Abstract：
The present study explores the bioinspired green synthesis of zinc oxide nanoparticles (ZnONPs) using marine Streptomyces plicatus and its potent antibacterial, antibiofilm activity against dental caries forming Streptococcus mutans MTCC and S. mutans clinical isolate (CI), cytotoxicity against oral KB cancer cells, hemolysis against blood erythrocytes and artemia toxicity. The bioinspired ZnONPs showed a distinctive absorption peak at 375 nm in UV-Vis spectra, the FT-IR spectra divulged the active functional groups, and XRD confirmed the crystalline nature of the nanoparticles with an average grain size of 41.76 nm. SEM analysis evidenced hexagonal morphology, and EDX spectra affirmed the presence of zinc. The ZnONPs exerted higher antagonistic activity against S. mutans MTCC (Inhibitory zone: 19 mm; MIC: 75 μg/ml) than S. mutans CI (Inhibitory zone: 17 mm; MIC: 100 μg/ml). Results of biofilm inhibitory activity showed a concentration-dependent reduction with S. mutans MTCC (15 %-95 %) more sensitive than S. mutans CI (13 %-89 %). The 50 % biofilm inhibitory concentration (BIC50) of ZnONPs against S. mutans MTCC was considerably lower (71.76 μg/ml) than S. mutans CI (78.13 μg/ml). Confocal Laser Scanning Microscopic visuals clearly implied that ZnONPs effectively distorted the biofilm architecture of both S. mutans MTCC and S. mutans CI. This was further bolstered by a remarkable rise in protein leakage (19 %-85 %; 15 %-77 %) and a fall in exopolysaccharide production (34 mg-7 mg; 49 mg-12 mg). MTT cytotoxicity of ZnONPs recorded an IC50 value of 22.06 μg/ml against KB cells. Acridine orange/ethidium bromide staining showed an increasing incidence of apoptosis in KB cells. Brine shrimp cytotoxicity using Artemia salina larvae recorded an LC50 value of 78.41 μg/ml. Hemolysis assay substantiated the biocompatibility of the ZnONPs. This study underscores the multifaceted application of bioinspired ZnONPs in dentistry.
摘要：
本研究探索了使用海洋plicatus链霉菌及其有效的抗菌生物的氧化锌纳米颗粒（ZnONPs）的生物启发绿色合成，抗龋齿形成变形链球菌MTCC和变形链球菌临床分离株（CI）的抗生物膜活性，对口腔KB癌细胞的细胞毒性，溶血对血液红细胞和卤虫毒性。受生物启发的ZnONPs在紫外-可见光谱中在375nm处显示出独特的吸收峰，FT-IR光谱揭示了活性官能团，和XRD证实了平均晶粒尺寸为41.76nm的纳米颗粒的结晶性质。SEM分析证明六边形形态，和EDX光谱证实了锌的存在。ZnONPs对变形链球菌MTCC(晕:19mm;MIC:75μg/ml)的拮抗活性高于变形链球菌MTCC(抑制区:17mm;MIC:100μg/ml)。生物膜抑制活性的结果表明，变异链球菌MTCC（15％至95％）的浓度依赖性降低比变异链球菌CI（13％至89％）更敏感。ZnONPs对变形链球菌MTCC的50％生物膜抑制浓度（BIC50）明显低于S.mutansCI（78.13μg/ml）（71.76μg/ml）。共聚焦激光扫描显微图像清楚地暗示ZnONPs有效地扭曲了变形链球菌MTCC和变形链球菌的生物膜结构。蛋白质渗漏的显著增加(19%-85%;15%-77%)和胞外多糖产量的下降(34mg至7mg;49mg至12mg)进一步支持了这一点。ZnONP的MTT细胞毒性记录的对KB细胞的IC50值为22.06μg/ml。吖啶橙/溴化乙锭染色显示KB细胞凋亡的发生率增加。使用卤虫幼虫的盐水虾细胞毒性记录的LC50值为78.41μg/ml。溶血试验证实了ZnONPs的生物相容性。这项研究强调了生物启发的ZnONPs在牙科中的多方面应用。
