Co-culturing of primary chondrocytes and mesenchymal stem cells to optimize cartilage formation

Trauma and disease of knee joints frequently involve structural damage to
articular cartilage.
Since 15 years autologous chondrocyte implantation (ACI) shows satisfactory
results for the restoration of focal cartilage lesions. However, the necessary
in vitro expansion of the harvested chondrocytes induces cellular
dedifferentiation, resulting in diminished cellular quality. Hendriks et al
combined primary bovine chondrocytes and human mesenchymal stem cells in an in
vitro co-culture system. This combination led to an increase of cartilage
specific matrix constituents at varying cell-cell ratios and, therefore,
introduces the possibility to investigate the potential of a single surgery
therapy for focal cartilage lesions.
This study will combine human mesenchymal stem cells and human primary
chondrocytes from the same donor at different ratios to evaluate the effect on
cartilage formation. We will obtain our cells from patients admitted to
reconstructive anterior cruciate ligament (ACL) surgery.

Evaluate the optimal cellular ratio of human mesenchymal stem cells and primary
chondrocytes for cartilage formation in an in vitro culture and in vivo nude
mice model.

Patients admitted to ACL reconstructive surgery will be informed about this
study by the treating surgeon and asked for approval to obtain bone marrow
during the operation and the use of their cells for laboratory cartilage
research. After approval we will combine the primary chondrocytes and
mesenchymal stem cells at different ratios and culture them in an in vitro and
in vivo model for six weeks followed by immunohistochemical, histological and
biochemical analysis on cartilage formation.

We expect, although cannot proof this because of lack of experience and
available data, that the additional surgical procedure (aspiration of bone
marrow before drilling the femoral hole) will not have any negative influence
on surgical outcome or patient recovery.