Electrochemically deposited poly(ethylene glycol)-based sol–gel thin films on stainless steel stents

Poly(ethylene glycol) (PEG) was modified with 3-isocyanatopropyltriethoxysilane (IPTS) to obtain PEG-disilane. This monomer was electrochemically polymerized and deposited onto a stainless steel surface to form a thin PEGylated sol–gel film. The monomer was characterized by 1H-NMR and FTIR spectroscopy. The sol–gel film was characterized by absorption–reflection infrared spectroscopy (AR-FTIR), energy dispersive X-ray analysis (EDX), cyclic voltammetry (CV), profilometry, scanning electron microscopy (SEM) and potentiodynamic polarization. AR-FTIR confirmed the formation of a polymer, while the stability of the polymeric film on stainless steel in buffer phosphate was studied by scanning electron microscopy (SEM). The polymer was successfully electrodeposited onto 316L coronary stents. Its flexibility was examined by dilating the coated stents and inspecting it by SEM. The hydrophilic, smooth PEGylated sol–gel coating significantly reduced the activation and adhesion of platelets as compared with the bare stainless steel surface. This coating, which can be applied to complex geometries, such as stents, is likely to serve as an excellent biomaterial.