은 나노입자가 첨가된 의치 조직조절재의 항균특성 및 세포독성에 관한 연구

Abstract

The aim of this study was to develop a new antimicrobial tissue conditioner containing silver nanoparticles (Ag0) and to evaluate its biological performance. Samples of tissue conditioner (Coe-soft, GC cooperation, Tokyo, Japan) containing Ag0 with the concentrations of 0 (control), 0.1, 0.5, 1.0, 2.0% were fabricated as 20 x 2.0 (diameter x thickness) mm in size for present experiments. In antimicrobial assay, samples were placed on separate culture plate and microbial suspensions (180 μL) of three tested strains (Staphylococcus aureus, Candida albicans and Escherichia coli) were inoculated. Microbial growth was verified at 24 hours and extended to 72 hours and the antimicrobial effects of samples were evaluated as a percentage of viable cells in withdrawn suspension (100 μL). The borderline of the antimicrobial effect was determined at 99.9 % of microbial reduction. To test the cytotoxicity of the modified tissue conditioner loaded with Ag0, the extracts from experimental samples were prepared according to concentration of Ag0 (0, 0.1, 0.5, 1.0, and 2.0%) and incubated at 2, 8, 24 and 72 hours. The cytotoxic effects of the extracts to cultured human gingival fibroblast (HGF) were measured by MTT assay. Samples combined with 0.5, 1.0 and 2.0% Ag0 displayed bactericidal effect against three tested strains in 24 and 72 hour incubation time without statistical difference between two incubating periods (p >0.01). While 0, 0.1 and 0.5% Ag0 showed no cytotoxic effect at all of incubating times, significantly high cytotoxic effect (less than 25% cell viability) was revealed at 2.0% Ag0 in 24 and 72 hours respectively (p <0.01) and significantly moderate cytotoxic effect (between 25-50% cell viability) was observed at 1.0% Ag0 in 24 and 72 hours respectively and 2.0% at 8 hours (p < 0.01). Within the limitation of this study in vitro, the results suggest that 0.5% Ag0 loaded tissue conditioner could be a possible candidate for a novel antimicrobial tissue conditioner with uncompromised cytotoxicity.