PEGylated liposomes as delivery systems for Gambogenic acid: Characterization and in vitro/in vivo evaluation.

Abstract

Gambogenic acid (GNA), which possesses diverse anti-tumor activities both in vitro and in vivo, is regarded as a potential anticancer compound. However, the excessive irritation to the blood vessel, short elimination half-life and poor aqueous solubility restricted its clinical application. In this study, Gambogenic acid-loaded PEGylated liposomes (GNA-PEG-LPs) were developed to reduce toxicity, prolong the half-life and enhance anticancer efficacy both in vitro and in vivo. The average particle size of GNA-PEG-LPs was 90.13 ± 0.16 nm and their polydispersity index (PDI) was 0.092 ± 0.003. The encapsulation efficiency, drug loading and zeta potential of GNA-PEG-LPs were 88.13 ± 1.31%, 3.72 ± 0.04%, -22.10 ± 0.20 mV, respectively. Compared to free GNA, GNA-PEG-LPs showed enhanced cytotoxicity and apoptosis induction effect against A549, SGC-7901 and HepG2 cells. Mechanistically, western blot analysis revealed that up-regulation of Bax, down-regulation of Bcl-2 and activation of caspase-3 contributed to apoptosis. In addition, the blood vessel irritation test showed that the vascular irritation of GNA could be reduced by liposomal encapsulation. The hemolysis assay revealed that good hemocompatibility of the liposomes. Furthermore, pharmacokinetic study showed that the t1/2 and the AUC of GNA-PEG-LPs were higher than GNA solution approximately 2.84-fold and 2.97-fold, respectively. In vivo antitumor efficacy demonstrated that GNA-PEG-LPs significantly inhibited the tumor growth in LLC tumor-bearing C57BL/6 mouse model. Results of Immunohistochemistry indicated that GNA-PEG-LPs significantly suppressed the expression of Bcl-2 and increased the expression of Bax and caspase-3 compared with free GNA. Collectively, PEGylated liposomes could be a potential nanocarrier to prolong half-life, reduce toxicity and enhance anticancer efficacy both in vitro and in vivo.