Antimicrobial Silver-Polyethyleneimine-Polylactic Acid Polymer Composite Film for Coating Methacrylate-Based Denture Surfaces

Abstract

To prepare an antimicrobial polymer composite composed of silver- (Ag-) polyethyleneimine- (PEI-) polylactic acid (PLA) in chloroform, for coating the mucosal surfaces of methacrylate-based dentures as a prospective therapy for denture stomatitis. The water-insoluble, tightly bound, hard, micrometre-thin, and colourless film exerts its effects by direct contact with the pathogens and via the active constituents (Ag, PEI, and Ag-PEI) released slowly into the mucosa’s salivary layer. Silver and PEI were blended at 140°C, then bound to PLA. The Ag-PEI complex was characterised by dynamic light scattering and transmission electron microscopy, and the Ag-PEI-PLA composite was examined by atomic force microscopy and micro-computed tomography. The characteristic was measured by atomic force microscopy (AFM) and micro-computed tomography (micro-CT). The quantity of water-soluble Ag-PEI complex released from the composite film was measured with gravimetry. The cellular physiological effects were analysed by impedimetry and computer-based morphometry using human gingival epithelial cells. A real-time cell proliferation assay revealed moderate toxic effects of Ag-PEI on the epithelium. The viscous Ag-PEI-PLA solution produced could be applied as a thin film on methacrylate surfaces. Active antimicrobial components (Ag, PEI, and Ag-PEI) were released from the hard, tightly bound Ag-PEI-PLA coating. This study’s findings verified the applicability of the antimicrobial Ag-PEI-PLA composite for coating the inner surfaces of acrylate dentures. Owing to the well-known antimicrobial effects of silver and PEI and the supplementary effects of chloroform, this composite provides a new therapeutic method for denture stomatitis that can be easily performed by dentists.