Engineered Cartilage Regenerates Joints
Scientists find new use for nasal chondrocytes
According to a report in Science Translational Medicine, researchers at the University of Basel in Switzerland have found that cells taken from the nasal septum are able to adapt to the environment of the knee joint and can be used to repair articular cartilage defects. The cells’ ability to self-renew and to adapt to the joint environment is associated with the expression of homebox (HOX) genes.
Cartilage lesions in joints often appear in older people as a result of degenerative processes. However, they can also affect younger people after injuries and accidents. Such defects are difficult to repair and often require complicated surgery and long rehabilitation periods.
Cartilage cells from the nasal septum (nasal chondrocytes) have demonstrated the ability to generate new cartilage tissue after their expansion in culture. In an ongoing clinical study, the researchers took small biopsy samples (6 mm in diameter) from the nasal septum of seven subjects. They then cultured and multiplied the cells and applied them to a scaffold to create a cartilage graft 30 × 40 mm in size. A few weeks later, they removed damaged cartilage tissue from the subjects’ knees and replaced it with the engineered tissue from the nose.
During embryonic development, nasal septum cells develop from the neuroectodermal germ layer, which also forms the nervous system; their self-renewal capacity is attributed to their lack of expression of HOX genes, the researchers explained. In contrast, HOX genes are expressed in articular cartilage cells that are formed in the mesodermal germ layer of the embryo.
“The findings from basic research and preclinical studies on the properties of nasal cartilage cells and the resulting engineered transplants have opened up the possibility to investigate an innovative clinical treatment of cartilage damage,” said lead investigator Professor Ivan Martin.
Previous research had shown that the capacity of human nasal cells to grow and form new cartilage is conserved with age. This means that older people could benefit from the new method, as well as patients with large cartilage defects.
While the primary objective of the ongoing study is to confirm the safety and feasibility of cartilage grafts engineered from nasal chondrocytes when transplanted into joints, the method’s clinical effectiveness has been highly promising, the researchers say.
Source: University of Basel; August 28, 2014.