A Novel Paclitaxel-Loaded Polymeric Micelle System with Favorable Biocompatibility and Superior Antitumor Activity.

Background/Aim: Polymeric micelles are promising vehicles for paclitaxel delivery. Further improvement in the stability of the micelle formulation is desirable. Materials and Methods: Monomethoxy poly(ethylene glycol)-block-poly(D, L-lactide)-9-fluorenylmethoxycarbonyl-L-phenylalanine (mPEGPDLLA-Phe(Fmoc)) was synthesized through a classical esterification reaction. Paclitaxel-loaded mPEG-PDLLAPhe(Fmoc) micelles (PTX-PheMs) were prepared by the self-assembly method. Composition, structure and physicochemical properties were characterized. Pharmacokinetics were evaluated in rats. Therapeutic effect was evaluated in tumorbearing mice. Safety profile was assessed by a hemolysis assay and an acute-toxicity study. Results: The average size of PTX-PheMs was about 45 nm. The hemolysis and acute-toxicity tests confirmed its biocompatibility and safety. The pharmacokinetics and therapeutic effect experiments demonstrated its long circulation property and superior antitumor effect. Conclusion: mPEG-PDLLA-Phe(Fmoc) micelle is a biocompatible and effective drug delivery system for hydrophobic drugs such as PTX.