Running in parallel to the tissue engineering goal of growing replacement inner organs such as hearts and livers you will find research aimed at building new biological joints. Joint replacement could be far safer, more effective, and long-lasting if biological parts were used instead of the present state of the art artificial materials. In the long run the pendulum will swing back to favor the artificial, but for now biology is the wave of the future. For example, there is this recent news:
Artificial joint replacements can drastically change a patient's quality of life. Painful, arthritic knees, shoulders and hips can be replaced with state-of-the-art metal or ceramic implants, eliminating pain and giving a person a new lease on life. But, what if, instead of metal and plastic, doctors were able to take a patient's cells and grow an entirely new joint, replacing the old one with a fully functional biological joint? A team of University of Missouri and Columbia University researchers have found a way to create these biological joints in animals, and they believe biological joint replacements for humans aren't far away.
The scaffold was implanted in rabbits with a surgical technique currently used for shoulder replacement in humans. The surgery removes the entire humeral head, or the ball part of the ball-and-socket shoulder joints. The scaffolds are infused with a growth factor, which encourages the host's own cells, including stem cells, to become cartilage and bone cells. The advantage to this technique is that it avoids the need to harvest and implant cells, which requires multiple surgeries. ... The study found that the rabbits given the infused scaffolds resumed weight-bearing and functional use of their limbs faster and more consistently than those without. Four months later, cartilage had formed in the scaffolds creating a new, functional cartilage surface for the humeral head.
This is an encouraging demonstration, and one more in a long line of the same. The cartilage engineers have been advancing the state of their art steadily over the past few years, as a look back in the Fight Aging! archives shows. This is exactly the sort of thing that I like to see - consistent material progress towards the components of a general repair kit for human beings. It is a sign of health for this part of the field, and we can hope that in the years ahead the other needed areas of medical development will come to show the same or better levels of progress.