Current cartilage tissue engineering approaches involve taking a biopsy from a non-loadbearing healthy part of joint and isolation of chondrocytes to combine with materials/scaffolds in order to implant them to the defect site.
One drawback of this procedure is that high number of chondrocytes is needed to fill the defects for proper regeneration of tissue.
For this reason, 2D expansion of chondrocytes is needed that causes de-differentiation, a process in which cells lose their native phenotype and cartilage-specific gene expression patterns.
Therefore, in cartilage engineering field there is still a need for developing a biomaterial that would promote proliferation of primary chondrocytes in a 3D manner while preserving their phenotype and prevent their de-differentiation.
Our approach comprises of developing cartilage biomimetic materials to present primary chondrocytes a native-like microenvironment to enable their proliferation and preservation of chondrogenic phenotype.
Cartilage tissue is rich in sulfated glycosaminoglycans such as chondroitin sulfate, keratan sulfate or heparan sulfate that contribute to its swelling properties and compressive strength as well as entrapment of growth factors.
For mimicking this negatively charged environment, we modified biopolymers such as alginate with sulfate groups in order to study 3D expansion of primary chondrocytes and prevention of de-differentiation.