Biocompatibility of Tygon® tubing in microfluidic cell culture

Biocompatibility of fluids for multiphase drops-in-drops microfluidics

This paper addresses the biocompatibility of fluids and surfactants in the context of microfluidics and more specifically in a drops-in-drops system for mammalian cell based drug screening. In the drops-in-drops approach, three immiscible fluids are used to manipulate the flow of aqueous microliter-sized drops; it enables merging of drops containing cells with drops containing drugs within a Teflon tube. Preliminary tests showed that a commonly-used fluid and surfactant combination resulted in significant variability in gene expression levels in Jurkat cells after exposure to a drug for four hours. This result led to further investigations of potential fluid and surfactant combinations that can be used in microfluidic systems for medium to long-term drug screening. Results herein identify a fluid combination, HFE-7500 and 5-cSt silicone oil + 0.25% Abil EM180, which enabled the drops-in-drops approach; this combination also allowed gene expression at normal levels comparable with the conventional drug screening in both magnitude and variability.

High-Throughput Microfluidic Platform for 3D Cultures of Mesenchymal Stem Cells

The design of innovative tools for generating physiologically relevant three-dimensional (3D) in vitro models has been recently recognized as a fundamental step to study cell responses and long-term tissue functionalities thanks to its ability to recapitulate the complexity and the dimensional scale of the cellular microenvironment, while directly integrating high-throughput and automatic screening capabilities.This chapter addresses the development of a poly(dimethylsiloxane)-based microfluidic platform to (1) generate and culture 3D cellular microaggregates under continuous flow perfusion while (2) conditioning them with different combinations/concentrations of soluble factors (i.e., growth factors, morphogens or drug molecules), in a high-throughput fashion. The proposed microfluidic system thus represents a promising tool for establishing innovative high-throughput models for drug screening, investigation of tissues morphogenesis, and optimization of tissue engineering protocols.