It was founded on the edge of the American frontier as the Pittsburgh Academy in 1787, and evolved into the Western University of Pennsylvania by alteration of its charter in 1819. After surviving two devastating fires and various relocations within the area, the school moved to its current location in the Oakland neighborhood of the city and was renamed to the University of Pittsburgh in 1908. For most of its history Pitt was a private institution, until it became part of the Commonwealth System of Higher Education in 1966.
The university comprises 17 undergraduate and graduate schools and colleges located at its urban Pittsburgh campus, home to the university’s central administration and 28,766 undergraduate, graduate, and professional students. The university also includes four additional undergraduate schools located at campuses within Western Pennsylvania: Bradford, Greensburg, Johnstown, and Titusville. The 132-acre Pittsburgh campus comprises multiple historic buildings of the Schenley Farms Historic District, most notably its 42-story gothic revival centerpiece, the Cathedral of Learning.
The campus is situated adjacent to the flagship medical facilities of its closely affiliated University of Pittsburgh Medical Center (UPMC), as well as the Carnegie Museums of Pittsburgh, Schenley Park, and Carnegie Mellon University.
University of Pittsburgh research articles from Innovation Toronto
- Hybrid material presents potential for 4-D-printed adaptive devices – December 15, 2015
- Lab-Grown 3-D Intestine Regenerates Gut Lining in Dogs – October 9, 2015
- Toward a squishier robot – May 10, 2015
- Thumbs-up for mind-controlled robotic arm – December 18, 2014
- Cartilage, Made to Order – April 28, 2014
- Stem Cells from Muscle Can Repair Nerve Damage After Injury
- Polymer gel, heal thyself: University of Pittsburgh engineering team proposes new composites that can regenerate when damaged
- Snap to attention: Polymers that react and move to light
- Entering a New Dimension: 4D Printing
- Competition Changes How People View Strangers Online
- The Molecule “Scanner”
- Light that Moves and Molds Gels
- Maize Trade Disruption Could Have Global Ramifications
- Carnegie Mellon Method Uses Network of Cameras to Track People in Complex Indoor Settings
- The Diabetes ‘Breathalyzer’
- Pitt team finds mechanism that causes noise-induced tinnitus and drug that can prevent it
- New Gene Therapy Shows Broad Protection in Animal Models to Pandemic Flu Strains, including the Deadly 1918 Spanish Influenza
- Asthma Patients May Breathe More Easily Thanks To Game Changing Drug
- Pitt Chemists Demonstrate Nanoscale Alloys So Bright They Could Have Potential Medical Applications
- Recipe for Making Large Numbers of Stem Cells Requires Only One Ingredient
- Technology that Lets Spinal Cord-Injured Man Control Robot Arm with Thoughts
- Stem cells found to heal damaged artery in lab study; raises hope for developing new therapies for many diseases
- Pitt-led team finds molecule that polices TB lung infection, could lead to vaccine
- Woman with Quadriplegia Feeds Herself Chocolate Using Mind-Controlled Robot Arm
- Berkeley Lab Scientists Help Develop Promising Therapy for Huntington’s Disease
- Oscillating Gel Acts Like Artificial Skin, Giving Robots Potential Ability to ‘Feel’
- UW Scientists and Colleagues Achieve Breakthrough in Understanding Sense of Touch
- Breakthrough could make smartphones and laptops 1,000 times faster
- New Nanotech Technique for Lower-Cost Materials Repair
- Bird Flu Research Rattles Bioterrorism Field
- Singularity Summit: Quest for Immortality Never Dies
- Coming Soon: The Drone Arms Race
- Wireless chips and probes could monitor orthopedic implants
- Reprogrammed Cells Repair Damaged Livers
- Controlling a Computer With Thoughts?
- Nanostructured materials to put an end to icy airplanes and roads
- Wi-Fi and 3G could become competitors for mobile Internet access
- Polymer based filter proposed for Gulf of Mexico clean up
- Multifunctional Polymer Neutralizes Both Biological and Chemical Weapons
- Multifunctional Polymer Neutralizes Both Biological and Chemical Weapons
- Nano-particle coating prevents ice buildup on roads and power lines
- A New, Flying Jellyfish-like Machine
- Stingray movement could inspire the next generation of submarines
- Carnegie Mellon-Disney Motion Tracking Technology Is Extremely Precise and Inexpensive With Minimal Lag
- Robots Learn Proper Handoff, Follow Digitized Human Examples
- Virtual traffic lights help solve commuting hell
- VIDEO: Biofuel breakthrough: Quick cook method turns algae into oil
- VIDEO: Thought-controlled quadcopter takes to the skies
- VIDEO: Public Can Explore Time-Lapse Videos of Earth With New Tool From Carnegie Mellon and Google
- Hummingbird: An Educational Robotics Kit Designed To Get Girls Into Engineering
- Revolutionary Technology Enables Objects to Know Your Touch
- SideBySide Projection System Enables Projected Interaction Between Mobile Devices
- Carbon nanotube-reinforced polyurethane could make for bigger and better wind turbines
- Motion capture system makes actors the camera instead of putting them in front of it
- Tactile Technology for Video Games Guaranteed to Send Shivers Down Your Spine
- In Search of a Robot More Like Us
- Robots Arrive at Fukushima Nuclear Site with Unclear Mission
- Cubelets help make robotics a snap
- Fruit fly research could lead to simpler and more robust computer networks
- Dynamic Eye sunglasses use moving LCD spot to reduce glare
- Aiming to Learn as We Do, a Machine Teaches Itself
- Artificial Cells Communicate and Cooperate Like Biological Cells, Ants
- Solar-radiation management could have unwanted regional impacts
- Bye-Bye Batteries: Radio Waves as a Low-Power Source
- A Soft Spot for Circuitry
- Steel City Project Converts Gasoline Cars to Run on Electricity
- Robot Pack Mule to Carry Loads for G.I.s on the Move
- Customizing Electric Cars for Cost-Effective Urban Commuting
Researchers at the University of Rochester Medical Center have developed a new imaging technique that could revolutionize how eye health and disease are assessed. The group is first to be able to make out individual cells at the back of the eye that are implicated in vision loss in diseases like glaucoma. They hope their new technique could prevent vision loss via earlier diagnosis and treatment for these diseases.
In a study highlighted in the Proceedings of the National Academy of Sciences, Ethan A. Rossi, Ph.D., assistant professor of Ophthalmology at the University of Pittsburgh School of Medicine, describes a new method to non-invasively image the human retina, a layer of cells at the back of the eye that are essential for vision. The group, led by David Williams, Ph.D., Dean for Research in Arts, Sciences, and Engineering and the William G. Allyn Chair for Medical Optics at the University of Rochester, was able to distinguish individual retinal ganglion cells (RGCs), which bear most of the responsibility of relaying visual information to the brain.
There has been a longstanding interest in imaging RGCs because their death causes vision loss in glaucoma, the second leading cause of acquired blindness worldwide. Despite great efforts, no one has successfully captured images of individual human RGCs, in part because they are nearly perfectly transparent.
This new approach might eventually allow us to detect the loss of single ganglion cells. The sooner we can catch the loss, the better our chances of halting disease and preventing vision loss.
Instead of imaging RGCs directly, glaucoma is currently diagnosed by assessing the thickness of the nerve fibers projecting from the RGCs to the brain. However, by the time a change is typically detected in the retinal nerve fiber thickness, a patient may have lost tens of thousands of RGCs or more.
“In principle, this new approach might eventually allow us to detect the loss of single ganglion cells,” said Williams. “The sooner we can catch the loss, the better our chances of halting disease and preventing vision loss.”
Rossi and his colleagues were able to see RGCs by modifying an existing technology – confocal adaptive optics scanning light ophthalmoscopy (AOSLO). They collected multiple images, varying the size and location of the detector they used to gather light scattered out of the retina for each image, and then combined those images. The technique, called multi-offset detection, was performed at the University of Rochester Medical Center in animals as well as volunteers with normal vision and patients with age-related macular degeneration.
While RGCs were the main focus of Rossi’s investigations, they are just one type of cell that can be imaged using this new technique. In age-related macular degeneration, cone photoreceptors that detect color and are important for central vision are the first to die. AOSLO has been used to image cones before, but these cells were difficult to see in areas near Drusen, fatty deposits that are the most common early sign of the disease. Using their multi-offset technique in age-related macular degeneration patients, Rossi was able to assess the health of cones near Drusen and in areas where the retina had been damaged.
“This technique offers the opportunity to evaluate many retinal features that have previously remained inaccessible to imaging in the living eye,” said Rossi. “Not only RGCs, but potentially other nearly transparent cell classes as well.”
Rossi and his colleagues warn that their study included a small number of volunteers and an even smaller number of age-related macular degeneration patients. More studies will be needed to improve the robustness of the technique before it can be widely used in the clinic. Rossi is now setting up his own laboratory at the University of Pittsburgh and plans to continue working with Williams’ group in studying this technique and its ability to detect changes in retinal cells over the course of retinal diseases.
Pitt researcher uses zebrafish to help mammalian hearts regenerate, including promising results in human heart cells in vitro
Many lower forms of life on earth exhibit an extraordinary ability to regenerate tissue, limbs, and even organs—a skill that is lost among humans and other mammals. Now, a University of Pittsburgh researcher has used the components of the cellular “scaffolding” of a zebrafish to regenerate heart tissues in mammals, specifically mice, as well as exhibiting promising results in human heart cells in vitro.
The findings offer promise to overcoming heart disease, the leading cause of death for men and women.
The study, led by Yadong Wang, the William Kepler Whiteford Professor in Bioengineering in the Swanson School of Engineering and the principal investigator of the Biomaterials Foundry at Pitt, found that a single administration of extracellular matrices (ECM) from zebrafish hearts restored the function of the heart and regenerated adult mouse heart tissues after acute myocardial infarction.
“The heart beats as if nothing has happened to it,” said Wang. “And our approach is really simple.”
The study also found that the zebrafish ECM protected human cardiac myocytes—specialized cells that form heart muscle—from stresses.
ECM are the architectural foundations of tissues and organs; not only do they provide a “scaffolding” on which cells can grow and migrate, they assist in the signaling necessary for the organ to develop, grow, or regenerate.
In mammals, the heart quickly loses the ability to regenerate after the organism is born, except for a brief period after birth. In lower animals, such as zebrafish, the heart retains that ability throughout their lives: up to 20 percent of a zebrafish’s heart can be damaged or removed, and within days the heart’s capacity has been fully restored.
Wang and his team first separated the ECM from the cells so that the recipient heart would not reject the treatment. They did this by freezing the zebrafish cardiac tissue, causing the cell membranes to burst and allowing the researchers to retrieve the ECM, a process called decellularization. Wang noted that he and his colleagues are among the first to decellularize non-mammalian tissues for applications in regenerative medicine. They then injected the ECM into the hearts of mice with damaged heart muscles and watched the hearts repair themselves.
“It’s difficult to inject foreign cells into a body because the body will recognize them as foreign and reject them; that’s not the case with ECM,” said Wang. Wang explained that, because ECMs are composed of collagen, elastin, carbohydrates and signaling molecules and have no cell surface markers, DNA or RNA from the donor, the recipient is less likely to reject the treatment.
Wang said that restored function starts almost immediately, and healing is noticeable as early as five days after treatment; within a week, his team could see the heart beating more strongly than the hearts of the untreated animals.
The researchers tested the effectiveness of ECM from normal zebrafish and from zebrafish with damaged hearts, in which the ECM had already begun the healing process. They found that while both types of ECM were effective in repairing damage to the mice hearts, the ECM obtained from the zebrafish hearts that were healing were even more potent in restoring heart function in the mice.
Wang is now working on a process to regenerate nerves in mammals using the same process and hopes to expand the heart treatments to larger animals in a future study.
Learn more: How Do You Mend a Broken Heart?
One of the impediments to developing miniaturized, “squishy” robots is the need for an internal power source that overcomes the power-to-weight ratio for efficient movement. An international group involving Inha University, University of Pittsburgh and the Air Force Research Laboratory has built upon their previous research and identified new materials that directly convert ultraviolet light into motion without the need for electronics or other traditional methods.
The group includes M. Ravi Shankar, co-author and professor of industrial engineering at Pitt’s Swanson School of Engineering. Lead author is Jeong Jae Wie, assistant professor of polymer science and engineering at Inha University, South Korea. The experiments were conducted at the Air Force Research Laboratory’s (AFRL) Materials & Manufacturing Directorate at Wright-Patterson Air Force Base, Ohio, under the direction of Timothy J. White.
Other investigations have proposed the use of ambient energy resources such as magnetic fields, acoustics, heat and other temperature variations to avoid adding structures to induce locomotion. However, Dr. Shankar explains that light is more appealing because of its speed, temporal control and the ability to effectively target the mechanical response. For the material, the group zeroed in on monolithic polymer films prepared from a form of liquid crystalline polymer.
“Our initial research indicated that these flexible polymers could be triggered to move by different forms of light,” Dr. Shankar explained. “However, a robot or similar device isn’t effective unless you can tightly control its motions. Thanks to the work of Dr. White and his team at AFRL, we were able to demonstrate directional control, as well as climbing motions.”
According to Dr. Wie, the “photomotility” of these specific polymers is the result of their spontaneous formation into spirals when exposed to UV light. Controlling the exposure enables a corresponding motion without the use of external power sources attached directly to the polymer itself.
“Complex robotic designs result in additional weight in the form of batteries, limb-like structures or wheels, which are incompatible with the notion of a soft or squishy robot,” Dr. Wie said. “In our design, the material itself is the machine, without the need for any additional moving parts or mechanisms that would increase the weight and thereby limit motility and effectiveness.”
In addition to simple forward movement, Dr. White and the collaborative team were able to make the polymers climb a glass slide at a 15-degree angle. While the flat polymer strips are small – approximately 15mm long and 1.25mm wide – they can move at several millimeters per second propelled by light. The movement can be perpetual, as long as the material remains illuminated.
“The ability for these flexible polymers to move when exposed to light opens up a new ground game in the quest for soft robots,” Dr. Shankar said. “By eliminating the additional mass of batteries, moving parts and other cumbersome devices, we can potentially create a robot that would be beneficial where excess weight and size is a negative, such as in space exploration or other extreme environments.”
A team of University of Pittsburgh researchers has uncovered new details about the biology of telomeres, “caps” of DNA that protect the tips of chromosomes and play key roles in a number of health conditions, including cancer, inflammation and aging.
The new findings were published today in the journal Nature Structural and Molecular Biology.
Telomeres, composed of repeated sequences of DNA, are shortened every time a cell divides and therefore become smaller as a person ages. When they become too short, telomeres send a signal to the cell to stop dividing permanently, which impairs the ability of tissues to regenerate and contributes to many aging-related diseases, explained lead study author Patricia Opresko, Ph.D., associate professor of Environmental and Occupational Health at Pitt, and member of the University of Pittsburgh Cancer Institute Molecular and Cellular Cancer Biology program and Carnegie Mellon University Center for Nucleic Acids Science and Technology.
In contrast, in most cancer cells, levels of the enzyme telomerase, which lengthens telomeres, are elevated, allowing them to divide indefinitely.
“The new information will be useful in designing new therapies to preserve telomeres in healthy cells and ultimately help combat the effects of inflammation and aging. On the flip side, we hope to develop mechanisms to selectively deplete telomeres in cancer cells to stop them from dividing,” said Dr. Opresko.
A number of studies have shown that oxidative stress—a condition where damaging molecules known as free radicals build up inside cell—accelerates telomere shortening. Free radicals can damage not only the DNA that make up telomeres, but also the DNA building blocks used to extend them.
Oxidative stress is known to play a role in many health conditions, including inflammation and cancer. Damage from free radicals, which can be generated by inflammation in the body as well as environmental factors, is thought to build up throughout the aging process.
The goal of the new study was to determine what happens to telomeres when they are damaged by oxidative stress. The researchers suspected that oxidative damage would render telomerase unable to do its job.
“Much to our surprise, telomerase could lengthen telomeres with oxidative damage,” Dr. Opresko said. “In fact, the damage seems to promote telomere lengthening.”
Next, the team looked to see what would happen if the building blocks used to make up telomeres were instead subjected to oxidative damage. They found that telomerase was able to add a damaged DNA precursor molecule to the end of the telomere, but was then unable to add additional DNA molecules.
The new results suggest that the mechanism by which oxidative stress accelerates telomere shortening is by damaging the DNA precursor molecules, not the telomere itself. “We also found that oxidation of the DNA building blocks is a new way to inhibit telomerase activity, which is important because it could potentially be used to treat cancer.”
Dr. Opresko and her team are now beginning to further explore the consequences of oxidative stress on telomeres, using a novel photosensitizer, developed by Marcel Bruchez at Carnegie Mellon University that produces oxidative damage selectively in telomeres. “Using this exciting new technology, we’ll be able to learn a lot about what happens to telomeres when they are damaged, and how that damage is processed,” she said.
Imagine being in an accident that leaves you unable to feel any sensation in your arms and fingers. Now imagine regaining that sensation, a decade later, through a mind-controlled robotic arm that is directly connected to your brain.
That is what 28-year-old Nathan Copeland experienced after he came out of brain surgery and was connected to the Brain Computer Interface (BCI), developed by researchers at the University of Pittsburgh and UPMC. In a study published online today in Science Translational Medicine, a team of experts led by Robert Gaunt, Ph.D., assistant professor of physical medicine and rehabilitation at Pitt, demonstrated for the first time ever in humans a technology that allows Mr. Copeland to experience the sensation of touch through a robotic arm that he controls with his brain.
“The most important result in this study is that microstimulation of sensory cortex can elicit natural sensation instead of tingling,” said study co-author Andrew B. Schwartz, Ph.D., distinguished professor of neurobiology and chair in systems neuroscience, Pitt School of Medicine, and a member of the University of Pittsburgh Brain Institute. “This stimulation is safe, and the evoked sensations are stable over months. There is still a lot of research that needs to be carried out to better understand the stimulation patterns needed to help patients make better movements.”
This is not the Pitt-UPMC team’s first attempt at a BCI. Four years ago, study co-author Jennifer Collinger, Ph.D., assistant professor, Pitt’s Department of Physical Medicine and Rehabilitation, and research scientist for the VA Pittsburgh Healthcare System, and the team demonstrated a BCI that helped Jan Scheuermann, who has quadriplegia caused by a degenerative disease. The video of Scheuermann feeding herself chocolate using the mind-controlled robotic arm was seen around the world. Before that, Tim Hemmes, paralyzed in a motorcycle accident, reached out to touch hands with his girlfriend.
But the way our arms naturally move and interact with the environment around us is due to more than just thinking and moving the right muscles. We are able to differentiate between a piece of cake and a soda can through touch, picking up the cake more gently than the can. The constant feedback we receive from the sense of touch is of paramount importance as it tells the brain where to move and by how much.
For Dr. Gaunt and the rest of the research team, that was the next step for the BCI. As they were looking for the right candidate, they developed and refined their system such that inputs from the robotic arm are transmitted through a microelectrode array implanted in the brain where the neurons that control hand movement and touch are located. The microelectrode array and its control system, which were developed by Blackrock Microsystems, along with the robotic arm, which was built by Johns Hopkins University’s Applied Physics Lab, formed all the pieces of the puzzle.
In the winter of 2004, Mr. Copeland, who lives in western Pennsylvania, was driving at night in rainy weather when he was in a car accident that snapped his neck and injured his spinal cord, leaving him with quadriplegia from the upper chest down, unable to feel or move his lower arms and legs, and needing assistance with all his daily activities. He was 18 and in his freshman year of college pursuing a degree in nanofabrication, following a high school spent in advanced science courses.
He tried to continue his studies, but health problems forced him to put his degree on hold. He kept busy by going to concerts and volunteering for the Pittsburgh Japanese Culture Society, a nonprofit that holds conventions around the Japanese cartoon art of anime, something Mr. Copeland became interested in after his accident.
Right after the accident he had enrolled himself on Pitt’s registry of patients willing to participate in clinical trials. Nearly a decade later, the Pitt research team asked if he was interested in participating in the experimental study.
After he passed the screening tests, Nathan was wheeled into the operating room last spring. Study co-investigator and UPMC neurosurgeon Elizabeth Tyler-Kabara, M.D., Ph.D., assistant professor, Department of Neurological Surgery, Pitt School of Medicine, implanted four tiny microelectrode arrays each about half the size of a shirt button in Nathan’s brain. Prior to the surgery, imaging techniques were used to identify the exact regions in Mr. Copeland’s brain corresponding to feelings in each of his fingers and his palm.
“I can feel just about every finger—it’s a really weird sensation,” Mr. Copeland said about a month after surgery. “Sometimes it feels electrical and sometimes its pressure, but for the most part, I can tell most of the fingers with definite precision. It feels like my fingers are getting touched or pushed.”
At this time, Mr. Copeland can feel pressure and distinguish its intensity to some extent, though he cannot identify whether a substance is hot or cold, explains Dr. Tyler-Kabara.
Michael Boninger, M.D., professor of physical medicine and rehabilitation at Pitt, and senior medical director of post-acute care for the Health Services Division of UPMC, recounted how the Pitt team has achieved milestone after milestone, from a basic understanding of how the brain processes sensory and motor signals to applying it in patients
“Slowly but surely, we have been moving this research forward. Four years ago we demonstrated control of movement. Now Dr. Gaunt and his team took what we learned in our tests with Tim and Jan—for whom we have deep gratitude—and showed us how to make the robotic arm allow its user to feel through Nathan’s dedicated work,” said Dr. Boninger, also a co-author on the research paper.
Dr. Gaunt explained that everything about the work is meant to make use of the brain’s natural, existing abilities to give people back what was lost but not forgotten.
“The ultimate goal is to create a system which moves and feels just like a natural arm would,” says Dr. Gaunt. “We have a long way to go to get there, but this is a great start.”
The potential to develop “materials that compute” has taken another leap at the University of Pittsburgh’s Swanson School of Engineering, where researchers for the first time have demonstrated that the material can be designed to recognize simple patterns. This responsive, hybrid material, powered by its own chemical reactions, could one day be integrated into clothing and used to monitor the human body, or developed as a skin for “squishy” robots.
“Pattern recognition for materials that compute,” published today in the AAAS journal Science Advances (DOI: 10.1126/sciadv.1601114), continues the research of Anna C. Balazs, Distinguished Professor of Chemical and Petroleum Engineering, and Steven P. Levitan, the John A. Jurenko Professor of Electrical and Computer Engineering. Co-investigators are Yan Fang, lead author and graduate student researcher in the Department of Electrical and Computer Engineering; and Victor V. Yashin, Research Assistant Professor of Chemical and Petroleum Engineering.
The computations were modeled utilizing Belousov-Zhabotinsky (BZ) gels, a substance that oscillates in the absence of external stimuli, with an overlaying piezoelectric (PZ) cantilever. These so-called BZ-PZ units combine Dr. Balazs’ research in BZ gels and Dr. Levitan’s expertise in computational modeling and oscillator-based computing systems.
“BZ-PZ computations are not digital, like most people are familiar with, and so to recognize something like a blurred pattern within an image requires nonconventional computing,” Dr. Balazs explained. “For the first time, we have been able to show how these materials would perform the computations for pattern recognition.”
Dr. Levitan and Mr. Fang first stored a pattern of numbers as a set of polarities in the BZ-PZ units, and the input patterns are coded through the initial phase of the oscillations imposed on these units. The computational modeling revealed that the input pattern closest to the stored pattern exhibits the fastest convergence time to the stable synchronization behavior, and is the most effective at recognizing patterns. In this study, the materials were programmed to recognize black-and-white pixels in the shape of numbers that had been distorted.
Compared to a traditional computer, these computations are slow and take minutes. However, Dr. Yashin notes that the results are similar to nature, which moves at a “snail’s pace.”
“Individual events are slow because the period of the BZ oscillations is slow,” Dr. Yashin said. “However, there are some tasks that need a longer analysis, and are more natural in function. That’s why this type of system is perfect to monitor environments like the human body.”
For example, Dr. Yashin said that patients recovering from a hand injury could wear a glove that monitors movement, and can inform doctors whether the hand is healing properly or if the patient has improved mobility. Another use would be to monitor individuals at risk for early onset Alzheimer’s, by wearing footwear that would analyze gait and compare results against normal movements, or a garment that monitors cardiovascular activity for people at risk of heart disease or stroke.
Since the devices convert chemical reactions to electrical energy, there would be no need for external electrical power. This would also be ideal for a robot or other device that could utilize the material as a sensory skin.
“Our next goal is to expand from analyzing black-and-white pixels to grayscale and more complicated images and shapes, as well as to enhance the devices storage capability,” Mr. Fang said. “This was an exciting step for us and reveals that the concept of “materials that compute” is viable.”
A study from the University of Pittsburgh School of Medicine and the McGowan Institute for Regenerative Medicine identifies a mechanism by which bioscaffolds used in regenerative medicine influence cellular behavior, a question that has remained unanswered since the technology was first developed several decades ago.
The findings were recently published online in Science Advances.
Bioscaffolds composed of extracellular matrix (ECM) derived from pig tissue promote tissue repair and reconstruction. Currently, these bioscaffolds are used to treat a wide variety of illnesses such hernias and esophageal cancer, as well as to regrow muscle tissue lost in battlefield wounds and other serious injuries.
“Bioscaffolds fulfill an unmet medical need, and have already changed the lives of millions of people,” said lead study investigator Stephen Badylak, D.V.M., M.D., Ph.D., professor of surgery at Pitt and deputy director of the McGowan Institute, a joint effort of Pitt and UPMC.
Researchers know that ECM is able to instruct the human body to replace injured or missing tissue, but exactly how the ECM material influences cells to cause functional tissue regrowth has remained a fundamental unanswered question in the field of regenerative medicine.
In the new study, Dr. Badylak and his team showed that cellular communication occurs using nanovesicles, extremely tiny fluid-filled sacs that bud off from a cell’s outer surface and allow cells to communicate by transferring proteins, DNA and other “cargo” from one cell to another.
Exosomes are present in biological fluids such as blood, saliva and urine, where they influence a variety of cellular behaviors, but researchers had yet to identify them in solid body tissues.
“We always thought exosomes are free floating, but recently wondered if they are also present in the solid ECM and might facilitate the cellular communication that is critical to regenerative processes,” Dr. Badylak said.
To explore this possibility, researchers used specialized proteins to break up the ECM, similar to the process that occurs when a bioscaffold becomes incorporated into the recipient’s tissue.
The research team then exposed two different cell types – immune cells and neuronal stem cells – to isolated matrix bound vesicles, finding that they caused both cell types to mimic their normal regrowth behaviors.
“Sure enough, we found that vesicles are embedded within the ECM. In fact, these bioscaffolds are loaded with these vesicles,” Dr. Badylak said. “This study showed us that the matrix bound vesicles are clearly active, can influence cellular behavior and are possibly the primary mechanism by which bioscaffolds cause tissue regrowth in the body.”
Researchers also found that vesicles isolated from different source tissues have distinct molecular signatures, and they are now focused on harnessing this new information for both therapeutic and diagnostic purposes.
Researchers at the University of Pittsburgh have developed a unique method for detecting antibodies in the blood of patients in a proof-of-principle study that opens the door to development of simple diagnostic tests for diseases for which no microbial cause is known, including auto-immune diseases, cancers and other conditions.
The results, reported in the Journal of Immunological Methods and funded by the Bill & Melinda Gates Foundation, are the first evidence that it is possible to develop blood tests for any infectious disease by screening random libraries of non-biological molecular shapes.
“This ‘needle-in-a-molecular haystack’ approach is a new way to develop diagnostic assays,” said senior author Donald S. Burke, M.D., Pitt Graduate School of Public Health dean and director of Pitt’s Center for Vaccine Research. “The method does not rely on starting with known viral components. This is important because there are conditions for which there isn’t a known antigen, such as newly emerged epidemics, autoimmune diseases or even responses to traumatic injury.”
When a person’s immune system is faced with an antigen or foreign invader, such as an infectious disease, or even an injury with tissue damage, it responds by producing antibodies. Like puzzle pieces, specific parts of the surface of these antibodies fit to the shape of the molecules on the invader or the damaged tissue.
The Pitt researchers used a technique pioneered by co-author Thomas Kodadek, Ph.D., of the Scripps Research Institute, that synthesizes random molecular shapes called “peptoids” hooked onto microscopic plastic beads. The technique can produce millions of molecular shapes. The peptoids are not organic, but if they match to the corresponding shape on an antibody, that antibody will connect to them, allowing the scientist to pull out that bead and examine that peptoid and its corresponding antibody.
Using this technique, Dr. Burke’s team chemically generated a huge library of random molecular shapes. Then, using blood from HIV-infected patients and from non-infected people, the researchers screened a million of these random molecular shapes to find the ones that bound only to antibodies present in the blood of HIV-infected patients, but not the healthy controls. No HIV proteins or structures were used to construct or select the peptoids, but the approach, nonetheless, successfully led to selection of the best molecular shapes to use in screening for HIV antibodies.
“Electronic circuits are very sophisticated these days,” says Jinxing Li. “But a crack, even an extremely small one, can interrupt the flow of current and eventually lead to the failure of a device. Traditional electronics can be fixed with soldering, but repairing advanced electronics on a nanoscale requires innovation.”
Gadgets will soon be more ubiquitous than ever, appearing in our clothes, implants and accessories, says Li, a Ph.D. candidate in the lab of Joseph Wang, D.Sc., at the University of California at San Diego. But finding ways to fix nanocircuits, battery electrodes or other electronic components when they break remains a challenge.
Replacing whole devices or even parts can be tricky or expensive, particularly if they’re integrated in clothes or located in remote places. Creating devices that can fix themselves would be ideal, according to Wang, whose lab develops nanoscale machines. To work toward this goal, his lab and others have turned to nature for ideas.
A new way to use the chemical reactions of certain enzymes to trigger self-powered mechanical movement has been developed by a team of researchers at Penn State University and the University of Pittsburgh. A paper describing the team’s research, titled “Convective flow reversal in self-powered enzyme micropumps,” is published this week in the journal Proceedings of the National Academy of Sciences.
“These pumps provide precise control over flow rate without the aid of an external power source and are capable of turning on in response to specific chemicals in solution,” said Ayusman Sen, Distinguished Professor of Chemistry at Penn State. “They also can remain viable and capable of turning on even after prolonged storage.” Sen and Penn State Graduate Student Isamar Ortiz did the research team’s experiments, which reveal that “simple reactions triggered by enzymes can be used to combine sensing and fluid pumping into single non-mechanical, self-powered, nano/microscale pumps that precisely control flow rate, and that turn on in response to specific stimuli,” said Sen, who also made the initial discovery of enzyme pumps.
Potential uses of the self-powered enzyme micropumps include detecting substances, moving particles to build small structures, and delivering medications. “One potential use is the release of insulin to a diabetes patient from a reservoir at a rate proportional to the concentration of glucose in the person’s blood,” Sen said. “Another example is an enzyme pump that is triggered by nerve toxins to release an antidote agent to decontaminate and treat an exposed person. Also, because enzyme pumps can pump particles suspended in a fluid, it also should be possible to use them to assemble or disassemble small structures in specific locations by directional pumping.”