Count, size and quant your LNPs with Stunner

Significance of the topic

Lipid nanoparticles serve as critical delivery vehicles in mRNA therapeutics and vaccines. Accurate determination of nanoparticle size, concentration and nucleic acid payload ensures batch consistency, optimizes formulation parameters and accelerates process development.

Objectives and Study Overview

This application note evaluates the performance of the Stunner platform in delivering high-throughput measurements of LNP count, size distribution and RNA quantification. Two LNP formulations differing in lipid composition and particle diameter were assessed to demonstrate repeatability and dynamic range.

Methodology and Instrumentation

A plate-based assay combined high-throughput UV/Vis absorbance with rotating angle dynamic light scattering (RADLS) to extract size, particle concentration and RNA payload from a single 2 µL sample without dilution or dyes. LNPs were manufactured using the Sunscreen microfluidic mixer under variable flow rate conditions and buffer-exchanged into PBS. RADLS data were acquired at seven angles and processed to yield intensity, mass and number size distributions.

Použitá instrumentace

• Stunner platform integrating UV/Vis absorbance and RADLS
• Sunscreen microfluidic mixer by Unchained Labs for LNP production
• Plate-based format enabling up to 96 samples in under two minutes per sample

Key Results and Discussion

• Size distributions: Intensity, mass and number outputs reveal rare aggregates, common particle diameter and particle count profiles. Z-average diameter proved sensitive to aggregates and decreased from 206 nm to 161 nm after sequential filtration with 0.45 µm and 0.2 µm filters.
• Repeatability: Small LNPs (mean 82 nm) and large LNPs (mean 159 nm) measured across five instruments showed size CVs of 5% and 4% respectively. Number mean diameters of 48 nm and 127 nm were obtained.
• Particle concentration: Stunner’s estimated particle concentration metric achieved a six-order-magnitude dynamic range (1e7 to 1e13 particles/mL), linearity of R2 = 0.9983 and CVs below 32% at the lowest dilutions.
• RNA quantification: The RNA-LNP application separated turbidity and buffer contributions to quantify total RNA payload. Large and small LNPs yielded 26.5 ng/µL (CV 2.5%) and 32.7 ng/µL (CV 1.7%) RNA, with instrument-to-instrument variation below 1.5%.
• Process screening: Increasing total flow rate produced smaller LNP diameters and higher particle concentrations, while RNA loading per particle remained constant under fixed N/P ratios.

Benefits and Practical Applications

• High throughput measurement of size, concentration and payload in under two minutes per sample
• No external standards, dilutions or fluorescence dyes required
• Angle-independent RADLS yields accurate detection of aggregates and true number concentrations
• Unified platform accelerates formulation development, QA/QC and screening workflows

Future Trends and Potential Applications

Adoption of combined RADLS and UV/Vis platforms is expected to expand into diverse nanoparticle carriers including lipid-polymer hybrids and extracellular vesicles. Integration with real-time process analytics will enable continuous monitoring of critical quality attributes in large-scale production of gene therapies and vaccines. Advanced data analytics may further refine correlations between formulation parameters and delivery efficacy.

Conclusion

The Stunner platform demonstrates robust, high-throughput characterization of LNP size, concentration and RNA payload without consumables or multi-step preparations. Its precision, dynamic range and ease of use position it as a valuable tool for accelerating nanoparticle formulation and quality control.