Tag Archives: UB

Drink your spinach juice—illuminate your guts

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Contrast agents used for magnetic resonance imaging, x-ray imaging, ultrasounds, and other imaging technologies are not always kind to the humans ingesting them. So, scientists at the University at Buffalo (also known as the State University of New York at Buffalo) have developed a veggie juice that does the job according to a July 11, 2016 news item on Nanowerk (Note: A link has been removed),

The pigment that gives spinach and other plants their verdant color may improve doctors’ ability to examine the human gastrointestinal tract.

That’s according to a study, published in the journal Advanced Materials (“Surfactant-Stripped Frozen Pheophytin Micelles for Multimodal Gut Imaging”), which describes how chlorophyll-based nanoparticles suspended in liquid are an effective imaging agent for the gut.

The University of Buffalo has provided an illustration of the work,

A new UB-led study suggests that chlorophyll-based nanoparticles are an effective imaging agent for the gut. The medical imaging drink, developed to diagnose and treat gastrointestinal illnesses, is made of concentrated chlorophyll, the pigment that makes spinach green. Photo illustration credit: University at Buffalo.

A new UB-led study suggests that chlorophyll-based nanoparticles are an effective imaging agent for the gut. The medical imaging drink, developed to diagnose and treat gastrointestinal illnesses, is made of concentrated chlorophyll, the pigment that makes spinach green. Photo illustration credit: University at Buffalo.

A July 11, 2016 University at Buffalo (UB) news release (also on EurekAlert) by Cory Nealon, which originated the news item, expands on the theme,

“Our work suggests that this spinach-like, nanoparticle juice can help doctors get a better look at what’s happening inside the stomach, intestines and other areas of the GI tract,” says Jonathan Lovell, PhD, assistant professor in the Department of Biomedical Engineering, a joint program between UB’s School of Engineering and Applied Sciences and the Jacobs School of Medicine and Biomedical Sciences at UB, and the study’s corresponding author.

To examine the gastrointestinal tract, doctors typically use X-rays, magnetic resonance imaging or ultrasounds, but these techniques are limited with respect to safety, accessibility and lack of adequate contrast, respectively.

Doctors also perform endoscopies, in which a tiny camera attached to a thin tube is inserted into the patient’s body. While effective, this procedure is challenging to perform in the small intestine, and it can cause infections, tears and pose other risks.

The new study, which builds upon Lovell’s previous medical imaging research, is a collaboration between researchers at UB and the University of Wisconsin-Madison. It focuses on Chlorophyll a, a pigment found in spinach and other green vegetables that is essential to photosynthesis.

In the laboratory, researchers removed magnesium from Chlorophyll a, a process which alters the pigment’s chemical structure to form another edible compound called pheophytin. Pheophytin plays an important role in photosynthesis, acting as a gatekeeper that allows electrons from sunlight to enter plants.

Next, they dissolved pheophytin in a solution of soapy substances known as surfactants. The researchers were then able to remove nearly all of the surfactants, leaving nearly pure pheophytin nanoparticles.

The drink, when tested in mice, provided imaging of the gut in three modes: photoacoustic imaging, fluorescence imaging and positron emission tomography (PET). (For PET, the researchers added to the drink Copper-64, an isotope of the metal that, in small amounts, is harmless to the human body.)

Additional studies are needed, but the drink has commercial potential because it:

·         Works in different imaging techniques.

·         Moves stably through the gut.

·         And is naturally consumed in the human diet already.

In lab tests, mice excreted 100 percent of the drink in photoacoustic and fluorescence imaging, and nearly 93 percent after the PET test.

“The veggie juice allows for techniques that are not commonly used today by doctors for imaging the gut like photoacoustic, PET, and fluorescence,” Lovell says. “And part of the appeal is the safety of the juice.”

Here’s a link to and a citation for the paper,

Surfactant-Stripped Frozen Pheophytin Micelles for Multimodal Gut Imaging by Yumiao Zhang, Depeng Wang, Shreya Goel, Boyang Sun, Upendra Chitgupi, Jumin Geng, Haiyan Sun, Todd E. Barnhart, Weibo Cai, Jun Xia, and Jonathan F. Lovell. Advanced Materials DOI: 10.1002/adma.201602373 Version of Record online: 11 JUL 2016

© 2016 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim

This paper is behind a paywall.

Nanorobotic approach to studying how skin falls apart

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Scientists have combined robotic techniques with atomic force microscopy to achieve understanding of how skin falls apart at the nanoscale. From a Sept. 11, 2014 news item on Azonano,

University at Buffalo researchers and colleagues studying a rare, blistering disease have discovered new details of how autoantibodies destroy healthy cells in skin. This information provides new insights into autoimmune mechanisms in general and could help develop and screen treatments for patients suffering from all autoimmune diseases, estimated to affect 5-10 percent of the U.S. population.

…

“Our work represents a unique intersection between the fields of biology and engineering that allowed for entirely new investigational strategies applied to the study of clinical disease,” says Animesh A. Sinha, MD, PhD, Rita M. and Ralph T. Behling Professor and chair of the Department of Dermatology in the UB School of Medicine and Biomedical Sciences and senior author on the study.

A Sept. 9, 2014 University of Buffalo news release by Ellen Goldbaum (also on EurekAlert dated Sept. 10, 2014), which originated the news item, describes the condition and the research in more detail,

PV [Pemphigus Vulgaris] results in the often painful blistering of the skin and mucous membranes. Generally treated with corticosteroids and other immunosuppressive agents, the condition is life-threatening if untreated.

…

Sinha’s research team, in collaboration with scientists at Michigan State University, describe the use of atomic force microscopy (AFM), a technique originally developed to study nonbiological materials, to look at cell junctions and how they rupture, a process called acantholysis.

“It has been very difficult to study cell junctions, which maintain the skin’s barrier function by keeping cells attached to each other,” says Sinha. “These junctions, micron-sized spots on cell membranes, are very complex molecular structures. Their small size has made them resistant to detailed investigation.”

Sinha’s interest lies in determining what destroys those junctions in Pemphigus Vulgaris.

“We haven’t understood why some antibodies generated by the condition cause blisters and why other antibodies it generates do not,” says Sinha.

By studying the connections between skin cells using AFM and other techniques that probe cells at the nanoscale, Sinha and his colleagues report that pathogenic antibodies change structural and functional properties of skin cells in distinct ways.

“Our data suggest a new model for the action of autoantibodies in which there are two steps or ‘hits’ in the development of lesions,” says Sinha. “The first hit results in the initial separation of cells but only the pathogenic antibodies drive further intracellular changes that lead to the breaking of the cell junction and blistering.”

The researchers examined the cells using AFM, which requires minimal sample preparation and provides three-dimensional images of cell surfaces.

The AFM tip acts like a little probe, explains Sinha. When tapped against a cell, it sends back information regarding the cell’s mechanical properties, such as thickness, elasticity, viscosity and electrical potential.

“We combined existing and novel nanorobotic techniques with AFM, including a kind of nanodissection, where we physically detached cells from each other at certain points so that we could test what that did to their mechanical and biological functions,” Sinha adds.

Those data were then combined with information about functional changes in cell behavior to develop a nanomechanical profile, or phenotype, for specific cellular states.

He also envisions that this kind of nanomechanical phenotyping should allow for the development of predictive models for cellular behavior for any kind of cell.

“Ultimately, in the case of autoimmunity, we should be able to use these techniques as a high-throughput assay to screen hundreds or thousands of compounds that might block the effects of autoantibodies and identify novel agents with therapeutic potential in given individuals,” says Sinha.  “Such strategies aim to advance us toward a new era of personalized medicine”.

I found some more information about the nanorobotics technique, mentioned in the news release, in the researchers’ paper (Note: A link has been removed),

Nanorobotic surgery

AFM-based nanorobotics enables accurate and convenient sample manipulation and drug delivery. This capability was used in the current study to control the AFM tip position over the intercellular junction area, and apply vertical indentation forces, so that bundles of intercellular adhesion structures can be dissected precisely with an accuracy of less than 100 nm in height. We used a tip sharp enough (2 nm in tip apex diameter) to penetrate the cell membrane and the intermediate filaments. It has been shown that intermediate filaments have extremely high tensile strength by in vitro AFM stretching [19]. Thus, the vertical force and moving speed of the AFM cantilever (0.06 N/m in vertical spring constant) was controlled at a vertical force of 5 nN at an indentation speed of 0.1 µm/s to guarantee the rupture of the filament and to partially dissect cell adhesion structures between two neighboring cells.

For those who want to know more, here’s a link to and a citation for the paper,

Nanorobotic Investigation Identifies Novel Visual, Structural and Functional Correlates of Autoimmune Pathology in a Blistering Skin Disease Model by Kristina Seiffert-Sinha, Ruiguo Yang, Carmen K. Fung, King W. Lai, Kevin C. Patterson, Aimee S. Payne, Ning Xi, Animesh A. Sinha. PLOSONE Published: September 08, 2014 DOI: 10.1371/journal.pone.0106895

This is an open access paper.

Cooling it—an application using carbon nanotubes and a theory that hotter leads to cooler

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The only thing these two news items have in common is their focus on cooling down electronic devices. Well, there’s also the fact that the work is being done at the nanoscale.

First, there’s a Jan. 23, 2014 news item on Azonano about a technique using carbon nanotubes to cool down microprocessors,

“Cool it!” That’s a prime directive for microprocessor chips and a promising new solution to meeting this imperative is in the offing. Researchers with the U.S. Department of Energy (DOE)’s Lawrence Berkeley National Laboratory (Berkeley Lab) have developed a “process friendly” technique that would enable the cooling of microprocessor chips through carbon nanotubes.

Frank Ogletree, a physicist with Berkeley Lab’s Materials Sciences Division, led a study in which organic molecules were used to form strong covalent bonds between carbon nanotubes and metal surfaces. This improved by six-fold the flow of heat from the metal to the carbon nanotubes, paving the way for faster, more efficient cooling of computer chips. The technique is done through gas vapor or liquid chemistry at low temperatures, making it suitable for the manufacturing of computer chips.

The Jan. 22, 2014 Berkeley Lab news release (also on EurekAlert), which originated the news item, describes the nature  of the problem in more detail,

Overheating is the bane of microprocessors. As transistors heat up, their performance can deteriorate to the point where they no longer function as transistors. With microprocessor chips becoming more densely packed and processing speeds continuing to increase, the overheating problem looms ever larger. The first challenge is to conduct heat out of the chip and onto the circuit board where fans and other techniques can be used for cooling. Carbon nanotubes have demonstrated exceptionally high thermal conductivity but their use for cooling microprocessor chips and other devices has been hampered by high thermal interface resistances in nanostructured systems.

“The thermal conductivity of carbon nanotubes exceeds that of diamond or any other natural material but because carbon nanotubes are so chemically stable, their chemical interactions with most other materials are relatively weak, which makes for  high thermal interface resistance,” Ogletree says. “Intel came to the Molecular Foundry wanting to improve the performance of carbon nanotubes in devices. Working with Nachiket Raravikar and Ravi Prasher, who were both Intel engineers when the project was initiated, we were able to increase and strengthen the contact between carbon nanotubes and the surfaces of other materials. This reduces thermal resistance and substantially improves heat transport efficiency.”

The news release then describes the proposed solution,

Sumanjeet Kaur, lead author of the Nature Communications paper and an expert on carbon nanotubes, with assistance from co-author and Molecular Foundry chemist Brett Helms, used reactive molecules to bridge the carbon nanotube/metal interface – aminopropyl-trialkoxy-silane (APS) for oxide-forming metals, and cysteamine for noble metals. First vertically aligned carbon nanotube arrays were grown on silicon wafers, and thin films of aluminum or gold were evaporated on glass microscope cover slips. The metal films were then “functionalized” and allowed to bond with the carbon nanotube arrays. Enhanced heat flow was confirmed using a characterization technique developed by Ogletree that allows for interface-specific measurements of heat transport.

“You can think of interface resistance in steady-state heat flow as being an extra amount of distance the heat has to flow through the material,” Kaur says. “With carbon nanotubes, thermal interface resistance adds something like 40 microns of distance on each side of the actual carbon nanotube layer. With our technique, we’re able to decrease the interface resistance so that the extra distance is around seven microns at each interface.”

Although the approach used by Ogletree, Kaur and their colleagues substantially strengthened the contact between a metal and individual carbon nanotubes within an array, a majority of the nanotubes within the array may still fail to connect with the metal. The Berkeley team is now developing a way to improve the density of carbon nanotube/metal contacts. Their technique should also be applicable to single and multi-layer graphene devices, which face the same cooling issues.

For anyone who’s never heard of the Molecular Foundry before (from the news release),

The Molecular Foundry is one of five DOE [Department of Energy] Nanoscale Science Research Centers (NSRCs), national user facilities for interdisciplinary research at the nanoscale, supported by the DOE Office of Science. Together the NSRCs comprise a suite of complementary facilities that provide researchers with state-of-the-art capabilities to fabricate, process, characterize, and model nanoscale materials, and constitute the largest infrastructure investment of the National Nanotechnology Initiative. The NSRCs are located at DOE’s Argonne, Brookhaven, Lawrence Berkeley, Oak Ridge and Sandia and Los Alamos national laboratories.

My second item comes from the University of Buffalo (UB), located in the US. From a Jan. 21, 2014 University of Buffalo news release by Cory Nealon (also on EurekAlert),

Heat in electronic devices is generated by the movement of electrons through transistors, resistors and other elements of an electrical network. Depending on the network, there are a variety of ways, such as cooling fans and heat sinks, to prevent the circuits from overheating.

But as more integrated circuits and transistors are added to devices to boost their computing power, it’s becoming more difficult to keep those elements cool. Most nanoelectrics research centers are working to develop advanced materials that are capable of withstanding the extreme environment inside smartphones, laptops and other devices.

While advanced materials show tremendous potential, the UB research suggests there may still be room within the existing paradigm of electronic devices to continue developing more powerful computers.

To support their findings, the researchers fabricated nanoscale semiconductor devices in a state-of-the-art gallium arsenide crystal provided to UB by Sandia’s Reno [John L. Reno, Center for Integrated Nanotechnologies at Sandia National Laboratories]. The researchers then subjected the chip to a large voltage, squeezing an electrical current through the nanoconductors. This, in turn, increased the amount of heat circulating through the chip’s nanotransistor.

But instead of degrading the device, the nanotransistor spontaneously transformed itself into a quantum state that was protected from the effect of heating and provided a robust channel of electric current. To help explain, Bird [Jonathan Bird, UB professor of electrical engineering] offered an analogy to Niagara Falls.

“The water, or energy, comes from a source; in this case, the Great Lakes. It’s channeled into a narrow point (the Niagara River) and ultimately flows over Niagara Falls. At the bottom of waterfall is dissipated energy. But unlike the waterfall, this dissipated energy recirculates throughout the chip and changes how heat affects, or in this case doesn’t affect, the network’s operation.”

While this behavior may seem unusual, especially conceptualizing it in terms of water flowing over a waterfall, it is the direct result of the quantum mechanical nature of electronics when viewed on the nanoscale. The current is made up of electrons which spontaneously organize to form a narrow conducting filament through the nanoconductor. It is this filament that is so robust against the effects of heating.

“We’re not actually eliminating the heat, but we’ve managed to stop it from affecting the electrical network. In a way, this is an optimization of the current paradigm,” said Han [J. E. Han, UB Dept. of Physics], who developed the theoretical models which explain the findings.

What an interesting and counter-intuitive approach to managing the heat in our devices.

For those who want more, here’s a link to and citation for the carbon nanotube paper,

Enhanced thermal transport at covalently functionalized carbon nanotube array interfaces by Sumanjeet Kaur, Nachiket Raravikar, Brett A. Helms, Ravi Prasher, & D. Frank Ogletree. Nature Communications 5, Article number: 3082 doi:10.1038/ncomms4082 Published 22 January 2014

This paper is behind a paywall.

Now here’s a link to and a citation for the ‘making it hotter to make it cooler’ paper,

Formation of a protected sub-band for conduction in quantum point contacts under extreme biasing by J. Lee, J. E. Han, S. Xiao, J. Song, J. L. Reno, & J. P. Bird. Nature Nanotechnology (2014) doi:10.1038/nnano.2013.297 Published online 19 January 2014

This paper is behind a paywall although there is an option to preview it for free via ReadCube Access.

Paranoids celebrate! New wireless technology in the body coming soon

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I have a paranoid neighbour who I’m hoping will never hear about this research—thankfully, she doesn’t read blogs—because the idea someone could be monitoring her bodily functions wirelessly would fit in beautifully and likely exacerbate her delusions.

According to the May 31, 2013 news item on ScienceDaily, the idea of creating a ‘body area’ network is not new, the technology the researchers at the University of Buffalo are developing features a new approach to this research,

The military has for decades used sonar for underwater communication.

Now, researchers at the University at Buffalo are developing a miniaturized version of the same technology to be applied inside the human body to treat diseases such as diabetes and heart failure in real time.

The advancement relies on sensors that use ultrasounds — the same inaudible sound waves used by the navy for sonar and doctors for sonograms — to wirelessly share information between medical devices implanted in or worn by people.

“This is a biomedical advancement that could revolutionize the way we care for people suffering from the major diseases of our time,” said Tommaso Melodia, PhD, UB associate professor of electrical engineering.

The University of Buffalo May 31, 2013 news release by Cory Nealon details the project and the approach to developing a ‘proof of concept’ for this theory about ultrasound and wireless communication within the body,

His [Melodia] research, “Towards Ultrasonic Networking for Implantable Biomedical Device,” is supported by a five-year, $449,000 National Science Foundation (NSF) CAREER grant. The CAREER award is the foundation’s most prestigious for young investigators.

Details of Melodia’s work can be found at: http://1.usa.gov/17y2njQ.

…

… most work has focused on linking sensors together via electromagnetic radio frequency waves – the same type used in cellular phones, GPS units and other common wireless devices.

Radio waves can be effective but they have drawbacks such as the heat they generate. Also, because radio waves propagate poorly through skin, muscle and other body tissue, they require relatively large amounts of energy, he said.

Ultrasounds may be a more efficient way to share information, Melodia said, because roughly 65 percent of the body is composed of water. This suggests that medical devices, such as a pacemaker and an instrument that measures blood oxygen levels, could communicate more effectively via ultrasounds compared to radio waves.

“Think of how the Navy uses sonar to communicate between submarines and detect enemy ships,” Melodia said. “It’s the same principle, only applied to ultrasonic sensors that are small enough to work together inside the human body and more effectively help treat diseases.”

Another example involves connecting blood glucose sensors with implantable insulin pumps. The sensors would monitor the blood and regulate, through the pumps, the dosage of insulin as needed in real time.

“We are really just scratching the surface of what’s possible. There are countless potential applications,” he said.

Melodia will use the NSF grant to do more modeling and conduct experiments with ultrasonic, wireless body sensor networks. The grant will support UB PhD student G. Enrico Santagati, who already has contributed significantly to the project, as well as UB undergraduate students.

The research will address issues such as how to:

  • design transmission schemes to accurately relay information between sensors without causing body tissue to overheat
  • design networking protocols specialized for intra-body sensors
  • how to model ultrasonic interference
  • accurately simulate ultrasonic networks
  • design the first existing reconfigurable testbed for experimental evaluation of ultrasonic networks.

Melodia is a member of the Signals, Communications and Networking Research Group in UB’s Department of Electrical Engineering in the School of Engineering and Applied Sciences. The group carries out research in: wireless communications and networking, cognitive radios, extreme environment (i.e., underwater, underground) communications, secure communications, data hiding, information theory and coding, adaptive signal processing, compressed sensing,  multimedia systems, magnetic resonance imaging and radar systems.

Other members of the group include professors Stella N. Batalama, Adly T. Fam, Dimitris A. Pados, Mehrdad Soumekh; associate professors Michael Langberg, Weifeng Su and Leslie Ying; and assistant professors Nicholas Mastronarde, Gesualdo Scutari, Zhi Sun, Josep M. Jornet.

I wonder if this technology, once the bugs have been ironed out, will be appealing to hypochondriacs.

Zimbabwe and its international nanotechnology center, ZINC

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A Sept.24, 2012 news item on Nanowerk provides information about a new nanotechnology center in Zimbabwe,

With 14 percent of Zimbabwe’s population living with HIV/AIDS and tuberculosis as a co-infection, the need for new drugs and new formulations of available treatments is crucial.

To address these issues, two of the University at Buffalo’s [UB] leading research centers, the Institute for Lasers, Photonics and Biophotonics (ILPB), and the New York State Center of Excellence in Bioinformatics and Life Sciences have signed on to launch the Zimbabwe International Nanotechnology Center (ZINC) — a national nanotechnology research program — with the University of Zimbabwe (UZ) and the Chinhoyi University of Technology (CUT).

This collaborative program will initially focus on research in nanomedicine and biosensors at UZ and energy at CUT. ZINC has grown out of the NIH [US National Institute of Health] Fogarty International Center, AIDS International Training and Research Program (AITRP) that was awarded to UB and UZ in 2008 to conduct HIV research training and build research capacity in Zimbabwe and neighboring countries in southern Africa.

I decided to find out more about Zimbabwe and found a map and details in a Wikipedia essay,

Location of Zimbabwe within the African Union (accessed Sept. 24, 2012 from the Wikipedia essay on Zimbabwe)

Zimbabwe (… officially the Republic of Zimbabwe) is a landlocked country located in Southern Africa, between the Zambezi and Limpopo rivers. It is bordered by South Africa to the south, Botswana to the southwest, Zambia and a tip of Namibia to the northwest (making this area a quadripoint) and Mozambique to the east. The capital is Harare. Zimbabwe achieved recognised independence from Britain in April 1980, following a 14-year period as an unrecognised state under the predominantly white minority government of Rhodesia, which unilaterally declared independence in 1965. Rhodesia briefly reconstituted itself as black-majority ruled Zimbabwe Rhodesia in 1979, but this order failed to gain international acceptance.

Zimbabwe has three official languages: English, Shona and Ndebele.

Getting back to Zimbabwe, Alan on the Science Business website posted on Sept. 24, 2012 about ZINC and the partnership (excerpted from the posting),

University at Buffalo in New York and two universities in the southern African nation of Zimbabwe will collaborate on a new nanotechnology research program in pharmacology. University of Zimbabwe in Harare and the Chinhoyi University of Technology in Mashonaland West, working with Buffalo’s Institute for Lasers, Photonics, and Biophotonics, along with New York State Center of Excellence in Bioinformatics and Life Sciences also on the Buffalo campus, will establish the Zimbabwe International Nanotechnology Center (ZINC).

ZINC aims to develop an international research and training capability in nanotechnology that advances the field as contributor to Zimbabwe’s economic growth. The collaboration is expected to focus on research in nanomedicine and biosensors for health care at University of Zimbabwe, while the Chinhoyi University of Technology partnership will conduct research related to energy.

The University of Buffalo Sept. 24, 2012 news release provides more details,

The UB ILPB and TPRC [Translational Pharmacy Research Core] collaboration recognized that the fields of pharmacology and therapeutics have increasingly developed links with emerging areas within the field of nanosciences in an attempt to develop tissue/organ targeted strategies that will lead to disease treatment and eradication. Research teams will focus on emerging technologies, initially focused in nanobiotechnology and nanomedicine for health care.

“Developing nanoformulations for HIV and tuberculosis diagnostics and therapeutics, as well as new tuberculosis drug development, are just a few of the innovative strategies to address these co-infections that this research collaboration can provide,” said Morse [Gene D. Morse, PharmD, Professor of Pharmacy Practice, associate director of the New York State Center of Excellence in Bioinformatics and Life Sciences and director of the Translational Pharmacy Research Core {TPRC}].

“In addition, the development of new nanotechnology-related products will jumpstart the economy and foster new economic initiatives in Zimbabwe that will yield additional private-public partnerships.”

Morse says that the current plans for a “Center of Excellence” in clinical and translational pharmacology in Harare at UZ will create a central hub in Africa, not just for Zimbabwe but for other countries to gain new training and capacity building in many exciting aspects of nanotechnology as well.

Good luck to ZINC and its partners!