Surface properties of fluoropolymer biomaterials modified by radio-frequency magnetron sputtering

We investigated the properties of the multilayer system: metal with polymer layer modified by radio-frequency magnetron sputtering of a solid target made from hydroxyapatite. The material of the polymer layer is thermoplastic copolymer of tetrafluoroethylene with vinylidene fluoride. The roughness parameters and values of the surface potentials of metal, polymer, and hybrid substrates are determined in a semicontact regime using atomic-force microscope. Calcium phosphate coatings increase the roughness of surfaces of polymer and metal materials, thus presenting a stimulating factor for the attachment and proliferation of osteogenic cells. Using the Kelvin method, it is shown that calcium phosphate coatings change the surface potential of substrates. Wettability of the coatings was investigated by the “sit” drop method of the “Krüss Easy Drop” installation by measuring the effective contact angle. The hydrophobic polymer surface becomes hydrophilic after modification.