Cytotoxicities of Antibacterial Silane Coupling Agents

Abstract

We have considered that decreasing the surface free energy of the tooth surface may help prevent caries and periodontal disease. Recently, we successfully synthesized two antibacterial silane coupling agents, N-allyl-N-decyl-N-methyl-N-trimethoxysilylpropylammonium iodide (10-I) and N-allyl-N-methyl-N-trimethoxysilylpropyl-N-octadecylammonium iodide (18-I). The aim of this study was to investigate the cytotoxicities of these modifier agents. Glass plates were dipped in 20 mmol/l of 10-I and 18-I solutions for 1 hour at 20℃, and then were sterilized with ethylene oxide gas for 24 hours at 35℃. The modified glass plates were immersed in cell culture medium (MO5) for 24 hours at 37℃ to examine the toxicity of the extraction procedure. The extracted medium (100%) was diluted with the MO5 into ten different concentrations (0.5-50%). 0.5 ml of the V79 cell suspension (100 cells/ml) was seeded on a 24-well cell culture plate and pre-incubated for 6 hours at 37℃ in a 5% CO₂ atmosphere. After removal of MO5, 0.5 ml of the extracts containing MO5 was poured onto the cell culture of V79 cells. After 6-day cultivation, cells were stained with 0.1% methylene blue solution, and calculated. The cytotoxicities of various modified agents were evaluated according to the 50% inhibitory concentration (IC₅₀). The IC₅₀ value of 18-I was 18.8%, while that of 10-I was more than 100%. These results suggest that 10-I has no cytotoxicity, whereas 18-I has moderate cytotoxicity.