Objective    To prepare liposome-entrapped mitoxantrone (LEM)-GM-CSF and observe the cytotoxicity of HL-60/ADM cells treated with LEM-GM-CSF

LEM and dihydroxyanthraquinone (DHAQ) in vitro.     Methods    LEM was prepared by reverse phase evaporation (REV). High speed centrifugation was applied to separate LEM and dissociate DHAQ. Colorimetry was employed to determine encapsulation efficiency. The lip

osome structure and particle size were determined by transmission electron microscopy. GM-CSF was coupled to LEM by glutaraldehyde method. UV-spectrophotometric analysis was applied to measure the coupled efficiency. Flow cytometry was applied to determine the immunoconjugate retained efficiency. The cytotoxicity of HL60/ADM cells and interdiction efficiency of GM-CSF were investigated by MTT test.     Results    The encapsulation efficiency of LEM was 80%. Most liposomes were monolayer

and the particle size was 170-220 nm. Its coupled efficiency with GM-CSF was 42.3%

and the immunoconjugate retained efficiency was 74.6%. All LEM-GM-CSF

LEM and DHAQ had cytotoxicity on HL60/ADM

their cytotoxic power in decrement sequence: LEM-GM-CSF

LEM

DHAQ. After treated with LEM-GM-CSF

LEM and DHAQ for 24 h

the IC

50

of HL-60/ADM was 8.73

12.42

27.31 μg/ml respectively and for 48 h the IC

50

were 0.62

8.25

12.44 μg/ml. The inhibition rate increased in a dose-dependent manner.     Conclusion    The encapsulation efficiency

the coupled efficiency and the immunoconjugate retained efficiency of LEM-GM-CSF prepared by our method were satisfying. LEM-GM-CSF representing anti-leukaemia efficiency in vitro had cytotoxicity on HL60/ADM cells.