Evaluation of apparent fracture toughness of articular cartilage and hydrogels
Version of Record online: 2 APR 2014
Copyright © 2014 John Wiley & Sons, Ltd.
Journal of Tissue Engineering and Regenerative Medicine
How to Cite
Xiao, Y., Rennerfeldt, D. A., Friis, E. A., Gehrke, S. H. and Detamore, M. S. (2014), Evaluation of apparent fracture toughness of articular cartilage and hydrogels. J Tissue Eng Regen Med. doi: 10.1002/term.1892
- Version of Record online: 2 APR 2014
- Manuscript Accepted: 24 FEB 2014
- Manuscript Revised: 5 DEC 2013
- Manuscript Received: 20 MAY 2013
- the NIH/NIBIB. Grant Number: R21 EB008783
- articular cartilage;
Recently, biomaterials-based tissue-engineering strategies, including the use of hydrogels, have offered great promise for repairing articular cartilage. Mechanical failure testing in outcome analyses is of crucial clinical importance to the success of engineered constructs. Interpenetrating networks (IPNs) are gaining more attention, due to their superior mechanical integrity. This study provided a combination testing method of apparent fracture toughness, which was applied to both articular cartilage and hydrogels. The apparent fracture toughnesses of two groups, hydrogels and articular cartilage, were evaluated based on the modified single-edge notch test and ASTM standards on the single-edge notch test and compact tension test. The results demonstrated that the toughness for articular cartilage (348 ± 43 MPa/mm½) was much higher than that for hydrogels. With a toughness value of 10.8 ± 1.4 MPa/mm½, IPNs of agarose and poly(ethylene glycol) diacrylate (PEG-DA) looked promising. The IPNs were 1.4 times tougher than PEG-DA alone, although still over an order of magnitude less tough than cartilage. A new method was developed to evaluate hydrogels and cartilage in a manner that enabled a more relevant direct comparison for fracture testing of hydrogels for cartilage tissue engineering. Moreover, a target toughness value for cartilage of using this direct comparison method has been identified (348 ± 43 MPa/mm½), and the toughness discrepancy to be overcome between hydrogels and cartilage has been quantified. Copyright © 2014 John Wiley & Sons, Ltd.