Fabrication of nanocomposite hydrogels via homogeneous dispersion of bioactive nano particles

Abstract

Development of nanocomposite materials are of tremendous importance due to their novel catalytic, optical, electronic, and strong biocidal effects on different species bacteria. Nanocomposite hydrogel containing bio active metal and metal oxide show excellent antibacterial activity by binding themselves to microbial DNA and preventing bacterial replication. Such types of nanocomposite hydrogel can be direct implication on human or animals injured skin as a coating material to inhibit microbial growth. In this work, silver nanoparticles (AgNPs) have been synthesized using chemical reduction method and incorporate these into polymer network to fabricate silver nanocomposite hydrogels (AgNCHGs) by the simple free radical polymerizations method. N-isopropylacrylamide (NIPA) was used as a thermosensitive monomer and one or more ionic co-monomer from the following acrylamide (AAm), acrylic acid (AAc) and 2-Acrylamido-2-methylpropane sulfonic acid (AMPS) was taken to obtain AgNCHGs. AgNPs were incorporated into hydrogel network via three different routes. In the first case, synthesized hydrogel was immersed into salt of silver nitrate (AgNO3) solution and reduced by sodium borohydride (NaBH4) solution for in situ formation of nanoparticles inside the swollen hydrogel. In the second case, the AgNO3 salt and all gel precursors were mixed together to obtain AgNO3 containing hydrogels which was then reduced by NaBH4 solution to form Ag nanoparticles inside the hydrogel. In the final route, the AgNCHG hydrogel was synthesized by dissolving gel precursors in the prepared nanoparticles dispersion in water. The formation of AgNPs containing different AgNCHGs was characterized by using UV-vis spectrometer, Dynamic Light Scattering (DLS), Field Emission- Scanning Electron Microscope (FE-SEM) and X-ray diffractometer (XRD). The release of bioactive silver nanoparticles from nanocomposite hydrogels was tested by triggering the temperature and pH of the medium. The biocidal and wound healing properties of different nanocomposite hydrogels against bacteria, fungus were compared