ABSTRACT
Tissue engineering is increasingly poised to provide more viable alternatives to surgical procedures for the repair of orthopedic defects, such as focal articular cartilage lesions. Cartilage appears to be a relatively simple tissue, yet it is not amenable to regeneration with the techniques available to date. It is alymphatic and aneural, has no contact with blood, and exhibits low cellularity. The main constituents of cartilage are proteoglycans and type II collagen. Many researchers are currently pursuing the goal of creating functional cartilage, both
in vitro
and
in vivo
. By creating a tissue
in vitro
, the time required for healing is decreased, while the probability of a successful recovery is increased. Scaffolds that are designed to be used
in vivo
have the ability to reduce healing time even more dramatically because surgery can be done arthroscopically. However, current injectable materials do not fulfill all the structural and biological conditions needed to function in a mechanically loaded environment.
