Smart drug carrier based on polyurethane material for enhanced and controlled DOX release triggered by redox stimulus

A series of amphiphilic polymer mPEG-PUSS-mPEG were developed by a combination of ring opening polymerization (ROP) and polyaddition reaction and its self-assembled micelles were developed for hydrophobic anticancer drugs delivery. Polymeric critical micellar concentration (CMC) values in aqueous solution were about 2.8-5.5 mg/L. And the partition equilibrium constant (K-v) of pyrene in micellar solutions ranged from 1.52 x 10(5) to 2.20 x 10(5). The average sizes of the self-assembled blank and DOX-loaded micelles were 160-180 nm determined by dynamic light scattering (DLS). The morphology of the DOX-loaded micelles was spherical by transmission electron microscopy (TEM) and scanning electron microscopy (SEM).The in vitro drug release behaviors of DOX and PTX from mPEG-PUSS-mPEG micelles were investigated at different simulated conditions. We found that the PTX release was significantly accelerated by redox stimuli compared with DOX-loaded reduction-sensitive PU micelles. The change of the size of this system under different conditions was further evaluated by DLS. DOX-loaded mPEG-PUSS-mPEG micelles in 50% fetal bovine serum (FBS) were evaluated the hemocompatibility. In addition, the self-assembly process of polymers mPEG-PUSS-mPEG in aqueous solution for micellar formation was also investigated by means of dissipative particle dynamics (DPD) simulations. AndCCK-8 assays revealed that the mPEG-PUSS-mPEG materials had low toxicity, but the DOX-loaded micelles showed a high cytotoxicity against HepG2 tumor cells. All results demonstrate that mPEG-PUSS-mPEG self-assembled micelles are a very promising for hydrophobic anticancer drugs delivery.