Integrated PLGA-Ag nanocomposite systems to control the degradation rate and antibacterial properties

Biodegradable polymer based nanocomposite materials have attracted much attention since they can be used for biomedical and pharmaceutical applications. In order to have highly integrated PLGA nanocomposite materials, silver colloidal nanoparticles were prepd. in chloroform starting from silver nitrate and using polyvinylpyrrolidone as redn. and capping agent. TEM and AFM imaging give information on the size distribution of the silver nucleus (7.0 nm) and the capping shell (8.2-10.7 nm). PLGA-Ag nanocomposites were prepd. upon addn. of 1 or 3% wt. of silver nanoparticles to the PLGA/chloroform suspension. The effect of silver loading on polymer degrdn. was studied following the mass loss and the morphol. of nanocomposite films at different degrdn. stages. The concns. of Ag+, which is released during nanocomposite degrdn., were monitored and analyzed through the diffusion model, to have insight on the degrdn. kinetics. The release rate, and likely the degrdn. rate, was reduced at higher silver loading. Bacterial growth tests indicated that the cell growth is inhibited in the presence of PLGA-Ag nanocomposites and the efficiency is correlated to Ag+ release. Thus, controlling the nanoparticle loading, a tunable degrdn. and antibacterial action can be designed.