Authors
Rik Oude Egberink, Deni van Schie and Roland Brock
Department
Dept. of Medical BioSciences, Radboud university medical center, Geert Grooteplein 28, 6525 GA Nijmegen, The Netherlands,
Introduction
For cellular delivery in biomolecular research and clinical applications alike,
mRNA is packaged into nanometer-sized nanoparticles using lipid formulations,
peptides, or polymers. So far, only a few delivery approaches have yielded
efficient delivery. To understand, how formulation parameters affect mRNA
packaging, interaction with biological media and cellular uptake, ideally analytical
approaches should be used that enable an investigation of mRNA nanoparticles
at the relevant spatial dimensions which means below the resolution limit
obtained by conventional light microscopies.
STORM (stochastic optical resolution microscopy) super-resolution microscopy
provides the means to visualize individual mRNA nanoparticles and even
determine the stoichiometry of molecules within these nanoparticles.1 A
prerequisite for conducting STORM analyses is the labeling of the molecules of
interest with photoswitchable fluorophores. Here, we used mRNA labelled with
AZDye488 and AZDye647 to simultaneously analyze two different types of
mRNA nanoparticles. In this way, we were able to show that these two particle
types neither aggregate nor mutually exchange mRNA molecules.