Abstract The paper describes synthesis and testing of novel biodegradable polylactide-based polymer membranes with desired mechanical properties, which are capable of sustained and directed release of biomacromolecules with high molecular weight (in particular, streptokinase; m.w. 47 kDa). Streptokinase is a pharmaceutical agent, possessing a pronounced thrombolytic activity. The membranes synthesized had a percentage elongation of 2–11% and tensile strength of 25–85 MPa. They were biodegradable – yet being stored in aqueous media in the absence of biological objects, would be dissolved by no more than 10% in 6 months. The synthesized membranes were capable of controlled release of streptokinase into the intercellular space, with the enzyme retaining more than 90% of its initial activity. The rate of streptokinase release from the membranes varied from 0.01 to 0.04 mg/day per cm2 of membrane surface. The membrane samples tested in the work did not have any short-term toxic effects on the cells growing de novo on the membrane surface. The mitotic index of those cells was approximately 1.5%, and the number of non-viable cells on the surface of the polymer films did not exceed 3–4% of their total amount. The implantation of the synthesized polymers – as both individual films and coatings of nitinol stents – was not accompanied by any postoperative complications. The subsequent histological examination revealed no abnormalities. Two months after the implantation of polymer films, only traces of polylactide were found in the implant-surrounding tissues. The implantation of stents coated with streptokinase-containing polymers resulted in the formation of a mature and thick connective-tissue capsules. Thus, the polylactide membranes synthesized and tested in this work are biodegradable, possess the necessary mechanical properties and are capable of sustained and directed release of streptokinase macromolecules.

中文翻译：

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基于聚乳酸的支架涂层：可生物降解的聚合物涂层，能够维持溶栓酶链激酶的持续释放

摘要 本文描述了具有所需机械性能的新型可生物降解聚乳酸基聚合物膜的合成和测试，该膜能够持续和定向释放高分子量的生物大分子（特别是链激酶；mw 47 kDa）。链激酶是一种药剂，具有显着的溶栓活性。合成的膜具有 2-11% 的伸长率和 25-85 MPa 的拉伸强度。它们是可生物降解的——但在没有生物物体的情况下储存在水性介质中，在 6 个月内溶解不超过 10%。合成的膜能够将链激酶控制释放到细胞间隙中，酶保持其初始活性的 90% 以上。从膜中释放链激酶的速率为每平方厘米膜表面 0.01 至 0.04 毫克/天。工作中测试的膜样品对膜表面上从头生长的细胞没有任何短期毒性作用。这些细胞的有丝分裂指数约为 1.5%，聚合物薄膜表面的非活细胞数量不超过其总量的 3-4%。合成聚合物的植入——作为单独的薄膜和镍钛诺支架涂层——没有伴随任何术后并发症。随后的组织学检查未发现异常。植入聚合物薄膜两个月后，在植入物周围组织中仅发现微量聚乳酸。涂有含链激酶的聚合物的支架的植入导致成熟且厚的结缔组织囊的形成。因此，在这项工作中合成和测试的聚乳酸膜是可生物降解的，具有必要的机械性能，并且能够持续和定向释放链激酶大分子。