[Tissue reaction to implanted polyurethane designed for parts of the artificial heart]

Experiments on producing polyurethane membranes which could be used for elements of an artificial heart have been carried out in Poland for several years. In the Institute of Biocybernetics and Biomedical Engineering PAN in Warsaw two kinds of polyurethanes with symbols PU 47 and PU 90 have been worked out. They differ in physicochemical properties and they were subjected to investigations of tissue reaction in the Institute of Experimental Surgery and of Biomaterials Investigations of the Medical Academy in Wrocław. The investigations were carried out on 70 rats of the Wistar breed and on 30 rabbits of the New Zealand breed. Polyurethane circles were implanted into subcutaneous tissue, to peritoneal cavity and into muscles of the back in rats; polyurethane oars were implanted into muscles of the back along the backbone of the rabbits. Sections of the animals were carried out 3, 7, 14, 28, 90 and 180 days after the surgery taking 5 animals in each term. Macroscopic and microscopic as well as physicomechanical investigations were carried out. The carried out experimental investigations of the both kinds of polyurethanes showed good tolerance of the animals' organisms on the implanted material. Summing up, we can say that the tested polyurethane foils with symbols PU 47 and PU 90 satisfy the basic requirements made on the materials designed for temporal contact with a living organism.