

Medical technology firm Penumbra designed the tool. The process involves going in through the patient’s groin, and threading a tiny catheter into a blood vessel. That catheter goes up to the neck, at which point an even smaller catheter emerges from it and goes into the brain, whereupon it vacuums out the blood clot. “It requires years of training to be able to do this,” said Dr. Mayank Goyal, director of the Seaman Centre. “It places enormous demands on the interventionalist, on the imaging specialists, and on the emergency team that gets the patient to a designated stroke care facility. Teamwork is key for success.” The Penumbra System is intended for use on ischemic strokes, which involve blood clots in the brain, and constitute 80% of all strokes. Currently, such clots are treated with the drug t-PA, which has to be administered within three hours of the event. The new system involves less of a risk of bleeding, and may still work after more than three hours.

(Source: Gizmag)

The scaffolding used to attract stem cells and grow replacement teeth in place.

 (Source: Columbia University Medical Center)




Researchers at Columbia University Medical Center in New York City have developed a method of growing dental implants in place using stem cells. The process can result in a fully formed replacement tooth in less than nine weeks from initial implantation. Unlike current dental implants, these teeth conform to changes that occur to the jaw bone over time, limiting the need for costly and time consuming adjustments or replacement implants., July 21, 2010, by Janice Karin  —  Dr. Jeremy Mao and his colleagues at the Columbia’s Tissue Engineering and Regenerative Medicine Laboratory attach a scaffold infused with a growth factor to the empty tooth socket. Stem cells hone in on the scaffold, eventually forming a tooth of the correct shape and size to fit the individual patient’s mouth. In addition to forming a more naturally compatible tooth, this method eliminates the need to harvest stem cells or grow the implant in a petri dish or other laboratory environment then implanting it fully formed. This process also regenerates periodontal ligaments and alveolar bone, neither of which is possible with traditional dental implants, and makes for a much more effective and natural tooth replacement.

Dr. Mao’s procedure results in a fully formed tooth in approximately nine weeks. This is a significant time improvement over regular implants which can take as long as eighteen months from initial patient visit to a fully healed implanted tooth. A regular implant can also require visits to a long series of different types of dentists, adding complexity and expense to the mix. The new process is simpler, more natural, more efficient, probably longer lasting, and likely to be less expensive than traditional implants.

Although animal models have been successful, the new implant method has not yet been tried in human mouths. Although general use by dentists is still in the future, Columbia is actively looking to start the approval process and commercial development of the new implants.

TFOT has previously reported on a knee replacement technique using similar scaffolding that coaxes cartilage and bone regrowth. TFOT has also previously reported on other dental research and advancements including an herbal lollipop designed to help prevent cavities, the use of spectroscopy to discover early stages of tooth decay, and a study showing daily tooth brushing improves the health of patients confined to hospital beds.

Read more about the new tooth implant process in this Columbia University Medical Center press release and more about Dr. Mao’s previous stem cell research in this CUMC newsletter article

Columbia University Medical Center, July 21, 2010  —  When news media reported last year that Jeremy Mao’s research team had created a breast implant from stem cells, few noted that Dr. Mao is a dentist. Though Dr. Mao (who has a D.D.S. and a Ph.D.) spends less time treating patients, his career as a tissue engineer exemplifies a growing trend in dental research, particularly at the College of Dental Medicine. Research increasingly shows that oral health is entwined with general health and that dental research can bring benefits to a wide array of medical fields. Dr. Mao, who recently joined the College of Dental Medicine from the University of Illinois at Chicago, took a break from his busy schedule to talk with InVivo.

What connection does your stem cell work have to dentistry?

A lot, actually. My lab got into that mostly by serendipity, because the same stem cells that we used previously to make the bone and cartilage in an engineered temporomandibular joint (TMJ) can also make adipose tissue. When we were trying to engineer the joint, we also turned these human stem cells into fat cells. People asked us, ‘why make fat cells? most people are trying to get rid of their fat cells!’ But for patients with soft tissue defects resulting from congenital disorders, trauma or tumor surgery, engineered fat tissue from stem cells has the potential to provide a replacement. Breast cancer defects can potentially be fixed from the patient’s own stem cells instead of synthetic implants.

Earlier research has used fat cells leftover from liposuction to make soft tissue implants, but these quickly shrink because the cells have limited lifespan. Implants made from stem cell-derived fat cells are long lasting, because stem cells in the implant keep replenishing the supply.

So what does this have to do with dentistry? Dentistry is much more than just the teeth. A great deal of reconstructive and plastic surgery is performed in the craniofacial region. The soft tissue and hard tissue defects that result from oral surgery or craniofacial surgery can potentially be corrected using stem cells.

The bioengineered TMJ your team created a few years ago also got a lot of media attention. How much of a health issue is this type of disease?

About 10 million people in the United States have TMJ problems and in the most severe cases they can hardly talk or chew, and must rely on a liquid diet.

Today, surgeons use bone grafts harvested from the hip or rib to repair a badly diseased TMJ. The downside is you create a secondary trauma site. Why should a patient have to sacrifice a perfectly normal rib? Sometimes metal and synthetic materials are used, but none of these, including the bone graft, are satisfactory. They break, they chip, they wear out. And they don’t work that well.

The goal of tissue engineering is to enable tissue and organ replacements to be ‘grown’ by the patient, and look and function as nature’s originals. In our lab we’ve used human stem cells and put them through steps that nature uses to grow a TMJ that has the same shape and dimensions as the original structure. Also, TMJ is a prototype for larger joints such as the knee or hip. We recently engineered a part of a human-shaped knee joint from human stem cells. We want to grow functional joints from stem cells in patients with arthritis and trauma.

Dental researchers today seem to be less confined to strictly dental issues. How did that come about?

Earlier dental research has solved some of the ‘easier’ problems in dentistry, and in the process the practice of dentistry has changed. In the 1930s and 40s cavities and tooth decay were so prevalent that most people lost some or many teeth by their teens or early 20s. That’s not the case anymore in the United States, largely because of dental research. Dentists saw that people living in areas with naturally high levels of fluoride in the water didn’t get many cavities. Based on that research, most regions started to add fluoride to drinking water. Now some people reach their 20s and beyond without any tooth decay.
But there are so many other issues that are harder to deal with, like TMJ diseases. Dental professionals realized that if we want to provide effective treatment for these individuals, we can’t do it without research and so are using modern tools like molecular biology, stem cells, and tissue engineering to advance the field.

In addition, a lot of dental research has ramifications that go far beyond dentistry. For example, gum disease may trigger cardiovascular disease. Many craniofacial disfigurations are associated with defects in other regions of the body. A cut inside the mouth heals without scarring, just like a fetal wound, whereas a cut in the skin scars. Research on macromolecules in oral mucosa may provide clues to scarless skin healing. One scientific connection between dentistry and medicine is that the same stem cells that develop into the bulk of the teeth can also develop into bone, cartilage, fat, tendons, ligaments, and even cells that form internal organs.

—Susan Conova, by Anni Shaer  —   research team led by Levitt Shuichi Takayama at the University of Michigan has developed a new technology for growing lung cells outside the body. The scientists developed a tiny device, named “lung on a chip”, which causes the cells on it to act as if they would were they inside the body. Using this device, the team researched the effects of pulmonary diseases such as cystic fibrosis and asthma on lung cells, and found that some of the symptoms of these diseases may be causing further damage to the lungs. The team believe that in time, the chip may help scientists find a cure for lung illnesses.

When the airways in the lungs are blocked by thick fluids, breathing causes hissing sounds named “crackles”. In some pulmonary diseases such as cystic fibrosis, these crackles are rather common, since the body suffers from a deficiency in the protein which makes these fluids less gluey. When people who suffer from a pulmonary disease inhale, the plugs “explode”, causing the crackling sound. Until now, these sounds were considered as symptoms of the disease. However, the latest experiments conducted by the University of Michigan scientists imply that the crackles themselves damage the lung. If the plugs rupture, they cause a stress wave, similar to an explosion, damaging the surrounding cells.

In order to see the crackles’ progression, the researchers created the “lung on a chip”. Two rubber sheets were connected, with a groove carved across them. A porous polyester sheet was placed between the grooved sides, causing the rubber sheets to attach and creating two chambers, which were then filled with a nourishing liquid. When the lung cells began to grow, the top chamber was emptied to simulate an airway. This caused the cells to develop further than they do in a Petri dish. The cells began acting in a lung-like way in terms of protein secretion, tissue connections, and overall function. The device is exactly the size of the smallest airway branches in human lungs.

When the cell development was complete, the researchers ran the control part of the experiment. The team observed that liquid followed by air passing through the channels did not damage the cells. The team then turned on a “microfabricated plug generator”, which is a vial of liquid attached to the cell culture chamber on the chip and pumped air through it. Drops of liquid from the vial entered the simulated airways of the chip and due to the pressure, burst, creating “crackles”. Testing revealed that at least 24% of the lung cells die as a result of the bursts. The more frequent the plug bursts were, the more damage the surrounding cells suffered. Further research is necessary in order to fully understand the crackles’ effects and in order to explore more research possibilities of the “lung on a chip”. The chip’s developers hope their device will lead to the development of new treatments for respiratory diseases.

TFOT recently covered the use of artificial body parts in research, including a bionic eye capable of restoring the eye sight of people who suffer from age-related blindness, developed by the Boston Retinal Implant Project. Another related TFOT story focused on the creation of an artificial arm by the German company Festo. We have also covered a “blood test on a chip” device. The micro-sized laboratory is capable of analyzing minute blood samples, and was developed in Caltech (California Institute of Technology).

More information regarding the lung on a chip can be found on the University of Michigan News Service webpage.







Gravity: The force that helps stars ignite, planets stay together and objects orbit is one of the most pervasive yet weakest in the cosmos

Scientists have fine-tuned just about every equation and model to describe and predict gravity, yet its source within matter remains a complete and utter mystery.

Some think infinitesimal particles called gravitons exude the force in all matter, but whether or not they could ever be detected is questionable.

Still, a massive hunt is on for major shake-ups in the universe called gravitational waves. If detected (perhaps from a merger of black holes), Albert Einstein’s concept that the universe has a “fabric” of spacetime would be on solid ground.

Caption: Artist depiction of gravity waves around merging black holes. Credit: NASA

The New York Times, July 21, 2010, by Dennis Overbye  —   It’s hard to imagine a more fundamental and ubiquitous aspect of life on the Earth than gravity, from the moment you first took a step and fell on your diapered bottom to the slow terminal sagging of flesh and dreams.























That inspiration came to him courtesy of a thief.




















AFLOAT The astrophysicist Stephen Hawking goes weightless in a special jet

Zero Gravity Corp, via Associated Press

ZERO GRAVITY Dr. Erik Verlinde says, “For me gravity doesn’t exist.” In a recent paper he expounded on his theory.

Kirsten Luce for The New York Times