Zanni Elena, Bruni Erika, Chandraiahgari Chandrakanth Reddy, De Bellis Giovanni, Santangelo Maria Grazia, Leone Maurizio, Bregnocchi Agnese, Mancini Patrizia, Sarto Maria Sabrina, Uccelletti Daniela
Department of Biology and Biotechnology C. Darwin, Sapienza University of Rome, Piazzale Aldo Moro 5, Rome, Italy.
Research Center on Nanotechnology Applied to Engineering of Sapienza (CNIS), SNNLab, Sapienza University of Rome, Piazzale Aldo Moro 5, Rome, Italy.
J Nanobiotechnology. 2017 Aug 1;15(1):57. doi: 10.1186/s12951-017-0291-4.
Nanotechnologies are currently revolutionizing the world around us, improving the quality of our lives thanks to a multitude of applications in several areas including the environmental preservation, with the biodeterioration phenomenon representing one of the major concerns.
In this study, an innovative nanomaterial consisting of graphene nanoplatelets decorated by zinc oxide nanorods (ZNGs) was tested for the ability to inhibit two different pathogens belonging to bacterial genera frequently associated with nosocomial infections as well as biodeterioration phenomenon: the Gram-positive Staphylococcus aureus and the Gram-negative Pseudomonas aeruginosa. A time- and dose-dependent bactericidal effect in cell viability was highlighted against both bacteria, demonstrating a strong antimicrobial potential of ZNGs. Furthermore, the analysis of bacterial surfaces through Field emission scanning electron microscopy (FESEM) revealed ZNGs mechanical interaction at cell wall level. ZNGs induced in those bacteria deep physical damages not compatible with life as a result of nanoneedle-like action of this nanomaterial together with its nanoblade effect. Cell injuries were confirmed by Fourier transform infrared spectroscopy, revealing that ZNGs antimicrobial effect was related to protein and phospholipid changes as well as a decrease in extracellular polymeric substances; this was also supported by a reduction in biofilm formation of both bacteria. The antibacterial properties of ZNGs applied on building-related materials make them a promising tool for the conservation of indoor/outdoor surfaces. Finally, ZNGs nanotoxicity was assessed in vivo by exploiting the soil free living nematode Caenorhabditis elegans. Notably, no harmful effects of ZNGs on larval development, lifespan, fertility as well as neuromuscular functionality were highlighted in this excellent model for environmental nanotoxicology.
Overall, ZNGs represent a promising candidate for developing biocompatible materials that can be exploitable in antimicrobial applications without releasing toxic compounds, harmful to the environment.
纳米技术正在彻底改变我们周围的世界，由于在包括环境保护在内的多个领域有大量应用，从而改善了我们的生活质量，而生物劣化现象是主要关注的问题之一。
在本研究中，测试了一种由氧化锌纳米棒修饰的石墨烯纳米片组成的创新纳米材料（ZNGs）抑制两种不同病原体的能力，这两种病原体属于经常与医院感染以及生物劣化现象相关的细菌属：革兰氏阳性金黄色葡萄球菌和革兰氏阴性铜绿假单胞菌。针对这两种细菌，均突出显示了细胞活力方面的时间和剂量依赖性杀菌作用，证明了ZNGs具有强大的抗菌潜力。此外，通过场发射扫描电子显微镜（FESEM）对细菌表面的分析揭示了ZNGs在细胞壁水平的机械相互作用。由于这种纳米材料的纳米针状作用及其纳米刀片效应，ZNGs在这些细菌中引起了与生命不相容的深度物理损伤。傅里叶变换红外光谱证实了细胞损伤，表明ZNGs的抗菌作用与蛋白质和磷脂变化以及细胞外聚合物的减少有关；这两种细菌生物膜形成的减少也支持了这一点。应用于建筑相关材料的ZNGs的抗菌特性使其成为保护室内/室外表面的有前途的工具。最后，通过利用土壤自由生活线虫秀丽隐杆线虫在体内评估了ZNGs的纳米毒性。值得注意的是，在这个出色的环境纳米毒理学模型中，未突出显示ZNGs对幼虫发育、寿命、繁殖力以及神经肌肉功能的有害影响。
总体而言，ZNGs是开发生物相容性材料的有前途的候选者，这些材料可用于抗菌应用而不释放对环境有害的有毒化合物。
