Cholesteryl oleate-loaded cationic solid lipid nanoparticles as carriers for efficient gene-silencing therapy

Abstract

BackgroundCationic solid lipid nanoparticles (SLNs) have been given considerable attention for therapeutic nucleic acid delivery owing to their advantages over viral and other nanoparticle delivery systems. However, poor delivery efficiency and complex formulations hinder the clinical translation of SLNs.AimThe aim of this study was to formulate and characterize SLNs incorporating the cholesterol derivative cholesteryl oleate to produce SLN–nucleic acid complexes with reduced cytotoxicity and more efficient cellular uptake.MethodsFive cholesteryl oleate-containing formulations were prepared. Laser diffraction and laser Doppler microelectrophoresis were used to evaluate particle size and zeta potential, respectively. Nanoparticle morphology was analyzed using electron microscopy. Cytotoxicity and cellular uptake of lipoplexes were evaluated using flow cytometry and fluorescence microscopy. The gene inhibition capacity of the lipoplexes was assessed using siRNAs to block constitutive luciferase expression.ResultsWe obtained nanoparticles with a mean diameter of approximately 150–200 nm in size and zeta potential values of 25–40 mV. SLN formulations with intermediate concentrations of cholesteryl oleate exhibited good stability and spherical structures with no aggregation. No cell toxicity of any reference SLN was observed. Finally, cellular uptake experiments with DNA-and RNA-SLNs were performed to select one reference with superior transient transfection efficiency that significantly decreased gene activity upon siRNA complexation.ConclusionThe results indicate that cholesteryl oleate-loaded SLNs are a safe and effective platform for nonviral nucleic acid delivery.

Delivery of miRNA-29b Using R9-LK15, a Novel Cell-Penetrating Peptide, Promotes Osteogenic Differentiation of Bone Mesenchymal Stem Cells

“…The size and zeta potential of delivery systems influence their transfection efficiency [33, 34]. Delivery systems smaller than 200 nm with a zeta potential higher than 20 mV exhibit good stability and high cellular uptake [35]. Nanocomplexes formed by mixing R9-LK15 and miR-29b at a molar ratio of 3:1 had a diameter of 68.13 ± 8.74 nm and a zeta potential of 25.80 ± 4.51 mV.…”

Development and characterization of an improved formulation of cholesteryl oleate-loaded cationic solid-lipid nanoparticles as an efficient non-viral gene delivery system

“…The CO-SLNs were manufactured using the hot microemulsion technique, as previously described [27]. The components of the lipid matrix (41.7% of the formulation) were stearic acid (EMD Millipore, Billerica, MA, USA) and cholesteryl oleate (Tokyo Chemical Industry Co., Tokyo, Japan), poloxamer 188 (8.3% of the formulation, from EMD Millipore) and the cationic lipid octadecylamine (50% of the formulation, from Acros Organics, Geel, Belgium) was used as charged carrier [16]. Briefly, the lipid matrix was melted at a temperature above its melting point while the hydrophilic components were separately heated in ultrapure water (EMD Millipore).…”

“…The use of cholesteryl oleate (CO), a cholesterol derivative, in cSLN-nucleic acid formulations to improve cytotoxicity and transfection efficiency as a novel avenue for the development of highly efficient and biocompatible therapeutic carriers has been recently proposed [16]. In order to improve the capacity of CO-SLNs to transfect cells, protamine (P) has been previously incorporated to condense DNA and form lipoplexes on the nanoparticle surface [17].…”

Nanoparticle-Based Delivery of CRISPR/Cas9 Genome-Editing Therapeutics

“…These comprise a lipidic core containing cationic constituents, including cationic lipids (e.g. 1,2-dioleoyl-3-trimethylammoniumpropane (DOTAP)) capable of complexing with negatively-charged nucleic acid molecules and RNPs (71–73). Unlike liposomes, these lipid-based NPs do not possess a phospholipid bilayer and aqueous core; alternatively they contain monolithic lipid cores and their surfaces can still be decorated with cationic moieties (71, 73).…”

“…1,2-dioleoyl-3-trimethylammoniumpropane (DOTAP)) capable of complexing with negatively-charged nucleic acid molecules and RNPs (71–73). Unlike liposomes, these lipid-based NPs do not possess a phospholipid bilayer and aqueous core; alternatively they contain monolithic lipid cores and their surfaces can still be decorated with cationic moieties (71, 73). The general consensus is that lipid-based NPs, when delivered intravenously, tend to target the liver which, depending on whether one is trying to target the liver, could be considered an advantage or a drawback (74).…”