection and, accordingly, modification of this step represents a method by which the incidence of infection may be reduced. Therefore, this study uniquely examined the effects of polymeric nanoparticles on the adherence of blastospores of C albicans to human buccal epithelial cells (BEC) in vitro. Poly(propylcyanoacrylate) nanoparticles were produced by emulsion polymerisation using a range of anionic, cationic and non-ionic surfactants, their particle size and zeta potential characterised and incubated with stationary phase blastospores of C albicans for a defined period. Following this, the surface properties and size of blastospores with adsorbed nanoparticles were characterised. phosphate buffered saline-treated and nanoparticle-treated blastospores were incubated with human BEC for 2 h, following which the number of adherent blastospores was enumerated by light microscopy. The size and zeta potential of the nanoparticles were dependent on the surfactant employed in the manufacture process. Following nanoparticle adsorption, alteration of the zeta potential and an increase in the diameter of blastospores were observed. However, as this increase in diameter was indirectly related to the size of the nanoparticles, this may indicate a preference for the adsorption of smaller particles. In addition, following nanoparticle adsorption, the cell surface hydrophobicity (CSH) of C. albicans blastospores was increased and, importantly, the subsequent adherence to BEC in vitro was reduced. Most notably, the adherence of blastospores that had been treated with nanoparticles (stabilised with docusate sodium) was circa 73% lower than that of untreated blastospores. A moderate correlation between increased CSH and reduced adherence and a low correlation between blastospore zeta potential and adherence were observed, inferring that other mechanisms, most likely stearic hindrance, are responsible for the antiadherent properties of adsorbed nanoparticles. In light of their ability to reduce candidal adherence to BEC, it is suggested that polymeric nanoparticles may be useful in the prophylaxis of candidosis of the oral cavity. (C) 2003 Elsevier Ltd. All rights reserved.