Exploring the Applications of Lipid Nanoparticle Formulation in Biomedical Research
Lipid nanoparticles have been shown to efficiently deliver mRNA and enable cell-specific expression of encoded proteins in vaccines, nutrition supplements, and diagnostic applications. These lipid-based delivery systems are safe and non-viral.
Two fluids containing the lipid and nucleic acid solutions are delivered through separate inlet channels in the NanoAssemblr cartridge under laminar flow. Microscopic features engineered in the channel allow these two fluids to intermingle within milliseconds.
Lipid nanoparticles (LNPs) are a versatile drug delivery system that can be used for many applications, including vaccines, gene therapy, diagnostics, and therapeutics. These particles have many advantages over other drug delivery systems, including their ability to target specific cells, cross the blood-brain barrier, and enhance transfection.
LNPs can have different characteristics for a particular application, such as organ-specific delivery, by altering the lipid structure. For example, increasing the alkyl length of a lipid can increase spleen- or liver-targeting, while decreasing the polarity of a lipid can improve cellular uptake by Kupffer cells. The lipids chosen to formulate the LNPs are essential to their stability, release, and encapsulation capabilities.
Biocompatible/physiological and generally recognized as safe lipids can be used. Adding ionizable cationic lipids to the lipid matrix can form stable nanocarriers that can encapsulate hydrophobic superparamagnetic iron oxide nanoparticles (SPIOs). Physical and chemical stability is essential to ensure a high-quality final product when developing a new lipid nanoparticle formulation.
One technique that can be used is Backgrounded Membrane Imaging (BMI), which combines membrane permeability and electrophoretic mobility to evaluate the stability of subvisible particles. BMI can be used to detect aggregation and other potential issues in lipid nanoparticles.
Continuous flow manufacturing on the NanoAssemblr GMP System has been shown to produce more uniform lipid nanoparticles than traditional T-tube mixing methods. siRNA-LNPs produced on the GMP System demonstrated encapsulation efficiencies above 95%, with serum factor VII siRNA knockdown efficacy maintained 72 hours following administration.
Lipid nanoparticles have been widely used as a non-viral gene delivery system to deliver antigen or mRNA vaccines for many virus diseases, cancer, and genetic disorders7. Two COVID-19 vaccines, mRNA-1273 and BNT162b21, use lipid nanoparticle-mRNA formulations.
The morphology of SLNs depends on the type of lipid and the amount added, with unilamellar structures (SUV) being the smallest, followed by lamellar vesicles (LVV) and multilamellar vesicle structures (MLV). The size of a lipid molecule determines its melting point, so the selection of lipids is critical for the desired morphology.
A key benefit of lipid nanoparticles is their ability to cross biological barriers such as the blood-brain barrier, thereby enabling RNAi therapeutics and other nucleic acid-based medicines to reach the brain after a single intravenous injection.
Moreover, lipid nanoparticles can also be engineered for organ selectivity by changing their structure, e.g., by altering the alkyl chain length of cholesterol derivatives. This can cause selective accumulation in liver endothelial cells, Kupffer cells, and hepatocytes. Barcoding allows for high-throughput profiling of lipid nanoparticle distribution at the cell level.
A key challenge in lipid-nanoparticle-based genome editing is the need for a reliable delivery method, and lipid-nanoparticles are currently the most clinically advanced non-viral gene-delivery system.
Lipid nanoparticles can be formulated to carry various bioactive molecules for topical administration. These include antioxidants, chemotherapeutic agents, and sunscreen protectors. Many of these molecules have poor water solubility or low skin permeation, making it challenging to apply them topically. Encapsulation in lipid nanoparticles can improve their solubility and stability.
The characterization of lipid-based formulations is critical to their development and clinical use. Several methods exist for characterizing these particles, including dark field microscopy, surface plasmon resonance, and background-subtracted membrane imaging (BMI).
BMI has become the most commonly used method for analyzing lipid-based formulations due to its ability to detect subvisible particles with high efficiency and accuracy. Unlike other colloidal carriers, such as liposomes and emulsions, SLNs offer advantages regarding drug loading efficiency, physical stability, and targeted delivery.
Lipid nanoparticles (LNP) have been explored as a novel pharmaceutical drug delivery system and formulation. LNPs have entered clinical trials for several diagnostic and therapeutic applications, including lipid-based nucleic acid aptamers, siRNA drugs, mRNA, and cancer cell targeting molecules.
Lipid-based therapies based on messenger RNA (mRNA) are becoming increasingly popular as promising new therapeutics. However, the success of mRNA-based therapies requires stable and efficient mRNA delivery systems that protect mRNA from degradation and ensure cellular uptake and release.
Researchers have developed lipid-based mRNA delivery vehicles such as SLNs and NLCs to overcome these obstacles. NLCs are a type of solid lipid nanoparticle with high mRNA loading capacity and stability, and they can be further modified to improve their functionality.
For example, NLCs with cationic or ionizable lipids (such as 1,2-distearoyl-sn-glycero-3-phosphocholine [DSPC]) have been shown to increase their stability and cellular uptake. The lipid-mRNA conjugate is delivered via a specialized cartridge containing an organic solvent and aqueous solution.
The cartridge is fitted with a series of microscopic features that allow the two fluids to intermingle in a controlled and reproducible manner. This process results in the self-assembly of lipid nanoparticles encapsulating mRNA. The lipid nanoparticles can then be administered to the patient via intravenous injection.