Faculty 2: University Award for the Best Master Thesis 2021

Cartilage defects and pathological changes, which include osteoarthritis, continue to increase due to the aging population and an unhealthy lifestyle. To date, the only permanent solution for advanced cartilage damage is joint replacement with prostheses. New therapeutic approaches use cells to restore damaged tissue. Cell suspensions and also in vitro tissue from cartilage cells are already being used for this so-called "cell-based regeneration" of cartilage tissue. A combination graft (cartilage-bone microtissue) would be a possibility for the treatment of "deep" cartilage defects and also a therapeutic approach for osteoarthritis. Currently, there are no therapeutic options to cure osteoarthritis.

Microtissues were successfully prepared from human cartilage and bone cells, transferred to co-cultures and extensively characterized in terms of tissue type. Different media compositions were tested, since individual cell types usually only form their tissue-typical characteristics (differentiation) in specific media, which represents a major challenge in a "combination" culture. For example, specific components in the osteoblast medium were shown to have a negative effect on cartilage cell differentiation.

The co-culture experiments showed that the two cell types influence each other's differentiation. The negative effect of osteoblast medium on cartilage cells was partially reversed by co-culturing with osteoblasts. Conversely, the degree of differentiation of chondrocytes had a reciprocal effect on osteoblast differentiation.

Further experiments on the degree of differentiation of chondrocytes and osteoblasts in the tissue composite are needed to pursue the idea of a combined graft.