Bone and skeletal injuries are a major cause of long-term disability around the world. Researchers at Lund University in Sweden have now developed a cell-free cartilage structure designed to guide the body as it repairs damaged bone.
According to the study, this engineered transplant can promote bone healing without provoking strong immune reactions. The method has already been tested successfully in animal models, and the researchers are preparing to evaluate the approach in human studies.
Large Bone Injuries Often Require Transplants
When large sections of bone are destroyed or removed, the body may struggle to repair the damage on its own. This can happen after cancer treatment, severe joint diseases such as rheumatoid arthritis and osteoarthritis, or serious infections. In these cases, bone tissue transplantation is often necessary to restore structure and function.
Researchers estimate that more than two million people worldwide require bone graft procedures each year. Current treatments usually depend on using a patient’s own tissue or cells to rebuild bone. While this approach can work, it is expensive, time consuming, and can add to the physical burden patients already face. It also contributes to rising healthcare costs, the researchers note.
Toward a Universal Bone Repair Technology
“Patient-specific grafts are both costly and time-consuming and do not always succeed. A universal approach in tissue engineering, with a reproducible manufacturing process, offers major advantages. In our study, we present just such a method and demonstrate important advances toward a non-patient-specific technology,” says Alejandro Garcia Garcia, associate researcher in molecular skeletal biology at Lund University.
To develop this new method, the team first grew cartilage tissue in the laboratory. They then removed all living cells from it in a process called decellularization. This step leaves behind the extracellular matrix, which is the natural framework that surrounds cells in tissues and provides both structural support and biological signals.
Because this framework remains intact, it still contains growth factors that can guide the body’s own cells. When placed at an injury site, the remaining cartilage structure can act like a blueprint that helps the body rebuild damaged bone step by step.
Off-the-Shelf Cartilage Grafts for Bone Repair
“The cartilage structure we have developed is based on stable, well-controlled and reproducible cell lines, and can stimulate bone formation without triggering strong immune reactions. We show that it is possible to create a ready-made, so-called ‘off-the-shelf’ graft that interacts with the immune system and can repair large bone defects. Because the material can be produced in advance and stored, we see this as an important step toward future clinical use of human bone tissue transplants,” says Paul Bourgine, who led the study. He is an associate professor and researcher in molecular skeletal biology at Lund University.
Preparing for Human Clinical Trials
One key advantage of this technology is that the cartilage scaffold can be manufactured ahead of time and used for many patients without tailoring it to each individual. The next phase of research will focus on evaluating the method in people while also expanding and standardizing production.
“The next step involves deciding which types of injuries to test this on first, such as severe defects in long bones of the arms and legs. At the same time, we need to develop the documentation required for ethical review and regulatory approval to conduct clinical trials. In parallel, we are establishing a manufacturing process that can be carried out on a larger scale while maintaining the same high level of quality and safety every time,” says Alejandro Garcia Garcia.