Laboratoire Matière et Systèmes Complexes

Continuous Droplet Interface Crossing Encapsulation (cDICE) : towards artificial cells and tissues

Gladys Massiera Laboratoire Charles Coulomb Université Montpellier II et CNRS

Lundi 23 Septembre à 11h30.

The Continuous Droplet Interface Crossing Encapsulation (cDICE)[1] is an easy and robust method for producing, at high yield, monodisperse lipid vesicles with a controlled content. We will discuss the physical mechanisms involved in the production of cDICE vesicles and capsules, and several applications of this method, such as its use as an artificial red blood cell, or for artificial tissues. The set-up consists of a cylindrical rotating topped-chamber, filled with a Dispersing Aqueous Solution (DAS) and a lower density lipid-in-oil solution (LOS) that form a vertical interface due to the centrifugal force. A capillary is introduced in the LOS and droplets of the aqueous solution to be encapsulated (EAS) continuously drip off the capillary. As soon as they detach from the capillary, they are centrifuged towards the LOS/DAS interface. During their ‘flight’ across the LOS layer, a monolayer of lipids adsorbs onto the aqueous droplets, which zip with another monolayer during the crossing of the LOS/DAS interface. The cDICE method allows to encapsulate various solutions (biopolymers, hemoglobin, colloids, polymeric gels, cells. . . ) in membranes that can be composite and/or assymetric, or polymeric. We will characterize accurately the vesicles produced and some specific applications will be detailed. Finally, we will also describe the key-steps for the success of this process. In particular, by imaging the crossing step and by characterizing the LOS solution, we will describe how the state of the LOS is crucial for two steps : the coating of the interfaces by the lipids (droplets and LOS/DAS) and the zipping of the monolayers to form the final EAS enclosing bilayer.

[1] Loiseau E, Abkarian M, Massiera G., Soft Matter 7, p.4610-4614, (2011). Continuous droplet interface crossing encapsulation (cDICE) for high through-put monodisperse vesicle design