Thesis of Majid Layachi

Amphithéâtre Pierre Glorieux (CERLA) Thesis defense of Majid Layachi - laboratory Phlam Development of a Microfluidic Device for High Throughput Photoporation Abstract : Cell transfection aims at introducing foreign material inside a biological living cell. This intracellular drug transport process is at the heart of many diagnosis procedures and a key step in gene therapy. In view of these stakes, high perfor-mances are of importance, namely the success rate (positive and viable cells), the quality (uptake) and the throughput (treatment rate). Research has been conducted to understand how the spontaneous uptake of macromolecules (endocy-tosis) is limited while workarounds to bypass cell barriers for controlled intracellular drug release has received consistent payo˙. However, up-to-date techniques mimicking bio-elements or introducing physical means su˙er several drawbacks. Nevertheless, Gold nanoparticle (AuNP) mediated photoporation has stood out as a promising tool to permeabilize cell membranes through laser induced Vapour NanoBubble (VNB) generation. Based on these VNBs, a novel micro˛uidic approach is presented in this work, o˙ering high throughput prospects with no contact with AuNPs to retrieve AuNP-free treated viable cells.
We set up a new opto˛uidic experiment, integrating the use of advected AuNPs to achieve VNB generation near suspen-ded cells. This method allows high throughput, high e°ciency and low cytotoxicity drug delivery. Based on hydrodynamic focusing, the approach allows the control and tuning of the cell-to-AuNP distance. With the optical setup used, through-put ranging from 103 to 104 cells/min can be achieved. Interestingly, it yields a better viability than the mixed AuNP-cell approach (∼ 80% vs. ∼ 40%). As a matter of fact, viability increases with distance whereas transfection rate decreases (∼ 30% vs. ∼ 50%). Both a transfection and a rheological tool, our opto˛uidic device is a bridge toward triggered single cell transfection, circumventing barriers to the clinical deployment of emerging cellular therapies. Keywords : Photoporation, plasmonic nanobubbles, micro˛uidics, high-throughput intracellular delivery, nanoparticule micro-positioning