Biomedical Engineers Develop Biocompatible Cartilage Replacement

Researchers have developed a method to grow biocompatible cartilage from the patient’s own bone marrow.

AsianScientist (Dec. 28, 2015) – A University of Hong Kong research team has developed a new cartilage regeneration technology to grow cartilage tissues out of cells taken from one’s body.

Using stem cells extracted from bone marrow, the researchers have grown cartilage tissues in the shape and fit needed for cartilage repairs and replacements. As the replacements are fully biocompatible, patients would heal more rapidly without the need to harvest donor cartilage from the patients.

The research team was led by Dr. Barbara Chan, Associate Professor of the Department of Mechanical Engineering. Chan’s team is a pioneer in cartilage tissue engineering, and the first to develop the technology to a stage that is ready for technology transfer and commercialization.

Cartilage injuries and diseases are very common. About 40 percent of adults over 65 years old have osteoarthritis. Cartilage has no nerves and so does not cause pain until the cartilage is gone and the bone underneath starts to be affected. Cartilage also has no blood vessels and therefore cannot heal on its own once injured. In the worst case, the knee joint has to be replaced by an artificial joint.

There have been many attempts to repair damaged cartilages, but results remain unsatisfactory. It is generally known that a defect is best replaced by a healthy cartilage transplant, which must be complete with underlying bone tissues, so as to protect the integrity of the entire cartilage tissue.

Currently, the clinical gold standard for repairing cartilage is a surgical procedure known as osteochondral autograft transplantation. It involves harvesting a graft from one part of the joint and transplanting it to replace the damaged cartilage. However, this procedure leaves the autograft donor sites injured and may lead to chronic pain and degeneration.

An alternative is to use the patients’ own cells such as stem cells and grow them into a three dimensional tissue-like structure until it becomes at least partially functional, before replacing the defective tissue.

Over the last eight years, the Tissue Engineering Laboratory at the University of Hong Kong has developed several patented platform technologies including ‘microencapsulation’ and ‘complex tissue engineering’ technologies, enabling researchers to grow complex tissues, which consist of multiple tissue components.

The core technology is to grow cartilage tissues complete with underlying bone tissues in vitro using the patient’s own stem cells isolated from clinically accessible sources such as bone marrow. This ‘complex tissue plug’ mimics the structural organization of native cartilage-bone tissues.

Animal studies in rabbits have shown that replacing defects in knee joint cartilage with these tissue engineered cartilage-bone tissue plugs gives rapid and sustained regeneration of high quality cartilage with structure, composition and mechanical properties comparable to that of the clinical gold standard autografts.

The use of these regenerative complex tissue plugs allows surgeons to use the same autograft surgical procedure to repair cartilage damage without the need to hurt the patients’ own cartilage. Currently, by working with orthopaedic surgeons, the research team is preparing to translate this technology for human applications.

Chan said the the technology would offer a novel solution to the treatment of cartilage related diseases.

“Damaged cartilages cannot self-heal. In our lifetime, our cartilages may be damaged, (through daily wear and tear, trauma or disease) to the point which can cripple us. As we live longer, grow fatter, and have sportier lifestyle, problems of bad knees and other joints can only get worse,” said Chen.


Source: The University of Hong Kong.
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