In the study, leaf extract of Carica papaya was utilized for the biogenic fabrication process of chitosan functionalized silver nanoparticles (Ag-Chito NPs). HRTEM analysis revealed that the fabricated Ag-Chito NPs was spherical in shape, with an average particle size of 13.31 (±0.07) nm. FTIR, UV–Vis, DLS, and other characterizations were also performed to analyze the diverse physicochemical properties of the particles. The antibacterial potency of the synthesized Ag-Chito NPs was tested against the two clinically isolated multidrug resistant uropathogenic bacterial strains, i.e. MLD 2 (Escherichia coli) and MLD 4 (Staphylococcus aureus) through MIC, MBC, time and concentration dependent killing kinetic assay, inhibition of biofilm formation assay, fluorescence and SEM imaging. Significantly, Ag-Chito NPs showed the highest sensitivity against the MLD 2 (MIC value of 12.5 μg/mL) strain, as compared to the MLD 4 (MIC value of 15 μg/mL) strain. From the hemolysis assay, it was revealed that Ag-Chito NPs exerted no significant toxicity up to 50 μg/mL against healthy human blood cells. Additionally, in silico analysis of chitosan (functionalized on the surface of AgNPs) and bacterial cell membrane protein also evidently suggested a strong interaction between Ag-Chito NPs and bacterial cells, which might be responsible for bacterial cell death.

在这项研究中，番木瓜的叶子提取物被用于壳聚糖功能化银纳米粒子 (Ag-Chito NPs) 的生物制造过程。HRTEM 分析表明，制备的 Ag-Chito NPs 呈球形，平均粒径为 13.31 (±0.07) nm。还进行了 FTIR、UV-Vis、DLS 和其他表征，以分析颗粒的各种物理化学性质。合成的 Ag-Chito NPs 的抗菌效力针对两种临床分离的多药耐药尿路致病细菌菌株，即 MLD 2（大肠杆菌）和 MLD 4（金黄色葡萄球菌）进行了测试) 通过 MIC、MBC、时间和浓度依赖性杀伤动力学测定、抑制生物膜形成测定、荧光和 SEM 成像。值得注意的是，与 MLD 4（MIC 值为 15 μg/mL）菌株相比，Ag-Chito NPs 对 MLD 2（MIC 值为 12.5 μg/mL）菌株的敏感性最高。溶血试验表明，Ag-Chito NPs 对健康人血细胞的毒性高达 50 μg/mL。此外，壳聚糖（在 AgNPs 表面功能化）和细菌细胞膜蛋白的计算机分析也明显表明 Ag-Chito NPs 与细菌细胞之间存在强烈的相互作用，这可能是细菌细胞死亡的原因。