(667b) Self Sterilizing Polymer Surfaces Based On Silver/Tricalcium Phosphate Nanoparticles

The prevention of microbial surface contamination is a very important issue in today's health care system, in food and pharmaceutical production. Unwanted contamination events cause costly production time out, serious health problems and infections particularly in hospitals. The present contribution shows the development of a novel, transparent plastic film, which can kill bacteria (figure). This strongly antibacterial polymer surface contains 20-50 nm tricalcium phosphate nanoparticles which themselves serve as carriers for 1-2 nm silver particles [1]. Since bacteria need calcium and phosphate for their metabolism, the silver gets released when the calcium phosphate particles are taken up by the micro-organism as nutrition. The antibacterial effect of this triggered mechanism lead to an up to three orders of magnitude higher bacteria killing efficiency compared to conventionally used silver systems. Clinically relevant pathogens such as P. aeruginosa, C. albicans, E. coli were chosen to investigate the antibacterial performance. Figure: Silver nanoparticles are only released from the transparent polymer films when required or stimulated by the presence of microorganism. Scanning transmission electron micrograph of Ag-TCP showing the small 1-2nm silver particles. References: [1] S. Loher, O. D. Schneider, T. Maienfisch, S. Bokorny, W. J. Stark, Small, 2008, 4(6), 824-832.