Preparation and Characterization of Silver Nanoparticle Incorporated Polydimethylsiloxane for Implanted Medical Devices

Synthesis of a silver (Ag) embedded polydimethylsiloxane (PDMS) nanocomposite and a Ag nanoparticle spray-coated PDMS film, to be used in antimicrobial implanted medical devices are demonstrated. A homogeneous mixture was prepared by dissolving the PDMS prepolymer in dicholomethane, to which a solution of silver nitrate in methanol was added, to form the Ag-PDMS nanocomposite. In preparing the silver nanoparticle spray-coated PDMS film, silver nitrate in methanol was sprayed onto semi-cured PDMS. The curing agent crosslinks the polymer and simultaneously reduces Ag ions to form Ag nanoparticles. The release behavior of Ag from both nanocomposite and spray-coated films were analyzed at 12 and 24 hour intervals using Inductively Coupled Plasma Mass Spectrometry. The presence and size of nanoparticles were determined using UV-Visible Spectroscopy and electron microscopy. Antimicrobial studies were performed for Pseudomonas aeruginosa, Staphylococcus aureus and Escherichia coli. The nanocomposite and spray-coated films demonstrated higher inhibition of microbial attachment when compared to pure PDMS, out of which the nanocomposite film showed higher level of inhibition.