title: Corrosion stability and bioactivity in simulated body fluid of silver/hydroxyapatite and silver/hydroxyapatite/lignin coatings on titanium obtained by electrophoretic deposition.
abstract: Hydroxyapatite is the most suitable biocompatible material for bone implant coatings. However, its brittleness is a major obstacle, and that is why, recently, research focused on creating composites with various biopolymers. In this study, hydroxyapatite coatings were modified with lignin in order to attain corrosion stability and surface porosity that enables osteogenesis. Incorporating silver, well known for its antimicrobial properties, seemed the best strategy for avoiding possible infections. The silver/hydroxyapatite (Ag/HAP) and silver/hydroxyapatite/lignin (Ag/HAP/Lig) coatings were cathaphoretically deposited on titanium from ethanol suspensions, sintered at 900 °C in Ar, and characterized by X-ray diffraction, scanning electron microscopy, field emission scanning electron microscopy, attenuated total reflection Fourier transform infrared, and X-ray photoelectron spectroscopy. The corrosion stability of electrodeposited coatings was evaluated in vitro in Kokubo's simulated body fluid (SBF) at 37 °C using electrochemical impedance spectroscopy. Bioactivity was estimated by immersion in SBF to evaluate the formation of hydroxyapatite on the coating surface. A microcrystalline structure of newly formed plate-shaped carbonate-hydroxyapatite was detected after only 7 days, indicating enhanced bioactive behavior. Both coatings had good corrosion stability during a prolonged immersion time. Among the two, the Ag/HAP/Lig coating had a homogeneous surface, less roughness, and low values of contact angle.
authors.affiliation: Faculty of Technology and Metallurgy, University of Belgrade, Karnegijeva 4, 11000 Belgrade, Serbia.
authors.forename: Sanja
authors.initials: S
authors.lastname: Eraković
authors.forename: Ana
authors.initials: A
authors.lastname: Janković
authors.forename: Djordje
authors.initials: D
authors.lastname: Veljović
authors.forename: Eriks
authors.initials: E
authors.lastname: Palcevskis
authors.forename: Miodrag
authors.initials: M
authors.lastname: Mitrić
authors.forename: Tatjana
authors.initials: T
authors.lastname: Stevanović
authors.forename: Djordje
authors.initials: D
authors.lastname: Janaćković
authors.forename: Vesna
authors.initials: V
authors.lastname: Mišković-Stanković
mesh_terms: D001826:Body Fluids / Q000737:chemistry / Q000378:metabolism; D020099:Coated Materials, Biocompatible / Q000737:chemistry*; D058266:Dielectric Spectroscopy; D017886:Durapatite / Q000737:chemistry*; D004586:Electrophoresis; D008031:Lignin / Q000737:chemistry*; D016062:Porosity; D012834:Silver / Q000737:chemistry*; D013499:Surface Properties; D014025:Titanium / Q000737:chemistry*
chemical_list: D020099:Coated Materials, Biocompatible; D012834:Silver; D008031:Lignin; D017886:Durapatite; D014025:Titanium