The role of tissue engineering in articular cartilage repair and regeneration

Abstract

Articular cartilage repair and regeneration continue to be largely intractable because of the poor regenerative properties of this tissue. The field of articular cartilage tissue engineering, which aims to repair, regenerate, and/or improve injured or diseased articular cartilage functionality, has evoked intense interest and holds great potential for improving articular cartilage therapy. This review provides an overall description of the current state of and progress in articular cartilage repair and regeneration. Traditional therapies and related problems are introduced. More importantly, a variety of promising cell sources, biocompatible tissue engineered scaffolds, scaffoldless techniques, growth factors, and mechanical stimuli used in current articular cartilage tissue engineering are reviewed. Finally, the technical and regulatory challenges of articular cartilage tissue engineering and possible future directions are also discussed.

Fig 1

Schematic illustration of composition and structure of articular cartilage lining the bone (not drawn to scale). There are four zones with different structures in articular cartilage: superficial, middle, deep, and calcified.

Fig 2

The concept of tissue engineering. Tissue engineering incorporates many critical factors including cells, scaffolds, bioactive factors, and physical stimuli to assemble biomimetic tissue engineered constructs for replacing damaged tissues in humans.

Fig 3

The totipotent, pluripotent, multipotent, and unipotent stem cells.

Fig 4

Human bone marrow-derived mesenchymal stem cells after 6 days of culture, exhibiting a fibroblastic morphology.

Fig 5

A scaffold-free, modular approach for the engineering of articular cartilage from stem cells.

Fig 6

Chondrocyte self-assembly and ECM development in a scaffold-free process. Sequences of cadherin and collagen VI expression and distribution parallel those seen in native cartilage development. (Used under the Creative Commons Attribution License, from Ofek et al., PloS ONE, 2008)

Fig 7

Cells can respond to mechanical forces via several coupling mechanisms, such as stretch activated ion channels and focal adhesion complexes.