Self-Assembled Star-Shaped sPCL-PEG Copolymer Nanomicelles with pH-Sensitivity for Anticancer Drug Delivery

As matters stand, chemotherapy is faced with high toxic and side effects, high risks, and long treatment cycles. Thus, stability, high encapsulation efficiency, intelligent controllability, and good biocompatibility are of great importance for drug delivery vehicles. Herein, a novel doxorubicin hydrochloride (DOX)-loaded micelle-like nanoparticle with pH responsive star-shaped polycaprolactone-polyethyleneglycol copolymer (sPCL-PEG-CT, sPP) is developed through esterification with inositol-polycaprolactone (sPCL) and carboxylated polyethylene glycol (TC-PEG-CT). sPP nanomicelles (sPP NMs) have a high encapsulation efficiency of greater than 85%, an average size of 95 nm, and a zeta potential of -18 mV. In addition, in vitro release tests show that approximate to 70% of the drug is released from sPP/DOX NMs into phosphate buffer saline solution (PBS) (pH 5.0) at 37 degrees C for 12 h. More importantly, the cumulative release is approximate to 90% for 170 h, displaying a more sustainable drug release behavior. The work explores a new synthesis route of star-shaped polycaprolactone-polyethyleneglycol copolymer NMs. The sPP NMs have a promising future in drug carrier, especially for hydrophobic drugs.