Water loss and defects dependent strength and ductility of articular cartilage

Water loss and surface defects of articular cartilage extremely aggravate the risk of osteoarticular diseases. The effects of water content and surface defects on the mechanical properties of cartilage need to be taken into further account. By using a self-developed in -situ tensile tester, the tensile stress-strain relationship and real-time morphological changes under conditions of different water contents are obtained with and without a micro void. It is confirmed that tissue structure and permeability are the main factors affecting the strength and ductility of cartilage. The less water content contributes to the lower permeability, inducing higher strength but poorer plasticity. Raman spectroscopy analysis results directly reveal the transition from the bonding water with stronger hydrogen bonds to the free water with weaker hydrogen bonds in cartilage layer caused by both drying treatment and tensile deformation, which results in decreased permeability and enhanced resistance to deformation. Raman-based organic matrix content is nega-tively correlated with permeability but positively correlated with the strength of cartilage. The obtained experimental data may facilitate to predict cartilage damage and develop artificial cartilage materials.(c) 2022 The Author(s). Published by Elsevier B.V. This is an open access article under the CC BY-NC-ND license (http://creativecommons.org/licenses/by-nc-nd/4.0/).

Automated summary

Water loss and surface defects pose a significant risk to osteoarticular diseases. This study investigates the effects of water content and surface defects on the mechanical properties of cartilage. The results demonstrate that tissue structure and permeability are the main factors influencing the strength and ductility of cartilage. Raman spectroscopy analysis reveals the transition of water bonds in the cartilage layer, leading to decreased permeability and increased resistance to deformation. The organic matrix content determined by Raman spectroscopy is negatively correlated with permeability and positively correlated with cartilage strength.