Vol 10, Issue 5, 2017 Online - 2455-3891 Print - 0974-2441 BIOLOGICAL SYNTHESIS OF NANOPARTICLES FROM MEDICINAL PLANTS AND ITS USES IN INHIBITING BIOFILM FORMATION HARSHITA AGARWAL, MAHALINGAM GAYATHRI* Department of Biotechnology, School of Bioscience and Technology, VIT University, Vellore - 632 014, Tamil Nadu, India. Email: gayathrigopinath@vit.ac.in Received: 03 February 2017, Revised and Accepted: 01 March 2017 ABSTRACT Pathogenic micro-organisms have become the main problem in today’s world. All microbes are getting resistant to antibiotics. This is due to the formation of biofilm layer above the micro-organisms. Learning the characteristics of biofilm can help us in treating the infectious disease induced via micro-organisms. They affect human’s life in some or the other way. For example, the plaque formed in our teeth that cause tooth decay is due to the bacterial biofilm. When micro-organisms stick to moist or wet surfaces, it produces glue-like, slimy contents which are known as biofilms. Biofilms belong to the sessile communities, communities in which organisms are considered as immobile. Biofilms are enclosed within a matrix, known as extracellular polymeric matrix, which are secreted by micro-organisms. Biofilms attached to the surfaces are affected by certain characteristics like the growth medium, substratum to which it is attached and cellular surfaces. Each of these factors can either increase or decrease the hold of biofilm on the surfaces. With the help of biofilms, micro-organisms protect themselves from antibiotics and cause various infectious disease. Recent studies had proved medicinal plants to be effective in treating disease caused by microbes. Medicinal plants produce active compounds during secondary metabolism which help in the treatment of infectious disease. The problem that arises with antibiotics is that they are unable to penetrate through the biofilm. This problem is solved by converting antibiotics in nanoparticle size. Nanoparticles have high penetrating ability than the antibiotics. They help in controlling microbial growth by killing them. Keywords: Medicinal plants, Nanoparticles, Biofilm. INTRODUCTION Micro-organisms have developed resistance against antibiotics with the help of biofilms. Biofilms formed by micro-organisms, covers the microbes which prevent the passage of antibiotics and interferes with the interaction between antibiotics and micro-organisms. Biofilms are formed when micro-organisms get attached to the moist surface. After coming in contact to the moist surface, it produces gel-like, slimy substances. Micro-organisms encapsulate themselves in this slimy layer, which is known as biofilm. It is made up of extracellular polymeric matrix, produced by micro-organisms [3]. The lifestyle of micro-organisms changes completely on the formation of biofilm. The physiological changes have been observed in the microbes with the formation of biofilms. Biofilms increase the life span of micro-organisms. It also increases the microbial growth rate. Micro-organisms enter inside the host and combat its innate immune defense system with the help of biofilm [8]. Hence, biofilm increases the persistence period of micro- organisms inside the host. Biofilm has the complex structure which reduces the attacking ability of antibiotics. It protects micro-organisms from the attack of antibiotics as it does not allow antibiotics to reach microbial surface [11]. Experiments have been performed which shows that Staphylococcus aureus has become resistant to methicillin as it is covered by biofilms [1]. Polysaccharides, such as silica acid, help in protecting micro-organisms by inhibiting the attack of neutrophils toward microbes. Thus, pathogens which were once considered as extracellular are converted into intracellular with the help of biofilm. It helps microbes to penetrate inside the host [10] (Figs. 1 and 2). Therapeutics plants have the rich assets of ingredients which are utilized for the development of drugs. There are 8000 species of plants in India which are designated as medicinal plants. Medicinal plants have proved to be the best for the treatment of disease [2]. During secondary metabolism, medicinal plants secrete active compounds which have been helpful in treating infectious disease. Medicinal plants have been used for the extraction, synthesis, and development of drugs. Extracts of methanol and ethanol from the medicinal plants have been studied and it has proved to be effective in treating biofilm and thus, the pathogens [16]. The objective of most of the conventional treatment is to kill or repress the growth of micro-organisms. Continuous exposures to these treatments make micro-organisms resistant toward them. This method affects pathogenic microbes only for a limited period. It has been observed that many pathogenic micro-organisms start developing resistant against such treatment after certain period [9]. It is because of the virulent factor that they produce during the treatment which makes them resistant. One such virulent factor is biofilm. Biofilm helps bacteria in fighting against the antibiotics treatment and immune system response. Thin, slimy layers of microbes that occur in moist environment are considered as biofilms. Biofilms are impermeable in nature which prevents the passage of antibiotics into the microbes. It has become important to develop new methods or medicines to treat micro-organisms that cause infectious disease. Nanotechnology has proved to be a standout among the most dynamic regions of research and development in advanced medical science. Nanoparticle is the most essential part of nanotechnology. It has proved to be effective in treating many diseases [5]. Nanoparticles are made up of both natural and inorganic materials. Nanoparticles made up from these materials have antibiofilm and antibacterial properties. Experiments have been performed and it has been proved that these nanoparticles can be used for the development of drugs which can be used for the treatment of biofilms. This proves that nanoparticle has different mechanisms to control biofilm growth and also different strategies to stop microbial growth and kill them. When the biofilms are treated with nanoparticles, it gets destroyed [20]. The interaction between nanoparticle and biofilm are as follows: • Nanoparticle is transferred to the biofilm surface • Nanoparticle gets attached to the surface © 2017 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/ajpcr.2017.v10i5.17469 Review Article