CUHK Research: Changing the world

Stem cell sheet for tissue repair Professor Patrick Yung Shu-hang, Co-Director of the Centre for Neuromusculoskeletal Restorative Medicine and a world-recognised leader in orthopaedic sports medicine, joined CUHK’s Faculty of Medicine in 2016 after practising as an orthopaedic surgeon for more than 20 years. He leads a team of researchers to make advances in sports medicine and arthroscopy surgery and is also committed to serving the professional sport communities in Hong Kong. “In the course of my clinical work, I have come across a lot of literature on basic research. But not all of them are practical for doctors and patients when it comes to clinical application,” Professor Yung says. “That’s what drove me to go into basic research. I want to develop something that is good for clinical use.” Professor Yung is currently working on two projects at the centre. The first one, which he collaborates with Professor Pauline Lui Po- yee, Associate Professor of Orthopaedics and Traumatology, is to develop a therapy for tendon repair with tendon-derived stem cells (TDSC) in vitro . About half of people aged 50 or above suffer from tendon problems in their knee joints or shoulders, including adhesive capsulitis (also known as frozen shoulder) and rotator cuff tears, according to Professor Yung. The ability to heal is further limited by conditions such as diabetes and high blood pressure. “A broken bone can heal if it is fixed in the right position, but a torn tendon is not so easy to heal,” Professor Yung says. “Even if it is reconnected, it may not restore its function due to degeneration from ageing. So I want to look into stem cell therapy to strengthen tendon repair.” The CUHK team, which started stem cell research for tissue repair nine years ago, has been exploring a different path. Traditionally, stem cell therapy involves an autograft, a procedure in which a patient’s healthy stem cells are collected from the bone marrow of their hips to replace the damaged cells. But there are risks. Such transplants are prone to immunogenicity i.e. a tendency to trigger an unwanted immune response from the human body. “Also, stem cells are primitive and they can evolve into various types of tissues – they can duly become bones and tendons, but they can also run out of control and evolve into cancer cells in the worst-case scenario. So the biggest challenge of this therapy is to manage the cell cultivation and make sure they become tendon cells,” Professor Yung says. Why don’t we cultivate stemcells outside the human body? Then we can reduce the chance of immunogenicity. 37