Department of Physics, University of Illinois at Chicago, 801 S. Paulina Street, Chicago, IL 60612, USA.
Center for Wound Healing and Tissue Regeneration, College of Dentistry, University of Illinois at Chicago, 801 S. Paulina Street, Chicago, IL 60612, USA.
J Inorg Biochem. 2020 May;206:110997. doi: 10.1016/j.jinorgbio.2020.110997. Epub 2020 Jan 11.
Several studies have focused on the antimicrobial effects of cerium oxide nanoparticles (CeO-NP) but few have focused on their effects on bacteria under initial biofilm formation conditions. Streptococcus mutans is a prolific biofilm former contributing to dental caries in the presence of fermentable carbohydrates and is a recognized target for therapeutic intervention. CeO-NP derived solely from Ce(IV) salt hydrolysis were found to reduce adherent bacteria by approximately 40% while commercial dispersions of "bare" CeO-NP (e.g., 3 nm, 10-20 nm, 30 nm diameter) and Ce(NO)·6HO were either inactive or observed to slightly increase biofilm formation under similar in vitro conditions. Planktonic growth and dispersal assays support a non-bactericidal mode of biofilm inhibition active in the initial phases of S. mutans biofilm production. Human cell proliferation assays suggest only minor effects of hydrolyzed Ce(IV) salts on cellular metabolism at concentrations up to 1 mM Ce, with less observed toxicity compared to equimolar concentrations of AgNO. The results presented herein have implications in clinical dentistry.
已有多项研究聚焦于氧化铈纳米颗粒（CeO-NP）的抗菌效果，但鲜少关注其在细菌初始生物膜形成条件下的作用。变形链球菌是一种高产生物膜形成菌，在可发酵碳水化合物存在的情况下会导致龋齿，是治疗干预的公认靶点。研究发现，仅由 Ce(IV) 盐水解得到的 CeO-NP 可使黏附细菌减少约 40%，而商业分散的“裸”CeO-NP（例如 3nm、10-20nm、30nm 直径）和 Ce(NO)·6HO 在类似的体外条件下要么无活性，要么观察到略微增加生物膜形成。浮游生长和分散测定支持生物膜抑制的非杀菌模式，在 S. mutans 生物膜产生的初始阶段具有活性。人体细胞增殖测定表明，在高达 1mM Ce 的浓度下，Ce(IV) 盐的水解产物对细胞代谢的影响很小，与等摩尔浓度的 AgNO 相比，观察到的毒性更小。本文的研究结果对临床牙科具有重要意义。
