Articular cartilage defects are an ongoing problem in the orthopedic field, since cartilage presents limited repair capabilities and any damage can lead to pain, disability and early osteoarthritis. Current available treatments often result in fibrous repair tissue with insufficient mechanical properties. Cell-based strategies have shown potential for durable repair, but obtaining clinically relevant cell numbers that retain chondrogenic potential is challenging. The use of autologous chondrocytes is the golden standard, but these cells can only be harvested in small numbers from non-load bearing tissue, and tend to dedifferentiate upon 2D expansion.
A promising alternative is the use of articular cartilage progenitor cells (ACPCs), a small subpopulation of chondrocytes that reside mainly in the surface of articular cartilage. Unlike chondrocytes, ACPCs can be expanded up to 30 passages without losing their chondrogenic potential. Moreover, under certain conditions, ACPCs have shown to produce larger quantities of cartilage-like extracellular matrix in less time than articular chondrocytes.
In this project we investigate the potential of ACPCs to replace chondrocytes for cartilage repair by analyzing which conditions might lead to the best cartilage mini tissues, and if the use of high amounts of these building blocks with more mature matrix might lead to better cartilage repair.