Thick collagen-based 3D matrices including growth factors to induce neurite outgrowth

TL;DR

This study develops a dense 3D collagen matrix functionalized with growth factors to promote and observe neurite outgrowth from neural cells, providing a versatile platform for neural tissue research.

Contribution

It introduces a novel collagen-based 3D matrix supporting neurite outgrowth with incorporated growth factors, enabling direct observation and manipulation of neural cells.

Findings

Significant neurite outgrowth observed in PC-12 and SH-SY5Y cells.

Growth factors can be impregnated or chemically conjugated into the matrix.

Neurite extension occurs over tens of microns within the 3D environment.

Abstract

Designing synthetic microenvironments for cellular investigations is a very active area of research at the crossroads of cell biology and materials science. The present work describes the design and functionalization of a three-dimensional (3D) culture support dedicated to the study of neurite outgrowth from neural cells. It is based on a dense self-assembled collagen matrix stabilized by 100-nm-wide interconnected native fibrils without chemical crosslinking. The matrices were made suitable for cell manipulation and direct observation in confocal microscopy by anchoring them to traditional glass supports with a calibrated thickness of similar to 50 mu m. The matrix composition can be readily adapted to specific neural cell types, notably by incorporating appropriate neurotrophic growth factors. Both PC-12 and SH-SY5Y lines respond to growth factors (nerve growth factor and brain-derived neurotrophic factor, respectively) impregnated and slowly released from the support. Significant neurite outgrowth is reported for a large proportion of cells, up to 66% for PC12 and 49% for SH-SY5Y. It is also shown that both growth factors can be chemically conjugated (EDC/NHS) throughout the matrix and yield similar proportions of cells with longer neurites (61% and 52%, respectively). Finally, neurite outgrowth was observed over several tens of microns within the 3D matrix, with both diffusing and immobilized growth factors. (C) 2012 Acta Materialia Inc. Published by Elsevier Ltd. All rights reserved.