title: Effect of Sr on the bioactivity and corrosion resistance of nanoporous niobium oxide coating for orthopaedic applications.
abstract: In this study, strontium incorporated Nb2O5 was synthesized in two different proportions by sol-gel methodology and was deposited on 316L SS by spin coating method. The synthesis conditions were optimized to obtain a nanoporous morphology. The prepared Sr-incorporated Nb2O5 coatings were uniform, smooth and well adherent on to the substrate 316L SS. The coatings were characterized by attenuated total reflectance-infrared spectroscopy (ATR-IR), X-ray diffraction analysis (XRD), scanning electron microscopy (SEM), energy dispersive X-ray analysis (EDX), atomic force microscopy (AFM) and transmission electron microscopy (TEM) and the formation of Sr-incorporated Nb2O5 coatings with nanoporous morphology was confirmed. Static water contact angle measurements showed an enhancement in the wettability of the obtained coatings. In vitro bioactivity test of the coated substrates showed that 0.05M Sr-incorporated Nb2O5 coating had better bioactivity compared to 0.1M Sr-incorporated coating. Solution analysis studies confirmed the controlled release of Sr ions from the coating, which aid and enhance hydroxyapatite (HAp) growth. Electrochemical studies confirmed that the coatings provided excellent corrosion protection to the base material as increased charge transfer resistance and decreased double layer capacitance was observed for the coated substrates.
authors.affiliation: Department of Chemistry, Anna University, Chennai 600025, India.
authors.forename: S Anne
authors.initials: SA
authors.lastname: Pauline
authors.affiliation: Department of Chemistry, Anna University, Chennai 600025, India. Electronic address: nrajendran@annauniv.edu.
authors.forename: N
authors.initials: N
authors.lastname: Rajendran
mesh_terms: D000327:Adsorption; D002152:Calorimetry, Differential Scanning; D020099:Coated Materials, Biocompatible / Q000737:chemistry*; D003343:Corrosion; D055664:Electrochemical Techniques; D006244:Hardness; D018625:Microscopy, Atomic Force; D058608:Nanopores / Q000648:ultrastructure; D009556:Niobium / Q000737:chemistry*; D009985:Orthopedics / Q000379:methods*; D010087:Oxides / Q000737:chemistry*; D012996:Solutions; D013052:Spectrometry, X-Ray Emission; D013054:Spectrophotometry, Atomic; D013193:Stainless Steel / Q000737:chemistry; D013324:Strontium / Q000737:chemistry*; D013818:Thermogravimetry; D017155:Wettability; D014961:X-Ray Diffraction
chemical_list: D020099:Coated Materials, Biocompatible; D010087:Oxides; D012996:Solutions; D009556:Niobium; D013193:Stainless Steel; C073337:niobium pentoxide; D013324:Strontium
keywords: Electrochemical impedance spectroscopy; Implants; Nanostructures; Niobium oxide; Polarization; Strontium