CUHK Research: Changing the world

“We thought, ‘Why don’t we cultivate stem cells outside the human body and wait till they really grow into tendon stem cells?’ Then we can reduce the chance of immunogenicity.” The CUHK team has successfully cultivated tendon stem cells outside the human body into a decellularised stem-cell sheet using tendon, which has the cells removed but retains the cells’ extracellular matrix i.e. secreted proteins and other molecules that surround and support the cells. Without the cell itself, the risk of uncontrolled action of implanted cells is eliminated. The sheet can be used as a bioactive material and wrapped around a damaged tendon or ligament, via minimally invasive surgery, to stimulate tissue regeneration. Having tested the cell sheet on mice and rabbits, the team is planning to conduct tests on large animal models such as cattle and sheep, whose joints are of similar sizes as humans’, before starting clinical trials. The invention would be suitable for patients suffering from musculoskeletal injuries. “The global demand for anterior cruciate ligament surgeries is huge. If we can have donors of stem cells and set up a stem cell bank for in vitro cultivation, a lot of people will benefit,” Professor Yung says. Stem cell therapy for osteoarthritis Another research, led by Professor Yung together with Wayne Lee Yuk-wai, Assistant Professor of Orthopaedics and Traumatology, is the development of stem cell therapy to treat osteoarthritis, a common degenerative joint disease. Osteoarthritis occurs when the protective cartilage that cushions the ends of the bones wears down over time. In serious cases, a joint replacement surgery is needed, but it is expensive. Scientists around the world, including the CUHK team, have been finding ways to regenerate cartilage. “Millions of people suffer from osteoarthritis around the world. In Hong Kong, it is a four- year wait for a patient to get a knee joint replacement at a public hospital. If our stem cell therapy can make its way through to clinical success, it will be of great benefit to many,” Professor Yung says. Apart from Professor Yung, other CUHK researchers and 12 scholars from Karolinska Institutet in Sweden are working in five directions at the centre, namely, stem cells and cell-based therapies, tissue engineering and 3D microtissue modelling, cellular and molecular mechanisms, pre-clinical and clinical translation, and enabling technologies. 38