The use of nanotechnology in several areas of dentistry has received considerable attention. Still, little is known regarding the use of nanosized pharmaceutical formulations in the oral cavity.
Liposomes, vesicular lipid structures 100–200 nm in size, are a well-recognized nanoformulation. Interactions of liposomes with dental restorative materials have been studied to investigate the potential application in the oral cavity. The adsorption of four different types of liposomes onto four common dental restoratives, including resin composites and glass-ionomer cements, was examined Figure 1. The ability of the liposomes to retain on the restorative materials was evaluated by imposing an artificial flow, simulating the salivary flow rate, at the materials’ surface.
The study showed that liposomes with a positive surface charge exhibited significantly high adsorption to all the tested restorative materials (Figure 2) and retained well on their surface when exposed to a simulated salivary flow. The surface charge of the liposomes seems to be the main determinant in the immediate interaction between liposomes and dental restoratives. Liposomes were surface modified with the polymer pectin (negatively charged) to obtain a more hydrophobic character. These liposomes demonstrated only an intermediate initial level of adsorption; however, they remained on the surface at a level comparable to that of positive liposomes when exposed to flow. Thus, it seemed that hydrophobic interactions are involved in the prolonged binding of polymer-coated liposomes to hydrophobic material surfaces.
The present study proposes that liposomal interaction with dental restorative materials may inhibit, reduce or delay the harmful effects of bacterial adherence and the development of biofilm on the restorative materials, in particular if combined with active substances. A part of this study was performed by PhD Sanko Nguyen during her stay as a visiting scientist at NIOM.
Nguyen S, Adamczak M, Hiorth M, Smistad G, Kopperud HM. Interactions of liposomes with dental restorative materials. Colloids Surf B Biointerfaces 2015; 136: 744–751.