Polymeric carriers of drugs from site-specific therapy

Three types of water-soluble polymeric drug carrier systems facilitating targeted drug delivery and controlled drug release were synthesized. All systems consist of an inert soluble synthetic polymer, drug and homing device (targeting moiety). In the first ''classical'' system, both drug and targeting moiety are bound to a nondegradable polymer by means of biodegradable oligopeptide side chains statistically distributed along the polymer chain. The second, ''star-like'' system contains a targeting moiety (antibody) in the centre and a hydrophilic polymer, bearing drug molecules, in the shell of the system. The third, ''biodegradable'' carrier system is based on block copolymers of poly(ethylene glycol) containing biodegradable oligopeptide sequences both in the main polymer chain and in the spacers between main chain and drug molecules. Strategy and details of the synthesis of all three systems are given.