www.ejpmr.com Sharique et al. European Journal of Pharmaceutical and Medical Research 261 GREEN NANOTECHNOLOGY A BOON IN SILVER NANOPARTICLE (AgNPs) SYNTHESIS- CERTAIN ASPECTS OF AgNPs BIOMEDICAL APPLICATIONS AND AN OUTLINE OF ITS TOXICOLOGICAL IMPACTS - A MINIREVIEW Shazia Khan, Dr. Ayesha S. Ali and Dr. Sharique A. Ali* Department of Biotechnology and Bioscience, Saifia Science College, Bhopal, MP- India. Article Received on 23/07/2020 Article Revised on 13/08/2020 Article Accepted on 03/09/2020 BACKGROUND Nanotechnology has become one of the most important technologies in the area of science, which deals with the manufacture, manipulation, and application of structures by controlling shape and size at nanoscale. [1] Nanomaterials have been used unknowingly for thousands of years and Silver has been known, for more than 4000 B.C.E. for its antimicrobial applications. Persian kings insisted on drinking water only out of silver vessels, for their ability to preserve fresh water. In 1800s Silver nitrate was used for the treatment of ulcerations and infected wounds and to prevent gonococcal ophthalmic infections in newborns and was ingested for the treatment of stomach ulcers. Doctors used silver sutures and wire, silver wire was used to close vesicovaginal fistulae in post-partum women when closure with silk sutures had failed. [2] Prior the discovery of antibiotics silver leaf were used to treat infections during world war I, colloidal silver was used in hospitals as an bactericidal agent for at least 1200 years. [3] The silver in its ionic form is noxious for the micro- organisms and therefore having multiple applications in medical field. [4] Silver in its nitrate form induces strong antimicrobial effect but when silver nanoparticles (AgNPs) are used the surface area exposed to different types of microbes increases substantially. [5] The attractive and unique physiochemical properties of nano silver makes them more effective and highly in demand for infinite use in various fields. The distinctive feature of AgNPs is that they do not induce modification on living cells and, so, are unable to cause microbial resistance. Literature review give an insight of applications of silver nanoparticles in medicine, agriculture, biosensors, cosmetics, food preservation, water purification, energy generation, antimicrobial activities, targeted drug delivery, etc. Usually silver nanoparticles that are used are of 1–100 nm size which was synthesized by two approaches “Top- down” and “Bottom-up”. In “Top-down” approach bulk material breaks down into fine particles by size reduction method using various techniques like Pulse laser ablation, evaporation–condensation, ball milling, sputtering, pulse wire discharge method etc. In “Bottom- up” approach atoms combines and grow into particle of nanoscale by chemical & biological method. Various chemical methods are used for the fabrication of nanostructure materials such as controlled precipitation, sol–gel synthesis, hydrothermal reactions, sonochemical SJIF Impact Factor 6.222 Review Article ISSN 2394-3211 EJPMR EUROPEAN JOURNAL OF PHARMACEUTICAL AND MEDICAL RESEARCH www.ejpmr.com ejpmr, 2020,7(10), 261-273 ABSTRACT Silver nanoparticles due to its vast applications in medical and physiochemical field have received global attention. Earlier they were synthesized by chemical and physical methods which due to their shortcoming are replaced by green synthesis using microorganisms and plants. Green nanotechnology has made the synthesis of nanoparticles cost effective, hazard free, faster and eco-friendly. Silver is used as an antimicrobial agent since long back; with the advent of antibiotics there use was decreased. Due to the rise in drug resistance, the scientists are focusing on the use of silver due to its oligodynamic action with antibiotics/drugs to enhance their efficacy. Apart from this due to its antimicrobial activity it is used in stents, catheters, orthodontic and orthodontic implants, water purification systems, cosmetics, agriculture, paints etc. It is expected that the use of silver nanoparticles will escalate in future due to its various antimicrobial properties which indicate huge production and usage of silver nanoparticles. This large scale production and usage will lead to toxicological impacts on the humans, animals and environment; the area that still needs exhaustive research. In this review paper we are exploring the potential of different biological sources for green synthesis of silver nanoparticle, their applications and outline the toxicological effects of excessive use of silver nanoparticles in future. KEYWORDS: nanotechnology, nanoparticles, silver, microorganisms, green synthesis, toxicity. *Corresponding Author: Dr. Sharique A. Ali Department of Biotechnology and Bioscience, Saifia Science College, Bhopal, MP- India.