Reinforcement of Interfacial Adhesion of a Coated Polymer Layer on a Cobalt鈥揅hromium Surface for Drug-Eluting Stents

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• 作者：Tarek M. Bedair ; Youngjin Cho ; Tae Jung Kim ; Young Dong Kim ; Bang Ju Park ; Yoon Ki Joung ; Dong Keun Han
• 刊名：Langmuir
• 出版年：2014
• 出版时间：July 15, 2014
• 年：2014
• 卷：30
• 期：27
• 页码：8020-8028
• 全文大小：529K
• ISSN：1520-5827

文摘

During the balloon expansion of several commercially available drug-eluting stents, various types of defects in the polymer layer have been observed. The aim of this study is to prevent these defects by increasing the interfacial adhesion between the metal substrate and the drug-in-polymer matrix using poly(caprolactone) (PCL) brushes onto a cobalt鈥揷hromium (Co鈥揅r or CC) alloy surface. The chemical modification of the Co鈥揅r surface was accomplished by grafting ricinoleic acid (RA) onto the metal substrate followed by surface-initiated ring opening polymerization of 蔚-caprolactone. The unmodified, RA-grafted (CC-RA), and PCL-grafted Co鈥揅r substrates (CC-RA-PCL3D and CC-RA-PCL6D) were characterized by various surface analyses. Poly(d,l-lactide) containing sirolimus was spray coated onto the unmodified and modified substrates. The adhesion property of the polymer coating on the PCL-grafted surfaces was improved compared to those of other samples. Among all of the drug-in-polymer coated samples, both CC-RA-PCL3D and CC-RA-PCL6D exhibited a stabilized drug release profile over 49 days. It was also revealed that CC-RA-PCL6D showed the slowest drug release of all the samples. On the basis of these results, the proposed nanocoupling method has shown not only improved adhesion of the drug-in-polymer matrix to the Co鈥揅r substrate but also controlled drug release.