MICROFLUIDIC TOOLS FOR CELL BIOLOGY

Video: Wound healing assay in microfluidic device

Introduction

Microfluidics is widely used to develop tools for cell biology. The micrometer scale of microfluidic devices is particularly adapted to work with cells, and miniaturization of the systems allow to easily implement high throughput assays. Moreover, the fluid properties at this scale help to create stable concentrations of gradients, and to precisely control fluid composition and temperature.

Recent developments of microfluidics have led to a better control of the cells’ micro-environment, enabling innovative cell biology research.

Parallelization of experiments. The reduced size of microfluidic devices allows to create high throughput experiments and collect more data than with regular assays.

Cell culture medium renewal. The renewal of cell culture medium can be precisely controlled and automated.

Spatial control over fluid composition. Fluids have a laminar behavior at the micrometer scale, allowing to create gradients.

Control of temperature and gas. The small volumes used in microfluidics allow dynamic control over temperature and dissolved gas.

Control of the cells’ substrate. Thanks to micro-patterning methods, the cells’ substrate parameters can be controlled.

Compatibility with live cell imaging. Microfluidics allows to perform numerous tasks, such as drug exposure, while imaging the cellular response.

Single cell manipulation and analysis. Microfluidics allows to perform single cell manipulation in a very accurate way.

These advantages led to an increasing number of research groups using microfluidic technologies to push forward their cell biology research, as shown by the large and still increasing number of publications about microfluidics and cell biology.

Number of publications per year with the words “microfluidic” and “biology”

Source: Google Scholar

Taking advantage of the precise control of microenvironment provided by microfluidics, the research community has developed numerous microfluidic devices dedicated to cell proliferation. Contrary to conventionnal cell culture, microfluidics offers the possibility to mimic in vivo micro-environments while working at a high throughput.

The small dimensions of microfluidic devices ensure laminar flows even at high velocity. Very simple microfluidic chips designs can be used for this application, such as straight channels with defined height and width. Moreover, this method allows to apply flow patterns (such as oscillatory flows) to mimic some in vivo conditions. If you want to calculate shear stress, you can find a microfluidics-adapted shear stress calculator at Darwin Microfluidics.

Microfluidics enhances conventional cell migration assays in two distinct ways. The first one is the possibility to create a stable concentration gradient at a cellular length scale, the second one is the possibility to use microfluidics for live cell imaging to quantify cellular response.

Microfluidics is a widely used tool to investigate the effect of cell deformation. Different techniques are possible: confining cells in small channels, applying a mechanical pressure on the cells thanks to deformable channels or applying shear stress using laminar flow.

Cells can easily be encapsulted in water-in-oil droplets, creating discrete micro-reactors. This allows to study cellular behavior at a single cell level, rather than a population average.

Organs on chips are microengineered biomimetic systems that replicate key functions of living organs. These microdevices provide a more accurate model than conventional cell culture for simulating complex cell-cell and cell-matrix interactions.

References