Posts belonging to Category bioengineering



DNA Origami, The New Revolution To Come For Nanotechnology

For the past few decades, some scientists have known the shape of things to come in nanotechnology is tied to the molecule of life, DNA. This burgeoning field is called “DNA origami.” The moniker is borrowed from the art of conjuring up birds, flowers and other shapes by imaginatively folding a single sheet of paper. Similarly, DNA origami scientists are dreaming up a variety of shapes — at a scale one thousand times smaller than a human hair — that they hope will one day revolutionize computing, electronics and medicine. Now, a team of Arizona State University and Harvard scientists has invented a major new advance in DNA nanotechnology. Dubbed “single-stranded origami” (ssOrigami), their new strategy uses one long noodle-like strand of DNA, or its chemical cousin RNA, that can self-fold — without even a single knot — into the largest, most complex structures to date. And the strands forming these structures can be made inside living cells or using enzymes in a test tube, allowing scientists the potential to plug-and-play with new designs and functions for nanomedicine: picture tiny nanobots playing doctor and delivering drugs within cells at the site of injury.

A DNA origami with an emoji-like smiley face

I think this is an exciting breakthrough, and a great opportunity for synthetic biology as well,” said Hao Yan, a co-inventor of the technology, director of the ASU Biodesign Institute’s Center for Molecular Design and Biomimetics, and the Milton Glick Professor in the School of Molecular Sciences.

We are always inspired by nature’s designs to make information-carrying molecules that can self-fold into the nanoscale shapes we want to make,” he said.

As proof of concept, they’ve pushed the envelope to make 18 shapes, including emoji-like smiley faces, hearts and triangles, that significantly expand the design studio space and material scalability for so-called, “bottom-upnanotechnology.

Source: https://asunow.asu.edu/

The Smell Of Death

Scientists in Korea have developed a bioelectronicnose’ that can specifically detect a key compound produced in decaying substances. When food begins to rot, the smell that we find repulsive comes from a compound known as cadaverine. That is also the substance responsible for the stench of rotting bodies, or cadavers—hence the name. The compound is the result of a bacterial reaction involving lysine, which is an amino acid commonly found in various food products. A previous study has shown that a receptor in zebrafish has an affinity for cadaverine. To make this receptor in the laboratory, scientists have turned to Escherichia coli bacteria as a host cell because it can easily produce large quantities of proteins. However, the production of this receptor in E. coli has been a challenge because it needs to be embedded in a membrane.

In this study, a team of researchers led by Associate Professor Hong Seunghun at Seoul National University packaged the cadaverine receptor from the zebrafish into nanodiscs, which are water friendly, membrane-like structures. The researchers then placed the receptor-containing nanodiscs in a special orientation on a carbon nanotube transistor, completing the bioelectronic nose. During testing with purified test compounds and real-world salmon and beef samples, the nose was selective and sensitive for cadaverine, even at low levels. The researchers suggest that the detector could someday prove useful in natural disaster scenarios, to recover corpses for identification.

The findings have been published in the journal ACS Nano.

Source: http://pubs.acs.org/

Paraplegic Rats Walk After Stem Cell Treatment

Engineered tissue containing human stem cells has allowed paraplegic rats to walk independently and regain sensory perception. The implanted rats also show some degree of healing in their spinal cords. The research, published in Frontiers in Neuroscience, demonstrates the great potential of stem cellsundifferentiated cells that can develop into numerous different types of cells—to treat spinal cord injury.

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Spinal cord injuries often lead to paraplegia. Achieving substantial recovery following a complete tear, or transection, is an as-yet unmet challenge.

Led by Dr. Shulamit Levenberg, of the Technion-Israel Institute of Technology, the researchers implanted human stem cells into rats with a complete spinal cord transection. The stem cells, which were derived from the membrane lining of the mouth, were induced to differentiate into support cells that secrete factors for neural growth and survival.

The work involved more than simply inserting stem cells at various intervals along the spinal cord. The research team also built a three-dimensional scaffold that provided an environment in which the stem cells could attach, grow and differentiate into support cells. This engineered tissue was also seeded with human thrombin and fibrinogen, which served to stabilize and support neurons in the rat’s spinal cord.

Rats treated with the engineered tissue containing stem cells showed higher motor and sensory recovery compared to control rats. Three weeks after introduction of the stem cells, 42% of the implanted paraplegic rats showed a markedly improved ability to support weight on their hind limbs and walk. 75% of the treated rats also responded to gross stimuli to the hind limbs and tail.

In contrast, control paraplegic rats that did not receive showed no improved mobility or sensory responses.

In addition, the lesions in the spinal cords of the treated rats subsided to some extent. This indicates that their spinal cords were healing.

Source: https://medicalxpress.com/

3D-Printed Plastic Objects Connect To The Internet Without Any Electronics

Researchers from the University of Washington (UW) have developed 3D-printed plastic objects that can connect to the internet without any electronics or batteries. The researchers found a way to 3D-print plastic objects that can absorb or reflect ambient WiFi signals and send data wirelessly to any WiFi receiver like a smartphone or router.

Possible use cases include an attachment for laundry detergent that can sense when soap is running low, or a water sensor that notifies your smartphone when there is a leak.

As the UW explains in its news release, the researchers “replaced some functions normally performed by electrical components with mechanical motion activated by springs, gears, switches and other parts that can be 3-D printed — borrowing from principles that allow battery-free watches to keep time.” The scientists found that those mechanical motions can trigger gears and springs that connect to an antenna, all within the object.
The team opens new approach: “Can objects made of plastic materials be connected to smartphones and other Wi-Fi devices, without the need for batteries or electronics? A positive answer would enable a rich ecosystem of ‘talking objects3D printed with commodity plastic filaments that have the ability to sense and interact with their surroundings. Imagine plastic sliders or knobs that can enable rich physical interaction by dynamically sending information to a nearby Wi-Fi receiver to control music volume and lights in a room. This can also transform inventory management where for instance a plastic detergent bottle can self-monitor usage and re-order supplies via a nearby Wi-Fi device.
Such a capability democratizes the vision of ubiquitous connectivity by enabling designers to download and use our computational modules, without requiring the engineering expertise to integrate radio chips and other electronics in their physical creations. Further, as the commoditization of 3D printers continues, such a communication capability opens up the potential for individuals to print highly customized wireless sensors, widgets and objects that are tailored to their individual needs and connected to the Internet ecosystem
.”

Source: http://printedwifi.cs.washington.edu/
https://www.geekwire.com/

How To Remove Air Pollution Inside Cars

You might think sitting in your car with your windows closed keeps you safe from air pollution. The makers of a new pollution-busting filter say you’d be wrong.

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When you’re in your car you’re directly in the lanes of traffic and you’re actually taking air into the car. That’s coming from the exhaust of the cars in front of you. This means that there are greatly elevated levels of air pollution inside of a vehicle. This is both for nitrogen dioxide and for particulate matter“,  says Matthew Johnson,  Professor of Chemistry at the University of Copenhagen (Denmark).

Toxic air pollution passes through air inlets inside cars. Emissions from diesel vehicles are worst. The team from University of Copenhagen and start-up Airlabs has created Airbubbl, which contains two filters.
We have a chemical filter that’s removing nitrogen dioxide and ozone and odour from the air stream. We also have a high performance particle filter that’s removing soot and road dust and brake dust and these other components. We combine that inside this case. This plugs into the cigarette lighter. We have some quiet fans at the two ends of the device and we’ve used computational fluid dynamics in order to direct the airflow towards the passengers,” explains Johnson.
Independent tests in London saw nitrogen dioxide concentrations inside cars fall by 95 percent in 10 minutes. The Airbubbl is lightweight and easily attachable. A Kickstarter campaign has been launched to market the device.

Source: https://www.reuters.com/

Crowdfunding: https://www.kickstarter.com/

Swiss Army Knife NanoVaccine To Fight Tumors

Scientists are using their increasing knowledge of the complex interaction between cancer and the immune system to engineer increasingly potent anti-cancer vaccines.
Now researchers at the National Institute ofBiomedical Imaging and Bioengineering (NIBIB) have developed a synergistic nanovaccine packing DNA and RNA sequences that modulate the immune response, along with anti-tumor antigens, into one smallnanoparticle. The nanovaccine produced an immune response that specifically killed tumor tissue, while simultaneously inhibiting tumor-induced immune suppression. Together this blocked lung tumor growth in a mouse model of metastatic colon cancer.

Large particles (left) containing the DNA and RNA components are coated with electronically charged molecules that shrink the particle. The tumor-specific neoantigen is then complexed with the surface to complete construction of the nanovaccine.
Upper left: electron micrograph of large particle

 

The molecular dance between cancer and the immune system is a complex one and scientists continue to identify the specific molecular pathways that rev up or tamp down the immune system. Biomedical engineers are using this knowledge to create nanoparticles that can carry different molecular agents that target these pathways. The goal is to simultaneously stimulate the immune system to specifically attack the tumor while also inhibiting the suppression of the immune system, which often occurs in cancer patients. The aim is to press on the gas pedal of the immune system while also releasing the emergency brake.

A key hurdle is to design a system to reproducibly and efficiently create a nanoparticle loaded with multiple agents that synergize to mount an enhanced immune attack on the tumor. Engineers at the NIBIB report the development and testing of such a nanovaccine in the journal Nature Communications.

Source: https://www.nibib.nih.gov/

How To Trap DNA molecules With Your Smartphone

Researchers from the University of Minnesota College of Science and Engineering have found yet another remarkable use for the wonder material graphenetiny electronictweezers” that can grab biomolecules floating in water with incredible efficiency. This capability could lead to a revolutionary handheld disease diagnostic system that could be run on a smart phoneGraphene, a material made of a single layer of carbon atoms, was discovered more than a decade ago and has enthralled researchers with its range of amazing properties that have found uses in many new applications from microelectronics to solar cells. The graphene tweezers developed at the University of Minnesota are vastly more effective at trapping particles compared to other techniques used in the past due to the fact that graphene is a single atom thick, less than 1 billionth of a meter.

The physical principle of tweezing or trapping nanometer-scale objects, known as dielectrophoresis, has been known for a long time and is typically practiced by using a pair of metal electrodes. From the viewpoint of grabbing molecules, however, metal electrodes are very blunt. They simply lack the “sharpness” to pick up and control nanometer-scale objects.

Graphene is the thinnest material ever discovered, and it is this property that allows us to make these tweezers so efficient. No other material can come close,” said research team leader Sang-Hyun Oh, a Professor at the University of Minnesota. “To build efficient electronic tweezers to grab biomolecules, basically we need to create miniaturized lightning rods and concentrate huge amount of electrical flux on the sharp tip. The edges of graphene are the sharpest lightning rods.

The team also showed that the graphene tweezers could be used for a wide range of physical and biological applications by trapping semiconductor nanocrystals, nanodiamond particles, and even DNA molecules. Normally this type of trapping would require high voltages, restricting it to a laboratory environment, but graphene tweezers can trap small DNA molecules at around 1 Volt, meaning that this could work on portable devices such as mobile phones.

The research study has been published  in Nature Communications.

Source: https://cse.umn.edu/

Artificial Intelligence Chip Analyzes Molecular-level Data In Real Time

Nano Global, an Austin-based molecular data company, today announced that it is developing a chip using intellectual property (IP) from Arm, the world’s leading semiconductor IP company. The technology will help redefine how global health challenges – from superbugs to infectious diseases, and cancer are conquered.

The pioneering system-on-chip (SoC) will yield highly-secure molecular data that can be used in the recognition and analysis of health threats caused by pathogens and other living organisms. Combined with the company’s scientific technology platform, the chip leverages advances in nanotechnology, optics, artificial intelligence (AI), blockchain authentication, and edge computing to access and analyze molecular-level data in real time.

In partnership with Arm, we’re tackling the vast frontier of molecular data to unlock the unlimited potential of this universe,” said Steve Papermaster, Chairman and CEO of Nano Global. “The data our technology can acquire and process will enable us to create a safer and healthier world.”

We believe the technology Nano Global is delivering will be an important step forward in the collective pursuit of care that improves lives through the application of technology,” explained Rene Haas, executive vice president and president of IPG, Arm. “By collaborating with Nano Global, Arm is taking an active role in developing and deploying the technologies that will move us one step closer to solving complex health challenges.”

Additionally, Nano Global will be partnering with several leading institutions, including Baylor College of Medicine and National University of Singapore, on broad research initiatives in clinical, laboratory, and population health environments to accelerate data collection, analysis, and product development.
The initial development of the chip is in process with first delivery expected by 2020. The company is already adding new partners to their platform.

Source: https://nanoglobal.com/
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www.prnewswire.com

Polymeric Materials Outperform Natural Antibodies

Experts from the Biotechnology Group led by Professor Sergey Piletsky at the University of Leicester (UK) in collaboration with the spin-off company MIP Diagnostics Ltd, have announced the development of polymeric materials with molecular recognition capabilities which hold the potential to outperform natural antibodies in various diagnostic applications.

chemical background

 In a newly released article ‘A comparison of the performance of molecularly imprinted polymer nanoparticles for small molecule targets and antibodies in the ELISA format’ the researchers successfully demonstrated that polymer nanoparticles produced by the molecular imprinting technique (MIP nanoparticles) can bind to the target molecule with the same or higher affinity and specificity than widely used commercially available antibodies and against challenging targets.

Additionally, their ease of manufacture, short lead time, high affinity and the lack of requirement for cold chain logistics make them an attractive alternative to traditional antibodies for use in immunoassays.

Professor Piletsky, from our Department of Chemistry, explained: “It is now well over twenty years since the first demonstration that molecularly imprinted polymers can be used as the recognition material in assays for clinically significant drugs“. 

Source: https://www2.le.ac.uk/

Photovoltaics: Light Absorption Enhanced by Up to 200 Percent

Sunlight reflected by solar cells is lost as unused energy. The wings of the butterfly Pachliopta aristolochiae are drilled by nanostructures (nanoholes) that help absorbing light over a wide spectrum far better than smooth surfaces. Researchers of Karlsruhe Institute of Technology (KIT) in Germany, have now succeeded in transferring these nanostructures to solar cells and, thus, enhancing their light absorption rate by up to 200 percent.

 “The butterfly studied by us is very dark black. This signifies that it perfectly absorbs sunlight for optimum heat management. Even more fascinating than its appearance are the mechanisms that help reaching the high absorption. The optimization potential when transferring these structures to photovoltaics (PV) systems was found to be much higher than expected,” says Dr. Hendrik Hölscher of KIT’s Institute of Microstructure Technology (IMT).

 

The scientists of the team of Hendrik Hölscher and Radwanul H. Siddique (formerly KIT, now Caltech) reproduced the butterfly’s nanostructures in the silicon absorbing layer of a thin-film solar cell. Subsequent analysis of light absorption yielded promising results: Compared to a smooth surface, the absorption rate of perpendicular incident light increases by 97% and rises continuously until it reaches 207% at an angle of incidence of 50 degrees. “This is particularly interesting under European conditions. Frequently, we have diffuse light that hardly falls on solar cells at a vertical angle,” Hendrik Hölscher says. However, this does not automatically imply that efficiency of the complete PV system is enhanced by the same factor, says Guillaume Gomard of IMT. “Also other components play a role. Hence, the 200 percent are to be considered a theoretical limit for efficiency enhancement.

The scientists have reported their results in the journal Science Advances. (DOI: 10.1126/sciadv.1700232.)

Source: http://www.kit.edu/

How To Correct Genes That Cause High Cholesterol

U.S. researchers have used nanotechnology plus the powerful CRISPR-Cas9 gene-editing tool to turn off a key cholesterol-related gene in mouse liver cells, an advance that could lead to new ways to correct genes that cause high cholesterol and other liver diseasesNanotechnology is the design and manipulation of materials thousands of times smaller than the width of a human hair.

We’ve shown you can make a nanoparticle that can be used to permanently and specifically edit the DNA in the liver of an adult animal,” said study author Daniel Anderson, an associate professor in chemical engineering at the Massachusetts Institute of Technology.

The study, published  in Nature Biotechnology, holds promise for permanently editing genes such as PCSK9, a cholesterol-regulating gene that is already the target of two drugs made by the biotechnology companies Regeneron Pharmaceuticals and Amgen.

In the study, the scientists were trying to develop a safe and efficient way to deliver the components needed for CRISPR-Cas9, a type of molecular scissors that can selectively trim away defective genes and replace them with new stretches of DNA.

The system consists of a DNA-cutting enzyme called Cas9 and a stretch of RNA that guides the cutting enzyme to the correct spot in the genome. Most teams currently use viruses to deliver CRISPR into cells, an approach that is limited because the immune system can develop antibodies to viruses.

To overcome this, the team chemically modified the CRISPR components to protect them from enzymes in the body that would normally break them down. They then inserted this material into nano-scale fat particles and injected them into mice, where they made their way to liver cells.

In tests targeting the PCSK9 gene, the system proved highly effective, . The PCSK9 protein made by this gene was undetectable in the treated mice, eliminating the gene in more than 80 percent of liver cells, which also experienced a 35 percent drop in total cholesterol, the researchers reported.

High levels of cholesterol can clog arteries, causing reduced blood flow that can lead to a heart attack or stroke.

Source: http://news.mit.edu/

New Genetic And Stem-Cell Technology To Grow Sheets Of Skin

Somewhere in Germany’s Ruhr valley, a nine-year-old boy is doing what children do: playing football, joking around with friends and going to school. Two years ago, he was confined to a hospital bed, dying of a rare and cruel genetic skin disease. The boy had junctional epidermolysis bullosa, or JEB. He, like other people with the disease, carried a mutation in a gene that controls the integrity of the skin. Doctors could only try to ease his suffering as some 80% of his skin simply fell away.

A team of Italian researchers came to his aid by combining stem-cell techniques with gene therapy. As a young scientist at Harvard Medical School in Boston, Massachusetts, in the 1980s, Michele De Luca — the lead author of the new study — watched pioneers in skin regeneration learn to grow small sheets of skin from cells taken from burns patients, and to use them in grafts. He extended the work in Italy, applying new genetic and stem-cell technologies. He developed ways to generate stem cells from human skin, replace disease-causing genes in them and grow sheets of healthy skin on scaffolds in the lab.

He chose JEB for his first clinical trial, which he registered with the Italian Medicines Agency in 2002. Four years later, he reported his first success, in which he created healthy skin patches from biopsies to replace small areas of sloughed-off skin on the legs of a patient with a form of JEB (F. Mavilio et al. Nature Med. 12, 1397–1402; 2006). New European Commission regulations introduced in 2007 required him to pause the project while he created facilities adhering to ‘good manufacturing practices’ (GMPs) and a spin-off company to meet the demands for strengthened oversight of cell-based therapies.

Having a company refocused his team’s attention on a different type of stem-cell therapy, one likely to yield a product for the market faster. Holoclar, a treatment that replaces the eye’s cornea in a form of blindness, became the world’s first commercial stem-cell therapy in 2015.

A few months later, at the University of Modena, De Luca got a call out of the blue from doctors in Germany who were trying to treat the little boy. Because the therapy had been in a clinical trial, albeit one on hold at the time, and because De Luca could provide GMP services, German regulatory authorities quickly approved the one-off compassionate use of the JEB therapy. Surgeons in Germany sent a skin biopsy to Modena, and two major skin transplants followed. Six months after the initial biopsy, the boy returned to school. During the many months since, he has not had so much as a blister, and loves to show off his ‘new skin’. By their nature, highly personalized treatments using gene therapies and products derived from an individual’s stem cells are likely to be applicable to only a subset of patients.

Scientists and clinicians have presented the details of the recovery in Nature (T. Hirsch et al.Nature http://dx.doi.org/10.1038/nature24487; 2017). This major clinical development was based on decades of basic research. The clinical data gathered during 21 months of follow-up after the boy’s treatment have also led to major insights into human skin biology, as discussed in an accompanying News & Views (M. Aragona and C. Blanpain Naturehttp://dx.doi.org/10.1038/nature24753; 2017). For example, normal regeneration of the epidermis is directed by only a few stem-cell clones that can self-renew.

Source: http://www.nature.com/