Aruna Ponnusamy, Lalitha Pottail, Muddukrishnaiah Kotakonda
Research Scholar of Chemistry, Avinashilingam Institute for Home Science and Higher Education for Women, Coimbatore, India.
Director R&D, Professor of Chemistry, Co ordinator, Prof. C. N. R. Rao Research Centre, Avinashilingam Institute for Home Science and Higher Education for Women, Coimbatore, India.
Microb Pathog. 2025 Feb;199:107197. doi: 10.1016/j.micpath.2024.107197. Epub 2024 Dec 6.
Microbes have been increasing their potential against newly developed drugs and antibiotics daily. The increased microbial drug resistance is still a challenging societal inconvenience. 2D nanomaterials, such as graphene, fascinate researchers with their unique physical and chemical properties and have a major role in current science and technology. Nowadays, researchers have been replacing graphene with its analogous 2D material, borophene, which is a single layer of boron with a honeycomb plane. Boron nanosheets which are theoretically investigated, have been synthesized by various top-down and bottom-up approaches. Our study focuses on synthesizing boron-based material from the precursor MgB which possesses a honeycomb boron structure with sandwiched Mg atoms. The Mg atoms have been selectively removed using the chelating agents at alkaline pH. The synthesized boron nanosheets have been characterized by FT-IR, Raman, XRD, FESEM, EDS, and TGA. The formation of B-H-B, B-B and B-O bond is confirmed by FT-IR and Raman spectra. It is also evident from XPS spectra which possess B1s spectra at 193 eV. The efficient chelation and exfoliation is confirmed by EDS and FESEM analysis which shows the presence of boron and trace amount of Mg with bark like projections. Though there are several studies on antibacterial activity of compounds, generally the studies are with laboratory cultures of bacterial strains. Clinical studies offer more valid results and are very sparse in literature. The use of clinical strains in the present study is one of the novelty. It has also been analyzed for its anti-bacterial activity against clinical strains of B. subtilis, S. aureus, E. coli, and K. pneumonia. Boron nanosheets possess an enhanced zone of inhibition (8 mm, 11 mm) against clinical strains of B. subtilis where the micro dilution studies show MIC and MBC values as 125 μg and 62.5 μg. The in vivo toxicity studies carried out using Brine Shrimp Lethality Assay reveal higher LC50 values of boron nanosheets (>1 mg/ml), which in turn portrays its non-toxic nature. Thus, the synthesized boron nanosheets are toxic to multidrug-resistant B. subtilis where it is non-toxic to mammalian cells. Thus, the study could advance the applications of borophene in biomedical applications.
微生物对抗新研发药物和抗生素的能力日益增强。微生物耐药性的增加仍是一个具有挑战性的社会难题。二维纳米材料，如石墨烯，以其独特的物理和化学性质吸引着研究人员，在当前的科学技术中发挥着重要作用。如今，研究人员已用其类似的二维材料硼烯取代了石墨烯，硼烯是具有蜂窝状平面的单层硼。理论研究的硼纳米片已通过各种自上而下和自下而上的方法合成。我们的研究重点是从前体MgB合成硼基材料，该材料具有夹有Mg原子的蜂窝状硼结构。在碱性pH值下使用螯合剂选择性地去除了Mg原子。合成的硼纳米片已通过傅里叶变换红外光谱（FT-IR）、拉曼光谱、X射线衍射（XRD）、场发射扫描电子显微镜（FESEM）、能谱（EDS）和热重分析（TGA）进行了表征。FT-IR和拉曼光谱证实了B-H-B、B-B和B-O键的形成。X射线光电子能谱（XPS）也表明在193 eV处存在B1s光谱。EDS和FESEM分析证实了有效的螯合和剥离，显示出硼的存在以及带有树皮状突起的痕量Mg。虽然有几项关于化合物抗菌活性的研究，但一般都是针对细菌菌株的实验室培养。临床研究能提供更有效的结果，但在文献中非常稀少。本研究中使用临床菌株是其中一个新颖之处。还分析了其对枯草芽孢杆菌、金黄色葡萄球菌、大肠杆菌和肺炎克雷伯菌临床菌株的抗菌活性。硼纳米片对枯草芽孢杆菌临床菌株具有增强的抑菌圈（8毫米、11毫米），微量稀释研究显示其最低抑菌浓度（MIC）和最低杀菌浓度（MBC）值分别为125微克和62.5微克。使用卤虫致死率测定法进行的体内毒性研究表明硼纳米片具有更高的半数致死浓度（LC50）值（>1毫克/毫升），这反过来表明其无毒性质。因此，合成的硼纳米片对多重耐药的枯草芽孢杆菌有毒，而对哺乳动物细胞无毒。因此，该研究可以推动硼烯在生物医学应用中的发展。
