Open Access Original article

The effect of high vacuum on the mechanical properties and bioactivity of collagen fibril matrices

Christopher R Anderton1*, Frank W DelRio1, Kiran Bhadriraju2 and Anne L Plant1

Author Affiliations

1 Material Measurement Laboratory, National Institute of Standards and Technology, Gaithersburg, MD, 20899, USA

2 Fischell Department of Bioengineering, University of Maryland, College Park, MD, 20742, USA

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Biointerphases 2013, 8:2  doi:10.1186/1559-4106-8-2

Published: 17 January 2013

Abstract

The extracellular matrix (ECM) environment plays a critical role in organism development and disease. Surface sensitive microscopy techniques for studying the structural and chemical properties of ECMs are often performed in high vacuum (HV) environments. In this report, we examine the affect HV conditions have on the bioactivity and mechanical properties of type I collagen fibrillar matrices. We find that HV exposure has an unappreciable affect on the cell spreading response and mechanical properties of these collagen fibril matrices. Conversely, low vacuum environments cause fibrils to become mechanically rigid as indicated by force microscopy, resulting in greater cell spreading. Time-of-flight secondary ion mass spectrometry results show no noticeable spectral differences between HV-treated and dehydrated matrices. While previous reports have shown that HV can denature proteins in monolayers, these observations indicate that HV-exposure does not mechanically or biochemically alter collagen in its supramolecular configuration. These results may have implication for complex ECM matrices such as decellularized scaffolds.

Keywords:
Collagen fibrils; Extracellular matrix; Quantitative cell imaging; Colloidal probe atomic force microscopy; Secondary ion mass spectrometry; Principal component analysis