Synthesis and characterization of degradable multivalent cationic lipids with disulfide-bond spacers for gene delivery

Abstract

Gene therapy provides powerful new approaches to cure a large variety of diseases, which are being explored in ongoing worldwide clinical trials. To overcome the limitations of viral gene delivery systems, synthetic nonviral vectors such as cationic liposomes (CLs) are desirable. However, improvements of their efficiency at reduced toxicity and a better understanding of their mechanism of action are required. We present the efficient synthesis of a series of degradable multivalent cationic lipids (CMVLn, n=2 to 5) containing a disulfide bond spacer between headgroup and lipophilic tails. This spacer is designed to be cleaved in the reducing milieu of the cytoplasm and thus decrease lipid toxicity. Small angle X-ray scattering demonstrates that the initially formed lamellar phase of CMVLn–DNA complexes completely disappears when reducing agents such as DTT or the biologically relevant reducing peptide glutathione are added to mimic the intracellular milieu. The CMVLs (n=3 to 5) exhibit reduced cytotoxicity and transfect mammalian cells with efficiencies comparable to those of highly efficient non-degradable analogues and benchmark commercial reagents such as Lipofectamine 2000. Thus, our results demonstrate that degradable disulfide spacers may be used to reduce the cytotoxicity of synthetic nonviral gene delivery carriers without compromising their transfection efficiency.

Preparation, Physicochemical Properties, and Transfection Activities of Tartaric Acid-Based Cationic Lipids as Effective Nonviral Gene Delivery Vectors

“…[14][15][16][17][18][19][20][21][22][23][24] Among the existing nonviral vectors, the cationic liposome, representing an attractive, alternative approach for gene delivery has a broad varity of advantages, such as biodegradability, easy preparation, good repeatability and potential clinical applications. [25][26][27][28][29] Cationic lipids generally consist of polar head group and hydrophobic tails connected through the backbone (Fig.…”

Reductive nanocomplex encapsulation of cRGD-siRNA conjugates for enhanced targeting to cancer cells

“…cleavage of single-strand crgD-sirNa conjugates in a reductive environment According to the reported concentrations of DTT (10-300 mM); [35][36][37][38][39][40] we used 100 mM of DTT to detect the cleavage of disulfide bond. The reaction was allowed to proceed at 37°C for 2 h, which was stopped by immediately storing the conjugates at -80°C until analysis.…”

Aptamer-functionalized peptide H₃CR₅C as a novel nanovehicle for codelivery of fasudil and miRNA-195 targeting hepatocellular carcinoma

“…After 24 hours, the culture medium was replaced by 100 μL of complete DMEM involving blank NPs (HP and SHP), plain fasudil, and coloaded NPs ( Fasudil HP miR195 , Fasudil SHP miR195 ) for 24 hours. Also, 100 nM miR195 was constantly used, and fasudil was loaded at three different drug concentrations (10,30, and 60 μM) as low-, moderate-, and high-dose fasudil groups. Cells treated with the same amount of PBS were used as control.…”