Microfluidic device combining hydrodynamic/dielectrophoretic trapping

The understanding of cell–cell and cell–matrix interactions via receptor and ligand binding relies on our ability to study the very first events of their contact. Of particular interest is the interaction between a T cell receptor and its cognate peptide–major histocompatibility complex. Indeed, analyzing their binding kinetics and cellular avidity in large-scale low-cost and fast cell sorting would largely facilitate the access to cell-based cancer immunotherapies. We thus propose a microfluidic tool able to independently control two types of micro-sized objects, put them in contact for a defined time and probe their adhesion state. The device consists of hydrodynamic traps holding the first type of cell from below against the fluid flow, and a dielectrophoretic system to force the second type of object to remain in contact with the first one. First, the device is validated by performing an adhesion frequency assay between fibroblasts and fibronectin coated beads. Then, a study is conducted on the modification of the cellular environment to match the dielectrophoretic technology requirements without modifying the cell viability and interaction functionalities. Finally, we demonstrate the capability of the developed device to put cancer cells and a population of T cells in contact and show the discrimination between specific and non-specific interactions based on the pair lifetime. This proof-of-concept device lays the foundations for the development of next generation fast cell–cell interaction technologies.

The project has been carried out by Dr. Lipp at the time of her PhD at LMIS4, under the superviosn of Prof. Philippe Renaud: LMIS1 is now happy to have recently welcomed Clémentine onboard for her postdoc. We all wish her good luck for her future scientific research!

Clémentine has been also interviewed for EPFL news; you can find her own words regarding the project at the follwoing link: https://actu.epfl.ch/news/a-lab-on-a-chip-for-t-cell-screening-and-sorting/

For more details concerning the publication, please visit: https://doi.org/10.1039/d3lc00400g