Lipid Nanoparticles Encapsulated with siRNA

Author: admin     Date: February 22, 2024

Nanoparticle-mediated gene therapy has garnered considerable attention over the past two decades. Lipid nanoparticles (LNPs) encapsulating siRNA are currently the most extensively clinically validated means of enabling RNA interference. However, determining the precise particle count and the fraction of loaded particles poses challenges. Although, in principle, particles can be counted in cryo-TEM images, the non-uniform distribution of LNPs in vitrified samples on electron microscopy grids makes it difficult to obtain an accurate particle count.


Moreover, the comparable size, shape, and electron density of empty and siRNA-loaded LNPs render cryo-TEM less effective in determining the fraction of siRNA loading. The Flow NanoAnalyzer is used here for quantitative, multi-parameter characterization of siRNA-loaded LNPs. Upon fluorescent staining with SYTO™ 82, the fraction of siRNA loading is determined.


Figure 1. Characterization of siRNA nanomedicine after SYTO™ 82 staining.


Figure 2. Concentration measurement of unstained siRNA-loaded LNPs by internal standard method.

The Flow NanoAnalyzer is able to detect the side-scatter signal from single nanomedicine particle, and upon SYTO™ 82 staining, empty and siRNA-loaded LNP samples are discriminated, and the fraction of siRNA loading is calculated.

Multi-parameter characyerization of mRNA LNPs

Author: admin     Date: February 22, 2024

Lipid nanoparticles (LNPs) are currently in the spotlight as delivery systems for mRNA therapeutics and have been utilized in the Pfizer/BioNTech and Moderna COVID-19 vaccines. In theory, mRNA can be used to express any type of protein. In addition to vaccines, mRNA has a broad application in the fields of protein replacement therapy, tumor treatment, gene editing, and regenerative medicine.


Delivery systems are required for nucleic acid drugs to function, as they are negatively charged. Among these systems, LNPs are mostly applicable and provide a highly efficient platform for the in vivo delivery of RNA. Accurate characterization of the physical and chemical properties of nucleic acid drugs, such as compositions, size distributions, and structure, is helpful and critical for drug design, research and development (R&D), and quality control.

In this research, a comprehensive characterization method was developed based on the Flow NanoAnalyzer platform. Researchers can achieve quantitative analysis of size distribution, particle concentration, empty shell rate, entrapment efficiency, and localization of nucleic acid drugs. This method holds high application value during the upfront stages of R&D, production, purification, quality control, and stability assessment of the drugs.


Figure 1. Typical data of nucleic aic drugs analysis 

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