Regenerative medicine, a new field combining tissue engineering and molecular biology to restore human tissues and function, has become a hot topic and is poised to become a multibillion dollar specialty. Plastic surgeons are in a unique position to apply the science of regenerative medicine because restoration is at the heart of what we do. These ten stories from the last year or so show science fiction becoming reality and reveal a fascinating look into the future.
- 3D Printers manufacture “living” blood vessels
Researchers from Lawrence Livermore National Labs recently reported using 3D “bioprinters” which use “bio-ink” instead of synthetic materials to create scaffolds for living tissue.To make blood vessels, tubes are printed out of cells and other biomaterials which self-assemble, a process the researchers call “co-engineering with nature.” The vessels are not quite ready for transplantation, but are useful for toxicology studies reducing reliance on laboratory animals.
- How to grow new eyes in a lab
Scientists at the Laboratory for Organogenesis and Neurogenesis in Kobe, Japan, are working on ways to re-program stem cells into nerve tissue and even complete eyes (which form embryonically as an extension of the brain.) Although a number of labs around the world have made important contributions to stem cell programming, Dr. Yoshiki Sasai is credited with figuring out how to get them to grow into complex 3-dimensional tissues such as eyes. Under the right conditions, these stem cell derived nerve formations organize into a cup-shaped structure that resembles an embryonic eye, even developing retina cells. This retinal tissue has been transplanted into partially blind animals, restoring some vision. Clinical trials are planned for humans with macular degeneration.
- Protein that reverses aging discovered
Scientists at Stanford University discovered a few years ago that mice with age-related cognitive decline (similar to Alzheimer’s disease) improved when injected with blood from younger mice. Studies have now revealed that it is due to a protein similar to growth factor hormone, called GDF11, and its effects are not limited to the brain. In more mice experiments, GDF11 reversed heart failure and improved muscle function and exercise tolerance. Humans have GDF11 as well, with levels diminishing as we age. However, data on the function of GDF11 in humans is very limited and in some cases contradictory. No clinical trials have been done.
- Functional artificial skin breakthrough
Bioengineered skin, complete with capillaries and lymphatic vessels, is set to begin clinical trials. The synthetic skin was developed at University Children’s Hospital in Zurich, Switzerland, and the researchers believe it will better resist fluid buildup as can occur with conventional skin grafts, and/or be used in burn patients who don’t have enough undamaged donor skin. They haven’t yet figured out how to add the other components of skin such as pigmentation and hair however.
- Will it be possible to re-grow lost limbs?
Developmental biologist Michael Levin at Tufts University believes he has discovered how cells use electric signals to communicate during the development of arms, legs, and even faces. If we can decipher the signals with enough precision, it may be possible to use them to program regrowth of lost limbs, just as some types of salamanders do. Significant hurdles remain but some of the pieces to the puzzle are starting to fall into place.
- Scientists create a beating mouse heart from human tissue cells
If growing a new arm seems far off, consider that a fully functional, beating heart has been built from scratch in a lab. Lei Yang at the University of Pittsburgh took a snippet of skin, reverse-engineered the cells into stem cells, then programmed them into “cardiovascular progenitor cells” which were then seeded on to a decellularized matrix. This decellularization process is how Alloderm and Strattice are made, both of which I have used extensively and helped to pioneer for reconstructive and revision breast surgery.
- Surgeons implant cartilage grown from patient’s own cells
Surgeons in Switzerland recently reported 5 cases of nose reconstruction using cartilage grown in a laboratory from the patient’s own cells. After growing the cartilage from a small piece, it was then shaped to fit the specific defect. A team from Ohio State University applied the same concept to patients with knee pain from cartilage damage. In Wales, researchers are combining the cartilage cells with 3D printing, envisioning customization of replacement parts for ears, noses, and possibly joints.
- Drug that restores hearing
Until now, people with sensorineural hearing loss from long-term exposure to noise had nothing other than hearing aids to offer help. Sensorineural hearing loss is caused by damage to receptor cells in the ear, and because they were not believed to have the capacity to regenerate, this type of hearing loss has been considered irreversible. Researchers at Harvard Medical School offer hope to millions now with the discovery of a drug codenamed LY411575 that appears to stimulate regeneration of damaged hearing cells, at least in mice.
- Thought-controlled robotic hand
Remember Luke Skywalker’s robotic hand in the original Star Wars? The technology is now a reality, thanks to research at the Johns Hopkins Applied Physics Lab funded by the Defense Advanced Research Projects Agency (Darpa). The prosthetic attaches directly to the bones in the arm, and sensors attach to the nerves allowing the hand to be controlled by the brain the same as a living hand. Additional research will allow for a sense of feeling and touch. Use the force Luke!
- Implants may offer relief from chronic pain
A small, flexible electronic implant has been developed that appears to be able to switch off pain signals before they travel to the brain. Because of its size – about the same as a grain of rice – the implant can be easily placed near a nerve. So far it has been only used on mice but the possibilities are very intriguing and encouraging for the millions of people with chronic pain.