Liposomal formulation of Galbanic acid improved therapeutic efficacy of pegylated liposomal Doxorubicin in mouse colon carcinoma

Maryam Ebrahimi Nik,Manouchehr Teymouri,Mohamadreza Amin,Mahdi Hatamipour,Mahmoud Reza Jaafari,Hamid Reza Sadeghnia,Mehrdad Iranshahi,Bizhan Malaekeh-Nikouei

doi:10.1038/s41598-019-45974-7

Abstract

Galbanic acid (Gba), a sesquiterpene coumarin, with strong antiangiogenic activity could serve as an excellent anti-cancer agent. However, Gba is a poor water-solube which hampered its clinical application. In this study, a pegylated liposomal Gba (PLGba) with HSPC/Cholesterol/mPEG2000-DSPE (56.2, 38.3, 5.3% molar ratio) was developed by the thin film hydration plus extrusion and calcium acetate gradient remote loading method, to address the issue of poor Gba solubility. Moreover, an integrin-targeting ligand (RGD peptide, cyclo[Arg-Gly-Asp-D-Tyr-Cys]) was post-inserted into liposomes in order to increase Gba cell delivery. Using fluorescently-labeled model liposomes, it was found that the targeting could improve the integrin-mediated cellular uptake of the liposomes in vitro in human umbilical vein endothelial cells (HUVECs), and in vivo as evidenced by chicken chorioallantoic membrane angiogenesis (CAM) model. It also could enrich the liposome accumulation in C26 tumor. Interestingly, co-treatment with PLGba and pegylated liposomal doxorubicin (PLD, also known as Doxil®) had a synergistic and antagonistic antiproliferative effect on the C26 tumor cell line and the normal HUVEC, respectively. In C26 tumor bearing BALB/c mice, the PLGba and PLD combinatorial therapy improved the antitumor efficacy of the treatment as compared to those of single agents. This results have clear implications for cancer therapy.

Highlights

Galbanic acid (Gba), a sesquiterpene coumarin, with strong antiangiogenic activity could serve as an excellent anti-cancer agent
The fluorescence intensity measument was represented that median was increased 1.8-fold at 4 °C (Fig. 4A) and it rose by 4.4-fold at 37 °C (Fig. 4B) in samples treated with the RGD-targeted model liposome as compared to the samples treated with the non-targeted liposomes. It could be inferred from these findings that targeting pegylated liposomal Gba (PLGba) with the RGD peptide could significantly enhance Gba delivery to the integrin-overexpressing endothelial cells present in tumor’s vasculature[29] as we have proved that RGD peptide could internalize into the human umbilical vein endothelial cells (HUVECs) and tumor vasculature through integrin mediated endocytosis by confocal microscopy and intravital microscopy in our previous study[30,31]
We developed a method to encapsulate efficiently poorly water-soluble agent (Gba) into a stable pegylated liposomal formulation and modified the liposomes with an RGD peptide to improve Gba delivery to the tumor

Summary

Introduction

Galbanic acid (Gba), a sesquiterpene coumarin, with strong antiangiogenic activity could serve as an excellent anti-cancer agent. Using fluorescently-labeled model liposomes, it was found that the targeting could improve the integrin-mediated cellular uptake of the liposomes in vitro in human umbilical vein endothelial cells (HUVECs), and in vivo as evidenced by chicken chorioallantoic membrane angiogenesis (CAM) model. It could enrich the liposome accumulation in C26 tumor. The quest for new cancer-treating agents is underway to find a potential agent from nature with differential cytotoxicity between cancer cells and normal cells[4] To this end, enormous candidates of natural products, including Galbanic acid (Gba), are on the desk to be examined for their medical properties[5,6,7].

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Conclusion