USING YOUR OWN STEM CELLS to REGENERATE NEW BODY PARTS
Personalized Surgery: Growing Your Own Bone
by Julie Barr / March 4, 2015
Bone-related surgeries, undertaken by nearly one million patients in the US each year, can fail due to unsuccessful integration of prosthetic or donor bone implants. Nina Tandon SM ’06 is working to solve this problem by growing human bone from the cells of the patient. Tandon, CEO of EpiBone, leads the New York City-based company that is the first to grow human bones from stem cells, delivering custom-made bones. Not only are the bones more likely to integrate into the body because they are living, compatible bone, but also because they are created based on a CT scan of the target area and are made to fit exactly. “What we’re really proposing is a different view of the body,” says Tandon. “To view it as a renewable resource of stem cells that can regenerate new parts as you need them.”
At EpiBone, Tandon works every day in the lab to perfect their method. With the technology in place, they have successfully grown bone and are in the testing stages. With one pilot study completed and another to begin this spring, they hope to be done with pre-clinical trials in the next three years and get on the path of FDA approval to bring their technology to market. “I can’t wait for the day when someone who needs a transplant doesn’t have to wait on a list,” says Tandon. “And I’m hoping our research can get us one step closer to that day.” A Fulbright Scholar, Tandon completed her PhD and an MBA at Columbia University. She is a senior TED fellow and co-author of Super Cells: Building with Biology, a book that explores the new frontier of biotech. Tandon was recently named one of CNN’s “7 ‘tech superheroes’ to watch in 2015.
”Tandon, who co-founded the EpiBone project two years ago, has spent the greater part of the past 10 years studying and testing bone and organ regrowth—and it all started at MIT. As a graduate student studying bioelectrical engineering, Tandon did a research rotation with world-renowned professor and tissue engineering research scientist Gordana Vunjak-Novakovic. “It was through the work I did at MIT with Gordana that I realized the power of tissue engineering and regenerative medicine and the way it would change medicine forever,” says Tandon. “By engineering human tissue and cells from their own human stem cells, we can change the way medicine is done. Whether it’s organ donation or drug testing, we can make the medicine fit the individuals.”
3D printed bio-dough for your custom skeleton
by John Hewitt / July 7, 2015
3D printed skeletal parts can be a lifesaver. Replacement skulls made from transparent plastic can now be made to order and fitted in no time. Although there may be some benefits to using artificial materials for skulls, for many applications real bone is still the best option. The problem is that there really is no good way to feed calcium, phosphate, and protein into a printer and have living bone come out. One way around this dilemma is to print a material that cells can do something with. That way the body can better integrate with the material, and perhaps even replace it over time with its own stock. This would be particularly important for the meshwork of spongy tissue (known as trabeculae) that is typically found in the core of the spinal vertebral bodies, and long bones of the limbs. A potential substitute for this ‘cancellous bone’ has recently been reported in the journal Biofabrication. This bone is not only structural, but also provides unique niches for the production of various kinds of blood cells. The researchers combined two commonly used biomaterials into a thermoresponsive blend that could be printed and then quickly cured into a solid at 37 degrees Celsius. The main component, poly(lactic-co-glycolic acid) (PLGA), is the go to material for biodegradable applications. When stabilized with polyethylene glycol (PEG) and extruded through a print head, a porous solid with properties similar to cancellous bone can be made. Mechanically speaking that amounts to tolerating yield stresses up to 1.22 MPa and having a Young’s moduli of up to 57.3 MPa. Incidentally, you may have heard of PEG before. It happens to be the ‘magic ingredient’ that is being touted for use in the allegedly forthcoming head transplant surgery.
The researchers were also able to embed microspheres laced with proteins that could be released over time. Although they just used a common protein (lysozyme) here for testing purposes, the idea is probably to incorporate a bone-morphogenic protein like BMP that could aid in regrowth. To remove any doubt that the new material was biofriendly, the researchers also did the essential experiment of incubating it together with human mesenchymal stem cells obtained from bone marrow. We covered the 3D printed ‘total skull’ replacement operation over a year ago. The 22-year-old patient seems to be doing well and there is even a video (below) of the operation that has been released in the time since. While that is all very encouraging, having a lining of the real thing may still have much to offer, particularly for the skeletal bones.
More than just bone is probably going to be needed for any significant repair or major augmentation of the skeletal system. Fortunately, researchers are also coming up with ways to print other important elements like cartilage. Not only that, but they can potentially do it in less than an hour while you wait. Soon we might expect that if your hospital is not advertising its own state-of-the-art machine shop, you may may want to go somewhere else. One obvious place for a custom preformed cartilage insert would be for the meniscus of the knee. That is exactly the spot for a new implant (see pic above) made of a material called Samsonium. Scientists at Swansea University-UK have FDM printed this nylon titanium powder into a meniscus with the right degree of cushion and slipperiness to do the job. Reportedly ten times stronger than ABS or PLA filament, the material is described as ‘the purest form of a delta transition of nylon 6/9 with an optimized crystallinity.’ We’re not sure exactly what that means, but it sounds like the next time you have a major accident, you might want to at least ask about some of these goodies. To temper all this optimism we should probably leave you with at least one sobering dose of reality from the world of bone cements and materials: beware of off-label usage and make sure everything has been thoroughly vetted.
Human molar scaffolding
STEM-CELL DENTAL IMPLANTS GROW NEW TEETH IN YOUR MOUTH
by Denise Ngo / May 25, 2010
“Dr. Jeremy Mao has unveiled a technique that directs the body’s stem cells into a scaffolding that will aid in the regeneration of a new tooth. The loss of a tooth is a minor deformity and a major pain. Although dental implants are available, the healing process can take months on end, and implants that fail to align with the ever-growing jawbone tend to fall out. If only adult teeth could be regenerated, right? According to a study published in the latest Journal of Dental Research, a new tissue regeneration technique may allow people to simply regrow a new set of pearly whites. Dr. Jeremy Mao, the Edward V. Zegarelli Professor of Dental Medicine at Columbia University Medical Center, has unveiled a growth factor-infused, three-dimensional scaffold with the potential to regenerate an anatomically correct tooth in just nine weeks from implantation. By using a procedure developed in the university’s Tissue Engineering and Regenerative Medicine Laboratory, Dr. Mao can direct the body’s own stem cells toward the scaffold, which is made of natural materials. Once the stem cells have colonized the scaffold, a tooth can grow in the socket and then merge with the surrounding tissue.
Dr. Mao’s technique not only eliminates the need to grow teeth in a Petri dish, but it is the first to achieve regeneration of anatomically correct teeth by using the body’s own resources. Factor in the faster recovery time and the comparatively natural process of regrowth (as opposed to implantation), and you have a massively appealing dental treatment. Columbia University has already filed patent applications in regard to the technology and is seeking associates to aid in its commercialization. In the meantime, Dr. Mao is considering the best approach for applying his technique to cost-effective clinical therapies.”
ULTRASONIC TISSUE REPAIR
Skin-healing technology could be the end of chronic wounds
by Mark Bass / July 15, 2015
“My research group has just published work on the use of a small handheld ultrasonic emitter that accelerates tissue repair. This approach doesn’t provide the instant fix of Star Trek, but we found that healing times could be reduced by 30%. This both increases comfort for the patient and shortens how long the wound is susceptible to infection. Where such technology really comes into its own is in the treatment of individuals who don’t heal well to start with. After the age of 30, our bodies’ capacity to heal deteriorates – and by the time we are over 60 this deterioration becomes a real problem. Other risk factors that contribute to poor healing include diabetes, obesity and smoking. This means a large proportion of the population suffer healing delays, and that susceptibility to healing defects is escalating. As healing deteriorates, injuries can result in chronic wounds that never heal because the damaged skin cells become dormant. Such wounds include bed sores, venous leg ulcers, diabetic foot ulcers and pressure ulcers. Chronic wounds currently affect 200,000 UK patients and consume 2%-5% of annual healthcare spending worldwide. They are also incredibly painful and, in many cases, can only be resolved by amputation of the limb.
We have discovered that ultrasound treatments can reactivate dormant cells and therefore jump-start the healing process. It is well established that embryos in the womb are capable of perfect, scar-free healing. And even in adults, organs such as the liver will regenerate. However at the point of birth, we lose much of our capacity to heal and those capabilities continue to deteriorate throughout our lives. What the ultrasound treatment does is effectively turn back the clock and stimulate cells to perform the functions that they are capable of but have forgotten over time. Because it is jump-starting natural processes, such treatment is relatively risk-free – unlike many drug treatments that interfere with the chemical processes of the body and can lead to side effects.
The ultrasound device works by inducing nano-vibrations in the membranes and surrounding environments of skin cells. Those vibrations cause channels to open on the surface of the cell that allow calcium to move across its membranes. Calcium is the signalling currency of the cell and the mineral’s movements across membranes control many of the cell’s functions. In the case of ultrasound, the new position of the calcium within each cell gives it a defined front and back. This causes the cells to move towards the damage site, pulling the edges of the wound together and promoting healing. We have demonstrated this effect in cells isolated from venous leg ulcer patients. More importantly, we have been able to reverse a number of healing defects caused by diabetes, age and congenital disorders, so that the treated wounds heal as quickly as young, healthy wounds. This means we will soon be in a position to prevent, and possibly reverse, the formation of chronic wounds.”