New Cartilage Can be Grown From Stem Cells Found in Adult Ears

Cartilage is found throughout the body giving shape to noses and ears and cushion for the joints. However when damaged, is not easily replaced which is why synthetic materials is often used to replace damaged cartilage.

However, Japanese scientists have grown new cartilage using stem cells found in the ear of all places. Specifically, the perichondrium which lines the cartilage of the ear. Perichondrium is also the layer under which a hematoma develops after ear trauma (ie wrestling) that can lead to cauliflower ear if left untreated.

The stem cells were isolated from the perichondrium and injected into mice where chunks of cartilage developed and remained still healthy after 10 months.

So rather than using artificial materials to reconstruct knees and noses, theoretically, stem cells can be retrieved from the patient's ear, injected into mice, cartilage grown and retrieved, and used to replace the damaged cartilage in the patient without worry of rejection.

Reference:
Reconstruction of human elastic cartilage by a CD44+ CD90+ stem cell in the ear perichondrium. DOI: 10.1073/pnas.1109767108