Electrochemical and surface analysis of biofunctionalized anodized zirconium to promote osseointegration

CERE, SILVIA; MARISCOTTI VALENTINA; R. PROCACCINI; A. GOMEZ SANCHEZ; KATUNAR, M.R; TANO DE LA HOZ, MARÍA FLORENCIA

evento on line por COVID

Congreso; 71st Annual ISE Meeting Belgrade Online; 2020

international society of electrochesmistry

Zirconium is a promising candidate for permanent implants both in orthopedic and dental applications due to its capability of promote the growth of new bone tissue with low cytotoxicity and excellent corrosion resistance [1,2]. Zirconium is covered in air or oxygenated media by a thin surface film of zirconium oxide, responsible of its outstanding in vivo and in vitro results [3,4]. Anodization represents an efficient route for surface modification that allows the surface design in the nano and micro scales fundamental for the improving implants performance [5]. In previous works, anodic growth of ZrO2 surface films in phosporic acid resulted beneficial for implant osseointegration due to the modification of the topography and the chemistry of the surface, including P incorporation to the oxide film structure [1,2]. This, in turn, can induce the precipitation of Ca-P compounds on the surface. Furthermore, in vitro and in vivo tests have shown that the surface of ZrO2 created by anodic oxidation at 60 V improves cell proliferation and the integration of the material into bone tissue [2,6]. In the past decade, numerous studies have focused on controlling the interaction between tissue and implanted materials by immobilizing functional biomolecules that could stimulate and interact with the extracellular matrix environment [7-9]. In this work, the effect of functionalization of anodized zirconium with a bioactive peptide (RGD) as potential manufacturing material for osseointegrable implants to stimulate early bone integration is presented. The surface modification was evaluated by surface methods including scanning electron microscopy, Raman spectroscopy, and X-ray photoelectron spectroscopy (XPS). Surface analysis shows the presence of ZrO2 covering the surface. XPS shows the presence of the peptide on the surface after modification. Electrochemical tests were performed in simulated body fluid solution (SBF) in order to determine the effect of functionalization with the organic molecules on the corrosion resistance of anodized zirconium. Anodic polarization curves and electrochemical impedance spectroscopy results indicate that both anodized and functionalized with the RGD peptide surfaces present excellent corrosion resistance in SBF after 24 hours of immersion. EIS results evidences that both surfaces behave as non-ideal capacitors, characteristic of passive films on valve metals. These results demonstrate that the functionalization treatment with RGD peptide does not cause any detrimental effect on the anodic oxide formed on zirconium during anodization.