Characterization of the doxorubicin-pluronic F68 conjugate micelles and their effect on doxorubicin resistant human erythroleukemic cancer cells

Doxorubicin-pluronic F68 conjugate (DOX-P) was synthesized and its structure was confirmed by FTIR and 1 H-NMR spectra. Using human erythroleukemic cancer cells as model, DOX-P application in chemotherapy was further investigated. Differential scanning calorimetry analysis was applied to compare the fusion and crystallization characterization between pluronic F68 and DOX-P. Morphology and size assessment were measured using a transmission electron microscopy (TEM) to confirm the capability of forming micelles of DOX-P. Tumor cell lines K562 and K562/AO2 were used to investigate the effect of DOX-P on tumor cell resistance. The Tm and Tc of DOX-P were lower than pluronic F68 resulted from the connection of DOX to pluronic F68. Morphology images confirmed the existence of DOX-P micelles, with an average size of about 20 nm. Drug release profile showed that the DOX-P conjugate maintained a sustained DOX release. From cell experiment in vitro, DOX-P micelles could circumvent the DOX resistance of K562/AO2 cells. With advantages of EPR effect and reducing tumor resistance, DOX-P micelles might develop as new tumor targeted delivery system for chemotherapy. © 2011 Sun CZ, et al.