We report the synthesis of a novel heat shock www.selleckchem.com/products/ag-1478-tyrphostin-ag-1478.html protein 90 (hsp90) inhibitor conjugated to a star polymer. Making use of reversible addition-fragmentation chain-transfer (RAFT) polymerization, we prepared star polymers comprising PEG connected to a predesigned functional core. The stars were cross-linked employing disulfide PAK3 linkers, plus a tagged version of our hsp90 inhibitor was conjugated towards the polymer core to create nanoparticles (14 nm). Dynamic light scattering showed the nanoparticles have been stable in cell growth media for 5 days, and high-performance liquid chromatography (HPLC) analysis of compound-release at 3 different pH values showed that release was pH dependent. Cell cytotoxicity studies and confocal microscopy verify that our hsp90 inhibitor was delivered to cells employing this nanoparticle delivery system. Further, delivery of our hsp90 inhibitor making use of star polymerkinase inhibitor Nutlin-3 induces apoptosis by a caspase 3-dependent pathway. These studies display that we can provide our hsp90 inhibitor effectively working with star polymers and induce apoptosis through the exact same pathway as the mother or father compound.