Le Ru Eric C, Böttger Roland, Andrews Darren, Baumhof Patrick, Rakonjac Jelena V, Laufersky Geoffry, Darby Brendan L
Marama Labs Limited, 32 Salamanca Road, Wellington, 6012, New Zealand.
The MacDiarmid Institute for Advanced Materials and Nanotechnology, School of Chemical and Physical Sciences, Victoria University of Wellington, P.O. Box 600, Wellington 6140, New Zealand.
Nano Lett. 2025 Apr 23;25(16):6813-6819. doi: 10.1021/acs.nanolett.5c01491. Epub 2025 Apr 8.
UV/visible spectroscopy is the method of choice for RNA quantification, thanks to its simplicity and accuracy. However, it cannot be used to quantify RNA in lipid nanoparticles (LNPs), such as those used for drug delivery in mRNA vaccines, because of light scattering by LNPs. Alternative methods such as the RiboGreen fluorescence assay require much more sample preparation and lack reproducibility and accuracy. Here we propose and demonstrate an alternative approach using an integrating sphere setup to measure scatter-free absorption spectra. RNA spectra of RNA-loaded LNPs can then be directly measured, and the total RNA concentration can be deduced. The method shows very good linearity and precision (∼1.5%), and the accuracy is estimated to be ∼5% when applied to various mRNA-LNP formulations. This work paves the way for the routine characterization of payload concentration in LNP formulation research.
紫外/可见光谱法因其简单性和准确性，是RNA定量的首选方法。然而，它不能用于定量脂质纳米颗粒（LNP）中的RNA，例如用于mRNA疫苗药物递送的那些LNP，因为LNP会产生光散射。诸如RiboGreen荧光测定法等替代方法需要更多的样品制备，并且缺乏重现性和准确性。在这里，我们提出并展示了一种使用积分球装置来测量无散射吸收光谱的替代方法。然后可以直接测量负载RNA的LNP的RNA光谱，并推导出总RNA浓度。该方法显示出非常好的线性和精密度（约1.5%），当应用于各种mRNA-LNP制剂时，估计准确度约为5%。这项工作为LNP制剂研究中有效载荷浓度的常规表征铺平了道路。
