Advanced Microfluidic Device Designed for Cyclic Compression of Single Adherent Cells.

Kenneth K Y Ho,Ying Lin Wang,Allen P Liu,Jing Wu

doi:10.3389/fbioe.2018.00148

Abstract

Cells in our body experience different types of stress including compression, tension, and shear. It has been shown that some cells experience permanent plastic deformation after a mechanical tensile load was removed. However, it was unclear whether cells are plastically deformed after repetitive compressive loading and unloading. There have been few tools available to exert cyclic compression at the single cell level. To address technical challenges found in a previous microfluidic compression device, we developed a new single-cell microfluidic compression device that combines an elastomeric membrane block geometry to ensure a flat contact surface and microcontact printing to confine cell spreading within cell trapping chambers. The design of the block geometry inside the compression chamber was optimized by using computational simulations. Additionally, we have implemented step-wise pneumatically controlled cell trapping to allow more compression chambers to be incorporated while minimizing mechanical perturbation on trapped cells. Using breast epithelial MCF10A cells stably expressing a fluorescent actin marker, we successfully demonstrated the new device design by separately trapping single cells in different chambers, confining cell spreading on microcontact printed islands, and applying cyclic planar compression onto single cells. We found that there is no permanent deformation after a 0.5 Hz cyclic compressive load for 6 min was removed. Overall, the development of the single-cell compression microfluidic device opens up new opportunities in mechanobiology and cell mechanics studies.

Highlights

Cells and tissues in our body experience various kinds of chemical and mechanical signals in physiological and pathological conditions
Single-Cell Microfluidic Compression Device unloading was found to result in an increase in residual deformation, which was suggested to be an adaptive process for cells to protect themselves against mechanical damage (Bonakdar et al, 2016)
We describe our effort in developing a microfluidic device for singlecell static and cyclic compression

Summary

INTRODUCTION

Cells and tissues in our body experience various kinds of chemical and mechanical signals in physiological and pathological conditions. There is a growing interest in studying the response of cells from compressive stress in other physiological environments, for example during development (Mammoto and Ingber, 2010) and in cancer (Jain et al, 2014; Ricca et al, 2018) Mechanical forces, such as compression generated by living cells are crucial for the control of embryonic development. With the integration of microsized and fast-operating valves in the microfluidic system, several microfluidic platforms have been developed for studying biological responses of cells under a compressive stress (Kim et al, 2007; Hosmane et al, 2011; Si et al, 2015) These microengineering devices allow the application of compression to cells. We showed the device capability to apply cyclic compression on cells and found that there is no permanent change in the height of the breast epithelial MCF-10A cells after cyclic compression

MATERIALS AND METHODS

RESULTS AND DISCUSSION

CONCLUSION