New Cationic Microbubbles for Nucleic Acids Transfer

Dr Nathalie Mignet and Simona Manta at the University of Paris Descartes are working on a project researching the use of gas filled microbubbles formed using ultrasound and their ability to interact with cells. The aim of their research is to develop a mechanism whereby the gas microbubbles would be capable of delivering both a cytotoxic agent (Paclitaxel) and RNA interference to promote tumour regression.

The main limitation of this techniques is the low transfection efficiency of commercially available microbubbles.  Therefore the group decided to design cationic microbubbles with the aim of binding the DNA  tighter to the microbubble shell and provided the capacity for the DNA to fuse with cellular membranes.

The Izon Science qNano is being used by the research group to measure size and concentration of the synthesized microbubbles in different lipid-based formulations. The qNano uses Tunable Resistive Pulse Sensing (TRPS) to give accurate measurements not possible with other sizing methods. Precise particle size, concentration and charge measurements represent an essential part of the research when assessing the physical properties, reaction kinetics and drug efficacy. The complexity of the situation was added to, because of the inherent difficulty in working with microbubbles due to buoyancy effects.

To assist the team, Izon Science provided onsite training and ongoing support to the team throughout their project. Microbubble stability was then further characterised and the size and concentration measurements obtained by the qNano to give a complete and accurate data. The results obtained using TRPS demonstrated that specific conditions should be taken to insure the reliability of the data due to the buoyancy effects. Izon’s nanopore technology is now being relied upon to provide particle-by-particle measurement for a much higher degree of detail and precision.

This project  demonstrated the ability to exploit original cationic lipids to produce stable gas microbubbles that can be simultaneously loaded with Paclitaxel and bind to siRNA molecules.