# Lab-on-a-chip for Isolating Circulating Adipose Stromal Cells: Pre-processing Module

Mohammad Hussein Baz, Lucas Charpin, Coralie Sengenès, Emmanuelle Trévisiol, Anne Marie Gué

► To cite this version:

Mohammad Hussein Baz, Lucas Charpin, Coralie Sengenès, Emmanuelle Trévisiol, Anne Marie Gué. Lab-on-a-chip for Isolating Circulating Adipose Stromal Cells: Pre-processing Module. International Symposium on Microscale Separations and Bioanalysis (MSB), May 2023, Tallahassee, Florida, United States., 2023. [https://hal-04117613](https://hal-04117613)

HAL Id: hal-04117613

https://laas.hal.science/hal-04117613

Submitted on 5 Jun 2023

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# Lab-on-a-chip for Isolating Circulating Adipose Stromal Cells: Pre-processing Module

M. H. Baz¹,², L. Charpin¹,³, C. Sengenès², E. Trévisiol³, A.M. Gué¹

¹ CNRS, LAAS – ² Restore Lab, Toulouse – ³ TBI, Toulouse, FRANCE

## Context :

Circulating Adipose-derived Stromal Cells (ASC) can be considered as biomarkers of type II diabetes as recent research shows. However isolating ASC from whole blood is a difficult task, since no unique specific marker is assigned to these cells. They also have a wide size-distribution, hence a preconcentration step has to be done in order to completely isolate them. In this work, we demonstrate an ASC preconcentration module based on hydrodynamic filtration.

<figure><img src="image_1.png" /></figure>

**Filtration of whole blood:**

In the side-outlet: the smaller cells (Red Blood Cells, RBC)

In the main-outlet: the bigger cells (White Blood Cells, WBC)

## Materials and Methods :

<figure><img src="image_2.png" /><figcaption>Hydrodynamic filtration chip
design</figcaption></figure>

$$Q^* = \frac{Q_1}{Q_{in}} = \frac{Q_2}{Q_{12}} = \dots = \frac{Q_{100}}{Q_{99,100}}$$

$$Q^* = \left(\frac{R_c}{W}\right)^2 \left(3 - \left(\frac{2R_c}{W}\right)\right)$$

<figure><img src="image_3.png" /><figcaption>Dry-film photolithography</figcaption></figure>

<figure><img src="image_4.png" /><figcaption>PDMS microfluidic chips for whole blood filtration</figcaption></figure>

<figure><img src="image_5.png" /></figure>

<figure><img src="image_6.png" /></figure>

<figure><img src="image_7.png" /></figure>

<figure><img src="image_8.png" /><figcaption>Hydro filtration chip</figcaption></figure>

### A. Whole blood filtration

<figure><img src="image_9.png" /></figure>

<figure><img src="image_10.png" /></figure>

<figure><img src="image_11.png" /><figcaption>Purification of 99,9 % of RBCs
from whole blood samples</figcaption></figure>

### B. Whole blood sample spiked with fluorescent beads

<figure><img src="image_12.png" /></figure>

<figure><img src="image_13.png" /></figure>

<figure><img src="image_14.png" /><figcaption>100 % recovery
of 15 µm
fluorescent
beads</figcaption></figure>

### C. Whole blood sample spiked with ASCs

**Quasi-total ASC recovery !**

<figure><img src="image_15.png" /><figcaption>Fluorescent ASCs</figcaption></figure>

<figure><img src="image_16.png" /><figcaption>Main-outlet</figcaption></figure>

<figure><img src="image_17.png" /><figcaption>Side-outlet</figcaption></figure>

## Conclusions and perspectives :

We demonstrate a highly promising blood pre-processing chip which outperforms standard leukocyte separation protocols that adopt stringent conditions. The chip demonstrated 100 % filtering of beads from extremely low concentrations in bead/blood mixtures. Experiments with ASC/blood mixtures showcase high recovery and detection of ASC which is indeed very promising. Work is undergoing on another magnetophoresis chip that depletes remaining leukocytes in order to finally purify ASC.