Polyether Polyol Derivatives as New Bioconjugate Carriers

Polyether polyol (PEP) is a random copolymer of ethylene glycol (EO) and glycidol. It shares the same characteristics as polyethylene glycol (PEG) for being hydrophilic, water-soluble, flexible, biocompatible and resistant to protein adsorption. The pendant hydroxyl groups (provided by glycidol units) of PEP exists in tunable, multiple number and they provide anchorage points for attachment with therapeutic molecules. To establish PEP as a new class of material for bioconjugation, we have synthesized a series of PEP derivatives. PEP has certain advantages over PEG as a bioconjugation carrier since: 1) the payload is higher; 2) multivalency is possible; 3) delivery of multiple drugs and presentation of multiple biospecific ligands are allowed. To demonstrate these properties with an example, PEP-platinate was synthesized and characterized. The drug solubility was significantly enhanced and controlled release was achieved. The polymeric carrier was non-toxic while the conjugate was cytotoxic against tumor cells both in vitro and in vivo.