Layer dependence in strain distribution and chondrocyte damage in porcine articular cartilage exposed to excessive compressive stress loading

Wenjing Huang, Mia Warner, Hikaru Sasaki, Katsuko S. Furukawa, Takashi Ushida

Research output: Contribution to journalArticlepeer-review

Abstract

Exposure to excessive stress is associated with the pathogenesis of osteoarthritis, a joint disease involved in the degeneration of articular cartilage. Mechanical properties of mature articular cartilage are known to be depth zone-dependent. Although chondrocyte death was observed in articular cartilage after excessive stress loading in vitro, few studies have investigated the correlation between chondrocyte death and local mechanical strains in a depth dependent manner. Here, we developed a real-time observation system of cut cartilage samples under an excessive stress loading (18 MPa) at low (3.5%/s) and high (35%/s) strain rates on the microscope stage, which is regarded as injurious compression in vivo. Using this system, real-time monitoring of local deformations was conducted during compression, and local chondrocyte death was investigated after short-term culture. The results showed that the dead cells were mainly observed in the surface layer at a high strain rate. In contrast, the dead cells were relatively concentrated not in the surface layer but in the middle layer at a low strain rate. The local strain measurements showed that the dead cell distributions were correlated with depth-dependent local strain rates at both low and high strain rates. Moreover, when the surface layer was removed, both depth-dependence in dead cell distributions and in local strain rates disappeared at low and high strain rates. Although the mechanisms underlying mechanically induced osteoarthritis are still elusive, those results suggest a correlation between local chondrocyte death and transient strain rates in a depth dependent manner, and the surface layer played a crucial role in regulating chondrocyte damages and local strains in middle and deep layers. Our study, therefore, could contribute to an analytical understanding of cartilage degeneration under excessive stress loadings.

Original languageEnglish
Article number104088
JournalJournal of the Mechanical Behavior of Biomedical Materials
Volume112
DOIs
Publication statusPublished - Dec 2020
Externally publishedYes

All Science Journal Classification (ASJC) codes

  • Biomaterials
  • Biomedical Engineering
  • Mechanics of Materials

Fingerprint Dive into the research topics of 'Layer dependence in strain distribution and chondrocyte damage in porcine articular cartilage exposed to excessive compressive stress loading'. Together they form a unique fingerprint.

Cite this