Huan Zhiguang, Fratila-Apachitei Lidy E, Apachitei Iulian, Duszczyk Jurek
Department of BioMechanical Engineering, Delft University of Technology, Mekelweg 2, Delft 2628 CD, The Netherlands.
J Funct Biomater. 2012 May 11;3(2):349-60. doi: 10.3390/jfb3020349.
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.
在本研究中，通过结合钛磁控溅射和等离子体电解氧化（PEO）在316L不锈钢（SS）表面形成了多孔氧化层，目的是制备一种用于药物洗脱支架（DES）应用的无聚合物药物载体。氧化过程在Na3PO4电解液中恒电流进行。表面孔隙率、平均孔径和粗糙度随PEO处理时间而变化，在最佳条件下，表面孔隙率为7.43%，平均孔径为0.44 µm，粗糙度（Ra）为0.34 µm。能谱分析表明，多孔层由Ti、O和P组成。横截面形态显示为双层结构，表面是多孔二氧化钛，与316L SS界面处是未氧化的致密钛膜。PEO处理后，润湿性和表面自由能显著增加。本研究结果证实了通过溅射技术和PEO在不锈钢上形成多孔TiO2层的可行性。此外，所得的多孔氧化层有潜力用作DES的药物载体，从而避免与基于聚合物的载体相关的并发症。
