Antithrombogenic materials

Blood-compatible polymer materials are required to inhibit both platelet adhesion and coagulation just as the endothelial on the polymer surface. It is known that there are many investigations in the design and the synthesis of socalled antithrombogenic materials. The immobilization of biologically active substances such as heparin [74, 75], urokinase [76], and prostaglandins [77-81] is one of the practical approaches. 

In conclusion, the control of surface microstructure, including the size and distribution of crystalline and amorphous phases, is a promising innovative concept for the molecular design of excellent antithrombogenicity materials with semicrystalline states. 

N. Yui, K. Kataoka, Y. Sakurai, K. Sanui, N. Ogata, A. Takahara, and T. Kajiyama, ESCA study of new antithrombogenic materials Surface chemical composition of polyipropylene oxide) segmented nylon 610 and its blood compatibility, Makromol, Chem., 187 943-953 (1986). 

Y. Mori and S. Nagaoka. A new antithrombogenic material with long polyethylene oxide chains. Trans. Am. Soc. Artif. Intern. Organs 28 459-463 (1982). 

Yui N, Kataoka K, Sakurai Y, Akutsu T (eds) (1986) Microdomain-structured polymers as antithrombogenic materials in artificial heart. Springer, Berlin Heidelberg New York... 

Yui N, Tanaka J, Sanui K and Ogata N (1984) Polyether-segmented polyamides as a new designed antithrombogenic material Microstructure of poly (propylene oxide)-segmented nylon 610, Makromol Chem 185 2259-2267. 

Biomaterials with Low Thrombogenicity. Poly(ethylene oxide) exhibits extraordinary inertness toward most proteins and biological macromolecules. The polymer is therefore used in bulk and surface modification of biomaterials to develop antithrombogenic surfaces for blood contacting materials. Such modified surfaces result in reduced concentrations of ceU adhesion and protein adsorption when compared to the nonmodifted surfaces. 

A new material with good antithrombogenic properties, suitable as biomedical material which assures the endothelialization of the inner surface of a polyurethane tube to imitate the inner wall of a natural blood vessel has been synthesized by blending PVA with polycarbonate urethane)(PCU) [229],... 

As for the effect of anionic group, there are a number of reports dealing with the antithrombogenic behavior of sulfonate-modified surfaces of segmented polyurethane (SPU). An interesting feature of the adsorptive behavior of fibrinogen on these material surfaces will be discussed in Sect. 4.1. 

EFE-immobilized surface may minimize platelet adhesion and activation by preventing fibrinogen from adsorption or by altering the conformation of adsorbed fibrinogen at an early stage of blood contact. The antithrombogenicity increases hydrophilicity of surface on behalf of MAMEC for implantation. Clinical applications of this material to artificial organs could be expected to develop in the near future. 

A layer of adsorbed albumin reduces in vitro platelet adhesion materials that preferentially adsorb albumin will be antithrombogenic in vivo. 

Correlations between Electrochemical and Antithrombogenic Characteristics of Conducting Materials ... 

Fluorosilicone, dimethylsilicone homopolymers, as well as their copolymers, are negatively charged and inhibit the blood clotting reaction. There are a number of polyelectrolytes which have negative zeta potentials and are antithrombogenic. The most promising is the ethylene-acrylic acid copolymer, neutralized to the extent of 60% with sodium ions. Another useful and related material is the vinyl acetate-crotonic acid copolymer. 

---