From a petrochemical engineer, Dr. Nguyen Ngoc Tuan shifted his research to biological materials, and together with his colleagues successfully developed biodegradable artificial ligaments and promoted ligament tissue regeneration.
Dr. Nguyen Ngoc Tuan (34 years old), Ecole Normale Superieur (ENS-PSL), Paris (France), and his colleagues are pursuing new techniques in the field of tissue engineering. This research is a continuation of the project to develop biodegradable artificial ligaments that he has been conducting at Sorbonne Paris Nord University (France) since 2017.
“There are many organ tissues in the body that, when damaged or lost, will be very difficult or impossible to heal. Therefore, regenerating these damaged tissues becomes an attractive problem for scientists,” Dr. Tuan told. VnExpress.
Biodegradable artificial ligaments developed from biopolymer fibers (polycaprolactone and formerly Polyethylene terephthalate) can promote the regeneration of torn ligament tissue. It is used as a temporary replacement graft for damaged ligaments to stabilize the knee joint and become a material scaffold to promote tissue cell regeneration into new ligaments.
The biopolymer fiber bundles of the artificial ligament were tested for biological activity on fibroblast cells in vitro after 10 days, showing clear adhesion and growth of cell clusters. Photo: Researchers
Interestingly, the polymer fibers will slowly degrade in the body without causing cytotoxicity during the process of regenerating the new ligament, so there is no need for surgical removal. This is a useful solution for patients with knee-related injuries, often seen in sports people, popular in football players, heavy laborers or people who exercise incorrectly.
The results of the study show the potential to promote faster injury recovery, with less risk, efficiency and cost compared to traditional tissue grafting surgery. The study is considered a “breakthrough in the field of tissue engineering and regenerative medicine”, published in the international journal Polymer Degradation and Stability (2020-2021,NXB Elsevier), Scientific Report (2021, NXB Springer-Nature), Biointerphases (2020, American Institute of Physics).
Artificial ligament implantation process on laboratory mice. Photo: Researchers
Dr. Tuan said that the biggest challenge is to “meet the strict requirements for implantation into the body”, because the material needs to be biocompatible with cells, non-cytotoxic, and have tissue-appropriate mechanical properties. For example, for biopolymer fibers for artificial ligaments, they need to withstand the pulling, twisting, and weight of the body on the knee joint, to keep the joints fixed. In addition, there is a requirement to enhance cell adhesion and promote cell growth into target tissues.
To address this issue, the team activated the fiber surface by coating it with polystyrene sulfonate molecules that are bioactive to cells through strong chemical bonds. The team used ozonation techniques to control the ability to completely cover the 3D surface of the polymer fiber bundles. The entire process went through strict medical controls before the product was tested in vitro and implanted in mice, sheep, and then humans.
“The reproducibility of these materials is also a challenge to overcome,” he said. The materials need to meet requirements for functional stability, manufacturing, and pass rigorous testing by health organizations such as the FDA (USA) or CE (Europe).
Professor Veronique, Sorbonne Paris Nord University, member of the board of the French Society of Biomedical Engineering, and head of the research team, said that anterior cruciate ligament (ACL) rupture is one of the most common sports injuries affecting athletes. Due to the poor healing ability of the ACL, surgical intervention is often required. According to the professor, today, ligament reconstruction surgery (utograft replacement) is the “gold standard”. However, more than 50% of cases show risks from pain, bone necrosis at the attachment point and a very long recovery time (6 to 12 months). “Therefore, the development of bioactive and biodegradable artificial ligaments is a necessary direction to solve these problems,” he said.
Currently, this technology is being used by Texinov and Movmedix companies to produce and put into clinical trials in Europe and the US. “The artificial ligament market simulates natural ligaments, is made from biocompatible materials, works in vivo without causing systemic reactions in the body. Implanting artificial ligaments is a very specialized technique, recommended for athletes and patients who need high performance”, Dr. Julien Steinbrunn, Director of Research and Development, Movmedix company, assessed.
Dr. Nguyen Ngoc Tuan. Photo: NVCC
Although he studies regenerative medicine, few people know that Dr. Tuan started out as a petrochemical engineer. He said he started pursuing research on macromolecular materials when he was a student at Ba Ria University (Vung Tau). Thanks to the help of the head of the department at that time, Associate Professor Dr. Nguyen Van Thong, he received the Scientific Research Fund for Students from the university. “That was a big turning point that guided me to pursue the research path later,” he said.
In 2017, Tuan received a PhD scholarship in biomaterials for anterior cruciate ligament reconstruction of the knee, under the guidance of Professor Veronique Migonney of Sorbonne Paris Nord University. The research is part of the LIGA2BIO project from the Future Investment Program (PIA) from BPIfrance, in collaboration with biotechnology companies. After graduating, Dr. Tuan worked for the research and development department of the biotechnology company CERAVER for implants and then did a postdoctoral research at Ecole Normale Superieur focusing on biomaterials and cells.
He is currently collaborating with research groups from Compiègne University of Technology (France) and Saarland University (Germany) in developing scaffold-guided gene transfer and gene transfer for bone, cartilage and ligament tissue regeneration.
“We aim to address the limitations of biomaterials for regenerating difficult or impossible to regenerate organ tissues and train scientific personnel in this field,” he said.
Dr. Tuan added that Vietnam currently has many large research groups and biomaterial technology companies participating in this field. However, he recognized the need for multidisciplinary research groups, such as chemistry, mechanics, biology and medicine, with close coordination between research groups and manufacturing companies. “I am always looking for opportunities to cooperate and work with research groups in the field of tissue engineering in Vietnam.”