In vitro evaluation of the biomedical properties of chitosan and quaternized chitosan for dental applications.

The aim of this study was to evaluate the potential dental applications of chitosan (CS) and N-[1-hydroxy-3-(trimethylammonium)propyl]chitosan chloride (HTCC). HTCC was prepared by reacting CS with glycidyltrimethylammonium chloride (GTMAC). CS and HTCC were characterized by infrared (FITR) and (1)H NMR spectroscopy. The antibacterial activity of CS and HTCC against oral pathogens, their proliferation activity and effects on the ultrastructure of human periodontal ligament cells (HPDLCs) were investigated. The results indicated that four oral strains were susceptible to CS and HTCC with minimum inhibitory concentrations (MICs) ranging from 0.25 to 2.5mg/mL. The in vitro 3-(4,5-dimethyl-2-thizolyl)-2,5-diphenyl-2H-tetrazolium bromide (MTT) assay determined that CS at 2000, 1000, 100, and 50microg/mL could stimulate the proliferation of HPDLCs. Instead, HTCC inhibited the proliferation at the same concentrations but accelerated the proliferation of HPDLCs at relatively low concentrations (10, 3, 1.5, 1, and 0.3microg/mL). Transmission electron microscopy (TEM) observations revealed that the ultra-architecture of HPDLC was seriously destroyed by HTCC treatment at 1000microg/mL. Taken together, these results contribute information necessary to enhance our understanding of CS and HTCC in the dental field.