Gas-Phase Electrophoresis (nES GEMMA Instrumentation) of SARS-CoV-2-Based Virus-like Particles

Area of Science:

• Analytical Chemistry
• Biophysics
• Nanotechnology

Background:

• Virus-like particles (VLPs) are non-infectious viral mimics of significant interest for vaccine development, gene therapy, and diagnostics.
• Accurate characterization of VLPs, including size, stability, and molecular weight, is crucial for their applications.
• Existing methods for VLP characterization can be complex or limited in scope.

Purpose of the Study:

• To demonstrate the feasibility of using gas-phase electrophoresis on a nano-electrospray gas-phase electrophoretic mobility molecular analyzer (nES GEMMA) for characterizing SARS-CoV-2 VLPs.
• To evaluate the nES GEMMA's capability in determining VLP size, size distribution, stability, and molecular weight.
• To showcase the potential of nES GEMMA for analyzing host-cell proteins and VLP building blocks alongside VLPs.

Main Methods:

• Gas-phase electrophoresis was employed using a nES GEMMA instrument at ambient pressure with a high laminar sheath flow of particle-free air and a tunable electric field.
• Singly charged particles, including SARS-CoV-2 VLPs, were separated based on their size.
• Particle-number-based detection was utilized for analyte quantification.

Main Results:

• The study successfully demonstrated gas-phase electrophoresis of SARS-CoV-2 VLPs using the nES GEMMA.
• VLPs were detected as broad, size-heterogeneous peaks, indicating their inherent heterogeneity.
• The nES GEMMA allowed for the simultaneous analysis of VLPs, host-cell proteins, and VLP building blocks, providing insights into particle size, number concentration, and molecular weight.

Conclusions:

• Gas-phase electrophoresis on a nES GEMMA is a viable and robust method for characterizing SARS-CoV-2 VLPs.
• This technique offers valuable information on VLP properties essential for their development and application in areas like vaccine research.
• The nES GEMMA provides a versatile platform for analyzing various macromolecular components within VLP-containing samples.