Open AccessGeneration of an in vitro model of the outer annulus fibrosus‐cartilage interface
Author(s) -
Chong Jasmine E.,
Santerre J. Paul,
Kandel Rita A.
Publication year - 2020
Publication title -
jor spine
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.125
0ISSN - 2572-1143
DOI - 10.1002/jsp2.1089
Subject(s) - cartilage , aggrecan , intervertebral disc , in vitro , extracellular matrix , annulus (botany) , biomedical engineering , type ii collagen , anatomy , fibrocartilage , perichondrium , tissue engineering , intervertebral disk , chemistry , microbiology and biotechnology , osteoarthritis , pathology , materials science , articular cartilage , medicine , biology , lumbar , biochemistry , composite material , alternative medicine
Current treatments for degenerative disc disease do not restore full biological functionality of the intervertebral disc (IVD). As a result, regenerative medicine approaches are being developed to generate a biological replacement that when implanted will restore form and function of the degenerated IVD. Tissue‐engineered models to date have focused on the generation of nucleus pulposus and annulus fibrosus IVD components. However, these tissues need to be integrated with a cartilage endplate in order for successful implantation to occur. The purpose of this study was to generate an in vitro annulus fibrosus‐cartilage interface model which would enable us to better understand the biological and biomechanical implications of such interfaces. It was hypothesized that in vitro‐formed outer annulus fibrosus (OAF) and cartilage tissues would integrate in direct‐contact coculture to yield an interface containing extracellular matrix with aspects resembling the native OAF‐CEP interface. In vitro‐formed tissues were generated using bovine OAF cell‐seeded angle‐ply, multi‐lamellated polycarbonate urethane scaffolds and articular chondrocytes, which were then placed in direct‐contact coculture. 2‐week old OAF tissues integrated with 3‐day old cartilage by 1 week of coculture. Immunohistochemical staining of 2‐week interfaces showed that distributions of collagen type I, collagen type II, and aggrecan were similar to the native bovine interface. The apparent tensile strength of the in vitro interface increased significantly between 2 and 4 weeks of coculture. In summary, an annulus fibrosus‐cartilage interface model can be formed in vitro which will facilitate the identification of conditions required to generate an entire tissue‐engineered disc replacement suitable for clinical use.