Single LNP analysis

With super-resolution microscopy, analyzing individual LNPs has never been easier. This technique offers high-detail imaging in physiological-like conditions, enabling clear visualization and distinction of individual LNPs, even when they are close together.

Our Nanoimager offers simultaneous analysis of thousands of individual LNPs, at a single LNP level. This enhanced clarity provides critical insights into the loading efficiency of both cargo and ligand, and allows scientists to optimize their production processes to maximize and perfect their yield.

Figure (left): SMLM offers quantitative insights into LNP characteristics, including accurate sizing, detection of cargo and efficiency of ligand loading, at a single LNP level.

Morphology, Size and Stability

Single Molecule Localization Microscopy (SMLM), specifically dSTORM, provides a powerful tool for examining the morphology of individual lipid nanoparticles (LNPs) with unprecedented resolution.

Unlike techniques like flow cytometry and mass-spectrometry, which aggregate data, dSTORM provides precise nanometer-level details on LNP morphology and size. It is crucial for quality control to measure size variability accurately: small particles may indicate degradation, large ones could be aggregates, and high polydispersity suggests instability. Thus, assessing size variability helps evaluate sample quality.

With the full information on size variations and structural anomalies, scientists can accurately assess their LNP behavior, and optimize the formulations for effective therapeutic applications.

Figure (left): Size distribution of two distinct LNP populations, measured with SMLM. The LNP Surface marker is in magenta.

Cargo loading

One of the key challenges in LNP development for therapeutics is to have the cargo encapsulated in as many LNPs as possible. For that, it is essential to assess how many LNPs contain cargo and under what conditions.

By combining SMLM imaging of the LNP surface marker, fluorescence imaging of the cargo, and advanced software tools, scientists can quantify their cargo positivity at a single LNP level. This valuable information attests to the loading efficiency without compromising on inaccuracies like signal averaging.

Figure (left): Size distribution of 3 LNP populations: Top row – empty LNP, middle row – cargo-containing LNP, bottom row – 1:1 mix of empty LNPs and cargo-containing LNPs.
Surface marker is in magenta, RNA cargo is in cyan (diffraction limited images).

Ligand loading

Drug delivery using LNPs is most effective when the LNP surface is loaded with ligands that direct the LNPs to specific target cells. Super-resolution microscopy encompasses the ability to inspect individual LNPs and measure ligand positivity and abundance accurately and reproducibly.

The abundance of ligands on each individual LNP correlates with targeting efficiency, so quantifying the ligand occurrence using SMLM is very valuable in assessing the effectiveness of ligand loading, alongside the ligand interactions with its targets. Gaining data on both the fraction of ligand positivity and its abundance provides the researcher with information on individual LNPs, as well as on their entire population.

Figure (left): Montage of representative SMLM LNP images. Surface marker is in magenta, ligand is in yellow.