Abstrakt

The variety of mechanical properties characterizes properly designed PURs. They may be biocompatible and reveal compatibility with blood, making them attractive materials for the fabrication of tissue scaffolds; however, like all synthetic materials, PURs don’t reveal sufficient biocompatibility. PURs may undergo certain chemical modifications (e.g., 1,4:3,6-dianhydro-D-sorbitol, ascorbic acid (AA), growth factors, covering with gelatin, plasma modifications to impart them the bioactivity. In the regeneration of soft and hard tissues, as well as in cardiovascular system regeneration, more common have become the scaffolds - three-dimensional (3D), porous structures, which are biological substitutes enabling for regeneration, maintenance, and improvement of tissues functions representing mechanical properties suitable to support regenerated tissue. Moreover, in specific applications, it is required that such material, after application to the human body, undergo gradual degradation, at a rate directly proportional to the growth of the reconstructed tissue, and the degradation products cannot be harmful and toxic for the system. The tissue scaffolds degradation rate, according to the literature, has to be controlled in a way that the tissue scaffold maintains its physicochemical and mechanical properties for at least 3-6 months. Searching for new materials of described characteristic lead me to undertake the design of new PUR systems, which will be undergoing degradation and at the same time will be biocompatible and of physicochemical, mechanical, and thermal properties suitable for this purpose. In the literature was reported an application of aromatic diisocyanates for PUR synthesis, which are used for the fabrication of tissue scaffolds. Such materials, after long-term in vitro interaction with the living tissues, undergo degradation to the harmful for the living system aromatic diamines. In performed studies, we have applied aliphatic and cycloaliphatic diisocyanates (1,6-hexamethylene diisocyanate (HDI) and 4,4’-methylene bis(cyclohexyl isocyanate) (HMDI), which degradation products (in the living system) are nontoxic amines removable from the system in natural life cycles .In our research we were using an amorphous α,ω-dihydroxy(ethylene-butylene adipate) macrodiol (PEBA) to improve the degradation behavior of PURs and tissue scaffolds fabricated with their use, and we proposed modificators of their biological properties.

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