Characterization of Porous TiO2 Surfaces Formed on 316L Stainless Steel by Plasma Electrolytic Oxidation for Stent Applications

Journal of Functional Biomaterials

Zhiguang Huan²  Lidy E. Fratila-Apachitei¹  Iulian Apachitei² 

[1] Department of BioMechanical Engineering, Delft University of Technology, Mekelweg 2, Delft 2628 CD, The Netherlands;

关键词: drug eluting stent;    plasma electrolytic oxidation;    titanium oxide layer;    stainless steel;    surface porosity;   

DOI  :  10.3390/jfb3020349

来源: mdpi

【 摘 要 】

In this study, a porous oxide layer was formed on the surface of 316L stainless steel (SS) by combining Ti magnetron sputtering and plasma electrolytic oxidation (PEO) with the aim to produce a polymer-free drug carrier for drug eluting stent (DES) applications. The oxidation was performed galvanostatically in Na₃PO₄ electrolyte. The surface porosity, average pore size and roughness varied with PEO treatment duration, and under optimum conditions, the surface showed a porosity of 7.43%, an average pore size of 0.44 µm and a roughness (Ra) of 0.34 µm. The EDS analyses revealed that the porous layer consisted of Ti, O and P. The cross-sectional morphology evidenced a double-layer structure, with a porous titania surface and an un-oxidized dense Ti film towards the interface with 316L SS. After the PEO treatment, wettability and surface free energy increased significantly. The results of the present study confirm the feasibility of forming a porous TiO₂ layer on stainless steel by combining sputtering technology and PEO. Further, the resultant porous oxide layer has the potential to be used as a drug carrier for DES, thus avoiding the complications associated with the polymer based carriers.

【 授权许可】

CC BY   
© 2012 by the authors; licensee MDPI, Basel, Switzerland.