Challenges in engineering osteochondral tissue grafts with hierarchical structures

Abstract

Introduction: A major hurdle in treating osteochondral (OC) defects is the different healing abilities of two types of tissues involved – articular cartilage and subchondral bone. Biomimetic approaches to OC-construct engineering, based on recapitulation of biological principles of tissue development and regeneration, have potential for providing new treatments and advancing fundamental studies of OC tissue repair.

Areas covered: This review on state of the art in hierarchical OC tissue graft engineering is focused on tissue engineering approaches designed to recapitulate the native milieu of cartilage and bone development. These biomimetic systems are discussed with relevance to bioreactor cultivation of clinically sized, anatomically shaped human cartilage/bone constructs with physiologic stratification and mechanical properties. The utility of engineered OC tissue constructs is evaluated for their use as grafts in regenerative medicine, and as high-fidelity models in biological research.

Expert opinion: A major challenge in engineering OC tissues is to generate a functionally integrated stratified cartilage–bone structure starting from one single population of mesenchymal cells, while incorporating perfusable vasculature into the bone, and in bone–cartilage interface. To this end, new generations of advanced scaffolds and bioreactors, implementation of mechanical loading regimens and harnessing of inflammatory responses of the host will likely drive the further progress.

Keywords:

• anatomical shape
• biomimetics
• osteochondral grafts
• tissue engineering

Declaration of interest

I Gadjanski has received research funding from The Ministry of Education and Science of Serbia (grants ON174028 and III41007) and G Vunjak-Novakovic has received research funding from the National Institutes of Health (grants DE016525, EB002520, and AR061988). In addition, G Vunjak-Novakovic is a co-founder of epiBone, a Columbia University spin out focused on growing human bones for craniofacial repair. The authors have no other relevant affiliations or financial involvement with any organization or entity with a financial interest in or financial conflict with the subject matter or materials discussed in the manuscript. This includes employment, consultancies, honoraria, stock ownership or options, expert testimony, grants or patents received or pending, or royalties.

Notes

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