Schwass D R, Lyons K M, Love R, Tompkins G R, Meledandri C J
1 Sir John Walsh Research Institute, Faculty of Dentistry, University of Otago, P.O. Box 56, Dunedin 9054, New Zealand.
2 MacDiarmid Institute for Advanced Materials and Nanotechnology, and Department of Chemistry, University of Otago, P.O. Box 56, Dunedin 9054, New Zealand.
Adv Dent Res. 2018 Feb;29(1):117-123. doi: 10.1177/0022034517736495.
A novel silver nanoparticle (AgNP) formulation was developed as a targeted application for the disinfection of carious dentine. Silver nitrate (AgNO) was chemically reduced using sodium borohydrate (NaBH) in the presence of sodium dodecyl sulfate (SDS) to form micelle aggregate structures containing monodisperse 6.7- to 9.2-nm stabilized AgNPs. AgNPs were characterized by measurement of electrical conductivity and dynamic light scattering, scanning electron microscopy, transmission electron microscopy, and inductively coupled plasma mass spectrometry. Antimicrobial activity of AgNPs was tested against planktonic cultures of representative gram-positive and gram-negative oral bacteria using well diffusion assays on tryptic soy broth media and monoculture biofilms grown with brain heart infusion ± sucrose anaerobically at 37°C on microtiter plates. Biofilm mass was measured by crystal violet assay. Effects were compared to silver diamine fluoride and chlorhexidine (negative controls) and 70% isopropanol (positive control) exposed cultures. In the presence of AgNPs, triplicate testing against Streptococcus gordonii DL1, C219, G102, and ATCC10558 strains; Streptococcus mutans UA159; Streptococcus mitis I18; and Enterococcus faecalis JH22 for planktonic bacteria, the minimum inhibitory concentrations were as low as 7.6 µg mL and the minimum bacteriocidal concentrations as low as 19.2 µg mL silver concentration. Microplate readings detecting crystal violet light absorption at 590 nm showed statistically significant differences between AgNP-exposed biofilms and where no antimicrobial agents were used. The presence of sucrose did not influence the sensitivity of any of the bacteria. By preventing in vitro biofilm formation for several Streptococcus spp. and E. faecalis, this AgNP formulation demonstrates potential for clinical application inhibiting biofilms.
一种新型银纳米颗粒（AgNP）制剂被开发用于龋损牙本质消毒的靶向应用。在十二烷基硫酸钠（SDS）存在下，使用硼氢化钠（NaBH）对硝酸银（AgNO）进行化学还原，以形成包含单分散6.7至9.2纳米稳定化AgNP的胶束聚集体结构。通过测量电导率、动态光散射、扫描电子显微镜、透射电子显微镜和电感耦合等离子体质谱对AgNP进行表征。使用胰蛋白胨大豆肉汤培养基上的打孔扩散试验以及在37℃厌氧条件下在微量滴定板上用脑心浸液±蔗糖培养的单培养生物膜，测试AgNP对代表性革兰氏阳性和革兰氏阴性口腔细菌的浮游培养物的抗菌活性。通过结晶紫测定法测量生物膜质量。将效果与氟化银胺和洗必泰（阴性对照）以及70%异丙醇（阳性对照）处理的培养物进行比较。在存在AgNP的情况下，对戈登链球菌DL1、C219、G102和ATCC10558菌株；变形链球菌UA159；缓症链球菌I18；以及粪肠球菌JH22的浮游细菌进行一式三份测试，最低抑菌浓度低至7.6μg/mL，最低杀菌浓度低至19.2μg/mL银浓度。在590nm处检测结晶紫光吸收的微量滴定板读数显示，暴露于AgNP的生物膜与未使用抗菌剂的生物膜之间存在统计学显著差异。蔗糖的存在不影响任何细菌的敏感性。通过防止几种链球菌属和粪肠球菌的体外生物膜形成，这种AgNP制剂显示出抑制生物膜的临床应用潜力。
