Homologous chondrocytes in combination with chitosan to repair articular cartilage defects

Wanjun XIAO; Guangyu FAN

ABSTRACT

BACKGROUND:

Injectable hydrogel-chitosan is the latest developed material for cartilage tissue engineering. It provides a novel cell attachment mechanism.

OBJECTIVE:

To investigate the effect of allologous chondrocytes in combination with chitosan in repairing cartilage defects. DESIGN, TIME AND

SETTING:

Randomized controlled animal trial was performed at the Central Laboratory of China Medical University from November 2004 to March 2006. MATERIALS Thirty 2-week-old New Zealand rabbits weighing 0.3 kg were selected to model cartilage defect.

METHODS:

Thirty rabbits were randomly divided into three groups. In the experimental group, the defects were repaired by the injection of second passage of chondrocytes (2.5?1011 L-1) combined with chitosan into articular capsule; the cell suspension group was only injected with chondrocyte suspension (2.5?1011 L-1); the control group was not given any treatment. MAIN OUTCOME

MEASURES:

The animals were sacrificed at the 4th, 8th, and 12th weeks after operation, respectively to harvest the lateral condyle of knee joint. Hematine-eosine staining, gross and histological examinations, and electron microscopic evaluations were performed to observe the repair condition.

RESULTS:

The gross observation showed that there was no obvious swelling or other inflammatory responses in each rabbits. Histological examination suggested that in the experimental group, the cartilage defects were repaired by the hyaline cartilage tissue with smooth surface, which integrated smoothly with articular cartilage at 12 weeks after operation. No obvious defect repair was observed in the other groups. The transmission electron microscopic observation showed that in the new-formation tissues of the experimental group, there were round or oval chondrocytes, and abundant rough endoplasmic reticulum, ribosome and Golgi complex in cytoplasm. At 8 to 12 weeks, plenty of collagen fibers were found in cell suspension group. In the control group, only fibrous tissues were seen on the surface of defects.

CONCLUSION:

The articular cartilage defects of rabbits are repaired with allograft of chondrocytes seeded onto chitosan, indicating chitosan can serve as carrier in cell transplantation.