Issue 12, 2014

Small-molecule axon-polarization studies enabled by a shear-free microfluidic gradient generator

Abstract

A deep understanding of the mechanisms behind neurite polarization and axon path-finding is important for interpreting how the human body guides neurite growth during development and response to injury. Further, it is of great clinical importance to identify diffusible chemical cues that promote neurite regeneration for nervous tissue repair. Despite the fast development of various types of concentration gradient generators, it has been challenging to fabricate neuron-friendly (i.e. shear-free and biocompatible for neuron growth and maturation) devices to create stable gradients, particularly for fast diffusing small molecules, which typically require high flow and shear rates. Here we present a finite element analysis for a polydimethylsiloxane/polyethylene glycol diacrylate (PDMS/PEG-DA) based gradient generator, describe the microfabrication process, and validate its use for neuronal axon polarization studies. This device provides a totally shear-free, biocompatible microenvironment with a linear and stable concentration gradient of small molecules such as forskolin. The gradient profile in this device can be customized by changing the composition or width of the PEG-DA barriers during direct UV photo-patterning within a permanently bonded PDMS device. Primary rat cortical neurons (embryonic E18) exposed to soluble forskolin gradients for 72 h exhibited statistically significant polarization and guidance of their axons. This device provides a useful platform for both chemotaxis and directional guidance studies, particularly for shear sensitive and non-adhesive cell cultures, while allowing fast new device design prototyping at a low cost.

Graphical abstract: Small-molecule axon-polarization studies enabled by a shear-free microfluidic gradient generator

Supplementary files

Article information

Article type
Paper
Submitted
07 Feb 2014
Accepted
13 Apr 2014
First published
14 Apr 2014
This article is Open Access
Creative Commons BY license

Lab Chip, 2014,14, 2047-2056

Author version available

Small-molecule axon-polarization studies enabled by a shear-free microfluidic gradient generator

H. Xu, M. M. Ferreira and S. C. Heilshorn, Lab Chip, 2014, 14, 2047 DOI: 10.1039/C4LC00162A

This article is licensed under a Creative Commons Attribution 3.0 Unported Licence. You can use material from this article in other publications without requesting further permissions from the RSC, provided that the correct acknowledgement is given.

Read more about how to correctly acknowledge RSC content.

Social activity

Spotlight

Advertisements