Construction of dimeric drug-loaded polymeric micelles with high loading efficiency for cancer therapy

Polymeric micelles (PMs) have been applied widely to transport hydrophobic drugs to tumor sites for cancer treatment. However, the low load efficiency of the drug in the PMs significantly reduces the therapeutic efficiency. We report here that disulfide-linked camptothecin (CPT) as a kind of dimeric drug can be effectively embedded in the core of poly(ε-caprolactone)–poly(ethylene glycol)–poly(ε-caprolactone) (PCL–PEG–PCL) PMs for improving drug-loading efficiency, and PEG can be used as a hydrophilic shell. Moreover, the dimeric CPT-loaded PCL–PEG–PCL PMs exhibited excellent solubility in phosphate-buffered saline (PBS) media and significant cytotoxicity to cancer cells.