In situ synthesis of silver nanoparticles on the surface of PDMS with high antibacterial activity and biosafety toward an implantable medical device

We developed a straightforward method to fabricate antibacterial silicon films via the in situ synthesis of silver nanoparticles (AgNPs) on a polydimethylsiloxane (PDMS) film. To grow AgNPs attached on the film, AgNP seeds were synthesized through the reduction of silver ions electrostatically bound to hydroxyl groups formed on the surface of the film after treatment with air plasma. In the growth reaction, silver ions were reduced on the seeds of AgNPs by sodium citrate in a solution of AgNO3, which allowed for the formation of AgNPs with sizes of up to ~ 500 nm, which The formed AgNPs on the films were characterized using UV-vis spectrophotometer, scattering electron microscope and induced coupled mass spectrometer. The amount of AgNPs was estimated to be less than 0.05% of the total film weight. Even though it was coated with a small amount of AgNPs, the PDMS film exhibited reduction of E. coli and S. aureus with values of log10 4.8 and log10 5.7, respectively. The biosafety of the AgNP-attached PDMS film was examined by contact of cells with the film or film eluent. Counting of viable cells revealed no significant cytotoxicity of the in situ-fabricated AgNPs on the PDMS film.