PEG-COATED NANOSPHERES FROM AMPHIPHILIC DIBLOCK AND MULTIBLOCK COPOLYMERS - INVESTIGATION OF THEIR DRUG ENCAPSULATION AND RELEASE CHARACTERISTICS

The development of long-circulating carriers capable of continuously d elivering drugs intravenously provides a potential approach to achieve targeting of drugs to specific sites of action. In this research, pol yethylene glycol (PEG)-coated nanospheres were prepared in a single st ep process using amphiphilic diblock and multiblock copolymers, and th eir drug encapsulation properties and release characteristics were inv estigated in vitro, The results obtained indicate that the parameters controlling drug release characteristics of these nanospheres are the chemical composition of their hydrophobic core (i.e. polyester or poly anhydride), as well as the molecular weight and surface density of the ir hydrophilic (i.e. PEG) chains.