57 results about "Electron exchange" patented technology

Disclosed is a method for chemically modifying the surface of polytetrafluoroethylene materials, which allows biocompatibility of the materials to be improved. The method comprises the steps of: mixing a hydrogen compound, such as sodium hydroborate, with a cyclic compound, such as anthraquinone or derivatives thereof, in an organic solvent, such as dichloromethane, so as to produce a reactant solution; adding polytetrafluoroethylene materials, such as ePTFE artificial blood vessels, PTFE films or porous PTFE membranes, to the reactant solution; applying heat or ultraviolet energy to the mixture containing the polytetrafluoroethylene materials, so as to remove fluorine from the surface of the polytetrafluoroethylene materials by electron exchange reaction; removing the remaining reactants from the polytetrafluoroethylene materials; and drying the polytetrafluoroethylene materials. The expanded polytetrafluoroethylene artificial blood vessels and the like, whose surface were modified according to the present invention, have a hydrophilic surface changed from a hydrophobic surface, a remarkably reduced fluorine content, and increased cell adhesion. Furthermore, the surface-modified ePTFE artificial blood vessels may be coated with a biodegradable polymer, such as cell adhesion proteins or polylactide, etc. Also, the surface-modified ePTFE films exhibit remarkably increased permeability.