Target Specific Intracellular Delivery of siRNA/PEI−HA Complex by Receptor Mediated Endocytosis

Abstract

Hyaluronic acid (HA) plays important biological roles in tissue integrity, angiogenesis, wound healing, and cell motility through the interaction with receptors on cell membranes. In this work, we investigated the effect of HA modification on the receptor-mediated endocytosis labeling HA derivatives with quantum dots (QDots). HA-QDot conjugates with a degree of modification less than ca. 25 mol % appeared to be more efficiently taken up to B16F1 cells by HA receptor mediated endocytosis than QDots alone. On the basis of bioimaging study, polyethyleneimine, PEI-HA conjugate with 24.2 mol % PEI content was developed as a target specific intracellular delivery carrier of siRNA. The siRNA/PEI-HA complex exhibited higher gene silencing efficiency in B16F1 cells with HA receptors than siRNA/PEI complex. Anti-PGL3-Luc siRNA/PEI-HA complex appeared to silence PGL3-Luc gene in the range of 50%-85% depending on the serum concentration up to 50 vol %. According to in vivo biodistribution test, siRNA/PEI-HA complex accumulated mainly in the tissues with HA receptors such as liver, kidney, and tumor. Furthermore, intratumoral injection of anti-VEGF siRNA/PEI-HA complex resulted in an effective inhibition of tumor growth by the HA receptor mediated endocytosis to tumor cells in C57BL/6 mice. Considering all these results, anti-VEGF siRNA/PEI-HA complex was thought to be applied successfully as target specific antiangiogenic therapeutics for the treatment of diseases in the tissues with HA receptors, such as liver cancer and kidney cancer.

Hyaluronic Acid in Drug Delivery Systems

“…The siRNA/PEI-HA complex was more efficient in LYVE-1 receptors B16F1 cells than in HEK-293 cells without HA receptor and provided higher levels of siRNA delivery than did the physical mixture of HA and PEI (Han et al, 2009). Also, the siRNA/PEI-HA complexes exhibited higher gene silencing efficiency reducing VEGF production which resulted in tumor growth inhibition (Jiang et al, 2009).…”

Delivery Methods to Target RNAs in the Kidney

“…MAPK1 mRNA expression in isolated glomeruli was significantly suppressed in mice treated with the MAPK1 siRNA PEG-PLL complexes, whereas control or HVJ-E viral vector mediated siRNA had no effect on protein expression. Based on a conception that hyaluronic acid (HA) plays an important role on receptormediated endocytosis, the effect of HA modification of siRNA/PEI complex has been investigated in B16F1 melanoma tumor-bearing mice (Jiang et al, 2008). The hyaluronic acid conjugated complex exhibited higher gene silencing efficiency in B16F1 murine melanoma cells with HA receptors than the siRNA/PEI complex alone.…”

“… Dendrimers are unique molecular architectures having well defined structures with inner cavities to bind biomolecules that make them appropriate for gene delivery. Quantum dots (Qdot) were applied for bioimaging purposes in the study, where uptake of siRNA/PEI complexes was enhanced with hyaluronic acid (HA) conjugation (referred earlier in 4.4.2, Jiang et al, 2008). Nanofibrous scaffold mediated RNAi was applied successfully silencing GAPDH in human embryonic kidney 293 cells (HEK 293) (Cao et al, 2010).…”

High gene delivery efficiency of alkylated low-molecular-weight polyethylenimine through gemini surfactant-like effect

“…1 Among the various nonviral systems, polyethyleneimine (PEI) is one of the most intensively studied systems due to its high transfection efficiency. 2,3 Unfortunately, the high transfer efficiency of PEI is usually accompanied by high toxicity, so various means of structure modification have been tried in order to obtain a good compromise between efficiency and toxicity for PEI, such as poly(lactic-co-glycolic acid)-linear PEI with a molecular weight of 22,000 Da (lPEI22K); 4 branched PEI (bPEI)-govalbumin with a molecular weight of 600 Da (bPEI0.6K); 5 heparin-grafted bPEI with a molecular weight of 1,800 Da (bPEI1.8K); 6 hyaluronic acid-grafted bPEI with a molecular weight of 25,000 Da (bPEI25K); 7 polyethylene glycol-g-bPEI with a molecular weight of 25,000 Da (bPEI25K); 8 and hydrophobic grafting (cholesteryl, cholanic acid, fatty acid residues, and hydrophobic chains). 9 Among the many modification methods of PEI, grafting PEI with hydrophobic moieties has proved to be an effective way of obtaining a favorable tradeoff between efficacy and toxicity, by: 1) increasing the transfection efficiency by elevated lipophilicity, which enhances the affinity of PEI to biomembranes and facilitates the cellular entry; 10 2) improving the stability of polyplexes against serum and DNAase; 11 and 3) lowering the toxicity by reduced charge density, which causes less cell damage.…”