This journal is © The Royal Society of Chemistry 2019 J. Mater. Chem. B Cite this: DOI: 10.1039/c9tb01287g The effect of hybrid coatings based on hydrogel, biopolymer and inorganic components on the corrosion behavior of titanium bone implants† Mariia Saveleva, * ab Alina Vladescu, cd Cosmin Cotrut, de Louis Van der Meeren, a Maria Surmeneva, d Roman Surmenev, d Bogdan Parakhonskiy * a and Andre G. Skirtach a Modification of titanium (Ti) bone implant materials with hybrid organic–inorganic coatings is a novel promising approach to improve the osteoconductivity and osteointegration of implants and prevent their failure after implantation. However, in these coatings, which are mostly hydrophilic, chemically active moieties capable of releasing oxidizing ions can have a significant influence on the corrosion resistance of Ti, which is critical for the Ti implant osteointegration behavior. In this research, in order to study the dependence of the change of the corrosion behavior of Ti on the composition of the coating, Ti surfaces were modified with various coatings: organic (alginate hydrogel crosslinked with Ca 2+ ions (Alg), and dextran sulfate (DS)), inorganic (porous calcium carbonate CaCO 3 ), and composite organic– inorganic (Alg-CaCO 3 , DS-CaCO 3 ). The morphology and composition of these materials before and after the corrosion experiment, performed in simulated body fluid (SBF), were followed by extensive charac- terization. Electrochemical impedance spectroscopy (EIS) was performed to study the corrosion behavior of the prepared materials in SBF. The characteristics obtained during the EIS measurements revealed the dependence of the variation of the corrosion resistance level on the composition of the coating. The bare Ti surface had the higher value of the total impedance compared with the modified surfaces, while the Ti surfaces modified with organic coatings demonstrated the best charge transfer resistance in comparison with the coatings containing the inorganic CaCO 3 component and uncoated Ti. Introduction Titanium (Ti) is one of the most widely used materials for orthopaedic implants manufacturing and bone defects recovering due to its biocompatibility, remarkable mechanical properties and high corrosion resistance. The good osteointegration of Ti along with its inertness provides the long-lasting stability of a Ti implant, including protection against degradation and inflammation at the bone–implant interface. 1 The new knowl- edge accumulated in the last decades on biological and physical–chemical aspects regarding the living tissue reactions with artificial materials, and regenerative and immunological processes, as well as continuous searching for and designing new bioinspired materials and techniques, encouraged the development of a new-generation of bioactive implants. These materials are foreseen to be capable of active interaction with the physiological environment in the surrounding tissues, which will improve osteointegration of an implant by stimulating osteogenesis and recovery of bone. 1 Regarding the design of new improved Ti implants, special attention is paid to the develop- ment of the Ti surface, which interacts with the surrounding biological environment. Modern methods of Ti surface proces- sing include: (i) to modify the surface topography of Ti in order to increase the surface roughness; and (ii) to deposit functional coatings on the Ti surface. The roughness of the implant surface strongly affects the adhesion of biomolecules and cells and cell colonization of the implant surface. 2 The Ti surface can be structured by chemical etching, 3 electrochemical oxidation, 4 electro- phoretic deposition, 5 and abrasive techniques (sandblasting). 6 a Department of Biotechnology, Faculty of Bioscience Engineering, Ghent University, Coupure Links 653, 9000 Ghent, Belgium. E-mail: bogdan.parakhonskiy@ugent.be b Educational and Research Institute of Nanostructures and Biosystem, Saratov State University, Astrakhanskaya 83, Saratov 410026, Russia. E-mail: mssaveleva@yandex.ru c National Institute of Research and Development for Optoelectronics – INOE 2000, Department for Advanced Surface Processing and Analysis by Vacuum Technologies, 409 Atomistilor St., 077125 Magurele, Romania d Physical Materials Science and Composite Materials Centre, Tomsk Polytechnic University, Lenin’s Avenue, 30, Tomsk, 634050, Russia e Faculty of Materials and Science Engineering, University Politehnica of Bucharest, Splaiul Independent -ei 313, 060042, Bucharest, Romania † Electronic supplementary information (ESI) available. See DOI: 10.1039/ c9tb01287g Received 26th June 2019, Accepted 23rd September 2019 DOI: 10.1039/c9tb01287g rsc.li/materials-b Journal of Materials Chemistry B PAPER Published on 24 September 2019. Downloaded by Saratov State University on 10/15/2019 8:42:36 AM. View Article Online View Journal