Scientists use stem cells to treat arthritis in Liesel, a gorilla at Budapest Zoo August 31, 2023

Scientists from the University of Sheffield have used stem cell therapy to treat osteoarthritis of a gorilla for the first time. Honorary Associate Professor, Endre Sós, the Lead of the zoo team said: "Our task is to provide the best medical care and best quality of life for these animals, despite their age-related conditions.

Liesel, the elderly matriarch at the Budapest Zoo has been finding it difficult to walk on her left leg for some time now, suggesting that she may be suffering from arthritis. A team, led by Endre Sós (Chief Vet and Acting Director General at the Budapest Zoo) and Mark Wilkinson (an orthopaedic surgeon and leading international expert in the biology and treatment of human arthritis) recently carried out a comprehensive assessment of Liesel's major joints and used mesenchymal stem cells to treat alterations in herleft hip and knee joints.

One of the popular residents of our zoo is Liesel (Her 40th birthday video is available on YouTube), the oldest member of the five-person gorilla team, who has successfully raised three offspring since her arrival in 1989, and is now a grandmother ten times over. Liesel was born in April 1977, so she is already 46 years old, which is quite old, since gorillas don't live that long in nature.

Osteoarthritis is a progressive degenerative process of the joint. Once the cartilage is worn and damaged, the process is irreversible and current treatments focus on symptomatic control and not on the treatment of the disease itself. The use of stem cells for the treatment of arthritis and regeneration of the damaged cartilage has been successfully piloted in several animal species in recent years, such as dogs and horses and small-scale clinical trials in humans have also proven to be a promising treatment for this condition.

Stem CellX was established following successful research trials on arthritis-affected dogs and has been developing proprietary technologies for the formulation of stem cell-based products for arthritis treatment in animals. Stem CellX founder and Professor at the University of Sheffield, Endre Kiss-Tóth has long been collaborating with Mark Wilkinson to explore novel treatment options for human arthritis. They are now jointly leading a preclinical programme to test Stem CellX technologies for the development of a similar stem cell treatment in human patients. The company partnered with Budapest Zoo recently to provide this treatment for animals in need. Liesel is the first primate in the world to have successfully benefited from the work of the aforementioned research team.

The mesenchymal stem cells used for the procedure were isolated from a piece of fat tissue donated by N'yaounda, a young female gorilla who underwent a planned minor operation in 2022. A specialist team at Stem CellX then isolated, purified and cultured these cells at their R&D base in Hungary to formulate a cell suspension that could be kept deep-frozen until the treatment injection.

Honorary Associate Professor, Endre Sós, the Lead of the zoo team said: "The advanced husbandry and veterinary practices in modern zoos result in increased longevity in many species, including apes. Our task is to provide the best medical care and best quality of life for these animals, despite their age-related conditions. Stem-cell therapy hopefully brings in a new era in this field as well."

Professor Mark Wilkinson, Leader of clinical orthopeadic team said: "I was delighted to be part of the team doing this ground-breaking work and having the opportunity to treat Liesel's arthritis. Hopefully this new research will lead to application of the treatment to humans in due course that will provide patients with a real solution to the pain and suffering that arthritis causes."

Professor Endre Kiss-Tóth, founder of Stem CellX said: "It has been a great privilege to be part of this word-first collaboration and bring together Stem CellX expertise in stem cell technologies, with the internationally leading clinical skills and knowledge in OA pathogenesis of the University of Sheffield and thus provide a novel treatment option for Liesel to improve the quality of life in her golden years. We are now holding our breath and following her recovery closely in the hope to see marked improvement in her movements and in the use of her OA affected leg."

Based on our experience so far, the treatment is clearly benefiting Liesel, which our visitors will see for themselves if they also visit our apes during their visit to the zoo.