Abstract:
A novel kind of redox-responsive amphiphilic polyurethane triblock copolymer, PEG-PU(
SS)-PEG, was designed and synthesized, in which PEG was the hydrophilic polyethylene glycol at both ends of the copolymer chain, and the middle hydrophobic polyurethane block PU(
SS) was prepared from bis(2-hydroxyethyl) disulfide and hexamethylene diisocyanate (HDI) via step-growth polymerization. PEG-PU(
SS)-PEG could self-assemble into stable micelles with the average diameter of about 100 nm through nano-precipitation method in aqueous solution, in which the hydrophilic corona and the hydrophobic cores were composed of PEG and PU(
SS) blocks, respectively. Hydrophobic anti-cancer drugs, such as curcumin, could be loaded into the hydrophobic micellar cores to construct redox-responsive drug nanocarriers with the drug loading content and the drug loading efficiency as high as 22.2% and 71.3%, respectively. Due to the existence of the disulfide linkages in the hydrophobic PU(
SS) blocks, in the presence of glutathione (GSH), the copolymer chains could be triggered to depolymerize, resulting in the disintegration of the nano-micelles and release of loaded curcumin. After being co-incubated with GSH for 6 h, the cumulative release amount of curcumin could reach about 90%. Therefore, PEG-PU(
SS)-PEG was a potential candidate for the fabrication of drug nanocarriers.