A polymeric cell stretching device for real-time imaging with optical microscopy

Abstract

This paper reports the design, fabrication and characterization of a cell stretching device based on the side stretching approach. Numerical simulation using finite element method provides a guideline for optimizing the geometry and maximizing the output strain of the stretched membrane. An unique PDMS-based micro fabrication process was developed for obtaining high parallelization, well controlled membrane thickness and an ultra-thin bottom layer that is crucial for the use with confocal microscopes. The stretching experiments are fully automated with both device actuation and image acquisition. A programmable pneumatic control system was built for simultaneous driving of 24 stretching arrays. The actuation signals are synchronized with the image acquisition system to obtain time-lapse recording of cells grown on the stretched membrane. Experimental results verified the characteristics predicted by the simulation. A platform with 15 stretching units was integrated on a standard 24 mm × 50 mm glass slide. Each unit can achieve a maximum strain of more than 60 %. The platform was tested for cell growth under cyclic stretching. The preliminary results show that the device is compatible with all standard microscopes.

Time dependence of cellular responses to dynamic and complex strain fields

“…To address these challenges, we built upon our previous design 31 as well as those of others 32,33 and we developed the 2x2 microstretcher array which working principle is summarized in Fig. 1.…”

“…Previous pneumatic-based microfluidic stretchers were generally permanently closed [31][32][33][34] . The general approach used here consists instead in extending the cell chamber height in such a way as to leave only a thin PDMS layer to act as the top sealant.…”

Fabrication and characterization of silicone-based dielectric elastomer actuators for mechanical stimulation of living cells

“…Radial strain can be generated with a chamber located underneath 13 or around 14 a circular membrane. Linear strain can be generated with two chambers located on opposite sides of a square membrane 15 . In this configuration, adding a second set of chambers enables much greater flexibility on the strain profile 16 .…”

Computationally Informed Design of a Multi-Axial Actuated Microfluidic Chip Device

“…High throughput screening represents the major outcome of such a vast technological improvement that necessitates a fine control over microfluidic, mechanical, and multiphysical interactions 18 . Mechanotransduction and mechanosensitivity are universally recognized as fundamental pathways for the correct physiological development of in vitro tissues 19, 20 , and this aspect has been long investigated in tissue-engineered models by applying mechanical stimulation to substrates or scaffolds seeded with cells 21, 22 .…”

“…Mechanotransduction and mechanosensitivity are universally recognized as fundamental pathways for the correct physiological development of in vitro tissues 19, 20 , and this aspect has been long investigated in tissue-engineered models by applying mechanical stimulation to substrates or scaffolds seeded with cells 21, 22 . However, with the advances in micro- and nano-scale technologies, a new class of microfabricated devices for the study of biological processes under mechanical stimulation 18, 23 has been developed. In this framework, the notable work from groups as the one led by D.E.…”