The human knee is a complex and problematic joint. I think it’s fair to say that it hasn’t adapted well to our greatly expanded life expectancy and trend towards obesity; painful osteoarthritis is the number one cause of chronic disability in the US and many other countries.
Degradation of the knee cartilage can be brought on by all sorts of causes – trauma, hereditary and developmental factors or even just plain wear and tear – but the result is the same. Without healthy cartilage cushioning the point where the femur sits on top of the tibia, those two bones grind away at each other with the full weight of the body behind them, causing painful and incapacitating damage over time.
As yet, nobody has discovered a more effective barrier than human cartilage itself, so there’s no shortage of research going into the creation of new cartilage to replace or repair worn out joints.
One promising stream involves the idea of using 3D printing technology to deposit stem cells directly into damaged areas of cartilage so it can grow back as healthy tissue.
Dr. Rocky Tuan, director of the Center for Cellular and Molecular Engineering at the University of Pittsburgh School of Medicine, is working on techniques that give a patient’s stem cells the perfect conditions to grow into healthy cartilage – particularly a type of 3D bio-printed scaffolding that holds the stem cells in place to give the tissue its correct shape as it grows.
The intent is that eventually, surgeons will be able to print stable stem cell structures directly and precisely into the joint through a catheter. The technique is similar to previous attempts such as the BioPen, but with the advantage that the extruded cells are solidified using regular visible light instead of ultraviolet light, which can have a negative effect on living cells.
Dr. Tuan is now looking to improve the resilience and effectiveness of the scaffolding material using a nanofiber electrospinning technique he developed with another colleague in 2010.
Cartilage problems are debilitating, and they affect people at stages of their lives when they have maximal access to cash. Research teams are well aware of the commercial potential that can be unlocked when they find a solid solution to the problem – so it’s fair to say that osteoarthritis is living on borrowed time. But the sword can’t drop quickly enough for those of us who suffer daily joint pain.