Optimization, Structural Characterization, Thermal Properties, and Bactericidal Activity of Novel Alginate/Kaolin/Ag Bionanocomposite against Streptococcus Mutans Biofilm

Abstract

Decreasing the effectiveness of existing antimicrobial agents and increasing antimicrobial resistance to them is one of the major challenges of the healthcare system. This study was aimed at determining the optimal conditions for synthesizing novel alginate/kaolin/Ag nanocomposite with the highest antimicrobial activity against Streptococcus mutans (S. mutans) biofilm. For this purpose, silver nanoparticles and alginate biopolymer were synthesized by the coprecipitation and biological methods, respectively. In situ method was used to synthesize nanocomposites. The antibacterial activity of nanocomposites against S. mutans biofilm was measured in 9 experiments designed by the Taguchi method to determine the highest level of antibacterial performance. Nanocomposites synthesized in experiment 3 (60 mg/ml alginate, 0.9 mg/ml kaolin, and 4 mg/ml Ag) and experiment 5 (70 mg/ml alginate, 0.6 mg/ml kaolin, and 4 mg/ml Ag) had the strongest antibacterial activity against the S. mutans biofilm, which completely stopped the growth of the bacterium. Various characterization tests were used to identify nanocomposite components materials that confirmed the formation of nanocomposite with desirable properties. Thermal analysis showed that the temperature range of thermal stability of nanocomposite is higher than the temperature range of thermal stability of alginate polymer. This novel nanocomposite showed desirable antibacterial potential against the S. mutans biofilm. As a result, it can be used as an antimicrobial and antibiofilm agent in various biomedical and dental fields.