Blood compatibility has been studied for hydrophilic polymers such as poly(vinyl alcohol) (PVA), its derivative, and polyethylene grafted with water-soluble monomers. The surfaces in contact with electrolyte solutions have been characterized by measuring the zeta potentials. The study of plasma protein adsorption on these polymers has revealed that bovine serum albumin as well as bovine serum fibrinogen adsorbs to a lesser extent as the hydrophilicity of the polymers increases. Platelet deposition and fibrin formation, examined using platelet-rich plasma, have been found to take place less significantly on PVA as well as sodium acrylate- and acrylamide-grafted polyethylene than on nongrafted and acrylic acid-grafted polyethylene. Ex vivo experiments with canine whole blood have shown that formation of thrombus on PVA is less than on siliconized glass but increases upon heat treatment which reduces the hydrophilicity. When PVA tubes of about 1 mm diameter are anastomosed to the carotid artery of rat, the patency rate is found to depend strongly on the anastomotic technique. From the results on the zeta potential and the experiments in vitro and ex vivo it can be concluded that the material having a surface from which solvated, neutral chains are extended into the outer aqueous phase may exhibit excellent resistance to thrombus formation.

In this work we present a simple model for the kinetics of spreading of film-forming liquids on polymer gels. The model is compared with experiments and fair agreement is obtained. The spreading process can be theorized by considering the gel as a thick liquid layer containing a fibrous material (i.e., the polymer network). The spreading theory of Joos and Pintens is extended in such a way that the penetration of the flow into the bulk of the gel—which plays the major role in the kinetics of the spreading—is described by the Debye–Brinkman equation. It is also shown that spreading experiments can provide information on the surface structure of the underlying gel.

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