Structure and properties of synthetic polymers of pharmacological and biomedical interest

Abstract

Some recent results obtained on synthetic or semisynthetic polymers of biomedical and pharmacological interest are reported. Studies on biomedical polymers are centered on poly(amido-amines). These are regular polymers able in several cases to give stable complexes with heparin. Block and graft copolymers of poly(amido-amines) with conventional polymers, such as polystyrene and polyethylene, have been prepared. These new materials can be heparinized, and in this form they acquire non-thrombogenic properties. The same poly(amido-amines) can be grafted on glass, and on silicone rubber, considerably increasing their thromboresistant properties after heparinization. Studies on pharmacologically active polymers are mainly concerned with oligomeric or polymeric derivatives of drugs. In these derivatives, non-macromolecular active substances are linked to oligomeric or polymeric matrices by means of covalent bonds of limited stability to biological environments. A dramatic improvement, as far as the duration of activity, and in some cases the lowering of unfavourable side-effects are concerned, was achieved in the case of nicotinic acid, and of some antiinflammatory drugs.