[Development and assessment of efficacy of L-polylactide matrix for creation of a tissue-engineered vascular graft]. / Razrabotka i otsenka éffektivnosti matritsy iz L-polilaktida dlia sozdaniia tkaneinzhenernogo sosudistogo implantata.

In order to create a tissue-engineered vascular graft we elaborated a matrix consisting of nanofibres of biodegradable polymer L-polylactide. We worked out the methodology of crystallization of the matrix on a rod, making it possible to manufacture specimens possessing strength and deformity characteristics superior to those of native vessels. This was followed by a series of chronic experiments on implanting the elaborated matrix into the abdominal aorta of rats for the duration of up to 16 months. We obtained satisfactory parameters of the patency of the matrices (71%). According to the findings of histological examination, in the course of time there occurred biodegradation of the matrix and formation of a new vascular wall, with no evidence of either inflammation or neointimal hyperplasia in the zone of the anastomoses. Resorption of the polymeric fibres commenced 12 weeks after exposure and completely terminated after 64 weeks. By that time, both neointima and neoadventitia were formed, whose composition and structure were close to those of the native vessel. Insufficiently high mechanical properties of the zone of reconstruction turned out to be the cause of the formation of aneurysms.

[Composite materials based on chitosan and montmorillonite: prospects for use as a matrix for stem and regenerative cell cultivation].

This paper examines the structural and mechanical properties of composite materials based on chitosan and micro- and nanoparticles of Na-montmorillonite and possibility of application for cultivation and targeted delivery of mesenchymal stem cells and regenerative cells. It's have been shown by addition of Na-montmorillonite biomaterial acquires stability of structural and mechanical properties in the sterilization process the handling of liquid media in cell culture. In vitro studies using dermal fibroblasts and adipose tissue mesenchymal stem cells demonstrated that this material has a set of properties to ensure matrix biocompatibility.