Polydimethylsiloxane-polycarbonate Microfluidic Devices for Cell Migration Studies Under Perpendicular Chemical and Oxygen Gradients

Abstract

This paper reports a microfluidic device made of polydimethylsiloxane (PDMS) with an embedded polycarbonate (PC) thin film to study cell migration under combinations of chemical and oxygen gradients. Both chemical and oxygen gradients can greatly affect cell migration in vivo; however, due to technical limitations, very little research has been performed to investigate their effects in vitro. The device developed in this research takes advantage of a series of serpentine-shaped channels to generate the desired chemical gradients and exploits a spatially confined chemical reaction method for oxygen gradient generation. The directions of the chemical and oxygen gradients are perpendicular to each other to enable straightforward migration result interpretation. In order to efficiently generate the oxygen gradients with minimal chemical consumption, the embedded PC thin film is utilized as a gas diffusion barrier. The developed microfluidic device can be actuated by syringe pumps and placed into a conventional cell incubator during cell migration experiments to allow for setup simplification and optimized cell culture conditions. In cell experiments, we used the device to study migrations of adenocarcinomic human alveolar basal epithelial cells, A549, under combinations of chemokine (stromal cell-derived factor, SDF-1α) and oxygen gradients. The experimental results show that the device can stably generate perpendicular chemokine and oxygen gradients and is compatible with cells. The migration study results indicate that oxygen gradients may play an essential role in guiding cell migration, and cellular behavior under combinations of gradients cannot be predicted from those under single gradients. The device provides a powerful and practical tool for researchers to study interactions between chemical and oxygen gradients in cell culture, which can promote better cell migration studies in more in vivo-like microenvironments.

Gas Partial Pressure in Cultured Cells: Patho-Physiological Importance and Methodological Approaches

“…One advantage is that using sophisticated fabrication techniques, chips can be designed to mimic cell microenvironments to optimally fit different applications. For instance, microfluidic devices were developed to study cancer metastasis under chronic and intermittent hypoxia (Acosta et al, 2014), to mimic radial biological gradients (Li et al, 2015) or to investigate cell migration under perpendicular chemical and oxygen gradients (Chiang et al, 2017). Microfluidic-based chip fabrication also allows for superimposing intermittent hypoxia to modulated glucose flow in a setting mimicking pancreatic islets (Lo et al, 2012).…”

Microbioreactors as Engineering Tools for Bioprocess Development

“…Consequently, microfluidic devices present many features that are perfectly adapted to the needs of not only chemical and biochemical analyses, but also to a vast pool of applications in biology. The possibilities of controlling fluid dynamics and applying to microsystems can be very useful for the investigation of genetic responses to environment changes (Tay et al, 2010;Li et al, 2016b;Chiang et al, 2017), diagnoses (Chin et al, 2011;Huo et al, 2015;Patou et al, 2015;Li et al, 2016a), molecular screening (DeMello, 2006;Dittrich and Manz, 2006;Yu et al, 2014), microbial screening (El-Ali et al, 2006;Stott et al, 2010;Sjostrom et al, 2014;Jacques et al, 2017;Xie et al, 2017), simulation of cellular microenvironments (Chang et al, 2005;Sung and Shuler, 2009;Houshmand et al, 2016). Microfluidics is also a great strategy for the study of the omics sciences: genomics and transcriptomics (Wang and Bodovitz, 2010;Shalek et al, 2014;Macosko et al, 2015;Kim et al, 2016), proteomics (Sanders and Manz, 2000;Wang and Bodovitz, 2010;Wang and Yang, 2016) and metabolomics (Wang and Bodovitz, 2010;de Raad et al, 2016;Maisch et al, 2016), revolutionizing the methods for single cell studies and, therefore, the understanding of cellular properties, behaviour and cell heterogeneity.…”

“…Chiang et al (2017) Dong et al(2017)Vittayarukskul andLee (2017) PMMA Presents biological compatibility, good visibility for detection and ease of microfabricating. It is also impermeable to gases and does not support highlevel temperatures.Adams et al(2008)Asl et al(2016)Li et al(2016)Van Anh et al(2016)Silicon It supports high levels of temperature and pressure and has a great thermoconductivity.…”

A microfluidic oxygen sink to create a targeted cellular hypoxic microenvironment under ambient atmospheric conditions

“…This approach enables general assessment of cell responses to hypoxia under such an artificial environment against a control culture under normoxia. Generation of localised pO 2 gradients using the N 2 /O 2 gas replacement technique or oxygenscavenging chemicals (such as pyrogallol) have been utilised in microfluidic chips [8][9][10]. These techniques, however, are limited in their ability to combine selective O 2 depletion and generation of spatially placed microenvironmental hypoxia in same culture conditions and vessel with unexposed cells.…”