Original Article COMPARATIVE IN VITRO ANTI-BIOFILM EFFICACY OF PHYTOSYNTHESIZED IRON AND SILVER NANOPARTICLES S. GOKUL BRINDHA a , V. S. HANSIYA b , P. UMA MAHESWARI c , N. GEETHA d* a,b,c Research Scholars of Department of Botany, Bharathiar University, Coimbatore 641 046, Tamil Nadu, India, d* Received: 23 Jul 2019, Revised and Accepted: 22 Oct 2019 Faculty of Department of Botany, Bharathiar University, Coimbatore 641 046, Tamil Nadu, India Email: geethadrbot@gmail.com ABSTRACT Objective: The objective of the work was to evaluate the efficacy of anti-biofilm activity of green synthesized silver and iron oxide nanoparticles comparatively. Methods: Nanoparticles were synthesized using a rapid, single-step and completely by a green biosynthetic method employing aqueous leaf extracts of Moringa oleifera Lam. The synthesized nanoparticles were characterized by UV-Vis spectrophotometry and X-Ray Diffraction. Bacterial strains used in this study included Staphylococcus epidermidis and Pseudomonas aeruginosa. The biofilm reduction was evaluated through ring test using crystal violet as a staining agent. Results: Colour change was observed after half an hour, which indicated the formation of silver and iron nanoparticles. Synthesis of nanoparticles was confirmed by UV and XRD. The anti-biofilm forming ability of AgNPs and FeNPs were compared with standard antibiotic. It was found that FeNPs showed more biofilm destruction ability (58%) for S. compared to P. aeruginosa (50%) and standard (30%). Whereas, AgNPs displayed significant biofilm destruction ability (78%) for P. aeruginosa compared to S. epidermidis (43%) and standard (34%). Conclusion: Based on the results obtained in this investigation, it is concluded that FeNPs have anti-biofilm activity against S. epidermidis whereas AgNPs have anti-biofilm activity against P. aeruginosa. Keywords: Anti-biofilm, Silver nanoparticles, Iron nanoparticles, P. aeruginosa, S. epidermidis © 2020 The Authors. Published by Innovare Academic Sciences Pvt Ltd. This is an open-access article under the CC BY license (http://creativecommons.org/licenses/by/4.0/) DOI: http://dx.doi.org/10.22159/ijap.2020v12i1.35047 Journal homepage: https://innovareacademics.in/journals/index.php/ijap INTRODUCTION Medicinal plants have been a primary source of therapeutic agents since ancient times to cure various human diseases. As the phytomedicine is healthier than synthetic products, the discovery of new drugs for various diseases from a natural source is still considered important. Due to the occurrence of therapeutic agents and different compounds, plants are used as medicine in various countries and are the source of many powerful and potent phytomedicines [1]. More than 25% of the approved drugs in the world are prepared from a variety of plant materials as roots, leaves, bark, and stems etc [2]. Using the plants as medicine have greater advantages including low toxicity, long-time oral consumption, low cost, and relatively lower toxicity even at higher dose. Photosynthesis of nanoparticles has contributed for the development of a relatively new and largely unexplored area of research in nanotechnology. At present, there is a growing demand for nanoparticles due to their broad applications in various fields, such as therapeutics, diagnostics, surgical devices and nanomedicine based antimicrobial agents, catalysis and sensor technology in analytical chemistry [3, 4]. However, the development of the simple and eco-friendly process for synthesis of nanomaterials would help in increasing further interest towards the application of metallic nanoparticles. Silver ions and silver-based compounds are toxic to microorganisms and this makes silver an admirable choice for manifold roles in the medical field. Silver is considered as one of the most widespread antimicrobial substances that exhibit low toxicity in human cells and has diverse roles both in in vitro and in vivo applications. Iron oxide has received specific notice because of their diverse scientific and technological applications such as biosensor [5], antimicrobial activity [6], food preservation [7], magnetic storage media, ferrofluids, magnetic resonance imaging, magnetic refrigeration, cell sorting, targeted drug delivery, and hyperthermic cancer treatments [8]. Besides, it has also been widely used in biomedical research because of its biocompatibility and magnetic properties [9]. In recent years, the number of infections coupled with antibiotic- resistant bacteria has increased. Many of these infections are caused by microorganisms growing in biofilms. Both gram-positive and gram-negative bacteria can form biofilms on indwelling medical devices such as catheters, mechanical heart valves and prosthetic joints. The most common biofilm-forming bacteria linked with human diseases Enterococcus faecalis, Staphylococcus aureus, Klebsiella pneumoniae, Staphylococcus epidermidis, Staphylococcus viridans, Proteus mirabilis, Pseudomonas aeruginosa [10]. Iron oxide nanoparticles were synthesized using Lactobacillus fermentum isolates [11]. These nanoparticles had an antibacterial and anti- biofilm effect on coated catheters. Successfully synthesized Fe nanoparticles using the Annona squamosa leaf extract showed their inhibitory effect on Pseudomonas aeruginosa biofilm [12]. The increase biofilm resistance to conventional treatments has forced the need to search for new control strategies [13]. The seek for greener and safer alternatives than antibiotics and chemical preservatives is ongoing, especially in the upcoming context of phytomedicine. Plant-based antimicrobials are widely used on the perception of their safety and long history of their use. Moringa oleifera Lam. is one such plant that has received much publicity for its huge uses. The flavonoids extracted from its seed coat exhibited inhibitive potential as well as disruptive activities against biofilm formation [14]. It has also been for treating against buccal cavity or intestinal lesions inhabiting biofilm-forming pathogenic bacteria [15]. So far, there is no comparative study for the assessment in vitro biofilm efficacy of silver and iron nanoparticles synthesized using Moringa oleifera leaf extract. Therefore, this study was aimed to synthesized and characterize silver and iron nanoparticles and to evaluate the antibiofilm potential of these synthesized nanoparticles using gram-positive bacterium Staphylococcus aureus and gram- negative bacterium Pseudomonas aeruginosa. MATERIALS AND METHODS Chemicals Chemicals such as silver nitrate (AgNO3) and Ferric chloride (FeCl3) International Journal of Applied Pharmaceutics ISSN- 0975-7058 Vol 12, Issue 1, 2020