Center of Research Excellence in Desalination & Water Treatment and Center for Environment and Water, King Fahd University of Petroleum and Minerals, Dhahran 31261, Saudi Arabia.
Epidemic Disease Research Department, Institute for Research & Medical Consultations (IRMC), Imam Abdulrahman Bin Faisal University, P.O. Box 1982, 31441 Dammam, Saudi Arabia.
Mater Sci Eng C Mater Biol Appl. 2020 Aug;113:110992. doi: 10.1016/j.msec.2020.110992. Epub 2020 Apr 22.
In the present research work, copper oxide-titanium dioxide nanocomposites were synthesized for the first time using advanced pulsed laser ablation in liquid (PLAL) technique for disinfection of drug-resistant pathogenic waterborne biofilm-producing bacterial strains. For this, a series of copper oxide-titanium dioxide nanocomposites were synthesized by varying the composition of copper oxide (5%, 10%, and 20%) with titanium dioxide. The pure titanium dioxide and copper oxide-titanium dioxide nanocomposites were characterized by advanced instrumental techniques. XRD, TEM, FE-SEM, EDX, elemental mapping and XPS analysis results consistently revealed the successful formation of copper oxide-titanium dioxide nanocomposites using PLAL technique. The antibacterial and antibiofilm activities of pure titanium dioxide and copper oxide-titanium dioxide nanocomposites were investigated against biofilm-producing strains of Methicillin-resistant Staphylococcus aureus and Pseudomonas aeruginosa by various methods. Our results revealed that the PLAL synthesized copper oxide-titanium dioxide nanocomposites showed enhanced anti-biofilm and antibacterial activity compared to pure titanium dioxide in a dose-dependent manner against targeted pathogens. Furthermore, the effects of pure titanium dioxide and copper oxide-titanium dioxide nanocomposites on bacterial morphology, biofilm formation, aggregation and their colonization by targeted pathogens were also examined using scanning electron microscopy. Microscopic images clearly showed that the cell envelope of almost all the cells were rumples, rough, had irregularities and abnormal appearance with the major damage being characterized by the formation of "pits". Many depressions and indentations were also seen in their cell envelope and the original shape of Pseudomonas aeruginosa cells changed from normal rod to swollen, large and elongated which indicates the loss of membrane integrity and damage of cell wall and membrane. The findings suggested that PLAL synthesized copper oxide-titanium dioxide nanocomposites have good potential for removal of biofilm or killing of pathogenic bacteria in water distribution network and for wastewater treatment, hospital and environmental applications. In addition, cytotoxic activity of pure TiO and PLAL synthesized copper oxide-titanium dioxide nanocomposites against normal and healthy cells (HEK-293) and cancerous cells (HCT-116) were also evaluated by MTT assay. The MTT assay results showed no cytotoxic effects on HEK-293 cells, which suggest TiO and PLAL synthesized copper oxide-titanium dioxide nanocomposites are non-toxic to the normal cells.
在本研究工作中，首次使用先进的脉冲激光烧蚀在液体（PLAL）技术合成氧化铜-二氧化钛纳米复合材料，用于消毒耐药的水生生物膜产生的病原菌。为此，通过改变氧化铜（5%、10%和 20%）的组成，用钛白粉合成了一系列氧化铜-二氧化钛纳米复合材料。通过先进的仪器技术对纯二氧化钛和氧化铜-二氧化钛纳米复合材料进行了表征。XRD、TEM、FE-SEM、EDX、元素映射和 XPS 分析结果一致表明，成功地使用 PLAL 技术合成了氧化铜-二氧化钛纳米复合材料。通过各种方法研究了纯二氧化钛和氧化铜-二氧化钛纳米复合材料对耐甲氧西林金黄色葡萄球菌和铜绿假单胞菌生物膜产生菌株的抗菌和抗生物膜活性。我们的结果表明，与纯二氧化钛相比，PLAL 合成的氧化铜-二氧化钛纳米复合材料在针对目标病原体的剂量依赖性方式下表现出增强的抗生物膜和抗菌活性。此外，还通过扫描电子显微镜检查了纯二氧化钛和氧化铜-二氧化钛纳米复合材料对细菌形态、生物膜形成、聚集及其在目标病原体中的定植的影响。显微镜图像清楚地表明，几乎所有细胞的细胞包膜都是皱巴巴的、粗糙的、不规则的和异常的，主要损伤特征是形成“凹坑”。还可以看到它们的细胞膜上有许多凹陷和凹陷，铜绿假单胞菌细胞的原始形状从正常棒状变为肿胀、大而伸长，这表明细胞膜的完整性丧失，细胞壁和细胞膜受损。研究结果表明，PLAL 合成的氧化铜-二氧化钛纳米复合材料具有去除水分配网络中生物膜或杀死病原菌以及处理废水、医院和环境应用的良好潜力。此外，还通过 MTT 测定法评估了纯 TiO 和 PLAL 合成的氧化铜-二氧化钛纳米复合材料对正常和健康细胞（HEK-293）和癌细胞（HCT-116）的细胞毒性。MTT 测定结果表明对 HEK-293 细胞没有细胞毒性作用，这表明 TiO 和 PLAL 合成的氧化铜-二氧化钛纳米复合材料对正常细胞没有毒性。
