Device Makes Quick Genetic Tests

May 3, 2012 By Leave a Comment

Canadian researchers have developed a medical device the size of a toaster that can perform the same genetic tests as a fully equipped laboratory in a fraction of the time.

The key to the device — developed at the University of Alberta — is a small plastic chip that can make several determinations: from whether a patient is resistant to cancer drugs or have an infection like malaria, writes Bryan Alary of Phys.Org. The chip also can determine whether specific infectious diseases are in a herd of cattle. The technology is licensed by Aquila Diagnostic Systems, based in Edmonton, Alberta.

“We’re basically replacing millions of dollars of equipment that would be in a conventional, consolidated lab with something that costs pennies to produce and is field portable so you can take it where needed,” said Jason Acker, an associate professor of laboratory medicine and pathology at the University of Alberta.

The device uses polymerase chain reaction technology to amplify and detect targeted sequences of DNA, but in a miniaturized form that fits on a chip the size of two postage stamps. The chip contains 20 gel posts — each the size of a pinhead — that are designed to identify sequences of DNA within a single drop of blood.

Each of the gel posts is manufactured to conduct its own genetic test. Therefore, clinicians can use the device to determine not only that patients have malaria, but also the type of malaria, and whether their DNA makes them resistant to certain antimalarial drugs. It takes about one hour for a chip to analyze the blood.

Linda Pilarski, an experimental oncologist with the Faculty of Medicine & Dentistry, developed the device. As an oncologist, Pilarski is interested in technology that has pharmacogenomic testing capabilities, such as determining whether breast cancer patients are genetically disposed to resist certain drugs.

“With most cancers you want to treat the patient with the most effective therapeutic as possible,” she says. “That’s what this does: it really enables personalized medicine. It will be able to test every patient at the right time, right in their doctor’s office.”

Source: “Nano Nod for Lab-on-a-Chip,” Phys.Org, 4/25/12
Source: “The Domino Chip,” YouTube, 4/25/12

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Bipolymer Microthreads Regenerate Human Tissue

May 2, 2012 By Leave a Comment

American researchers are developing a system that uses microthreads to regenerate human tissue and heal wounds.

George Pins, associate professor of biomedical engineering at Worcester Polytechnic Institute (WPI) in Massachusetts, got the idea of using microthreads as the basis for tissue engineering when he wanted to find a better way to repair torn anterior cruciate ligaments (ACLs) in the knee, according to a WPI press release. Currently, to repair ACLs, surgeons must remove a section of healthy tendon from another party of the body and graft it into the damaged tissue to replace it. Because the method harms one part of the body to repair another, the surgery is not considered ideal.

“The ACL, like other ligaments and tendons, is a fibrous cable-like structure,” Pins says. “So the original idea was to use thin collagen threads, bundled into cables that mimic the natural structures in the body, as a scaffold for the tissue engineering that would be used to replace the ACL.”

Collagen, a structural protein, is the building block for skin and connective tissues, such as tendons, ligaments, muscle, and cartilage. Pins and his colleagues theorized that thin threads of collagen would be tolerated by the body. As their work progressed, they also began making microthreads from fibrin, a main protein in blood clots. Because the body produces blood clots immediately in response to an injury, Pins thought that fibrin threads could become useful as “scaffolds” to help heal wounds.

Early in the research, Pins and the lab team made each thread by hand, using a large syringe to push out a bead of collagen or fibrin, pull it into a solution, and lift it out by hand to dry suspended over the edges of a cardboard box. Pins challenged several of his undergraduate students to develop an automated system to make the threads in a consistent manner.

Paul Vasiliadis, a member of the team, took the production of the threads to the next level. As a graduate student, he became the lead developer, and now uses a computer-controlled system capable of continuous extrusion with a range of specified thread diameters and quantities.

WPI explains some of the ways that the method has been improved:

The Pins lab continues to develop the microthread technology for use as potential ligament and tendon scaffolds while also working to optimize the composition and mechanical properties of the threads. For example, they are experimenting with ways to control the tensile strength of the threads, and to control the rate at which the threads dissolve once implanted in the body. They have also developed new technologies to tailor the surface topographies and biochemistries of the microthreads to provide specific signaling cues that they predict will direct cell-mediated tissue responses.

The threads also are being used as biological sutures to deliver bone marrow-derived adult stem cells known as human mesenchymal stem cells (hMSCs) to cardiac tissue damaged by disease or trauma. The research team has found that when hMSCs are delivered to damaged hearts, they moderately improve cardiac function.

Another application for the fibrin-based microthreads is as a platform to restore muscle tissue that was damaged by traumatic injury. Here, the microthreads are seeded with new cells that could regenerate muscle tissue, and they serve as a muscle-like scaffold to promote the body’s own healing and regenerative processes.

“This is becoming a platform technology, growing in ways we hadn’t imagined when we first began this line of research,” Pins says. “It’s exciting to see the clinical potential for this technology accelerating.”

Source: “WPI Team Scales-up Production of Biopolymer Microthreads,” Worcester Polytechnic Institute press release, 4/30/12
Source: “The Threads of Hope,” YouTube, 4/30/12

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Blood Type Identified Quickly on Paper

May 1, 2012 By Leave a Comment

For those who need to learn a person’s blood type quickly, there’s a new device that will literally spell it out for them on paper.Blood

The blood types are common knowledge: A+, AB-, O+, etc. As Bethany Halford writes in Chemical & Engineering News, Australian researchers have invented a method that makes these letters and symbols appear on paper — depending on what the specific type is — within a minute. She explains:

The presence or absence of certain antigens on red blood cells determines a person’s blood type. Specific antibodies will react with these antigens and make the red blood cells clump. Researchers led by Wei Shen, of Australia’s Monash University, use an ink-jet printer to apply these antibodies in the shapes of letters A, B, and X as well as a vertical line onto postage-stamp-sized pieces of paper towel. O and rhesus-negative blood types don’t have antigens that react with these antibodies, so the researchers preprint an O in the same spot as the X and a horizontal line intersecting the vertical line on the paper in red waterproof ink.

Someone needing to know a person’s blood type puts a few drops of the person’s blood on the paper and washes it with saline. In about a minute, the letters of the blood type appear. If the blood is type A-positive, antigens will react with antibodies on the A printed on the paper to produce a clump of red blood cells in that letter’s shape and with antibodies in a vertical line to complete a “+” sign.

Antigens also will react with antibodies to form a red X over the preprinted O, to indicate that the blood type is not O. For O-negative blood, antibodies would not react with antigens, leaving the preprinted paper to read “O” above a “-” sign.

Shen got the idea after seeing the film adaptation of J. K. Rowling’s book, Harry Potter and the Chamber of Secrets, in which questions written into a magical diary are answered by the diary in writing. Shen wondered whether technology could be developed if someone wrote on paper, “What’s my blood type?”

Source: “Blood Typing Made Simple,” Chemical & Engineering News, 4/30/12
Image by US Navy, used under Fair Use: Reporting.

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Device Speeds Detection, Treatment of Bacteria

April 30, 2012 By 1 Comment

When a patient has a stubborn infection, sometimes doctors are at a loss to know what type of infection it is and how to treat it. Making cultures of the bacteria to unveil their identity can take hours, sometimes too long for sick patients. In the meantime, doctors often throw a wide spectrum of antibiotics at the infection, a practice that increases the number of multi-drug-resistant pathogens.

To shorten the length of time to detect the bacteria, researchers at the University of Michigan, Ann Arbor, have developed a method that rapidly detects bacterial growth and determines their drug sensitivity, reports Aaron A. Rowe in Chemical & Engineering News. The method and the results of testing it have been published in Analytical Chemistry.

The team of researches, led by Raoul Kopelman, adds bacteria and magnetic beads within a microfluidic device. The machine then stirs that mixture with mineral oil to produce oil-coated droplets, each containing microbes and a single bead. An electromagnet then spins the beads within a magnetic field. Rowe explains the method further:

As the bacteria grow inside the droplets, they excrete chemicals that thicken the liquid. That goo slows the rotation of the magnetic beads, a deceleration that scientists can measure as they watch the droplets through a microscope.

To test the method’s effectiveness, the researchers mixed Escherichia coli bacteria with different concentrations of an antibiotic. At low concentrations, the bacteria grew, slowing the beads’ rotation by 50% after 100 minutes. At higher levels of the antibiotic, the microbes died, the viscosity stayed the same, and the beads rotated at the same rate.

To commercialize the technique, the researchers have started a company, Life Magnetics. The technique still requires culturing a patient’s infection, but that process takes less time because the viscosity measurements can be made in droplets that contain only 50 cells.

Source: “Microfluidic Device Quickly Tests Antibiotic Effectiveness,” Chemical & Engineering News, 4/24/12
Source: “Asynchronous Magnetic Bead Rotation, for Single Cell Detection and Growth,” YouTube

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Scientists Create Plastic Solar Cell

April 27, 2012 By Leave a Comment

Scientists have discovered a method using polymers that could allow improved solar cells to be manufactured more cheaply and with more flexibility.Solar cell panel

Manufacturers already print or roll material onto surfaces to produce an electronically functional device, writes Jennifer Hicks in Forbes. This process is used to make organic solar cells and organic light-emitting diodes that go into displays on mobile phones.

These devices offer advantages over conventional silicon- or semiconductor-based electronics because they can be more flexible, irregularly shaped, and lighter in weight, reports Mitch Jacoby for Chemical & Engineering News. However, organic electronic devices tend to remain expensive because some of the manufacturing steps require vacuum processing to prevent the component materials — calcium, magnesium, and lithium — from reacting with oxygen and moisture. This is why electronics in solar cells or TVs are often covered with rigid, thick plates of glass or encapsulating layers.

Now, a team of scientists from the Georgia Institute of Technology (Georgia Tech) have developed a method to eliminate this problem. They spread a layer of polyethylen­imine or ethoxylated polyethyl­enimine one to 10 nanometers thick onto a conductor’s surface. The application turns the air-stable conductors into efficient, low-work function electrodes. The polymers are commercially available and are diluted in solvents before applied.

Bernard Kippelen, professor at Georgia Tech’s Center for Organic Photonics and Electronics, says:

Replacing reactive metals like lithium and calcium with stable conductors, including conducting polymers, completely changes the requirements of how electronics are manufactured and protected and paves the way for lower cost and more flexible devices. This technique is based on the printing of organic inks that have semiconducting properties that can be processed at temperatures below 200 C. This allows for the fabrication of electronics devices onto plastic or even paper substrates.

Plastic solar cells could eventually be made cheaper than crystalline silicon solar cells, but issues remain. Kippelen adds:

The goal is to reach a price point for a photovoltaic module that is below the cost of the raw silicon that is used to fabricate conventional silicon solar cells. But the road to get there is still long and the new printable electrodes and the demonstration of a completely plastic solar cell are only a small step in the right direction towards this challenging objective.

Source: “New Technique Creates First Plastic Solar Cell,” Forbes, 4/25/12
Source: “Electrodes By Solution Processing,” Chemical & Engineering News, 4/23/12
Image by Snowacinesy, used under its Creative Commons license.

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Polymer Alternative to DNA Created

April 26, 2012 By Leave a Comment

British scientists have developed polymer alternatives to DNA and RNA — the molecular architecture of life on Earth — that could lead to improvements in medicine and nanotechnology.DNA

DNA forms the template that contains all the information necessary to create an organism, writes Eryn Brown for Los Angeles Times via BostonHerald.com. RNA takes that information and translates it into proteins, the building blocks of life.

Researchers at the Medical Research Council (MRC) Laboratory of Molecular Biology in the United Kingdom found a way to use polymers to function the same way as DNA and RNA, and replicated copies of them, reports Today. The scientists called the new molecules, XNA, X standing for “xeno,” a Greek prefix meaning “strange,” “foreign,” or “alien.” The findings were reported in the journal Science.

Researchers made XNA building blocks to six different genetic systems by replacing the natural sugar components found in DNA with six different polymers, reports Christine Dell’Amore of National Geographic News. The team then evolved enzymes that can make XNA from DNA and others that changed XNA back into DNA.

“There is no overwhelming functional imperative for life to be based on DNA or RNA,” says Phil Holliger from the MRC Laboratory in Cambridge, who led the team, reports Chemistry World. “Other polymers can perform these functions, at least at a basic level.”

The research may provide a new way of developing designer nucleic-acid drugs that could resist breakdown or have other desirable properties, such as the ability to slip from the bloodstream into diseased cells. Specifically, the researchers created XNA fragments that could bind to molecular targets in the HIV virus. This ability could create a new platform for creating targeted drugs to treat diseases.

XNA-based drugs “might have a future to rival antibodies,” says Dr. Holliger. Antibody drugs are used to treat cancer and autoimmune diseases. However, they are difficult to develop and produce.

The research also poses questions about how life could be created in other parts of the universe. The findings could help scientists figure out how DNA and RNA became so crucial in the evolution of life on Earth and even help in the search for extraterrestrial organisms, says Dr. Vitor Pinheiro, a co-author of the paper. “If a genetic system doesn’t have to be based on DNA and RNA, what then do you define as life?” he asks.

Source: “Researchers Make Alternatives to DNA and RNA,” BostonHerald.com, 4/21/12
Source: “A Big Step ‘Closer to Artificial Life,’” Today, 4/21/12
Source: “Synthetic DNA Created, Evolves on Its Own,” National Geographic News, 4/19/12
Source: “Polymers Perform Non-DNA Evolution,” Chemistry World, 4/19/12
Image by Michael Ströck, used under its Creative Commons license.

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Laser Device Performs Delicate Surgery

April 25, 2012 By Leave a Comment

When surgeons use metal scalpels to cut away harmful tissue, there is a risk of cutting healthy tissue. This risk is especially acute for operations on critical organs, such as brains and intestines. Now there is a laser “scalpel” that targets diseased or damaged tissue while leaving healthy tissue intact.Laser Scalpel

A team of researchers from the University of Texas at Austin has developed a medical laser device that can fit onto endoscopes and send out powerful but incredibly brief pulses of light, reports the Optical Society of America. The pulses last only 200 quadrillionths of a second, so brief that healthy cells are untouched.

The researchers will present the device at the Conference on Lasers and Electro Optics in San Jose, CA, in early May. Adela Ben-Yakar of the University of Texas at Austin, the project’s principal investigator, says:

We are developing the next-generation clinical tools for microsurgery. [...] All the optics we tested can go into a real endoscope. The probe has proven that it’s functional and feasible and can be [manufactured] commercially.

The endoscope probe is thinner than a pencil and less than an inch long. The infrared light it emits penetrates up to one millimeter into living tissue, allowing surgeons to target individual cells or even smaller parts, such as cell nuclei. The device consists of three parts: commercial lenses; a specialized fiber to deliver the laser pulses from the laser to the microscope; and a 750-micrometer microelectromechanical scanning mirror.

The device could be used for eye surgery, repairing vocal cords or removing small tumors in the spinal cord or other tissues. Ben-Yakar’s group is collaborating on a project to treat scarred vocal folds with a probe tailored for the larynx and another to work on brain neurons and synapses.

This medical device has been tested on pig vocal cords and the tendons of rat tails. An earlier prototype was tested on human breast cancer cells. The first viable laser scalpel will still need at least five years of clinical testing before it receives approval from the U.S. Food and Drug Administration for use on humans.

Source: “Medical ‘Lightsabers’: Laser Scalpels Get Ultrafast, Ultra-accurate, and Ultra-Compact Makeover,” Optical Society of America press release, 4/23/12
Image by Ben-Yakar Group, University of Texas at Austin, used with permission.

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Mussel-Inspired Adhesive Has Many Useful Properties

April 24, 2012 By Leave a Comment

Inspired by mussels’ ability to adhere to many surfaces underwater, German researchers have developed a group of adhesives that are waterproof, can bind themselves together, react with surfaces, degrade with light, and are biocompatible.California Mussels

The materials have applications in medicine, reports Azom.com. They could be used for removable hydrogel pads that help regenerate skin or as a reversible superglue for repeated operations. The researchers wrote about their development in the journal, Angewandte Chemie.

Adhesives today have incredible bonding strength. They can hold together airfoils on airplanes, for example. However, there is a need for other applications as well: bonding that can occur underwater, repairs for underwater pipelines, sealing of bleeding wounds during operations, “self-healing” adhesives that would prevent catastrophic failures, and “on demand” debonding without residues to allow for replacement of components.

Mussels use the amino acid, dihydroxyphenylalanine (DOPA), to stick to all types of surfaces. The acid mixes with seawater to forum a polymer matrix capable of bonding to inorganic oxides in rock. Also, they bind to polyvalent metal ions, such as iron ions, that give the mussel adhesive the ability to self-heal.

Researchers at the Max Planck Institute for Polymer Research in Mainz produced polymers with DOPA-like components that self-healed; it takes a few minutes for a sliced gel sample to grow back together. Also, the adhesive can be split by irradiation with ultraviolet light. This characteristic means that the adhesive can be debonded.

Source: “Mussels Inspire Biocompatible Adhesive with Amazing Properties,” Azom.com, 4/15/12
Image by JoJan, used under its Creative Commons license.

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Polymers Hold Key to More Fuel-Efficient Cars

April 23, 2012 By Leave a Comment

Certain kinds of polymers may be useful in the near future to help reduce the weight of cars and therefore improve fuel efficiency.Fast car

Carbon fiber, or carbon-fiber reinforced polymer, is exceptionally strong and light, reports John Rosevear of The Motley Fool, but it also is expensive. Yet automobile manufacturers see the material as key to meeting increasing fuel-economy standards, without compromising passenger safety.

An agreement between Ford and Dow Chemical aims to move this goal to fruition. Researchers from both companies will focus on making carbon fiber more affordable and mass-production feasible. The partnership will combine Ford’s design and engineering capabilities with Dow’s strengths in research and development, materials sciences, and high-volume polymer processing, according to a press release from Ford.

The partnership will leverage work that Dow has begun through partnerships with Turkish carbon fiber manufacturer AKSA and the U.S. Department of Energy Oak Ridge National Laboratory. “This partnership with Ford on carbon fiber composites is a logical next step to progress already achieved through the use of lightweight, high-strength polymers and structural bonding technology,” says Florian Schattenmann, director of Research and Development for Dow Automotive Systems.

Ford has a goal to reduce the weight of its new vehicles by 250 to 750 pounds by 2020. Although that amount may be a small percentage of a car’s total weight, it is significant because weight is one of the most important factors in fuel consumption.

Reducing weight is especially important in plug-in hybrid and electric applications. Less weight means more distance between charges, the biggest challenge facing electric car makers.

If the partnership is successful, carbon fiber components could be found in mainstream car models by the end of the decade. The companies say that the components would help standard-engine cars meet new fuel efficiency standards of more than 50 miles per gallon.

Source: “Why Ford’s New Deal is a Big Deal,” The Motley Fool, 4/13/12
Source: “Ford and Dow Team Up to Bring Low-Cost, High-Volume Carbon Fiber Composites to Next-Generation Vehicles,” Ford Motor Company press release, 4/12/12
Image by Donkervoort-A, used under its Creative Commons license.

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Floating Plastics Help Create Alternative Fuel

April 20, 2012 By Leave a Comment

NASA is developing a technology that uses large arrays of plastic tubes that float in seawater and contain algae that can be converted into fuel.

The floating algae cultivation system, called Offshore Membrane Enclosure for Growing Algae (OMEGA), is designed to grow freshwater algae in municipal wastewater using photobioreactors, or flexible plastic tubes. NASA has spent $10 million on the project because it is looking into alternative sources for aviation fuel.

The algae treat the wastewater by consuming nutrients that, if released into large coastal waters, could create algal blooms that consume oxygen. As the algae grow, they absorb carbon dioxide and release oxygen.

Algae can double their numbers and be ready to harvest in three to five days. After the oil is removed from the algae, the remnant material can be used to produce fertilizer, natural gas, and animal feed.

The system has its challenges, reports Geek.com. For example, to produce 2.4 million gallons of algae for fuel use, a two-square-mile area would have to be covered with the plastic algae incubators. NASA claims that its system can produce more than 2,000 gallons of oil per acre, compared with 600 gallons from palm and 50 gallons from soy beans, reports Energy Digital. In contrast, jets use several hundred to a few thousand gallons of fuel per hour of flight.

Another factor to consider is the amount of energy needed to make the plastics, whose major components are oil, for the algae system versus the energy the system could create from its oil production. Yet another challenge is what one could do with the plastics after they have been used. Would they be put in a landfill or recycled?

Source: “NASA Invests $10 Million in Energy-Producing Floating Algae Bags,” Geek.com, 4/13/12
Source: “NASA Showcases Innovative Method to Grow Algae-Based Biofuels,” NASA, 4/17/12
Source: “Turning Algae Into Oil the NASA Way,” YouTube

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