Investigation of water‐insoluble hydrophobic polyethylenimines as RNAi vehicles in chronic myeloid leukemia therapy

Abstract

The discovery of RNA interference (RNAi) more than two decades ago opened avenues for avant‐garde cancer treatments that possess the ability to evade issues hampering current chemotherapeutic strategies, owing to its specific gene sequence‐driven mechanism of action. A potent short interfering RNA (siRNA) delivery vehicle designed to overcome physiological barriers is imperative for successful RNAi therapy. For this purpose, this study explored the characteristics and therapeutic efficacy of low‐molecular weight (MW) polyethylenimine (PEI) with high cholesterol substitution, yielding water‐insoluble polymers, in chronic myeloid leukemia (CML) K562 cells. A strong impact of cholesterol grafting on the physicochemical attributes of the resultant polymers and their corresponding complexes with siRNA was observed, with the siRNA binding capacity of polymers increasing and complex dissociation sensitivity decreasing with increase in cholesterol content of the polymers. The modified polymer complexes were significantly smaller in size and possessed higher cationic charge compared to the parent polymer. The interaction with anionic heparan sulfate preoteoglycans present on the cell surface was significant in cellular uptake of the complexes. The therapeutic efficacy of siRNA/polymer complexes was reflected in their ability to effectively silence the reporter green fluorescent protein gene and endogenous CML oncogene BCR‐ABL as well as significantly inhibit colony formation by K562 cells post BCR‐ABL silencing. The results of this study demonstrated beneficial effects of high levels of hydrophobic substitution on low MW PEI on their functional performance bestowing them the potential to be potent RNAi agents for CML therapy.

Tuning the Potency of Farnesol-Modified Polyethylenimine with Polyanionic Trans-Booster to Enhance DNA Delivery

“…Modified PEI holds significant promise for gene delivery, but selecting the appropriate approach to create successful gene carrier remains a challenge to attain satisfactory therapeutic effects. PEI1.2k is a branched PEI which has been successfully modified with lipids and utilized for both pDNA and siRNA delivery in our lab previously. − In this present study, we prepared a library of PEI1.2k-SA-Far polymers (PEI1.2k-SA-Far5, PEI1.2k-SA-Far7, and PEI1.2k-SA-Far9; named as the original mole fraction of SA-Far added to the reaction) from PEI1.2k and SA-Far as described in the experimental section and depicted in Figure a. Due to controlled substitution of hydrophobic SA-Far on hydrophilic PEI1.2k, the resulting lipopolymers prepared here remained water-soluble.…”

Research Status and Prospect of Non-Viral Vectors Based on siRNA: A Review

“…Characterization results revealed that CHO-modified PEI had a significantly smaller size and an enhanced siRNA loading capacity compared with pure PEI. The good therapeutic effect of increased cell uptake was observed in the treatment of chronic myeloid leukemia [ 146 ]. By modifying PEI with tyrosine, Karimov et al were able to significantly enhance the transfection efficiency of siRNA, reduce PEI-induced toxicity, improve biocompatibility, and also show positive therapeutic effects in a mice tumor model.…”

Lipopolymer Mediated siRNA Delivery Targeting Aberrant Oncogenes for Effective Therapy of Myeloid Leukemia

“…One day after treatment with lipopolymer/siFLT3 complexes, cells were seeded in methylcellulose and colonies were counted as described previously (34). The colonies were stained by incubating with the MTT reagent for 2 h, followed by acquiring photographs of individual wells.…”