Stomatological Hospital, Southern Medical University, Guangzhou, China.
J Clin Lab Anal. 2021 Aug;35(8):e23872. doi: 10.1002/jcla.23872. Epub 2021 Jul 19.
Nanodiamonds (NDs) have been demonstrated to have bactericidal activity on several microorganisms and can be used in various kinds of dental materials. NDs are potential candidates for antibacterial dental materials. However, the possible inhibitory effect of NDs on oral pathogenic bacteria is largely unknown. This study was performed to investigate the inhibitory effects of carboxylated nanodiamond (cND) on Streptococcus mutans.
Fourier transform infrared spectroscopy was used to confirm carboxyl groups on the surface of commercial cND. The inhibitory effect of serially diluted cND on S. mutans was evaluated by spectrophotometry and plating methods. Escherichia coli was treated as a positive control in spectrophotometry. Chlorhexidine was used as a positive control in plating methods. Scanning electron microscopy (SEM) and transmission electron microscopy (TEM) were employed to confirm the antibacterial activity of cND.
The results showed that cND exhibited a significant inhibitory effect on S. mutans. For S. mutans, the minimum inhibitory concentration was 4 μg/ml and the minimum bactericidal concentration was 16 μg/ml. SEM and TEM results indicated that cND functioned as an antibacterial agent, likely due to its ability to disrupt the cell membrane of S. mutans.
In conclusion, these findings demonstrated an inhibitory effect of cND on S. mutans and suggest its use as a potential antibacterial dental material.
纳米金刚石（NDs）已被证明对多种微生物具有杀菌活性，并可用于各种牙科材料。NDs 是抗菌牙科材料的潜在候选材料。然而，NDs 对口腔致病菌的可能抑制作用在很大程度上尚不清楚。本研究旨在研究羧基化纳米金刚石（cND）对变形链球菌的抑制作用。
傅里叶变换红外光谱用于确认商业 cND 表面的羧基基团。通过分光光度法和平板法评估 cND 的连续稀释液对 S. mutans 的抑制作用。大肠杆菌在分光光度法中作为阳性对照，洗必泰在平板法中作为阳性对照。扫描电子显微镜（SEM）和透射电子显微镜（TEM）用于确认 cND 的抗菌活性。
结果表明，cND 对 S. mutans 表现出显著的抑制作用。对于 S. mutans，最小抑菌浓度为 4μg/ml，最小杀菌浓度为 16μg/ml。SEM 和 TEM 结果表明，cND 作为一种抗菌剂发挥作用，可能是因为其能够破坏 S. mutans 的细胞膜。
总之，这些发现表明 cND 对 S. mutans 具有抑制作用，并表明其可用作潜在的抗菌牙科材料。
