Bioengineered tissue implants regenerate damaged knee cartilage

Knee cartilage injuries can be effectively repaired by tissue engineering and osteoarthritis does not stop the regeneration process concludes research led by scientists at the University of Bristol.

The study, “Maturation of tissue engineered cartilage implanted in injured and osteoarthritic human knees”, published in the July 2006 (Volume 12, Number 7) issue of Tissue Engineering, demonstrates that engineered cartilage tissue can grow and mature when implanted into patients with a knee injury. The novel tissue engineering approach can lead to cartilage regeneration even in knees affected by osteoarthritis.

The tissue engineering method used in this study involved isolating cells from healthy cartilage removed during surgery from 23 patients with an average age of 36 years. After growing the cells in culture for 14 days, the researchers seeded them onto scaffolds made of esterified hyaluronic acid, grew them for another 14 days on the scaffolds, and then implanted them into the injured knees of the study patients.

Cartilage regeneration was seen in ten of 23 patients, including in some patients with pre-existing early osteoarthritis of the knee secondary to traumatic injury. Maturation of the implanted, tissue-engineered cartilage was evident as early as 11 months after implantation.

Antony Hollander, ARC Professor of Rheumatology & Tissue Engineering at Bristol University who led the study, said: “This is the first time we have shown that tissue-engineered cartilage implanted into knees can mature within 12 months after implantation, even in joints showing signs of osteoarthritis.

“Left untreated, many cartilage injuries will progress to osteoarthritis and the need for eventual replacement of the whole joint. Future investigations need to be carried out but this approach will allow us to improve further the outcome of cartilage repair.”