PROCESS FOR FUNCTIONALIZATION OF IMPLANTS SURFACE BY USING NANOCOMPOSITIONS WITH COMPLEMENTARY PROPERTIES

The invention relates to an implant structure, to a coating nanocomposite film and to a process for functionalization of implant surface, being meant to be used in the field of medicine. The implant structure, as claimed by the invention, comprises a thin film consisting of a mixture of bioactive glass, biocompatible polymer and a broad-spectrum antibiotic which is deposited by evaporation, using pulsed laser, onto a stainless steel substrate of the type 316L, with the following chemical composition, expressed in weight percentage: 0.013...0.030% C, 0.80...1.73% Mn, 0.3...0.7% Si, 0.019...0.036% P, 0.000...0.006% S, 16.50...17.65% Cr, 10.05...11.27% Ni, 2.00...2.39% Mo, 0.033...0.060% N, 0.21...0.44% Cu and 0.03...0.08% Co or another type of stainless steel. The film, as claimed by the invention, has the following composition: a. bioactive glass which may contain, in mass percentage, 56.5% SiO, 11% NaO, 3% KO, 15% CaO, 8.5% MgO, 6% PO, but also other percentage, b. a biocompatible polymer which may be polymethyl methacrylate or the like, and c. a broad-spectrum antibiotic which may be doxycycline, gentamicin, tetracycline or the like. The process, as claimed by the invention, takes place in an enclosure (1) of stainless steel provided with two vacuum pumps (2), a laser source (3), a cylindrical lens (4) made of MgFwith a focal lenght of 30 cm, for focusing the laser beam, and comprises the following steps: a. preparing the stainless steel substrate (5) by polishing and grinding with abrasive paper, immersing it in sodium hydroxide for 10...30 min at 75°C, treating it with oxalic acid at 85°C and cleaning it in an ultrasonic bath, b. preparing the deposition target (8) by mixing 0.4% bioactive glass, 3% polymer, 0.25% antibiotic, and 19.3 ml of solvent, the mixture being poured into a copper container and frozen at 77°K for 10 min, c. depositing the film with pulsed laser beam at a distance of 4 cm relative to the substrate.