Cartilage tissue wears with age, and this is a significant source of issues for older people. The challenge in cartilage tissue engineering lies in the structural properties of the tissue. Researchers have struggled to find a methodology for culturing three-dimensional tissue that recaptures a significant portion of the load-bearing strength and resilience of natural cartilage. Some inroads have been made, however, and in the research here, a better quality of graft is produced:

Articular cartilage is the tissue on the end of a bone that cushions the surface of the joint and is vital for painless movement. Because the tissue doesn't have its own blood supply, it has limited capacity to repair itself once damaged, leading to degenerative joint conditions like osteoarthritis. Traditional methods to prevent or delay onset of cartilage degeneration following traumatic events like microfracture surgery don't create the healthy cartilage needed to endure the forces of everyday movement. Even novel medical advances using patients' own articular cartilage cells (chondrocytes) have been unable to predictably restore cartilage structure and function in the long term.

Researchers investigated an alternative approach using engineered cartilage tissue grown from patients' own cartilage cells from the nasal septum which have a unique capacity to grow and form new cartilage tissue. This phase 1 study included 10 patients with full-thickness cartilage lesions of the knee. The researchers extracted a small biopsy specimen (6mm in diameter) from the nasal septum under local anaesthetic using a minimally invasive procedure. The harvested cells were multiplied by exposing them to growth factors for 2 weeks. The expanded cells were then seeded onto collagen membranes and cultured for 2 additional weeks, generating a 30 x 40mm cartilage graft. The engineered graft was then cut into the right shape and used to replace damaged cartilage that was surgically removed from the recipient's knee. Despite variable degrees of defect filling, MRI scans at 2 years revealed the development of new tissue with similar compositional properties of native cartilage. Moreover, nine recipients (one was excluded because of several independent sports injuries) reported substantial improvements in the use of their knee and in the amount of pain compared to before surgery. No adverse reactions were reported.

The researchers say that the small number of participants and the relatively short follow-up time will mean further studies will be needed. Similar to other early phase surgical studies, the trial did not involve a control group, so other studies will be needed to establish a comparison in effectiveness with currently available treatments, and to assess the possible bias of a placebo effect. "Our findings confirm the safety and feasibility of cartilage grafts engineered from nasal cells to repair damaged knee cartilage. But use of this procedure in everyday clinical practice is still a long way off as it requires rigorous assessment of efficacy in larger groups of patients and the development of manufacturing strategies to ensure cost effectiveness. Moreover, in order to extend the potential use of this technique to older people or those with degenerative cartilage pathologies like osteoarthritis, a lot more fundamental and pre-clinical research work needs to be done."