Light coaxes stem cells to repair teeth: Noninvasive laser therapy could radically shift dental treatment

May 29, 2014

images

Scientists have used low-power light to trigger stem cells inside the body to regenerate tissue. The research lays the foundation for a host of clinical applications in restorative dentistry and regenerative medicine more broadly, such as wound healing, bone regeneration, and more

A Harvard-led team is the first to demonstrate the ability to use low-power light to trigger stem cells inside the body to regenerate tissue, an advance they reported in Science Translational Medicine. The research, led by Wyss Institute Core Faculty member David Mooney, Ph.D., lays the foundation for a host of clinical applications in restorative dentistry and regenerative medicine more broadly, such as wound healing, bone regeneration, and more.

The team used a low-power laser to trigger human dental stem cells to form dentin, the hard tissue that is similar to bone and makes up the bulk of teeth. What’s more, they outlined the precise molecular mechanism involved, and demonstrated its prowess using multiple laboratory and animal models.

A number of biologically active molecules, such as regulatory proteins called growth factors, can trigger stem cells to differentiate into different cell types. Current regeneration efforts require scientists to isolate stem cells from the body, manipulate them in a laboratory, and return them to the body — efforts that face a host of regulatory and technical hurdles to their clinical translation. But Mooney’s approach is different and, he hopes, easier to get into the hands of practicing clinicians.

“Our treatment modality does not introduce anything new to the body, and lasers are routinely used in medicine and dentistry, so the barriers to clinical translation are low,” said Mooney, who is also the Robert P. Pinkas Family Professor of Bioengineering at Harvard’s School of Engineering and Applied Sciences (SEAS). “It would be a substantial advance in the field if we can regenerate teeth rather than replace them.”

The team first turned to lead author and dentist Praveen Arany, D.D.S., Ph.D., who is now an Assistant Clinical Investigator at the National Institutes of Health (NIH). At the time of the research, he was a Harvard graduate student and then postdoctoral fellow affiliated with SEAS and the Wyss Institute.

Arany took rodents to the laboratory version of a dentist’s office to drill holes in their molars, treat the tooth pulp that contains adult dental stem cells with low-dose laser treatments, applied temporary caps, and kept the animals comfortable and healthy. After about 12 weeks, high-resolution x-ray imaging and microscopy confirmed that the laser treatments triggered the enhanced dentin formation.

“It was definitely my first time doing rodent dentistry,” said Arany, who faced several technical challenges in performing oral surgery on such a small scale. The dentin was strikingly similar in composition to normal dentin, but did have slightly different morphological organization. Moreover, the typical reparative dentin bridge seen in human teeth was not as readily apparent in the minute rodent teeth, owing to the technical challenges with the procedure.

“This is one of those rare cases where it would be easier to do this work on a human,” Mooney said.

Next the team performed a series of culture-based experiments to unveil the precise molecular mechanism responsible for the regenerative effects of the laser treatment. It turns out that a ubiquitous regulatory cell protein called transforming growth factor beta-1 (TGF-β1) played a pivotal role in triggering the dental stem cells to grow into dentin. TGF-β1 exists in latent form until activated by any number of molecules.

Here is the chemical domino effect the team confirmed: In a dose-dependent manner, the laser first induced reactive oxygen species (ROS), which are chemically active molecules containing oxygen that play an important role in cellular function. The ROS activated the latent TGF-β1complex which, in turn, differentiated the stem cells into dentin.

Nailing down the mechanism was key because it places on firm scientific footing the decades-old pile of anecdotes about low-level light therapy (LLLT), also known as Photobiomodulation (PBM).

Since the dawn of medical laser use in the late 1960s, doctors have been accumulating anecdotal evidence that low-level light therapy can stimulate all kind of biological processes including rejuvenating skin and stimulating hair growth, among others. But interestingly enough, the same laser can be also be used to ablate skin and remove hair — depending on the way the clinician uses the laser. The clinical effects of low-power lasers have been subtle and largely inconsistent. The new work marks the first time that scientists have gotten to the nub of how low-level laser treatments work on a molecular level, and lays the foundation for controlled treatment protocols.

“The scientific community is actively exploring a host of approaches to using stem cells for tissue regeneration efforts,” said Wyss Institute Founding Director Don Ingber, M.D., Ph.D., “and Dave and his team have added an innovative, noninvasive and remarkably simple but powerful tool to the toolbox.”

Next Arany aims to take this work to human clinical trials. He is currently working with his colleagues at the National Institute of Dental and Craniofacial Research (NIDCR), which is one of the National Institutes of Health (NIH), to outline the requisite safety and efficacy parameters. “We are also excited about expanding these observations to other regenerative applications with other types of stem cells,” he said.


Journal Reference:

  1. P. R. Arany, A. Cho, T. D. Hunt, G. Sidhu, K. Shin, E. Hahm, G. X. Huang, J. Weaver, A. C.-H. Chen, B. L. Padwa, M. R. Hamblin, M. H. Barcellos-Hoff, A. B. Kulkarni, D. J. Mooney. Photoactivation of Endogenous Latent Transforming Growth Factor- 1 Directs Dental Stem Cell Differentiation for Regeneration. Science Translational Medicine, 2014; 6 (238): 238ra69 DOI: 10.1126/scitranslmed.3008234

http://www.sciencedaily.com/releases/2014/05/140528150559.htm

Advertisements

Artificial lung the size of a sugar cube may replace animal testing

May 29, 2014

bi_labgrownlungs_1122

What medications can be used to treat lung cancer, and how effective are they? Until now, drug companies have had to rely on animal testing to find out. But in the future, a new 3D model lung is set to achieve more precise results and ultimately minimize — or even completely replace — animal testing. From June 23-26, researchers will be presenting their new model at the BIO International Convention in San Diego, California (Germany Pavilion, Booth 4513-03).

Lung cancer is a serious condition. Once patients are diagnosed with it, chemotherapy is often their only hope. But nobody can accurately predict whether or not this treatment will help. To start with, not all patients respond to a course of chemotherapy in exactly the same way. And then there’s the fact that the systems drug companies use to test new medications leave a lot to be desired. “Animal models may be the best we have at the moment, but all the same, 75 percent of the drugs deemed beneficial when tested on animals fail when used to treat humans,” explains Prof. Dr. Heike Walles, head of the Würzburg-based “Regenerative Technologies for Oncology” project group belonging to the Fraunhofer Institute for Interfacial Engineering and Biotechnology IGB.

These tests are set to achieve better results in the future: “We’ve developed an innovative 3D test system that allows us to superbly simulate what happens in the human body. Our plan is for this system to replace animal tests in the future,” says Walles. Essentially what the researchers have done is to recreate the human lung in miniature — with a volume of half a cubic centimeter, each model is no bigger than a sugar cube. In a parallel effort, scientists at the Department of Bioinformatics at the University of Würzburg are working up computer simulation models for different patient groups. These are necessary because patients may have genetic variations that inhibit therapies from having the desired effect. Comparing the theoretical and biological models allows each research group to optimize their results.

The biological model is based human lung cancer cells growing on tissue. Thus an artificial lung is created. A bioreactor is used to make it breathe and to pump a nutrient medium through its blood vessels in the same way our bodies supply our lungs with blood. The reactor also makes it possible to regulate factors such as how fast and deeply the model lung breathes.

With the scientists having managed to construct the lung tissue, Walles is delighted to report that “treatments that generate resistance in clinics do the same in our model.” Researchers are now planning to explore the extent to which their artificial lung can be used to test new therapeutic agents. Should resistance crop up during testing, doctors can opt to treat the patient with a combination therapy from the outset and thus side-step the problem. Thinking long-term, there is even the possibility of creating an individual model lung for each patient. This would make it possible to accurately predict which of the various treatment options will work. The required lung cells are collected as part of the biopsy performed to allow doctors to analyze the patient’s tumor.

On the trail of metastases

Testing new medications is by no means the only thing the model lung can be used for. It is also designed to help researchers to better understand the formation of metastases; it is these that often make a cancer fatal. “As metastases can’t be examined in animals — or in 2D models where cells grow only on a flat surface — we’ve only ever had a rough understanding of how they form. Now for the first time, our 3D lung tissue makes it possible to perform metastases analysis,” explains Walles. “In the long term, this may enable us to protect patients from metastases altogether.” In order to travel through the body, tumor cells alter their surface markers — in other words, the molecules that bind them to a particular area of the body. Cancer cells are then free to spread throughout the body via the body’s circulatory system before taking up residence somewhere else by expressing their original surface markers. The scientists plan to use their model lung’s artificial circulatory system to research exactly how this transformation occurs. And in doing so, they may someday succeed in developing medication that will stop metastases from forming in the first place.


Story Source:                                                                                                                                                                          The above story is based on materials provided by Fraunhofer-Gesellschaft. Note: Materials may be edited for content and length.

http://www.sciencedaily.com/releases/2014/05/140528104022.htm

Bioinspired drones of the future

May 26, 2014

harvard-drone1

Using mechanisms adopted by birds, bats, insects and snakes, 14 research teams have developed ideas for improving drone-flying performance in complex urban environments.

The research teams presented their work May 23 in a special open-access issue of IOP Publishing’s journal Bioinspiration and Biomimeticsdevoted to bio-inspired flight control. Here are a few examples.

An algorithm developed by Hungarian researchers allows multiple drones to fly together like a flock of birds to improve search and rescue operations. In a test, it was able to direct the movements of a flock of nine quadcopters following a moving car.

A millimeter-sized microrobot drone developed by researchers from Harvard University can take off and land and hover in the air for sustained periods of time, with a new development: simple, fly-like manoeuvers. Such drones could be used in assisted agriculture pollination and reconnaissance in the future.

Hawk moths that can handle strong winds and whirlwinds were developed by a research team from the University of North Carolina at Chapel Hill, the University of California, and The Johns Hopkins University.

Stage performance of the Stanford jump glider versus a theoretical ballistic jump (photo credit: Alexis Desbiens)

A “jumpglider design” that could reduce the power required to operate drones has been developed by researchers at Université de Sherbrooke and Stanford University. Inspired by vertebrates like the flying squirrel, the flying fish and the flying snake (which use their aerodynamic bodies to extend their jumping range to avoid predators), it combines an aeroplane-shaped body with a spring-based mechanical foot that propels the robot into the air. It could be used to improve search and rescue efforts by being able to navigate around obstacles and over rough terrain.

Flight-control challenges

Flying animals can be found everywhere in our cities, notes special-issue Guest Editor David Lentink, PhD, from Stanford University. “From scavenging pigeons to alcohol-sniffing fruit flies that make precision landings on our wine glasses, these animals have quickly learned how to control their flight through urban environments to exploit our resources. To enable our drones to fly equally well in wind and clutter, we need to solve several flight control challenges during all flight phases: takeoff, cruising, and landing.

“This special issue provides a unique integration between biological studies of animals and bio-inspired engineering solutions. Each of the 14 papers presented in this special issue offers a unique perspective on bio-mimetic flight, providing insights and solutions to the take-off, obstacle avoidance, in-flight grasping, swarming, and landing capabilities that urban drones need to succeed.”

Promising discovery in fight against antibiotic-resistant bacteria

May 26, 2014

140522175719-large

UBC’s Bob Hancock and his team of researchers have discovered a peptide that could help destroy biofilms, which are responsible for two-thirds of human infections. Credit: Martin Dee

Researchers at the University of British Columbia have identified a small molecule that prevents bacteria from forming into biofilms, a frequent cause of infections. The anti-biofilm peptide works on a range of bacteria including many that cannot be treated by antibiotics.

“Currently there is a severe problem with antibiotic-resistant organisms,” says Bob Hancock, a professor in UBC’s Dept. of Microbiology and Immunology and lead author of the study published today in PLOS Pathogens. “Our entire arsenal of antibiotics is gradually losing effectiveness.”

Many bacteria that grow on skin, lung, heart and other human tissue surfaces form biofilms, highly structured communities of bacteria that are responsible for two-thirds of all human infections. There are currently no approved treatments for biofilm infections and bacteria in biofilms are considerably more resistant to standard antibiotics.

Hancock and his colleagues found that the peptide known as 1018 — consisting of just 12 amino acids, the building blocks of protein — destroyed biofilms and prevented them from forming.

Bacteria are generally separated into two classes, Gram-positives and Gram-negatives, and the differences in their cell wall structures make them susceptible to different antibiotics. 1018 worked on both classes of bacteria as well as several major antibiotic-resistant pathogens, including Pseudomonas aeruginosa, E. coli and MRSA.

“Antibiotics are the most successful medicine on the planet. The lack of effective antibiotics would lead to profound difficulties with major surgeries, some chemotherapy treatments, transplants, and even minor injuries,” says Hancock. “Our strategy represents a significant advance in the search for new agents that specifically target bacterial biofilms.”


Story Source:

The above story is based on materials provided by University of British Columbia. Note: Materials may be edited for content and length.

http://www.sciencedaily.com/releases/2014/05/140522175719.htm%5B/embed%5D

 

Added drug allows rapamycin to slow aging without risking diabetes

May 23, 2014

mTorPathway

New research at the Linus Pauling Institute at Oregon State University suggests a fix for serious side effects of rapamycin*, a drug that appears to mimic the ability of dietary restriction to slow the aging process.

Laboratory mice that have received rapamycin have reduced the age-dependent decline in spontaneous activity, demonstrated more fitness, improved cognition and cardiovascular health, had less cancer, and lived substantially longer than mice fed a normal diet.

However, rapamycin has some drawbacks, including an increase in insulin resistance that could set the stage for diabetes, observed in both humans and laboratory animals. The new findings, published in the Journals of Gerontology: Biological Sciences, help to explain why that happens, and what could be done to address it.

It found that both dietary restriction and rapamycin inhibited lipid synthesis, but only dietary restriction increased the oxidation of those lipids in order to produce energy. Rapamycin, by contrast, allowed a buildup of fatty acids and eventually an increase in insulin resistance, which in humans can lead to diabetes.

Metformin prevents diabetes side effect

However, the drug metformin can address that concern, and is already given to some diabetic patients to increase lipid oxidation. In lab tests, the combined use of rapamycin and metformin prevented the unwanted side effect.

“If proven true, then combined use of metformin and rapamycin for treating aging and age-associated diseases in humans may be possible,” the researchers wrote in their conclusion.

“This could be an important advance if it helps us find a way to gain the apparent benefits of rapamycin without increasing insulin resistance,” said Viviana Perez, an assistant professor in the Department of Biochemistry and Biophysics in the OSU College of Science.

“It could provide a way not only to increase lifespan but to address some age-related diseases and improve general health,” Perez said. “We might find a way for people not only to live longer, but to live better and with a higher quality of life.”

“There’s still substantial work to do, and it may not be realistic to expect with humans what we have been able to accomplish with laboratory animals,” Perez said. “People don’t live in a cage and eat only the exact diet they are given. Nonetheless, the potential of this work is exciting.”

This work was supported by the National Institutes of Health. Collaborators included researchers from Oklahoma University Health Science Center, the Oklahoma City VA Medical Center, University of Michigan-Flint, and South Texas Veterans Health Care System.


*Rapamycin, first discovered from the soils of Easter Island, or Rapa Nui in the South Pacific Ocean, is primarily used as an immunosuppressant to prevent rejection of organs and tissues. In recent years it was also observed that it can function as a metabolic “signaler” that inhibits a biological pathway found in almost all higher life forms — the ability to sense when food has been eaten, energy is available and it’s okay for cell proliferation, protein synthesis and growth to proceed.

Called mTOR in mammals, for the term “mammalian target of rapamycin,” this pathway has a critical evolutionary value — it helps an organism avoid too much cellular expansion and growth when energy supplies are insufficient. That helps explain why some form of the pathway has been conserved across such a multitude of species, from yeast to fish to humans.

Age-related diseases include many of the degenerative diseases that affect billions of people around the world and are among the leading causes of death: cardiovascular disease, diabetes, Alzheimer’s disease and cancer.

http://www.kurzweilai.net/added-drug-allows-rapamycin-to-slow-aging-without-risking-diabetes?utm_source=KurzweilAI+Weekly+Newsletter&utm_campaign=5d1ea74257-UA-946742-1&utm_medium=email&utm_term=0_147a5a48c1-5d1ea74257-282129417

Aliens Are Almost Definitely Out There, SETI Astronomers Tell Congress

May 23, 2014

SETI-2

Aliens almost definitely exist.

At least, that’s what two astronomers told Congress this week, as they appealed for continued funding to research life beyond Earth.

According to ABC News, Dan Werthimer, director of the SETI [search for extraterrestrial intelligence] Research Center at the University of California, Berkeley, told the House Committee on Science, Space and Technology Wednesday that the possibility of extraterrestrial microbial life is “close to 100 percent.”

“In the last 50 years, evidence has steadily mounted that the components and conditions we believe necessary for life are common and perhaps ubiquitous in our galaxy,” said Werthimer in his written testimony, adding: “The possibility that life has arisen elsewhere, and perhaps evolved intelligence, is plausible and warrants scientific inquiry.”

Werthimer’s colleague Seth Shostak, a senior astronomer at the SETI Institute, also told Congress that he believes our chances of finding extraterrestrial life are high.

“The chances of finding it I think are good and if that happens it will happen in the next 20 years depending on the financing,” Shostak told the committee. (Watch the full hearing here.)

This isn’t the first time in recent months that Congress has held a hearing on aliens. In December, the Science House Committee held a two-hour hearing about the ongoing search for extraterrestrial life. The Wire said at the time that the hearing was the “best thing Congress [had] done in months.”

http://www.huffingtonpost.com/2014/05/22/aliens-congress-seti-astronomers_n_5370315.html

Video

Larry Page: Where’s Google going next?

larry-page-at-ted-2014-feature1

Larry Page: Where’s Google going next?

Onstage at TED2014, Charlie Rose interviews Google CEO Larry Page about his far-off vision for the company. It includes aerial bikeways and internet balloons … and then it gets even more interesting, as Page talks through the company’s recent acquisition of Deep Mind, an AI that is learning some surprising things.

IBM discovers new class of ultra-tough, self-healing, recyclable plastics that could redefine almost every industry

May 18, 2014

terminator-2-liquid-metal-t-1000-self-healing-640x353

Stop the press! IBM Research announced this morning that it has discovered a whole new class of… plastics. This might not sound quite as sexy as, say, MIT discovering a whole new state of matter — but wait until you hear what these new plastics can do. This new class of plastics — or more accurately, polymers — are stronger than bone, have the ability to self-heal, are light-weight, and are 100% recyclable. The number of potential uses, spanning industries as disparate as aerospace and semiconductors, is dizzying. A new class of polymers hasn’t been discovered in over 20 years — and, in a rather novel twist, they weren’t discovered by chemists: they were discovered by IBM’s supercomputers.

One of the key components of modern industry and consumerism is the humble thermosetting plastic. Thermosetting plastics — which are just big lumps of gooey polymer that are shaped and then cured (baked) — are light and easy to work with, but incredibly hard and heat resistant. The problem is, once a thermoset has been cured, there’s no turning back — you can’t return it to its gooey state. This means that if you (the engineer, the designer) make a mistake, you have to start again. It also means that thermoset plastics cannot be recycled. Once you’re done with that Galaxy S5, the thermoset chassis can’t be melted down and reused; it goes straight to the dump. IBM’s new polymer retains all of a thermosetting plastic’s useful properties — but it can also be recycled.

IBM’s new class of polymers began life, as they often do in chemistry circles, as an accident. Jeannette Garcia had been working on another type of polymer, when she suddenly noticed that the solution in her flask had unexpectedly hardened. “We couldn’t get it out,” Garcia told Popular Mechanics. “We had to smash the flask with a hammer, and, even then, we couldn’t smash the material itself. It’s one of these serendipitous discoveries.” She didn’t know how she’d created this new polymer, though, and so she joined forces with IBM’s computational chemistry team to work backwards from the final polymer. Using IBM’s supercomputing might, the chemists and the techies were able to work back to mechanism that caused the surprise reaction.This new class of polymer is called polyhexahydrotriazine, or PHT. [DOI: 10.1126/science.1251484 – “Recyclable, Strong Thermosets and Organogels via Paraformaldehyde Condensation with Diamines”]. It’s formed from a reaction between paraformaldehyde and 4,4ʹ-oxydianiline (ODA), which are both already commonly used in polymer production (this is very important if they want the new polymer to be adopted by the industry). The end result shows very high strength and toughness, like other thermosets, but its heat resistance is a little lower than other thermosets (it decomposes at around 350C, rather than 425C).

Infographic-Pervasiveness-of-Polymers-640x1624

Rather uniquely, though, IBM’s new polymer is both recyclable and self-healing. As you can see in the video above, chunks of the polymer readily rejoin to create a whole — and then when stretched in the future, they break randomly, not along the joins, proving a very high level of self-healing. [Read more about self-healing plastics.] Unlike traditional thermosets, which produce tons of recyclable waste every year, IBM’s PHT can be fully reverted back to its base state with sulfuric acid — which, as Garcia points out, is “essentially free.” In short, then, IBM has created a new plastic that could impact a number of industries in a very big way. The advantages of self-healing, tough plastics are highly evident in the aerospace, transportation, and architecture/construction industries. Thermoplastics also play a big part in the electronics industry, from the low-level packaging of computer chips, through to the chassis of your smartphone. In all of these areas, recyclability and self-healing could be a huge boon. As Garcia says, “If IBM had this 15 years ago, it would have saved unbelievable amounts of money.” Not to worry, Jeannette — there’s still plenty of time for IBM to save (and make) billions of dollars with this new plastic

http://www.extremetech.com/extreme/182583-ibm-discovers-new-class-of-ultra-tough-self-healing-recyclable-plastics-that-could-redefine-almost-every-industry

 

The Internet of Things will thrive by 2025 but raise privacy, complexity concerns, experts say

May 17, 2014

Internet-of-Things-Graphic1

The Internet of Things will make substantial inroads into many aspects of everyday life in the next decade, according to predictions by more than 1,600 experts cited in a report (summarized here) about the future of the Internet by the Pew Research Center Internet Project and Elon University’s Imagining the Internet Center.

According to futurist Paul Saffo, managing director of Discern Analytics, most of these devices will be communicating on our behalf — interacting with the physical and virtual worlds more than interacting with us.

“The devices are going to disappear into what we wear and/or carry. For example, the glasses interface will shrink to near-invisibility in conventional glasses. The devices will also become robustly inter-networked. … “The biggest shift is a strong move away from a single do-everything device to multiple devices with overlapping functions and, above all, an inter-relationship with our other devices.”

Survey respondents expect the Internet of Things to be evident in many places, including:

  • Bodies: Many people will wear devices that let them connect to the Internet and will give them feedback on their activities, health and fitness. They will also monitor others (their children or employees, for instance) who are also wearing sensors, or moving in and out of places that have sensors.
  • Homes: People will be able to control nearly everything remotely, from how their residences are heated and cooled to how often their gardens are watered. Homes will also have sensors that warn about everything from prowlers to broken water pipes, although we have some of that now with online services.
  • Communities: Embedded devices and smartphone apps will enable more efficient transportation and give readouts on pollution levels. “Smart systems” might deliver electricity and water more efficiently and warn about infrastructure problems.
  • Goods and services: Factories and supply chains will have sensors and readers that more precisely track materials to speed up and smooth out the manufacture and distribution of goods.
  • Environment: There will be real-time readings from fields, forests, oceans, and cities about pollution levels, soil moisture, and resource extraction that allow for closer monitoring of problems.

“These experts say the next digital revolution is the expanding and often-invisible spread of the Internet of Things,” noted Janna Anderson, director of the Imagining the Internet Center and a co-author of the report. “They expect positive change that will impact health, transportation, shopping, industrial production and the environment. But they also warn about the privacy implications of this new data-saturated world and about the complexities involved in making networked devices work together.”

There will also be complicated, unintended consequences: “We will live in a world where many things won’t work and nobody will know how to fix them.

http://www.kurzweilai.net/the-internet-of-things-will-thrive-by-2025-but-raise-privacy-complexity-concerns-experts-say?utm_source=KurzweilAI+Weekly+Newsletter&utm_campaign=2706e19639-UA-946742-1&utm_medium=email&utm_term=0_147a5a48c1-2706e19639-282129417

New Implanted Devices May Reshape Medicine

May 14, 2014

implanted_devices-utdallas

Researchers from The University of Texas at Dallas and the University of Tokyo have created electronic devices that become soft when implanted inside the body and can deploy to grip 3-D objects, such as large tissues, nerves and blood vessels.

These biologically adaptive, flexible transistors might one day help doctors learn more about what is happening inside the body, and stimulate the body for treatments.
he research, available online and in an upcoming print issue of Advanced Materials, is one of the first demonstrations of transistors that can change shape and maintain their electronic properties after they are implanted in the body, said Jonathan Reeder BS’12, a graduate student in materials science and engineering and lead author of the work.

“Scientists and physicians have been trying to put electronics in the body for a while now, but one of the problems is that the stiffness of common electronics is not compatible with biological tissue,” he said. “You need the device to be stiff at room temperature so the surgeon can implant the device, but soft and flexible enough to wrap around 3-D objects so the body can behave exactly as it would without the device. By putting electronics on shape-changing and softening polymers, we can do just that.”

Shape memory polymers developed by Dr. Walter Voit, assistant professor of materials science and engineering and mechanical engineering and an author of the paper, are key to enabling the technology.

A planar organic thin-film transistor responds to a temperature change,
deploys into a helix and wraps around a rod after being inserted through
a 150 μm-thick opening in a thermal barrier.

The polymers respond to the body’s environment and become less rigid when they’re implanted. In addition to the polymers, the electronic devices are built with layers that include thin, flexible electronic foils first characterized by a group including Reeder in work published last year in Nature.

The Voit and Reeder team from the Advanced Polymer Research Lab in the Erik Jonsson School of Engineering and Computer Science fabricated the devices with an organic semiconductor but used adapted techniques normally applied to create silicon electronics that could reduce the cost of the devices.

“We used a new technique in our field to essentially laminate and cure the shape memory polymers on top of the transistors,” said Voit, who is also a member of the Texas Biomedical Device Center. “In our device design, we are getting closer to the size and stiffness of precision biologic structures, but have a long way to go to match nature’s amazing complexity, function and organization.”

The rigid devices become soft when heated. Outside the body, the device is primed for the position it will take inside the body.

During testing, researchers used heat to deploy the device around a cylinder as small as 2.25 millimeters in diameter, and implanted the device in rats. They found that after implantation, the device had morphed with the living tissue while maintaining excellent electronic properties.

“Flexible electronics today are deposited on plastic that stays the same shape and stiffness the whole time,” Reeder said. “Our research comes from a different angle and demonstrates that we can engineer a device to change shape in a more biologically compatible way.”

The next step of the research is to shrink the devices so they can wrap around smaller objects and add more sensory components, Reeder said.

UT Dallas researchers and materials engineers Taylor Ware, David Arreaga-Salas and Adrian Avendano-Bolivar were also involved in the study. Ware completed his PhD in 2013 and performs fundamental research on liquid crystalline polymers at the Air Force Research Labs.

The work was funded by the National Science Foundation Graduate Research Fellowship, NSF East Asia and Pacific Summer Institute, the Japan Science and Technology Agency, CONACYT (Consejo Nacional de Ciencia y Tecnología) Fellowship program and the Defense Advanced Research Projects Agency (DARPA) Young Faculty Award program.

http://www.utdallas.edu/news/2014/5/13-29981_New-Implanted-Devices-May-Reshape-Medicine_story-sidebar.html