CELLUSWIMM- swimming vesicles as pilotable drug conveyors

Most drug targeting strategies are based on concepts such as molecular recognition that could be considered as "passive" strategies. This project proposes to explore the possibilities of exploiting a physical phenomena called “buckling” to control the delivery of a drug in an active way.

When subjected to pressure cycles, air-filled spherical shells can “swim” in a liquid medium due to mechanical instability phenomena inducing the asymmetrical deformation of their membrane. A theoretical model was developed at the LIPhy to predict the swimming behaviour under different conditions, in particular the frequency and the amplitude of the pressure wave, the thickness of the shell membrane and its mechanical properties. This model shows that a micron-sized shell submitted to ultrasonic waves such as those emitted by echography devices, could swim at a speed that would enable the shell to travel upstream in blood circulation or in the lymphatic system.

This project consists in designing such shells on a micrometric scale by adsorbing cellulose and hemicellulose nanocrystals on the surface of micron-sized air bubbles produced in a microfluidic device, and to assemble them into an object whose displacement would be entirely controllable by ultrasonic waves. The existence of a biocompatible conveyor capable of moving through the body via ultrasound facilities would offer a unique solution for the vectorisation and dissemination of therapeutic molecules.