Bone and skeletal injuries are a major cause of long-term disability around the world. In light of this medical need, Swedish scientists have engineered a cell-free cartilage scaffold that can guide the body to rebuild damaged bone. By removing the cells but preserving the structure and natural growth signals, the material acts as a blueprint for the body’s own repair process.
To demonstrate the feasibility, in animal studies the process helped to regenerate bone without triggering strong immune reactions. The researchers now plan to scale up production and begin testing the approach in humans.
This engineered transplant can promote bone healing without provoking strong immune reactions.
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.
The researchers, from Lund University, 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.
According to lead scientist Alejandro Garcia Garcia, in conversation with Science Technology Daily: “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.”
Method development
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.
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.
Since 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.
Next stage
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.
As Garcia explains: “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”.
The research features in the publication Proceedings of the National Academy of Sciences, titled “Engineered and decellularized human cartilage graft exhibits intrinsic immunosuppressive properties and full skeletal repair capacity.”
