Construction of Nanophase Novel Coatings-Based Titanium for the Enhancement of Protein Adsorption Sahar A. Fadlallah 1,2 • Mohammed A. Amin 1,3 • Ghaida S. Alosaimi 1 Received: 1 July 2015 / Revised: 12 December 2015 / Published online: 14 March 2016 Ó The Chinese Society for Metals and Springer-Verlag Berlin Heidelberg 2016 Abstract In the recent years, biological nanostructures coatings have been incorporated into orthopedic and dental implants in order to accelerate osseointegration and reducing surgical restrictions. In the present work, chemical etching, anodization and metal doping surface modification methods were integrated in one strategy to fabricate innovative titanium surfaces denominated by titanium nanoporous, anodized titanium nanoporous, silver-anodized titanium nanoporous and gold-anodized titanium nanoporous. The stability properties of nanostructures-coated surfaces were elucidated using electrochemical impedance spec- troscopy (EIS) after 7 days of immersion in simulated biological fluids. Morphology and chemical compositions of new surfaces were characterized by scanning electron microscope and energy-dispersive X-ray analysis. The EIS results and data fitting to the electrical equivalent circuit model demonstrated the influence of adsorption of bovine serum albumin on new surfaces as a function of protein concentration. Adsorption process was described by the very well-known model of the Langmuir adsorption isotherm. The thermodynamic parameter DG ADS (-50 to 59 kJ mol -1 ) is calculated, which supports the instantaneous adsorption of protein from biological fluids to new surfaces and refers to their good biocompatibility. Ultimately, this study explores new surface strategy to gain new implants as a means of improving clinical outcomes of patients undergoing orthopedic surgery. KEY WORDS: Titanium; Nanoporous; Surface modification; Protein adsorption; Electrochemical impedance spectroscopy (EIS) 1 Introduction Titanium and titanium alloys have been broadly employed as implantation materials due to their favorable properties such as lower modulus, good tensile, excellent corrosion resistance and biocompatibility, so they are well suited to be used for orthopedic and dental applications as implants. At an early stage of implantation, titanium and its alloys considered bio-inert and they cannot bond with bone directly because they isolated from the surrounding bone by fibrous tissue, which leads to implant dislocation and premature loosening. Over the last 10 years, the research was directed to improve the titanium surfaces in the nanoscale regime to simulate the natural bone and to be able to demonstrate excellent osseointegration at the bone– implant interface [1–3]. In the recent years, there has been increasing interest in the formation of nanostructures bioactive coating based on titanium by different surface treatment methods, such as acid and alkali treatment [4–6] and electrochemical oxi- dation [7], which will improve osseointegration of titanium implants. The recent reports indicated that high surface Available online at http://link.springer.com/journal/40195 & Sahar A. Fadlallah sahar.fadlallah@yahoo.com 1 Materials and Corrosion Lab (MCL), Department of Chemistry, Faculty of Science, Taif University, Hawiya 888, Saudi Arabia 2 Chemistry Department, Faculty of Science, Cairo University, Cairo, Egypt 3 Chemistry Department, Faculty of Science, Ain Shams University, Abbassia, Cairo 11566, Egypt 123 Acta Metall. Sin. (Engl. Lett.), 2016, 29(3), 243–252 DOI 10.1007/s40195-016-0382-5