Defence Institute of Advanced Technology (DIAT), Girinagar, Pune-411025, India.
Nanotechnology. 2020 May 22;31(21):215604. doi: 10.1088/1361-6528/ab72b4. Epub 2020 Feb 4.
Antibiotic resistance is a highly challenging concern of infectious diseases, and it requires a rational approach to overcome. Through this work, we have synthesized ampicillin-capped gold nanoparticles (Amp-Au NPs) and studied its interaction with bacterial cells. In this process of synthesis, the primary amine group of ampicillin acts as both reducing as well as capping agent. In addition to synthesized gold nanoparticles, the β-lactam ring remains free to interact with bacteria. This approach not only utilizes the maximum efficiency of nanoparticles and antibiotics towards ampicillin sensitive bacterial cells but also proves to be effective against ampicillin resistance bacteria. Our results illustrate that the optimized system of Amp-Au NPs was formulated by taking 1.25 mM ampicillin and 10 of gold ions concentration. UV-vis spectrum of gold nanoparticles and the presence of ampicillin were recorded at around 540 nm and 259 nm, respectively. Microscopic images indicate that particles are nearly spherical and are in size range between 25 and 50 nm. Moreover, formulated Amp-Au NPs show successful accumulation onto the surface of the bacterial cell as a result of which pores were formed into the bacterial membrane. The entry of nanoparticles into bacterial cells was validated through both atomic force microscopy and fluorescent microscopy. The adhesive properties of this coating material and its stability in various pH, i.e. pH 3, pH 7 and pH 10 conditions, could make them a good candidate in the prevention of biofilm formation. Amp-Au NPs show promising antimicrobial activity against ampicillin resistance Escherichia coli bacteria. Furthermore, antimicrobial studies indicate that the efficacy of Amp-Au NPs increased against both ampicillin sensitive and ampicillin resistance bacteria up to sixteen folds and four folds respectively.
抗生素耐药性是传染病领域极具挑战性的问题，需要采取合理的方法加以克服。通过这项工作，我们合成了氨苄青霉素包裹的金纳米粒子（Amp-Au NPs），并研究了其与细菌细胞的相互作用。在合成过程中，氨苄青霉素的伯胺基团既起到还原作用，又起到封端作用。除了合成的金纳米粒子外，β-内酰胺环仍然可以自由地与细菌相互作用。这种方法不仅利用了纳米粒子和抗生素对氨苄青霉素敏感细菌细胞的最大效率，而且对氨苄青霉素耐药细菌也有效。我们的研究结果表明，优化的 Amp-Au NPs 系统是通过使用 1.25 mM 的氨苄青霉素和 10 个金离子浓度来制备的。金纳米粒子的紫外-可见光谱和氨苄青霉素的存在分别记录在约 540nm 和 259nm 处。显微镜图像表明，颗粒几乎呈球形，尺寸在 25nm 到 50nm 之间。此外，所制备的 Amp-Au NPs 成功地聚集在细菌细胞表面，导致细菌膜形成孔。通过原子力显微镜和荧光显微镜验证了纳米粒子进入细菌细胞的过程。这种涂层材料的粘附特性及其在各种 pH 值（即 pH3、pH7 和 pH10 条件）下的稳定性，使它们成为预防生物膜形成的良好候选材料。Amp-Au NPs 对氨苄青霉素耐药大肠杆菌具有良好的抗菌活性。此外，抗菌研究表明，Amp-Au NPs 对氨苄青霉素敏感和耐药细菌的疗效分别提高了 16 倍和 4 倍。
