Glycyrrhizin Acid and Glycyrrhetinic Acid Modified Polyethyleneimine for Targeted DNA Delivery to Hepatocellular Carcinoma.

Cao Cao,Gao Gao,Piao Piao,Shen Shen,Zhou Zhou,Zhan Zhan,Qiu Qiu

doi:10.3390/ijms20205074

Abstract

In the last 2–3 decades, gene therapy represented a promising option for hepatocellular carcinoma (HCC) treatment. However, the design of safe and efficient gene delivery systems is still one of the major challenges that require solutions. In this study, we demonstrate a versatile method for covalent conjugation of glycyrrhizin acid (GL) or glycyrrhetinic acid (GA) to increase the transfection efficiency of Polyethyleneimine (PEI, Mw 1.8K) and improve their targeting abilities of hepatoma carcinoma cells. GA and GL targeting ligands were grafted to PEI via N-acylation, and we systematically investigated their biophysical properties, cytotoxicity, liver targeting and transfection efficiency, and endocytosis pathway trafficking. PEI-GA0.75, PEI-GL10.62 and PEI-GL20.65 conjugates caused significant increases in gene transfection efficiency and superior selectivity for HepG2 cells, with all three conjugates showing specific recognition of HepG2 cells by the free GA competition assay. The endocytosis inhibition and intracellular trafficking results indicated that PEI-GA0.75 and GL10.62 conjugates behaved similarly to SV40 virus, by proceeding via the caveolae- and clathrin-independent mediated endocytosis pathway and bypassing entry into lysosomes, with an energy independent manner, achieving their high transfection efficiencies. In the HepG2 intraperitoneal tumor model, PEI-GA0.75 and PEI-GL10.62 carrying the luciferase reporter gene gained high gene expression, suggesting potential use for in vivo application.

Highlights

Hepatocellular carcinoma (HCC) is the fifth most common cancer in the world
Many non-viral deliveries, especially cationic polymers have attracted extensive attention [5,6,7]. Cationic polymers such as dendrimer polyamide-amine (PAMAM), linear or branched polyethyleneimine (PEI), poly-lysine (PLL), chitosan and their derivatives, have been widely investigated in the gene delivery field owing to their strong stability, low immunogenicity, and controllable structures [8]
We found that gene expression of PEI-glycyrrhetinic acid (GA) conjugates was optimal at feed ratio 1 (GA: PEI), PEI–glycyrrhizin acid (GL) conjugates only fixed at a feed ratio of 1

Summary

Introduction

Hepatocellular carcinoma (HCC) is the fifth most common cancer in the world. most patients are diagnosed at an advanced stage, resulting in higher death rates, and making HCC the second most mortal malignant tumor [1,2]. There are not many treatment options for late stage HCC due to multiple disadvantages of first-line therapy, such as resistance, lack of target, and severe side effects. In these regards, gene therapy has already been an attractive option to treat HCC. Many non-viral deliveries, especially cationic polymers have attracted extensive attention [5,6,7]. Cationic polymers such as dendrimer polyamide-amine (PAMAM), linear or branched polyethyleneimine (PEI), poly-lysine (PLL), chitosan and their derivatives, have been widely investigated in the gene delivery field owing to their strong stability, low immunogenicity, and controllable structures [8]. The inverse property between transfection efficiency and toxicity of the different weight PEI molecules results in great limitations for their in vivo and in vitro applications

Objectives

Results

Conclusion