Synthesis and Biological Characterization of Phyto-Fabricated Silver Nanoparticles fromAzadirachta indica

Abstract

Nanoparticles (NPs) have garnered a lot of interest in sectors like medicine, cosmetics, food, and pharmaceuticals for antibacterial catalytic properties, reduced toxicity, and easy production. Biological synthesis of silver nanoparticle (AgNPs) is considered as green, eco-friendly, and cost-effective approach; therefore, Azadirachta indica extracts were utilized for a dual role of fabrication and functionalization of AgNPs. Optical and physical characterizations were achieved for confirming the biosynthesized AgNPs. SEM images detected quasi-spherical AgNPs of 44.04 to 66.50 nm. Some of potent phytochemicals like flavonoids and proteins from Azadirachta indica formed a strong coating or capping on the AgNPs without affecting their secondary structure by interacting with Ag+ and NPs for the formation of AgNPs. AgNPs exhibited strong antibacterial activity (MIC 10 μg/ml) against multidrug-resistant bacteria Enterococcus faecalis; at different concentrations, no IC50 values were recorded for AgNPs as well as Azadirachta indica signifying low cytotoxicity in the exposed concentration range. The DNA degradation activity of AgNPs through the TUNEL assay revealed no significant increase in the overall FITC mean fluorescence intensity as well as a DNA fragmentation index with 5.45% DNA damage (10 μg/ml AgNPs). Drug uptake of AgNPs was also investigated through a permeability assay via Caco-2 cell lines at test concentrations where apparent permeability was detected as moderate.

Therapeutic applications of nanobiotechnology

“…NPs can disrupt biofilm framework (Fig. 9 ) and microbial structures [ 5 , 11 ]; as leading drug carriers, NPs are competent in delivering drug to target site or tissue, can provide extended permeability and retention (EPR) effect, and induce endocytosis [ 35 , 67 – 71 ]. In our previous article, we had explained and discussed the mechanism of action of MNPs in details [ 11 ].…”

“…1 Nanobiotechnology and its applications. (Parts of the figure reproduced with permission from all the authors) [ 5 , 6 ] …”

“…observed nanoparticles ( d ) are in nanometre size range (44.04 to 66.50 nm). (Reproduced with permission from all the authors) [ 5 ] …”

“…Nanomaterials or nanostructures can be synthesized from inorganic (silica, quantum dots, and metal nanoparticles) or organic (liposomes, micelles, dendrimers, polymeric nanoparticles) materials through physical, chemical, or biological approaches (illustrated in Fig. 3 ) [ 5 , 10 , 11 ]. Based on the applications and biological effects, nanostructures in diverse shapes, sizes, or chemical compositions can be synthesized with the intention of conjugation with drugs of choice, controlled dispersity, target delivery, and functionalization in therapeutics [ 12 , 13 ].…”

“…Due to their unique physio-biochemical properties like surface plasmon resonance (SPR), inorganic NPs, mainly MNPs (Fig. 2 ), have provided some extended applications in drug design and development; SPR is believed to be due to free electrons in outer shell of MNPs and responsible for zeta potential, biological activities, and interface with other charged surfaces or structures like biological cell [ 5 ]. Functionalized-iron oxide NPs carrying anti-cancer drug paclitaxel can yield superparamagnetic as well as receptor-mediated targeting effects [ 14 ].…”