Potential induced pH change: Towards electrochemical coating of medical implants by organic nanoparticles

The electrochemical deposition of organic nanoparticles on conducting surface, such as a coronary stents, in the absence of a polymeric matrix is demonstrated. A novel approach, whereby pH-responsive organic nanoparticles coagulate on a conducting surface as a result of applying positive potential, has been studied. Specifically, latex nanoparticles stabilized by sodium oleate in aqueous solutions were deposited by applying a positive potential that oxidized the water and caused the decrease of pH on various conducting surfaces. It was found that the applied potential, its duration and the concentration of the dispersed nanoparticles govern the deposition characteristics of the coating.This generic approach allows coating objects with complex geometries with thickness ranging from nanometers to microns and therefore can be utilized for coating medical and other devices as well as for controlling drug release.