OBJECTIVETo explore the antitumor effect and toxicity of pegylated liposomal daunorubicin (PL-DNR) on leukemia.

METHODSPL-DNR was prepared by dry lipid hydration and remote loading, and its physicochemical indexes were analyzed. The inhibiting effect of PL-DNR on leukemia cells was observed in terms of in vitro cytotoxicity experiment. The therapeutic effect in vivo was assessed by tumor inhibition in leukemia L1210-bearing mice. Apoptosis in cardiomyocytes was detected using the terminal deoxynucleotidyl transferase mediated dUTP nick end labeling method (TUNEL staining).

RESULTSThe average diameter of PL-DNR was (110 ± 10)nm and the encapsulation efficiency was 94.21%. The in vitro cytotoxicity experiment showed that the inhibiting ability of PL-DNR in the treatment groups was continuously enhanced as the experiment proceeded. The in vivo pharmacodynamic experiment also indicated obvious tumor-inhibiting effect of PL-DNR. At the end of the experiment, the tumor volume of the PL-DNR group was (433.71 ± 234.77)mm(3), significantly smaller than that of (1 293.77 ± 381.26) mm(3) in the DNR group (P < 0.05). Moreover, the tumor weight of the PL-DNR group was (0.66 ± 0.29)g and that of the DNR group was (1.25 ± 0.43)g (P < 0.05). The myocardial toxicity experiment showed that the median apoptosis index of cardiomyocytes in the PL-DNR group was 13.83%, significantly lower than that of 42.67% in the DNR group (P < 0.05), indicating a lower toxicity of PL-DNR to the myocardium.

CONCLUSIONCompared with the free DNR, PL-DNR can improve the therapeutic effect on leukemia and reduce the.