A Microfluidic Chip Architecture Enabling a Hypoxic Microenvironment and Nitric Oxide Delivery in Cell Culture.

Samineh Barmaki,Esko Kankuri,Jyrki Vuola,Ville Jokinen,Daniela Obermaier,Sami Franssila

doi:10.3390/mi11110979

Abstract

A hypoxic (low oxygen level) microenvironment and nitric oxide paracrine signaling play important roles in the control of both biological and pathological cell responses. In this study, we present a microfluidic chip architecture for nitric oxide delivery under a hypoxic microenvironment in human embryonic kidney cells (HEK-293). The chip utilizes two separate, but interdigitated microfluidic channels. The hypoxic microenvironment was created by sodium sulfite as the oxygen scavenger in one of the channels. The nitric oxide microenvironment was created by sodium nitroprusside as the light-activated nitric oxide donor in the other channel. The solutions are separated from the cell culture by a 30 µm thick gas-permeable, but liquid-impermeable polydimethylsiloxane membrane. We show that the architecture is preliminarily feasible to define the gaseous microenvironment of a cell culture in the 100 µm and 1 mm length scales.

Highlights

The cellular microenvironment is the small-scale environment in the immediate vicinity of cells
In our previous work [27], we showed a configuration where hypoxia was induced on HEK-293 cells cultured in a well that was separated from an underlying oxygen scavenging channel network by a thin PDMS membrane
The microfluidic chip consists of two interdigitated meandering channels that are 100 μm wide, 40 μm in depth, and 20 mm in length

Summary

Introduction

The cellular microenvironment is the small-scale environment in the immediate vicinity of cells Gaseous transmitters, such as oxygen (O2), hydrogen sulfide (H2S), carbon monoxide (CO), and nitric oxide (NO), have several major physiological and pathological roles in the body [1,2,3]. In the cells’ normal tissue microenvironment, the oxygen content ranges between 2 and 6% [4] Another important biological regulator is nitric oxide, a fundamental component in many fields of physiology and medicine. Direct addition of donor or scavenger chemicals into cell growth medium alters the composition of the medium, leading to potential toxic effects or other artifacts Both methods are only suitable for changing the gaseous environment of the entire cell culture without the possibility to create spatially patterned microenvironments

Methods

Results

Conclusion