Lipid nanoparticles encapsulate and protect mRNA as it reaches the target cells. There, ribosomes read the instructions of the mRNA strand to produce a protein that can fight disease.

This approach could one day deliver a whole new generation of drugs, taking programmable medicine to its ultimate promise. But many challenges remain.

Liquid Functional Materials

The advent of mRNA therapeutics has given rise to several exciting new potential applications for this technology, including vaccines, cell-based therapies, genome editing, and cellular reprogramming. However, efficient expression of the mRNA-encoded protein in cells requires it to be delivered into cells correctly, typically through a lipid nanoparticle formulation.

This requires complexing negatively charged mRNA with lipids to facilitate scavenger receptor-mediated endocytosis and subsequent mRNA escape from the endosomal compartment into the cytosol, which can be translated into protein. This makes it essential to optimize lipid formulations and delivery vehicles and to have analytical methods capable of measuring the critical quality attributes of these products.

As with any drug or vaccine candidate, comprehensive characterization is necessary for pre-clinical development and clinical trials. However, the rapid progression of mRNA candidates brings unique challenges to the analytical space. New analytical approaches must keep pace to ensure the identity, safety, and efficacy of evolving mRNA candidates to meet the needs of developing mRNA therapeutics.

Liquid-Liquid Coexistence

As biomolecular condensates regulate cellular structure and biochemistry, they also present new opportunities for drug pharmacology. For example, membrane-less organelles assembled by mRNAs may be targeted to sequester native proteins that modulate their activity.

Recent discoveries show that liquid-liquid phase separation is commonplace in living cells and plays a role in many active processes, including transcription, gene control, signaling, and cellular repair. For instance, RNA-mediated coactivator condensation at super-enhancers links DNA repair compartment formation to transcriptional control. Similarly, nucleo-cytoplasmic partitioning of the ESCRT-0 protein complex mediates nascent-peptide ubiquitination in the endosomal compartment.

Developing mRNA therapeutics requires a deep understanding of the physics and chemistry behind these dynamic interactions. This includes accurate vapor-liquid and liquid-vapor coexistence curves and the extended van der Waals-type equation of state (EOS). Analytical capabilities enable our customers to develop quality mRNA therapeutics using an advanced, flexible formulation in lipid spheres for high stability and delivery. These can then be rapidly tested in a clinical setting to verify their efficacy and safety. These insights are vital to unlocking the disruptive potential of mRNA-based vaccines and therapies.

Liquid-Liquid Patterning

Since mRNA is an unstable nucleic acid, it is prone to rapid degradation by omnipresent RNases. To increase its stability, mRNA is typically encapsulated in LNPs. However, preparing LNPs is time-consuming and requires high-quality raw materials that must be extensively screened for purity. This is why LC techniques like anion exchange (AEX) or ion-pair reversed-phase (IP-RP) are commonly used to analyze LNP lipid and nucleotide composition.

To be translated into a functional protein, mRNA must pass through the lipid bilayer of the cell. This is why most developed mRNA delivery formats aim to co-deliver innate immunoadjuvants or other therapeutic molecules with mRNA to augment its uptake and translation into cellular proteins.

However, despite mRNA’s increased uptake and translation efficiency in lipid nanoparticles, only a fraction of mRNA makes it to the cellular cytoplasm. Thus, mRNA vaccines still face significant hurdles in clinical translation. To address this, researchers are developing mRNA constructs with improved uptake and stability that can be readily administered to patients.

Self-Healing

Unlike vaccines, which typically require just one or two doses before the immune system learns to recognize and attack the pathogen, mRNA medicines that encode proteins for disease treatment have a longer road to the clinic. Their effectiveness depends on delivering the mRNA to tissues and preventing its degradation by cellular ribonuclease.

Lipid nanoparticles are the primary carrier vehicles for mRNA delivery, but their size and polydispersity index (PDI) determine how efficiently they carry cargo to cells. Changing these properties can significantly improve the performance of mRNA therapeutics and is a crucial focus of intellectual property efforts.

Many teams are tweaking the structure of lipids and adorning them with molecules that route them to specific tissue types. For example, some have tagged lipid nanoparticles with DNA barcodes to track their trajectories in animals. This will enable researchers to see how well a particular mRNA is delivered to target tissues and help guide future research. The researchers also found that the stiffness of a lipid determines how much mRNA it can provide to the cell.

Energy Storage

RNA-based vaccines and therapeutics rely on encapsulating in vitro-transcribed mRNA in lipid nanoparticles (LNPs) for transport to target cells. This technology has rescued the world from Covid-19 and is now driving innovations for various infectious diseases, cancers, genetic disorders, and other ailments.

Lipid-based LNPs provide a platform for mRNA delivery with high physiological stability and structural tunability. Moreover, they are highly biocompatible and can be made with degradable polymers that bind nucleic acid cargo via electrostatic interactions.

Nonetheless, the long-term stability of mRNA-LNP particles is a significant challenge for mRNA-based drugs and vaccines. Achieving mRNA-LNP product stability for drug supply and use requires multiple steps that must be considered at all stages of development, manufacture, and storage.

For instance, mRNA-LNPs require careful design to ensure they do not contain immature mRNA, which can inhibit translation and trigger an innate immune response. Furthermore, the lipid components of mRNA-LNPs must be essentially impurities-free and physically stable enough to endure handling and distribution hazards. In addition, mRNA-LNP products must be protected from temperature shocks and vibrations, common during storage and distribution.

Jane