Polyacetal and poly(ortho ester)-poly(ethylene glycol) graft copolymer thermogels: preparation, hydrolysis and FITC-BSA release studies.

Graft copolymers comprised of a polyacetal backbone with pendant poly(ethylene glycol) side-chains were prepared using a condensation reaction between a divinyl ethers, a diol and Fmoc-protected serinol, followed by deprotecting the amine and reacting the polyacetal with pendant amino groups with PEG-alpha-methoxy-omega-succimidylcarbonate. A series of materials having lower critical solution temperature (LCST) between 25 and 60 degrees C has been prepared. Since LCST is determined by the hydrophilic-hydrophobic balance, and this in turn is determined by the molecular weight of the polyacetal backbone, the molecular weight of the grafted PEG and the amount grafted, materials having a desired LCST could be readily prepared.