Nucleic acid carrier composed of a branched fatty acid lysine conjugate—Interaction studies with blood components

T14diLys/DOPE Liposomes: An Innovative Option for siRNA-Based Gene Knockdown?

BACKGROUND/OBJECTIVES

Bringing small interfering RNA (siRNA) into the cell cytosol to achieve specific gene silencing is an attractive but also very challenging option for improved therapies. The first step for successful siRNA delivery is the complexation with a permanent cationic or ionizable compound. This protects the negatively charged siRNA and enables transfection through the cell membrane. The current study explores the performance of the innovative, ionizable lipid 2-Tetradecylhexadecanoic acid-(2-bis{[2-(2,6-diamino-1-oxohexyl)amino]ethyl}aminoethyl)-amide (T14diLys), in combination with 1,2-dioleoyl-sn-glycero-3-phosphoethanolamine (DOPE), for siRNA delivery and the impact of the production method (sonication vs. extrusion) on the particle properties.

METHODS

Liposomes were produced either with sonication or extrusion and characterized. The extruded liposomes were combined with siRNA at different N/P ratios and investigated in terms of size zeta potential, encapsulation efficiency, lipoplex stability against RNase A, and knockdown efficiency using enhanced green fluorescent protein (eGFP)-marked colon adenocarcinoma cells.

RESULTS

The liposomes prepared by extrusion were smaller and had a narrower size distribution than the sonicated ones. The combination of siRNA and liposomes at a nitrogen-to-phosphate (N/P) ratio of 5 had optimal particle properties, high encapsulation efficiency, and lipoplex stability. Gene knockdown tests confirmed this assumption.

CONCLUSIONS

Liposomes produced with extrusion were more reproducible and provided enhanced particle properties. The physicochemical characterization and in vitro experiments showed that an N/P ratio of 5 was the most promising ratio for siRNA delivery.

Dual-targeting galactose-functionalized hyaluronic acid modified lipid nanoparticles delivering silybin for alleviating alcoholic liver injury

Alcoholic liver injury stands as a predominant pathogenic contributor to the global burden of liver diseases, with alcohol consumption serving as a significant determinant of worldwide morbidity and mortality. Given that liver-targeted therapy for mitigating alcoholic liver injury remains to be a major clinical challenge due to the poor specificity and instability associated with single targeting modification in actively targeted nanomedicine systems, bifunctional targeting modification may serve as a more promising strategy. Here, galactose-functionalized hyaluronic acid (Gal-HA) coated cationic solid lipid nanoparticles carrying silybin (Gal-HA/SIL-SLNPs) featuring dual-targeting hyaluronic acid (HA) and galactose (Gal) moieties, enabled specific liver surface targeting of asialoglycoprotein receptor (ASGPR) and cluster of differentiation 44 (CD44) proteins to enhance silybin uptake, while simultaneously ameliorating the deficiencies of positively charged lipid nanoparticles as drug carriers and preserving their stability in the bloodstream. Based on the findings, Gal-HA/SIL-SLNPs with excellent biocompatibility demonstrated improved cellular internalization and liver distribution, while also displaying ideal curative properties in a mouse model of alcohol-induced liver injury without causing damage to other organs. This work suggests that Gal-HA/SIL-SLNPs with dual modification may represent an encouraging approach for developing more effective liver targeted nano-drug delivery systems to achieve accurate medication for alcoholic liver injury.

Monomethyl branched-chain fatty acids enriched bacterial oil production by furan aldehydes tolerant halophile Lentibacillus salarius strain BPIITR using non-detoxified sugarcane bagasse

The structural diversity of monomethyl branched-chain fatty acids (mBCFAs) expanded their application in biolubricants, biofuels for enhancing cold flow and thermo-oxidative properties. Current study focuses on mBCFAs production from sugarcane bagasse hydrolysate in biorefinery approach with halophilic Lentibacillus salarius BPIITR. Halophilic bacterium exhibited tolerance towards furan aldehydes up to 150 mM in minimal medium and produced 3.40 ± 0.13 and 2.47 ± 0.15 gL^-1 lipid rich in mBCFAs, in xylose and glucose rich non-detoxified hydrolysate, respectively at bench-scale bioreactor. In addition, 2,5-furandicarboxylic acid and 2-furancarboxylic acids were co-produced as value-added products up to 41.34 ± 4.73 and 59.84 ± 5.17 mM, respectively. The biosynthesized bacterial oil exhibited onset oxidation temperature of 319.5 °C and low temperature viscosity ratio of 2.92. The accumulated lipid was rich in triacylglycerol content more than 67 % with 12-methyl tetradecanoic acid as major fatty acid.

Complexation of Oligo- and Polynucleotides with Methoxyphenyl-Functionalized Imidazolium Surfactants

Interaction between cationic surfactants and nucleic acids attracts much attention due to the possibility of using such systems for gene delivery. Herein, the lipoplexes based on cationic surfactants with imidazolium head group bearing methoxyphenyl fragment (MPI-n, n = 10, 12, 14, 16) and nucleic acids (oligonucleotide and plasmid DNA) were explored. The complex formation was confirmed by dynamic/electrophoretic light scattering, transmission electron microscopy, fluorescence spectroscopy, circular dichroism, and gel electrophoresis. The nanosized lipoplex formation (of about 100-200 nm), contributed by electrostatic, hydrophobic interactions, and intercalation mechanism, has been shown. Significant effects of the hydrocarbon tail length of surfactant and the type of nucleic acid on their interaction was revealed. The cytotoxic effect and transfection ability of lipoplexes studied were determined using M-HeLa, A549 cancer cell lines, and normal Chang liver cells. A selective reduced cytotoxic effect of the complexes on M-HeLa cancer cells was established, as well as a high ability of the systems to be transfected into cancer cells. MPI-n/DNA complexes showed a pronounced transfection activity equal to the commercial preparation Lipofectamine 3000. Thus, it has been shown that MPI-n surfactants are effective agents for nucleic acid condensation and can be considered as potential non-viral vectors for gene delivery.

Relationship and improvement strategies between drug nanocarrier characteristics and hemocompatibility: What can we learn from the literature

This article discusses the various blood interactions that may occur with various types of nano drug-loading systems. Nanoparticles enter the blood circulation as foreign objects. On the one hand, they may cause a series of inflammatory reactions and immune reactions, resulting in the rapid elimination of immune cells and the reticuloendothelial system, affecting their durability in the blood circulation. On the other hand, the premise of the drug-carrying system to play a therapeutic role depends on whether they cause coagulation and platelet activation, the absence of hemolysis and the elimination of immune cells. For different forms of nano drug-carrying systems, we can find the characteristics, elements and coping strategies of adverse blood reactions that we can find in previous researches. These adverse reactions may include destruction of blood cells, abnormal coagulation system, abnormal effects of plasma proteins, abnormal blood cell behavior, adverse immune and inflammatory reactions, and excessive vascular stimulation. In order to provide help for future research and formulation work on the blood compatibility of nano drug carriers.

Synthesis of cationic carbon dots and their effects on human serum proteins and in vitro blood coagulation

Cationic carbon dots (CCDs) are a promising alternative to gene-delivery systems, and good biosafety levels are crucial for their in vivo use. In this study, spherical and monodispersed CCDs with an average surface potential of +28.7 mV were prepared using sucrose and glutamate (denoted SG-CCDs) using a one-pot autoclave-assisted method. Molecular interactions between the SG-CCDs and four major human serum proteins (albumin, immunoglobulin G, fibrinogen, and transferrin) were investigated. The results were further verified on human serum, and the effect of the SG-CCDs on in vitro blood coagulation was examined. The results showed that the fluorescence of human serum was clearly quenched by the SG-CCDs through a dynamic collision mechanism. Moreover, SG-CCDs at a concentration of 20 μM exhibited minor effects on the secondary structure of human serum. The activated partial thromboplastin and prothrombin time as well as the fibrinogen concentration were not changed, indicating that the SG-CCDs did not interfere with the coagulation process. This study provided an understandable background on the behaviour of CCDs in clinical applications.

Barriers and Strategies of Cationic Liposomes for Cancer Gene Therapy

Cationic liposomes (CLs) have been regarded as the most promising gene delivery vectors for decades with the advantages of excellent biodegradability, biocompatibility, and high nucleic acid encapsulation efficiency. However, the clinical use of CLs in cancer gene therapy is limited because of many uncertain factors in vivo. Extracellular barriers such as opsonization, rapid clearance by the reticuloendothelial system and poor tumor penetration, and intracellular barriers, including endosomal/lysosomal entrapped network and restricted diffusion to the nucleus, make CLs not the ideal vector for transferring extrinsic genes in the body. However, the obstacles in achieving productive therapeutic effects of nucleic acids can be addressed by tailoring the properties of CLs, which are influenced by lipid compositions and surface modification. This review focuses on the physiological barriers of CLs against cancer gene therapy and the effects of lipid compositions on governing transfection efficiency, and it briefly discusses the impacts of particle size, membrane charge density, and surface modification on the fate of CLs in vivo, which may provide guidance for their preclinical studies.