Synthetic Work and the Development of New Materials

The most actively pursued areas are the design of polymers for drug and enzyme delivery or entrapment, the use of synthetic techniques to modify the blood compatibility of existing materials, and the production of new forms of biodegradable polymer. Hydrogels as a group of polymers still command attention. Various chapters in previously cited symposium collections provide useful illustrations of current trends. 

In the synthesis of polymers with functional groups suitable for drug attachments, hydrophilic hydroxyl-containing polymers and copolymers of divinyl ether and maleic anhydride are commonly used as precursor backbones for further modification. Polyfvinyl alcohol) has also been used in this way, both as the starting point for enzyme immobilization work, sometimes via azido group reactions, and also as a precursor for new membranes of potential interest in the haemodialysis field.  

Surface modification frequently involves hydrogels and the use of coating,  

Kaetsu, M. Kumarkura. and M. Yoshida, BiotechnoL Bioeng., 1979, 21, 847 J. Drobnik, V. Sandek, F. Suek, J. Kalal, V. Vojtisek, and M. Barta, ibid., p. 1317 I. Kaetsu, M. Kumakura, 

Interest continues in the binding of heparin to polymers in an attempt to produce non-thrombogenic surfaces. This has been the aim in the use of glutaralde-hyde-protein complexes as coatings for latex rubber and polyurethanes. Glutaraldehyde has also been used to bind antibodies to partially hydrolysed polyamide surfaces for enzyme-linked radioassay techniques. One of the few examples of direct polymerization (as opposed to surface modification) in an attempt to produce polymers having improved compatibility involves the use of 2-methacryloyloxyethylphosphoryl choline in the formation of homopolymers and copolymers with methyl methacrylate. An isocyanato-urethane methacrylate has been synthesized from 2-hydroxyethyl methacrylate in connection with dental materials research in which the preparation of poly functional monomers for improvement of interfacial bonding with tooth tissue is a topic of some interest. 

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