Synthesis Of Lipid Nanoparticles Research Articles

Assessing Lipid Nanoparticle Protein Corona Formation and Cytocompatibility

Lipid nanoparticles(LNPs) represent an emerging new modality for mRNA delivery. Following administration and interaction with blood constituents, LNPs form a corona complex consisting of proteins adsorbed on the surface altering their stability, biological identity, and fate. Cytocompatibility of the LNPs is an important factor when considering their safety efficacy in delivering the encapsulated drug dose, lipid choice and the specific target cells. The aim of this study was to investigate the changes in LNP physical parameters in physiologically-relevant media. Key attributes such as particle size, polydispersity index and zeta-potential were measured using Dynamic Light Scattering (DLS) and Nanoparticle Tracking Analysis (NTA). Cytocompatibility was assessed via CellTiter-Glo® assay. Following 24-hour incubation of LNPs with Bovine Serum Albumin (BSA), the LNP z-average increased from 92.4 (± 49.0) nm to 131.4 (± 64.9) nm indicating interaction between LNPs and BSA. A decrease in percentage cell viability was demonstrated with increased lipid concentration for MCF-7 and A549 cell lines. This work shows changes in LNP physicochemical properties in the presence of protein and biologically relevant conditions consistent with protein surface adsorption. The cytocompatibility of LNPs can be associated with the type of lipids used in the synthesis of LNPs.

The manufacturing of 3D-printed microfluidic chips to analyse the effect upon particle size during the synthesis of lipid nanoparticles.

The process of 3D printing to produce microfluidic chips is becoming commonplace, due to its quality, versatility and newfound availability. In this study, a UV liquid crystal display (LCD) printer has been implemented to produce a progression of microfluidic chips for the purpose of liposomal synthesis. The emphasis of this research is to test the limitations of UV LCD printing in terms of resolution and print speed optimisation for the production of microfluidic chips. By varying individual channel parameters such as channel length and internal geometries, the essential channel properties for optimal liposomal formulation are being investigated to act as a basis for future experimentation including the encapsulation of active pharmaceutical ingredients. Using the uniquely designed chips, liposomes of ≈120 nm, with polydispersity index values of ≤0.12 are able to be reproducibly synthesised. The influence of total flow rates and lipid choice is investigated in depth, to provide further clarification on how a microfluidic setup should be optimised. In-depth explanations of the importance of each channel parameter are also explained throughout, with reference to their importance for the properties of a successful liposome.

Lipid nanoparticles for hepatic delivery of small interfering RNA

Clinical application of small interfering RNA (siRNA) requires safe and efficient delivery in vivo. Here, we report the design and synthesis of lipid nanoparticles (LNPs) for siRNA delivery based on cationic lipids with multiple tertiary amines and hydrophobic linoleyl chains. LNPs incorporating the lipid containing tris(2-aminoethyl)amine (TREN) and 3 linoleyl chains, termed TRENL3, were found to have exceptionally high siRNA transfection efficacy that was markedly superior to lipofectamine, a commercial transfection agent. In addition, inclusion of polyunsaturated fatty acids, such as linoleic acid and linolenic acid in the formulation further enhanced the siRNA delivery efficiency. TRENL3 LNPs were further shown to transport siRNA into the cytosol primarily via macropinocytosis rather than clathrin-mediated endocytosis. The new LNPs have demonstrated preferential uptake by the liver and hepatocellular carcinoma in mice, thereby leading to high siRNA gene-silencing activity. These data suggest potential therapeutic applications of TRENL3 mediated delivery of siRNA for liver diseases.