Contribution of collagen network features to functional properties of engineered cartilage

Journal article (2007)

Authors

YM Bastiaansen-Jenniskens External organisation
W Koevoet External organisation
ACW de Bart External organisation
JC van der Linden Computational Design and Mechanics - Mechanical, Maritime and Materials Engineering
AM Zuurmond External organisation
H Weinans External organisation
J.A.N. Verhaar External organisation
GJVM Osch External organisation
J DeGroot External organisation
Research Group
Computational Design and Mechanics (Mechanical, Maritime and Materials Engineering) (TU Delft)
More Info
expand_more

Published Date

2007

Language

Undefined/Unknown

Reuse Rights

Other than for strictly personal use, it is not permitted to download, forward or distribute the text or part of it, without the consent of the author(s) and/or copyright holder(s), unless the work is under an open content license such as Creative Commons.

Faculty

Mechanical, Maritime and Materials Engineering

Department

Precision and Microsystems Engineering

Research Group

Computational Design and Mechanics

Abstract

Background: Damage to articular cartilage is one of the features of osteoarthritis (OA). Cartilage damage is characterised by a net loss of collagen and proteoglycans. The collagen network is considered highly important for cartilage function but little is known about processes that control composition and function of the cartilage collagen network in cartilage tissue engineering. Therefore, our aim was to study the contribution of collagen amount and number of crosslinks on the functionality of newly formed matrix during cartilage repair.

Methods: Bovine articular chrondrocytes were cultured in alginate beads. Collagen network formation was modulated using the crosslink inhibitor ß-aminopropionitrile (BAPN; 0.25 mM). Constructs were cultured for 10 weeks with/without BAPN or for 5 weeks with BAPN followed by 5 weeks without. Collagen deposition, number of crosslinks and susceptibility to degradation by matrix metalloproteinase-1 (MMP-1) were examined. Mechanical properties of the constructs were determined by unconfined compression.

Results: BAPN for 5 weeks increased collagen deposition accompanied by increased construct stiffness, despite the absence of crosslinks. BAPN for 10 weeks further increased collagen amounts. Absence of collagen crosslinks did not affect stiffness but ability to hold water was lower and susceptibility to MMP-mediated degradation was increased. Removal of BAPN after 5 weeks increased collagen amounts, allowed crosslink formation and increased stiffness.

Discussion: This study demonstrates that both collagen amounts and its proper crosslinking are important for a functional cartilage matrix. Even in conditions with elevated collagen deposition, crosslinks are needed to provide matrix stiffness. Crosslinks also contribute to the ability to hold water and to the resistance against degradation by MMP-1.

Key words: Cartilage, Chondrocyte, Collagen, Crosslinks, Mechanical properties.