Our research is focused on understanding nanoparticle formation through turbulent mixing of solvent and antisolvent streams in confined geometries. Confined turbulent mixing enables reproducible production of lipid nanoparticles under continuous flow conditions, ranging from laboratory scale at hundreds of microliters to industrial scale at dozens of liters per minute. Lipid nanoparticles are typically prepared with microfluidic devices or by pipette mixing.
These microfluidic devices mix ethanol solvent and aqueous antisolvent streams in these capillary-like channels. However, these small channels and low flow rates yield a low Reynolds number, which leads to laminar mixing. And pipette mixing produces LNPs by injecting the solvent stream directly into an antisolvent bath.
The current methods to make lipid nanoparticles have poor scalability and reproducibility. For example, pipette mixing is inherently variable due to the unconfined manual mixing. While microfluidic devices address some of these issues, they operate at very low flow rates.
And they foul due to lipid RNA deposition on the channel walls. These issues highlight the need to have reproducible techniques with high throughput at laboratory to clinical scales. This protocol demonstrates reproducible and scalable production of lipid nanoparticles through turbulent mixing across different batch sizes.
Researchers can confidently perform LNP formulation screening or optimization at small scales before producing larger batches of materials for extended trials. Turbulent mixing ensures consistent nanoparticles regardless of the batch size. Confined to geometry turbulent mixers address the major issues with existing lipid nanoparticle production techniques.
Using turbulent conditions produces faster molecular scale mixing, which enables the incorporation of differently sized oligonucleotides into the LNP core. The CIJ mixer also eliminates the fouling caused by lipid deposition on the mixer walls. Turbulent flows at the same Reynolds number, have self-similar turbulent Kolmogorov scale vortices for consistent mixing.
