Anjum Sumaira, Abbasi Bilal Haider
Department of Biotechnology, Quaid-i-Azam University, Islamabad, Pakistan.
Int J Nanomedicine. 2016 Feb 22;11:715-28. doi: 10.2147/IJN.S102359. eCollection 2016.
Green synthesis of silver nanoparticles (AgNPs) by using plants is an emerging class of nanobiotechnology. It revolutionizes all domains of medical sciences by synthesizing chemical-free AgNPs for various biomedical applications. In this report, AgNPs were successfully synthesized by using whole plant extract (WPE) and thidiazuron-induced callus extract (CE) of Linum usitatissimum. The phytochemical analysis revealed that the total phenolic and flavonoid contents were higher in CE than that in WPE. Ultraviolet-visible spectroscopy of synthesized AgNPs showed a characteristic surface plasmon band in the range of 410-426 nm. Bioreduction of CE-mediated AgNPs was completed in a shorter time than that of WPE-mediated AgNPs. Scanning electron microscopy showed that both types of synthesized AgNPs were spherical in shape, but CE-mediated AgNPs were smaller in size (19-24 nm) and more scattered in distribution than that of WPE-mediated AgNPs (49-54 nm). X-ray diffraction analysis confirmed crystalline nature (face-centered cubic) of both types of AgNPs. Fourier-transform infrared spectroscopy revealed that the polyphenols and flavonoids were mainly responsible for reduction and capping of synthesized AgNPs. Energy dispersive X-ray analysis further confirmed the successful synthesis of AgNPs. Moreover, the synthesized AgNPs were found to be stable over months with no change in the surface plasmon bands. More importantly, CE-mediated AgNPs displayed significantly higher bactericidal activity against multiple drug-resistant human pathogens than WPE-mediated AgNPs. The present work highlighted the potent role of thidiazuron in in vitro-derived cultures for enhanced biosynthesis of chemical-free AgNPs, which can be used as nanomedicines in many biomedical applications.
利用植物进行银纳米颗粒（AgNPs）的绿色合成是纳米生物技术中一个新兴的领域。它通过合成无化学物质的AgNPs用于各种生物医学应用，彻底改变了医学科学的所有领域。在本报告中，使用亚麻全株提取物（WPE）和噻二唑隆诱导的愈伤组织提取物（CE）成功合成了AgNPs。植物化学分析表明，CE中的总酚和黄酮含量高于WPE。合成的AgNPs的紫外可见光谱显示在410 - 426 nm范围内有特征性的表面等离子体带。CE介导的AgNPs的生物还原比WPE介导的AgNPs完成得更快。扫描电子显微镜显示，两种类型的合成AgNPs均为球形，但CE介导的AgNPs尺寸较小（19 - 24 nm），且比WPE介导的AgNPs（49 - 54 nm）分布更分散。X射线衍射分析证实了两种类型的AgNPs的晶体性质（面心立方）。傅里叶变换红外光谱表明，多酚和黄酮主要负责合成的AgNPs的还原和包覆。能量色散X射线分析进一步证实了AgNPs的成功合成。此外，合成的AgNPs在几个月内保持稳定，表面等离子体带没有变化。更重要的是，CE介导的AgNPs对多重耐药的人类病原体显示出比WPE介导的AgNPs显著更高的杀菌活性。目前的工作突出了噻二唑隆在体外培养物中对增强无化学物质的AgNPs生物合成的重要作用，这些AgNPs可在许多生物医学应用中用作纳米药物。
