Researchers in the department of Chemical and Biomolecular Engineering at Ohio State University, Columbus, Ohio, US, are using Malvern’s NanoSight nanoparticle tracking analysis (NTA) to study extracellular vesicle yields from different cell culture lines.

Ohio eminent scholar Dr Michael Paulaitis and professor Jeffrey Chalmers have been leading the team characterising the microvesicles.

The work is part of a larger NIH-funded project headed by professor Thomas D Schmittgen and professor Mitch Phelps in the division of Pharmaceutics and Pharmaceutical Chemistry at the university.

The project aims to engineer cells to manufacture extracellular vesicles that target the liver, in order to deliver a specific microRNA species capable of retarding the growth of tumour cells.

Extracellular vesicles are released by almost all cell types. By transferring their molecular cargo, they have the potential to alter the function of recipient cells.

The overall project includes the development of cell lines capable of producing large numbers of extracellular vesicles that have specific gene inclusions and a surface tag for targeting.

NTA is being used to quantify extracellular vesicle particle numbers and yields in terms of their microRNA content and the presence of the surface markers.

The aim of the project is to further the development of specific therapeutic options for hepatocellular carcinoma (HCC), the third most prevalent cancer in the world.

Dr Paulaitis said: "The Malvern NanoSight NTA system allows us to directly and reliably quantify extracellular vesicle yields from the cell lines under investigation, which is critical to this project.

"We are also using the system to study the fusion of extracellular vesicles with synthetic nanoparticles, for the purpose of engineering the properties of the nanoparticles.

"We use a combination of the light scattering and fluorescence tracking functions of the NanoSight system to determine the proportion of fluorescently labelled nanoparticles that have bound to the extracellular vesicles.

"Having determined that we can quantify binding, the next step will be to scale up and apply NTA as a QC and process evaluation technique."

The Malvern NanoSight range of instruments uses nanoparticle tracking analysis to characterize nanoparticles from 10nm – 2000nm in solution.

Each particle is individually but simultaneously analysed by direct observation and measurement of diffusion events.

This particle-by-particle methodology produces high-resolution results for particle size distributions and concentrations, while visual validation provides users with additional confidence in their data.

Both particle size and concentration are measured, while the fluorescence tracking mode can provide differentiation of labelled or naturally fluorescing particles.

Research at Ohio State University is supported by NIH Common Fund Grant 1UH2TR000914-01 ‘Targeted delivery of microRNA loaded microvesicles for cancer therapy’ and by NSF Nanoscience and Engineering Center for Affordable Nanoengineering of Polymeric Biomedical Devices.