PREPARATION, CHARACTERIZATION AND ANTIBACTERIAL ACTIVITY OF CHITOSAN-SILVER NANOPARTICLE BY GREEN APPROACH

Abstract

The concept of treating an infected wound has been addressed for centuries, long before the knowledge of microbes was known to human. A wide range of attributes such as spider web, seaweed, honey, leaches etc. has been used in the past decades. Also, nobel metals have been used to fight various pathogens of wounds. Historically, silver (Ag) has been used in the field for long but it gained ground as an antiseptic in 1960’s. A wide range of silver wound dressings has been introduced since then. A Silver based dressing functions through the release of silver ions (Ag+) from elemental silver or silver compounds incorporated into the dressing. Silver ions (Ag+) then act as an antimicrobial agent by binding to the walls and DNA of the cells, thus interfering with cell division and replication. The presence of moisture is a prerequisite for Ag+ to be released. For this reason most test methods in the field involve completely wetting of products prior to measuring antimicrobial effects. Chitosan and silver nanoparticles (AgNPs) have shown wound healing properties individually and combination of both of these two may show improvement in wound healing activity. Thus, the composite films prepared in this project were evaluated for various in vitro evaluation tests. The AgNPs films have shown a significant difference in water absorption capacity and antibacterial activity as compared to the blank films. The aim of this project work is to study and investigate properties and characteristics of chitosan-silver nanocomposite film. The chitosan-silver nanocomposite films were prepared by mixing silver nitrate (AgNO3) with distilled water and acetic acid to prepare a 100 ml solution. Different concentrations of AgNO3, viz., 0%, 2%, 3% were prepared in 100ml of aqueous chitosan solution. The different mixtures were then poured into separate petri dishes and kept aside for cooling. A thin layer of Chitosan-silver nanocompositefilm was formed and extracted from the petri dish. These composite films were then characterized by Scanning electron microscopy (SEM), X-ray diffraction (XRD), Universal testing machine (UTM), and Fourier transform infrared (FTIR) spectroscopy techniques. Further, the water absorption and antimicrobial properties of the composite films were subsequently studied and reported in the present work.