IADR Abstract Archives
Antibacterial effect of ZnO/CuO nanocomposites with varying copper composition
Objectives: Recently, nanotechnology has become increasingly important as an alternative antimicrobial strategy. We developed and presented our novel fluoride-containing zinc and copper nanocomposite (ZCF) and its antibacterial effect at the 16th International Conference On Nuclear Microprobe Technology and Applications. Both zinc and copper are indispensable elements; however, the optimum human intake of copper is one-tenth that of zinc. Therefore, we aimed to develop low-copper ZCF and investigate the antibacterial effects of ZCF with varying compositions.
Methods: Nanocomposites comprising ZCF were prepared by a simple one-step homogeneous coprecipitation method at a low temperature (80°C). We analyzed the antibiotic susceptibility of Streptococcus mutans (ATCC 25175) to nanocomposites prepared using three different zinc-copper ratios (5:1 (ZCF51), 10:1 (ZCF101), and 20:1 (ZCF201)); Ca(OH)2 was used as a positive control and BHI medium alone was used as a negative control. Next, 1 μl bacterial suspension, 95 μl BHI medium, and 100 μl of BHI with ZCF were incubated in 96-well microtiter plates for 24 hours at 37°C. Next, 100-μl suspensions were diluted ten times, added to TSB agar plates, and incubated for 24 hours at 37°C. The colony numbers from all plates were counted and CFUs were calculated. The bacterial growth of each group was analyzed using the Games-Howell test (p<0.05).
Results: The control buffer allowed bacterial growth to 3.0×106 ± 4.6×105 CFU/mL, whereas Ca(OH)2, ZCF51, ZCF101 and ZCF201 allowed no bacterial growth.
Conclusions: Low-copper fluoride-containing ZnO–CuO nanocomposites also exert antibacterial effects.
Methods: Nanocomposites comprising ZCF were prepared by a simple one-step homogeneous coprecipitation method at a low temperature (80°C). We analyzed the antibiotic susceptibility of Streptococcus mutans (ATCC 25175) to nanocomposites prepared using three different zinc-copper ratios (5:1 (ZCF51), 10:1 (ZCF101), and 20:1 (ZCF201)); Ca(OH)2 was used as a positive control and BHI medium alone was used as a negative control. Next, 1 μl bacterial suspension, 95 μl BHI medium, and 100 μl of BHI with ZCF were incubated in 96-well microtiter plates for 24 hours at 37°C. Next, 100-μl suspensions were diluted ten times, added to TSB agar plates, and incubated for 24 hours at 37°C. The colony numbers from all plates were counted and CFUs were calculated. The bacterial growth of each group was analyzed using the Games-Howell test (p<0.05).
Results: The control buffer allowed bacterial growth to 3.0×106 ± 4.6×105 CFU/mL, whereas Ca(OH)2, ZCF51, ZCF101 and ZCF201 allowed no bacterial growth.
Conclusions: Low-copper fluoride-containing ZnO–CuO nanocomposites also exert antibacterial effects.