Count, size and quant your LNPs with Stunner

Significance of the topic

Lipid nanoparticles (LNPs) are central to modern drug delivery in areas such as mRNA vaccines, gene therapy, and targeted therapeutics. Precise measurement of particle concentration, size distribution, and payload content is crucial for reproducible formulation, scale-up, and quality control.

Objectives and study overview

This application note assesses the Stunner platform for integrated analysis of LNPs. The system combines rotating angle dynamic light scattering and UV/Vis absorbance to deliver high-throughput data on particle count, size metrics, and total RNA payload. Two LNP formulations (small SM102/PolyA and large DDAB/calf liver RNA) were evaluated under filtration and varying production flow rates to demonstrate performance.

Methodology and instrumentation

The study employed

• Stunner platform pairing rotating angle DLS (RADLS) with UV/Vis absorbance in a 2 µL plate-based format
• RADLS acquisition at multiple angles to generate angle-independent Z-average, intensity, mass, and number distributions
• UV/Vis absorbance with Unmix spectral deconvolution to quantify RNA without dyes or standards
• Sunscreen microfluidic mixer to produce LNPs at controlled total flow rates and flow rate ratios

Main results and discussion

Key findings include

• Size characterization: RADLS intensity, mass, and number distributions reveal aggregates and core particle populations; Z-average diameter decreased as aggregates were removed by successive filtration steps
• Repeatability: mass mean diameters showed 4–5 percent CV for small and large LNPs across five instruments; number mean diameter CV remained under 5 percent
• Particle concentration: direct RADLS measurements achieved a six-log dynamic range (1e7 to 1e13 particles/mL) with linearity R2=0.998 and 28–30 percent CV
• RNA payload quantification: UV/Vis Unmix reported 26.5 to 32.7 ng/µL RNA with under 3 percent CV and under 1.5 percent inter-instrument variation
• Formulation screening: increasing total flow rate reduced LNP size and increased particle count while maintaining constant RNA concentration, enabling calculation of RNA molecules per particle

Benefits and practical applications

The Stunner platform provides

• Simultaneous high-throughput measurement of particle concentration, size distribution, polydispersity, and payload in under two minutes per sample
• Elimination of dilutions, fluorescent dyes, and standard curves
• Efficient screening of LNP formulations for vaccine development, gene therapy, and nanomedicine production

Future trends and potential applications

Integration of multi-angle light scattering and label-free quantification aligns with emerging needs in personalized nanomedicine, real-time manufacturing control, and quality by design. Future advances may include expanded payload types, automated formulation optimization, and application of predictive analytics through machine learning.

Conclusion

By combining RADLS and UV/Vis absorbance, the Stunner platform offers a rapid, reagent-free, and comprehensive solution for LNP characterization, streamlining development workflows and ensuring robust quality control.

References

Unchained Labs. Count, size and quantify your LNPs with Stunner. Application Note Rev A, 2024.