In Vitro Mimetic Models for the Bone-Cartilage Interface Regeneration

In embryonic development, pure cartilage structures are in the basis of
bone-cartilage interfaces. Despite this fact, the mature bone and cartilage structures
can vary greatly in composition and function. Nevertheless, they collaborate in the
osteochondral region to create a smooth transition zone that supports the movements
and forces resulting from the daily activities. In this sense, all the hierarchical
organization is involved in the maintenance and reestablishment of the equilibrium
in case of damage. Therefore, this interface has attracted a great deal of interest in
order to understand the mechanisms of regeneration or disease progression in osteoarthritis.
With that purpose, in vitro tissue models (either static or dynamic) have
been studied. Static in vitro tissue models include monocultures, co-cultures, 3D
cultures, and ex vivo cultures, mostly cultivated in flat surfaces, while dynamic
models involve the use of bioreactors and microfluidic systems. The latter have
emerged as alternatives to study the cellular interactions in a more authentic manner
over some disadvantages of the static models. The current alternatives of in vitro
mimetic models for bone-cartilage interface regeneration are overviewed and discussed
herein.