[Physico-chemical and biological studies of plastic materials intended for long-term contact with blood].

The criteria used presently for evaluating the materials for haemotherapy, which are based on chemical, physicochemical and biological extracts of aqueous solutions have been found to differ from the results observed after actual prolonged contact of these materials with blood and its elements. All the investigated plastic materials complied with the required quality standards, and, despite this, some of them, such as natural latex or siliconized rubber, caused considerable adhesion of proteins, release of high amounts of haemoglobin from the erythrocytes, and have been found even most thrombogenic of all 8 plastic materials tested. Investigations by means of scanning microscopy demonstrated that adhesion of fibrinogen and thrombocytes to the surface of the plastic materials depended to a high extent on the smoothness of this surface. It depended also on migration of components specific for each material. This was also the cause of variations in the adsorption of albumin, globulin, and fibrinogen labelled with 125I after their mixing with plasma.