dr. darryl d'lima is trying to produce cartilage from stem cells. he wants use it to repair warn out joints with the help of a 3- d printer. >> what we do with the discarded tissue is instead of throwing it away, we bring it to the lab and we try to print fresh tissue, live tissue with a 3-d-printer. if that works, some day we think we might be able to print directly into the patient's knee. >> d'lima thinks that in 3 to 5 years that could be done right in the operating room, thereby eliminating the need to replace diseased joints. modern technology would enable the body renew itself continually, so that people would live longer. >> the challenges that i'm facing are so complex and so deep that i've got to have cell biologists, i've got to have stem cell specialists, i've got to have chemists, i've got to have engineers who understand printing technology, and i have to be a generalist who brings all these people together to solve the problem. >> unlike the biohackers, dr. d'lima can rely on funding from foundations for his research. for him, 3-d pri