Bedair Tarek M, Cho Youngjin, Kim Tae Jung, Kim Young Dong, Park Bang Ju, Joung Yoon Ki, Han Dong Keun
Center for Biomaterials, Biomedical Research Institute, Korea Institute of Science and Technology , Hwarangno 14-gil 5, Seongbuk-gu, Seoul 136-791, Republic of Korea.
Langmuir. 2014 Jul 15;30(27):8020-8. doi: 10.1021/la501990p. Epub 2014 Jul 3.
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-chromium (Co-Cr or CC) alloy surface. The chemical modification of the Co-Cr surface was accomplished by grafting ricinoleic acid (RA) onto the metal substrate followed by surface-initiated ring opening polymerization of ε-caprolactone. The unmodified, RA-grafted (CC-RA), and PCL-grafted Co-Cr 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-Cr substrate but also controlled drug release.
在几种市售药物洗脱支架的球囊扩张过程中，已观察到聚合物层中存在各种类型的缺陷。本研究的目的是通过在钴铬（Co-Cr或CC）合金表面使用聚己内酯（PCL）刷来增加金属基底与聚合物基质中药物之间的界面粘附力，从而防止这些缺陷。通过将蓖麻油酸（RA）接枝到金属基底上，然后进行ε-己内酯的表面引发开环聚合，实现了Co-Cr表面的化学改性。通过各种表面分析对未改性的、接枝了RA的（CC-RA）和接枝了PCL的Co-Cr基底（CC-RA-PCL3D和CC-RA-PCL6D）进行了表征。将含有西罗莫司的聚（d，l-丙交酯）喷涂到未改性和改性的基底上。与其他样品相比，聚合物涂层在接枝了PCL的表面上的粘附性能得到了改善。在所有聚合物包载药物的样品中，CC-RA-PCL3D和CC-RA-PCL6D在49天内均表现出稳定的药物释放曲线。还发现CC-RA-PCL6D在所有样品中药物释放最慢。基于这些结果，所提出的纳米偶联方法不仅显示出聚合物基质中药物与Co-Cr基底之间的粘附力得到改善，而且还实现了药物释放的控制。
