The old alcohol-aversion drug
disulfiram (DSF) has aroused wide attention as a drug repurposing strategy in terms of
cancer therapy because of the high antitumor efficacy in combination with
copper ion. However, numerous defects of DSF (e.g., the short half-life and
acid instability) have limited the application in
cancer treatment. Cu (DDC)2, the complex of
diethyldithiocarbamate (DDC, DSF metabolite) and Cu2+, have been proven as the vital active component on
cancer, which have aroused the attention of researchers from DSF to Cu (DDC)2. However, the poor water solubility of Cu (DDC)2 increase more difficulties to the treatment and in-depth investigations of Cu (DDC)2. In this study,
sphingomyelin (SM)-based PEGylated
liposomes (SM/Chol/
DSPE-mPEG2000 (55:40:5, mole%)) were produced as the carriers for Cu (DDC)2 delivery to enhance the water solubility. DDC was added to Cu-containing
liposomes with a higher encapsulation efficiency of more than 90%, and it reacted with Cu2+ to synthesize Cu (DDC)2. Due to the high phase transition temperature of SM and strong intermolecular hydrogen bonds with
cholesterol, SM-based
liposomes would be conducive to enhancing the stability of Cu (DDC)2 and preventing drug leakage during delivery. As proven by pharmacokinetic studies, loading Cu (DDC)2 into
liposomes improve bioavailability, and the area under the curve (AUC0-t) and the mean elimination half-life (t1/2) increased 1.9-time and 1.3-time to those of free Cu (DDC)2, respectively. Furthermore, the anticancer effect of Cu (DDC)2 was enhanced by the liposomal encapsulation, thus resulting in remarkable cell apoptosis in vitro and a
tumor-inhibiting rate of 77.88% in vivo. Thus, it was concluded that Cu (DDC)2
liposomes could be promising in
cancer treatment.