Category Archives: medicine

‘Smart’ fabric that’s bony

Researchers at Australia’s University of New South of Wales (UNSW) have devised a means of ‘weaving’ a material that mimics the bone tissue, periosteum according to a Jan. 11, 2017 news item on ScienceDaily,

For the first time, UNSW [University of New South Wales] biomedical engineers have woven a ‘smart’ fabric that mimics the sophisticated and complex properties of one nature’s ingenious materials, the bone tissue periosteum.

Having achieved proof of concept, the researchers are now ready to produce fabric prototypes for a range of advanced functional materials that could transform the medical, safety and transport sectors. Patents for the innovation are pending in Australia, the United States and Europe.

Potential future applications range from protective suits that stiffen under high impact for skiers, racing-car drivers and astronauts, through to ‘intelligent’ compression bandages for deep-vein thrombosis that respond to the wearer’s movement and safer steel-belt radial tyres.

A Jan. 11, 2017 UNSW press release on EurekAlert, which originated the news item, expands on the theme,

Many animal and plant tissues exhibit ‘smart’ and adaptive properties. One such material is the periosteum, a soft tissue sleeve that envelops most bony surfaces in the body. The complex arrangement of collagen, elastin and other structural proteins gives periosteum amazing resilience and provides bones with added strength under high impact loads.

Until now, a lack of scalable ‘bottom-up’ approaches by researchers has stymied their ability to use smart tissues to create advanced functional materials.

UNSW’s Paul Trainor Chair of Biomedical Engineering, Professor Melissa Knothe Tate, said her team had for the first time mapped the complex tissue architectures of the periosteum, visualised them in 3D on a computer, scaled up the key components and produced prototypes using weaving loom technology.

“The result is a series of textile swatch prototypes that mimic periosteum’s smart stress-strain properties. We have also demonstrated the feasibility of using this technique to test other fibres to produce a whole range of new textiles,” Professor Knothe Tate said.

In order to understand the functional capacity of the periosteum, the team used an incredibly high fidelity imaging system to investigate and map its architecture.

“We then tested the feasibility of rendering periosteum’s natural tissue weaves using computer-aided design software,” Professor Knothe Tate said.

The computer modelling allowed the researchers to scale up nature’s architectural patterns to weave periosteum-inspired, multidimensional fabrics using a state-of-the-art computer-controlled jacquard loom. The loom is known as the original rudimentary computer, first unveiled in 1801.

“The challenge with using collagen and elastin is their fibres, that are too small to fit into the loom. So we used elastic material that mimics elastin and silk that mimics collagen,” Professor Knothe Tate said.

In a first test of the scaled-up tissue weaving concept, a series of textile swatch prototypes were woven, using specific combinations of collagen and elastin in a twill pattern designed to mirror periosteum’s weave. Mechanical testing of the swatches showed they exhibited similar properties found in periosteum’s natural collagen and elastin weave.

First author and biomedical engineering PhD candidate, Joanna Ng, said the technique had significant implications for the development of next-generation advanced materials and mechanically functional textiles.

While the materials produced by the jacquard loom have potential manufacturing applications – one tyremaker believes a titanium weave could spawn a new generation of thinner, stronger and safer steel-belt radials – the UNSW team is ultimately focused on the machine’s human potential.

“Our longer term goal is to weave biological tissues – essentially human body parts – in the lab to replace and repair our failing joints that reflect the biology, architecture and mechanical properties of the periosteum,” Ms Ng said.

An NHMRC development grant received in November [2016] will allow the team to take its research to the next phase. The researchers will work with the Cleveland Clinic and the University of Sydney’s Professor Tony Weiss to develop and commercialise prototype bone implants for pre-clinical research, using the ‘smart’ technology, within three years.

In searching for more information about this work, I found a Winter 2015 article (PDF; pp. 8-11) by Amy Coopes and Steve Offner for UNSW Magazine about Knothe Tate and her work (Note: In Australia, winter would be what we in the Northern Hemisphere consider summer),

Tucked away in a small room in UNSW’s Graduate School of Biomedical Engineering sits a 19th century–era weaver’s wooden loom. Operated by punch cards and hooks, the machine was the first rudimentary computer when it was unveiled in 1801. While on the surface it looks like a standard Jacquard loom, it has been enhanced with motherboards integrated into each of the loom’s five hook modules and connected to a computer. This state-of-the-art technology means complex algorithms control each of the 5,000 feed-in fibres with incredible precision.

That capacity means the loom can weave with an extraordinary variety of substances, from glass and titanium to rayon and silk, a development that has attracted industry attention around the world.

The interest lies in the natural advantage woven materials have over other manufactured substances. Instead of manipulating material to create new shades or hues as in traditional weaving, the fabrics’ mechanical properties can be modulated, to be stiff at one end, for example, and more flexible at the other.

“Instead of a pattern of colours we get a pattern of mechanical properties,” says Melissa Knothe Tate, UNSW’s Paul Trainor Chair of Biomedical Engineering. “Think of a rope; it’s uniquely good in tension and in bending. Weaving is naturally strong in that way.”

The interface of mechanics and physiology is the focus of Knothe Tate’s work. In March [2015], she travelled to the United States to present another aspect of her work at a meeting of the international Orthopedic Research Society in Las Vegas. That project – which has been dubbed “Google Maps for the body” – explores the interaction between cells and their environment in osteoporosis and other degenerative musculoskeletal conditions such as osteoarthritis.

Using previously top-secret semiconductor technology developed by optics giant Zeiss, and the same approach used by Google Maps to locate users with pinpoint accuracy, Knothe Tate and her team have created “zoomable” anatomical maps from the scale of a human joint down to a single cell.

She has also spearheaded a groundbreaking partnership that includes the Cleveland Clinic, and Brown and Stanford universities to help crunch terabytes of data gathered from human hip studies – all processed with the Google technology. Analysis that once took 25 years can now be done in a matter of weeks, bringing researchers ever closer to a set of laws that govern biological behaviour. [p. 9]

I gather she was recruited from the US to work at the University of New South Wales and this article was to highlight why they recruited her and to promote the university’s biomedical engineering department, which she chairs.

Getting back to 2017, here’s a link to and citation for the paper,

Scale-up of nature’s tissue weaving algorithms to engineer advanced functional materials by Joanna L. Ng, Lillian E. Knothe, Renee M. Whan, Ulf Knothe & Melissa L. Knothe Tate. Scientific Reports 7, Article number: 40396 (2017) doi:10.1038/srep40396 Published online: 11 January 2017

This paper is open access.

One final comment, that’s a lot of people (three out of five) with the last name Knothe in the author’s list for the paper.

Eliminate cold storage for diagnostic tests?

There’s a nanoparticle coating that could eliminate the need for cold storage and/or refrigeration for diagnostic testing according to a Jan. 4, 2017 news item on Nanowerk,

Many diagnostic tests use antibodies to help confirm a myriad of medical conditions, from Zika infections to heart ailments and even some forms of cancer. Antibodies capture and help detect proteins, enzymes, bacteria and viruses present in injuries and illnesses, and must be kept at a constant low temperature to ensure their viability — often requiring refrigeration powered by electricity. This can make diagnostic testing in underdeveloped countries, disaster or remote areas and even war zones extremely expensive and difficult.

A team of engineers from Washington University in St. Louis and Air Force Research Laboratory have discovered an inexpensive work-around: a protective coating that could completely eliminate the need for cold storage and change the scope of medical diagnostic testing in places where it’s often needed the most.

“In many developing countries, electricity is not guaranteed,” said Srikanth Singamaneni, associate professor of mechanical engineering and materials science in Engineering & Applied Science at Washington University in St. Louis.

“So how do we best get them medical diagnostics? We did not know how to solve this problem previously.”

A Jan. 4, 2016 Washington University in St. Louis news release by Erika Ebsworth-Goold, which originated the news item, describes how previous research helped lead to a solution,

Singamaneni’s team previously used tiny gold nanorods in bio-diagnostic research, measuring changes in their optical properties to quantify protein concentrations in bio-fluids: the higher a concentration, the higher the likelihood of injury or disease.

In this new research, published in Advanced Materials, Singamaneni worked with faculty from Washington University’s School of Medicine and researchers from the Air Force Research Lab to grow metal-organic frameworks (MOFs) around antibodies attached to gold nanorods. The crystalline MOFs formed a protective layer around the antibodies and prevented them from losing activity at elevated temperatures. The protective effect lasted for a week even when the samples were stored at 60°C.

“This technology would allow point-of-care screening for biomarkers of diseases in urban and rural clinic settings where immediate patient follow-up is critical to treatment and wellbeing,” said Dr. Jeremiah J. Morrissey, professor of anesthesiology, Division of Clinical and Translational Research, Washington University School of Medicine and a co-author on the paper.

“On the spot testing eliminates the time lag in sending blood/urine samples to a central lab for testing and in tracking down patients to discuss test results. In addition, it may reduce costs associated with refrigerated shipping and storage.”

The protective MOF layer can be quickly and easily removed from the antibodies with a simple rinse of slightly acidic water, making a diagnostic strip or paper immediately ready to use. Singamaneni says this proof of concept research is now ready to be tested for clinical samples.

“As long as you are using antibodies, you can use this technology,” said Congzhou Wang, a postdoctoral researcher in Singamaneni’s lab and the paper’s lead author. “In bio-diagnostics from here on out, we will no longer need refrigeration.”

“The MOF-based protection of antibodies on sensor surfaces is ideal for preserving biorecognition abilities of sensors that are designed for deployment in the battlefield,” said Dr. Rajesh R. Naik, 711th Human Performance Wing of the Air Force Research Laboratory, Wright-Patterson Air Force Base, and a co-corresponding author of the paper.  “It provides remarkable stability and extremely easy to remove right before use.”

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

Metal-Organic Framework as a Protective Coating for Biodiagnostic Chips by Congzhou Wang, Sirimuvva Tadepalli, Jingyi Luan, Keng-Ku Liu, Jeremiah J. Morrissey, Evan D. Kharasch, Rajesh R. Naik, and Srikanth Singamaneni. Advanced Materials DOI: 10.1002/adma.201604433 Version of Record online: 7 DEC 2016

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

This paper is behind a paywall.

A final observation, there’s at least one other project aimed at eliminating the need for refrigeration in the field of medical applications and that’s the nanopatch, a replacement for syringes used for liquid medications and vaccines (see my Dec. 16, 2016 posting for a description).

High speed fabrication of adhesive and flexible electronics

For a university that celebrated its opening in Sept. 2009 (mentioned in my Sept. 24, 2009 posting; scroll down about 40% of the way; look for a reference to the House of Wisdom), the King Abdullah University of Science and Technology (KAUST) has made some impressive announcements including this one in a Jan. 3, 2017 press release on EurekAlert,

The healthcare industry forecasts that our wellbeing in the future will be monitored by wearable wirelessly networked sensors. Manufacturing such devices could become much easier with decal electronics. A KAUST-developed process prints these high-performance silicon-based computers on to soft, sticker-like surfaces that can be attached anywhere1.

Fitting electronics on to the asymmetric contours of human bodies demands a re-think of traditional computer fabrications. One approach is to print circuit patterns on to materials such as polymers or cellulose using liquid ink made from conductive molecules. This technique enables high-speed roll-to-roll assembly of devices and packaging at low costs.

Flexible printed circuits, however, require conventional silicon components to handle applications such as digitizing analog signals. Such rigid modules can create uncomfortable hot spots on the body and increase device weight.

For the past four years, Muhammad Hussain and his team from the KAUST Computer, Electrical and Mathematical Science and Engineering Division have investigated ways to improve the flexibility of silicon materials while retaining their performance.

“We are trying to integrate all device components–sensors, data management electronics, battery, antenna–into a completely compliant system,” explained Hussain. “However, packaging these discrete modules on to soft substrates is extremely difficult.”

Searching for potential electronic skin applications, the researchers developed a sensor containing narrow strips of aluminum foil that changes conductivity at different bending states.

The devices, which could monitor a patient’s breathing patterns or activity levels, feature high-mobility zinc oxide nanotransistors on silicon wafers thinned down lithographically to microscale dimensions for maximum flexibility. Using three-dimensional (3-D) printing techniques, the team encapsulated the silicon chips and foils into a polymer film backed by an adhesive layer.

Hussain and his colleagues found a way to make the e-sticker sensors work in multiple applications. They used inkjet printing to write conductive wiring patterns on to different surfaces, such as paper or clothing. Custom-printed decals were then attached or re-adhered to each location.

“You can place a pressure-sensing decal on a tire to monitor it while driving and then peel it off and place it on your mattress to learn your sleeping patterns,” said Galo Torres Sevilla, first author of the findings and a KAUST Ph.D. graduate.

The robust performance and high-throughput manufacturing potential of decal electronics could launch a number of innovative sensor deployments, noted Hussain.

“I believe that electronics have to be democratized–simple to learn and easy to implement. Electronic decals are a right step in that direction,” Hussain said.

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

Decal Electronics: Printable Packaged with 3D Printing High-Performance Flexible CMOS Electronic Systems by Galo A. Torres Sevilla, Marlon D. Cordero, Joanna M. Nassar, Amir N. Hanna, Arwa T. Kutbee, Arpys Arevalo, and Muhammad M. Hussain. Advanced Materials Technologies DOI: 10.1002/admt.201600175 Version of Record online: 13 OCT 2016

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

This paper is behind a paywall.

‘Brewing up’ conductive inks for printable electronics

Scientists from Duke University aren’t exactly ‘brewing’ or ‘cooking up’ the inks but they do come close according to a Jan. 3, 2017 news item on ScienceDaily,

By suspending tiny metal nanoparticles in liquids, Duke University scientists are brewing up conductive ink-jet printer “inks” to print inexpensive, customizable circuit patterns on just about any surface.

A Jan. 3, 2017 Duke University news release (also on EurekAlert), which originated the news item, explains why this technique could lead to more accessible printed electronics,

Printed electronics, which are already being used on a wide scale in devices such as the anti-theft radio frequency identification (RFID) tags you might find on the back of new DVDs, currently have one major drawback: for the circuits to work, they first have to be heated to melt all the nanoparticles together into a single conductive wire, making it impossible to print circuits on inexpensive plastics or paper.

A new study by Duke researchers shows that tweaking the shape of the nanoparticles in the ink might just eliminate the need for heat.

By comparing the conductivity of films made from different shapes of silver nanostructures, the researchers found that electrons zip through films made of silver nanowires much easier than films made from other shapes, like nanospheres or microflakes. In fact, electrons flowed so easily through the nanowire films that they could function in printed circuits without the need to melt them all together.

“The nanowires had a 4,000 times higher conductivity than the more commonly used silver nanoparticles that you would find in printed antennas for RFID tags,” said Benjamin Wiley, assistant professor of chemistry at Duke. “So if you use nanowires, then you don’t have to heat the printed circuits up to such high temperature and you can use cheaper plastics or paper.”

“There is really nothing else I can think of besides these silver nanowires that you can just print and it’s simply conductive, without any post-processing,” Wiley added.

These types of printed electronics could have applications far beyond smart packaging; researchers envision using the technology to make solar cells, printed displays, LEDS, touchscreens, amplifiers, batteries and even some implantable bio-electronic devices. The results appeared online Dec. 16 [2016] in ACS Applied Materials and Interfaces.

Silver has become a go-to material for making printed electronics, Wiley said, and a number of studies have recently appeared measuring the conductivity of films with different shapes of silver nanostructures. However, experimental variations make direct comparisons between the shapes difficult, and few reports have linked the conductivity of the films to the total mass of silver used, an important factor when working with a costly material.

“We wanted to eliminate any extra materials from the inks and simply hone in on the amount of silver in the films and the contacts between the nanostructures as the only source of variability,” said Ian Stewart, a recent graduate student in Wiley’s lab and first author on the ACS paper.

Stewart used known recipes to cook up silver nanostructures with different shapes, including nanoparticles, microflakes, and short and long nanowires, and mixed these nanostructures with distilled water to make simple “inks.” He then invented a quick and easy way to make thin films using equipment available in just about any lab — glass slides and double-sided tape.

“We used a hole punch to cut out wells from double-sided tape and stuck these to glass slides,” Stewart said. By adding a precise volume of ink into each tape “well” and then heating the wells — either to relatively low temperature to simply evaporate the water or to higher temperatures to begin melting the structures together — he created a variety of films to test.

The team say they weren’t surprised that the long nanowire films had the highest conductivity. Electrons usually flow easily through individual nanostructures but get stuck when they have to jump from one structure to the next, Wiley explained, and long nanowires greatly reduce the number of times the electrons have to make this “jump”.

But they were surprised at just how drastic the change was. “The resistivity of the long silver nanowire films is several orders of magnitude lower than silver nanoparticles and only 10 times greater than pure silver,” Stewart said.

The team is now experimenting with using aerosol jets to print silver nanowire inks in usable circuits. Wiley says they also want to explore whether silver-coated copper nanowires, which are significantly cheaper to produce than pure silver nanowires, will give the same effect.

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

Effect of Morphology on the Electrical Resistivity of Silver Nanostructure Films by Ian E. Stewart, Myung Jun Kim, and Benjamin J. Wiley. ACS Appl. Mater. Interfaces, Article ASAP
DOI: 10.1021/acsami.6b12289 Publication Date (Web): December 16, 2016

Copyright © 2016 American Chemical Society

This paper is behind a paywall but there is an image of the silver nanowires, which is not exactly compensation but is interesting,

Caption: Duke University chemists have found that silver nanowire films like these conduct electricity well enough to form functioning circuits without applying high temperatures, enabling printable electronics on heat-sensitive materials like paper or plastic.
Credit: Ian Stewart and Benjamin Wiley

Preprogramming silk protein-based materials

A new material based on silk proteins has been developed at Tufts University (US), according to a Dec. 26, 2016 news item on ScienceDaily,

Tufts University engineers have created a new format of solids made from silk protein that can be preprogrammed with biological, chemical, or optical functions, such as mechanical components that change color with strain, deliver drugs, or respond to light, according to a paper published online this week [Dec. 26 -30, 2016] in Proceedings of the National Academy of Sciences (PNAS).

Caption: This image shows examples of engineered 3-D silk constructs. Credit: Silklab, Department of Biomedical Engineering, School of Engineering, Tufts University

A Dec. 26, 2016 Tufts University news release (also on EurekAlert), which originated the news item, describes the research in more detail,

Using a water-based fabrication method based on protein self-assembly, the researchers generated three-dimensional bulk materials out of silk fibroin, the protein that gives silk its durability. Then they manipulated the bulk materials with water-soluble molecules to create multiple solid forms, from the nano- to the micro-scale, that have embedded, pre-designed functions.

For example, the researchers created a surgical pin that changes color as it nears its mechanical limits and is about to fail, functional screws that can be heated on demand in response to infrared light, and a biocompatible component that enables the sustained release of bioactive agents, such as enzymes.

Although more research is needed, additional applications could include new mechanical components for orthopedics that can be embedded with growth factors or enzymes, a surgical screw that changes color as it reaches its torque limits, hardware such as nuts and bolts that sense and report on the environmental conditions of their surroundings, or household goods that can be remolded or reshaped.

Silk’s unique crystalline structure makes it one of nature’s toughest materials. Fibroin, an insoluble protein found in silk, has a remarkable ability to protect other materials while being fully biocompatible and biodegradable.

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

Programming function into mechanical forms by directed assembly of silk bulk materials by Benedetto Marelli, Nereus Patel, Thomas Duggan, Giovanni Perotto, Elijah Shirman, Chunmei Li, David L. Kaplan, and Fiorenzo G. Omenetto. PNAS 10.1073/pnas.1612063114 December 27, 2016

This paper is behind a paywall.

Bionic pancreas tested at home

This news about a bionic pancreas must be exciting for diabetics as it would eliminate the need for constant blood sugar testing throughout the day. From a Dec. 19, 2016 Massachusetts General Hospital news release (also on EurekAlert), Note: Links have been removed,

The bionic pancreas system developed by Boston University (BU) investigators proved better than either conventional or sensor-augmented insulin pump therapy at managing blood sugar levels in patients with type 1 diabetes living at home, with no restrictions, over 11 days. The report of a clinical trial led by a Massachusetts General Hospital (MGH) physician is receiving advance online publication in The Lancet.

“For study participants living at home without limitations on their activity and diet, the bionic pancreas successfully reduced average blood glucose, while at the same time decreasing the risk of hypoglycemia,” says Steven Russell, MD, PhD, of the MGH Diabetes Unit. “This system requires no information other than the patient’s body weight to start, so it will require much less time and effort by health care providers to initiate treatment. And since no carbohydrate counting is required, it significantly reduces the burden on patients associated with diabetes management.”

Developed by Edward Damiano, PhD, and Firas El-Khatib, PhD, of the BU Department of Biomedical Engineering, the bionic pancreas controls patients’ blood sugar with both insulin and glucagon, a hormone that increases glucose levels. After a 2010 clinical trial confirmed that the original version of the device could maintain near-normal blood sugar levels for more than 24 hours in adult patients, two follow-up trials – reported in a 2014 New England Journal of Medicine paper – showed that an updated version of the system successfully controlled blood sugar levels in adults and adolescents for five days.  Another follow-up trial published in The Lancet Diabetes and Endocrinology in 2016  showed it could do the same for children as young as 6 years of age.

While minimal restrictions were placed on participants in the 2014 trials, participants in both spent nights in controlled settings and were accompanied at all times by either a nurse for the adult trial or remained in a diabetes camp for the adolescent and pre-adolescent trials. Participants in the current trial had no such restrictions placed upon them, as they were able to pursue normal activities at home or at work with no imposed limitations on diet or exercise. Patients needed to live within a 30-minute drive of one of the trial sites – MGH, the University of Massachusetts Medical School, Stanford University, and the University of North Carolina at Chapel Hill – and needed to designate a contact person who lived with them and could be contacted by study staff, if necessary.

The bionic pancreas system – the same as that used in the 2014 studies – consisted of a smartphone (iPhone 4S) that could wirelessly communicate with two pumps delivering either insulin or glucagon. Every five minutes the smartphone received a reading from an attached continuous glucose monitor, which was used to calculate and administer a dose of either insulin or glucagon. The algorighms controlling the system were updated for the current trial to better respond to blood sugar variations.

While the device allows participants to enter information about each upcoming meal into a smartphone app, allowing the system to deliver an anticipatory insulin dose, such entries were optional in the current trial. If participants’ blood sugar dropped to dangerous levels or if the monitor or one of the pumps was disconnected for more than 15 minutes, the system would alerted study staff, allowing them to check with the participants or their contact persons.

Study participants were adults who had been diagnosed with type 1 diabetes for a year or more and had used an insulin pump to manage their care for at least six months. Each of 39 participants that finished the study completed two 11-day study periods, one using the bionic pancreas and one using their usual insulin pump and any continous glucose monitor they had been using. In addition to the automated monitoring of glucose levels and administered doses of insulin or glucagon, participants completed daily surveys regarding any episodes of symptomatic hypoglycemia, carbohydrates consumed to treat those episodes, and any episodes of nausea.

On days when participants were on the bionic pancreas, their average blood glucose levels were significantly lower – 141 mg/dl versus 162 mg/dl – than when on their standard treatment. Blood sugar levels were at levels indicating hypoglycemia (less than 60 mg/dl) for 0.6 percent of the time when participants were on the bionic pancreas, versus 1.9 percent of the time on standard treatment. Participants reported fewer episodes of symptomatic hypoglycemia while on the bionic pancreas, and no episodes of severe hypoglycemia were associated with the system.

The system performed even better during the overnight period, when the risk of hypoglycemia is particularly concerning. “Patients with type 1 diabetes worry about developing hypoglycemia when they are sleeping and tend to let their blood sugar run high at night to reduce that risk,” explains Russell, an assistant professor of Medicine at Harvard Medical School. “Our study showed that the bionic pancreas reduced the risk of overnight hypoglycemia to almost nothing without raising the average glucose level. In fact the improvement in average overnight glucose was greater than the improvement in average glucose over the full 24-hour period.”

Damiano, whose work on this project is inspired by his own 17-year-old son’s type 1 diabetes, adds, “The availability of the bionic pancreas would dramatically change the life of people with diabetes by reducing average glucose levels – thereby reducing the risk of diabetes complications – reducing the risk of hypoglycemia, which is a constant fear of patients and their families, and reducing the emotional burden of managing type 1 diabetes.” A co-author of the Lancet report, Damiano is a professor of Biomedical Engineering at Boston University.

The BU patents covering the bionic pancreas have been licensed to Beta Bionics, a startup company co-founded by Damiano and El-Khatib. The company’s latest version of the bionic pancreas, called the iLet, integrates all components into a single unit, which will be tested in future clinical trials. People interested in participating in upcoming trials may contact Russell’s team at the MGH Diabetes Research Center in care of Llazar Cuko ( ).

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

Home use of a bihormonal bionic pancreas versus insulin pump therapy in adults with type 1 diabetes: a multicentre randomised crossover trial by Firas H El-Khatib, Courtney Balliro, Mallory A Hillard, Kendra L Magyar, Laya Ekhlaspour, Manasi Sinha, Debbie Mondesir, Aryan Esmaeili, Celia Hartigan, Michael J Thompson, Samir Malkani, J Paul Lock, David M Harlan, Paula Clinton, Eliana Frank, Darrell M Wilson, Daniel DeSalvo, Lisa Norlander, Trang Ly, Bruce A Buckingham, Jamie Diner, Milana Dezube, Laura A Young, April Goley, M Sue Kirkman, John B Buse, Hui Zheng, Rajendranath R Selagamsetty, Edward R Damiano, Steven J Russell. Lancet DOI:  Published: 19 December 2016

This paper is behind a paywall.

You can find out more about Beta Bionics and iLet here.

Sniffing out disease (Na-Nose)

The ‘artificial nose’ is not a newcomer to this blog. The most recent post prior to this is a March 15, 2016 piece about Disney using an artificial nose for art conservation. Today’s (Jan. 9, 2016) piece concerns itself with work from Israel and ‘sniffing out’ disease, according to a Dec. 30, 2016 news item in Sputnik News,

A team from the Israel Institute of Technology has developed a device that from a single breath can identify diseases such as multiple forms of cancer, Parkinson’s disease, and multiple sclerosis. While the machine is still in the experimental stages, it has a high degree of promise for use in non-invasive diagnoses of serious illnesses.

The international team demonstrated that a medical theory first proposed by the Greek physician Hippocrates some 2400 years ago is true, certain diseases leave a “breathprint” on the exhalations of those afflicted. The researchers created a prototype for a machine that can pick up on those diseases using the outgoing breath of a patient. The machine, called the Na-Nose, tests breath samples for the presence of trace amounts of chemicals that are indicative of 17 different illnesses.

A Dec. 22, 2016 Technion Israel Institute of Technology press release offers more detail about the work,

An international team of 56 researchers in five countries has confirmed a hypothesis first proposed by the ancient Greeks – that different diseases are characterized by different “chemical signatures” identifiable in breath samples. …

Diagnostic techniques based on breath samples have been demonstrated in the past, but until now, there has not been scientific proof of the hypothesis that different and unrelated diseases are characterized by distinct chemical breath signatures. And technologies developed to date for this type of diagnosis have been limited to detecting a small number of clinical disorders, without differentiation between unrelated diseases.

The study of more than 1,400 patients included 17 different and unrelated diseases: lung cancer, colorectal cancer, head and neck cancer, ovarian cancer, bladder cancer, prostate cancer, kidney cancer, stomach cancer, Crohn’s disease, ulcerative colitis, irritable bowel syndrome, Parkinson’s disease (two types), multiple sclerosis, pulmonary hypertension, preeclampsia and chronic kidney disease. Samples were collected between January 2011 and June 2014 from in 14 departments at 9 medical centers in 5 countries: Israel, France, the USA, Latvia and China.

The researchers tested the chemical composition of the breath samples using an accepted analytical method (mass spectrometry), which enabled accurate quantitative detection of the chemical compounds they contained. 13 chemical components were identified, in different compositions, in all 17 of the diseases.

According to Prof. Haick, “each of these diseases is characterized by a unique fingerprint, meaning a different composition of these 13 chemical components.  Just as each of us has a unique fingerprint that distinguishes us from others, each disease has a chemical signature that distinguishes it from other diseases and from a normal state of health. These odor signatures are what enables us to identify the diseases using the technology that we developed.”

With a new technology called “artificially intelligent nanoarray,” developed by Prof. Haick, the researchers were able to corroborate the clinical efficacy of the diagnostic technology. The array enables fast and inexpensive diagnosis and classification of diseases, based on “smelling” the patient’s breath, and using artificial intelligence to analyze the data obtained from the sensors. Some of the sensors are based on layers of gold nanoscale particles and others contain a random network of carbon nanotubes coated with an organic layer for sensing and identification purposes.

The study also assessed the efficiency of the artificially intelligent nanoarray in detecting and classifying various diseases using breath signatures. To verify the reliability of the system, the team also examined the effect of various factors (such as gender, age, smoking habits and geographic location) on the sample composition, and found their effect to be negligible, and without impairment on the array’s sensitivity.

“Each of the sensors responds to a wide range of exhalation components,” explain Prof. Haick and his previous Ph.D student, Dr. Morad Nakhleh, “and integration of the information provides detailed data about the unique breath signatures characteristic of the various diseases. Our system has detected and classified various diseases with an average accuracy of 86%.

This is a new and promising direction for diagnosis and classification of diseases, which is characterized not only by considerable accuracy but also by low cost, low electricity consumption, miniaturization, comfort and the possibility of repeating the test easily.”

“Breath is an excellent raw material for diagnosis,” said Prof. Haick. “It is available without the need for invasive and unpleasant procedures, it’s not dangerous, and you can sample it again and again if necessary.”

Here’s a schematic of the study, which the researchers have made available,

Diagram: A schematic view of the study. Two breath samples were taken from each subject, one was sent for chemical mapping using mass spectrometry, and the other was analyzed in the new system, which produced a clinical diagnosis based on the chemical fingerprint of the breath sample. Courtesy: Tech;nion

There is also a video, which covers much of the same ground as the press release but also includes information about the possible use of the Na-Nose technology in the European Union’s SniffPhone project,

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

Diagnosis and Classification of 17 Diseases from 1404 Subjects via Pattern Analysis of Exhaled Molecules by Morad K. Nakhleh, Haitham Amal, Raneen Jeries, Yoav Y. Broza, Manal Aboud, Alaa Gharra, Hodaya Ivgi, Salam Khatib, Shifaa Badarneh, Lior Har-Shai, Lea Glass-Marmor, Izabella Lejbkowicz, Ariel Miller, Samih Badarny, Raz Winer, John Finberg, Sylvia Cohen-Kaminsky, Frédéric Perros, David Montani, Barbara Girerd, Gilles Garcia, Gérald Simonneau, Farid Nakhoul, Shira Baram, Raed Salim, Marwan Hakim, Maayan Gruber, Ohad Ronen, Tal Marshak, Ilana Doweck, Ofer Nativ, Zaher Bahouth, Da-you Shi, Wei Zhang, Qing-ling Hua, Yue-yin Pan, Li Tao, Hu Liu, Amir Karban, Eduard Koifman, Tova Rainis, Roberts Skapars, Armands Sivins, Guntis Ancans, Inta Liepniece-Karele, Ilze Kikuste, Ieva Lasina, Ivars Tolmanis, Douglas Johnson, Stuart Z. Millstone, Jennifer Fulton, John W. Wells, Larry H. Wilf, Marc Humbert, Marcis Leja, Nir Peled, and Hossam Haick. ACS Nano, Article ASAP DOI: 10.1021/acsnano.6b04930 Publication Date (Web): December 21, 2016

Copyright © 2017 American Chemical Society

This paper appears to be open access.

As for SniffPhone, they’re hoping that Na-Nose or something like it will allow them to modify smartphones in a way that will allow diseases to be detected.

I can’t help wondering who will own the data if your smartphone detects a disease. If you think that’s an idle question, here’s an excerpt from Sue Halpern’s Dec. 22, 2016 review of two books (“Weapons of Math Destruction: How Big Data Increases Inequality and Threatens Democracy” by Cathy O’Neil and “Virtual Competition: The Promise and Perils of the Algorithm-Driven Economy” by Ariel Ezrachi and Maurice E. Stucke) for the New York Times Review of Books,

We give our data away. We give it away in drips and drops, not thinking that data brokers will collect it and sell it, let alone that it will be used against us. There are now private, unregulated DNA databases culled, in part, from DNA samples people supply to genealogical websites in pursuit of their ancestry. These samples are available online to be compared with crime scene DNA without a warrant or court order. (Police are also amassing their own DNA databases by swabbing cheeks during routine stops.) In the estimation of the Electronic Frontier Foundation, this will make it more likely that people will be implicated in crimes they did not commit.

Or consider the data from fitness trackers, like Fitbit. As reported in The Intercept:

During a 2013 FTC panel on “Connected Health and Fitness,” University of Colorado law professor Scott Peppet said, “I can paint an incredibly detailed and rich picture of who you are based on your Fitbit data,” adding, “That data is so high quality that I can do things like price insurance premiums or I could probably evaluate your credit score incredibly accurately.”

Halpern’s piece is well worth reading in its entirety.

Nanoparticle ‘caterpillars’ and immune system ‘crows’

This University of Colorado work fits in nicely with other efforts to ensure that nanoparticle medical delivery systems get to their destinations. From a Dec. 19, 2016 news item on,

In the lab, doctors can attach chemotherapy to nanoparticles that target tumors, and can use nanoparticles to enhance imaging with MRI, PET and CT scans. Unfortunately, nanoparticles look a lot like pathogens – introducing nanoparticles to the human body can lead to immune system activation in which, at best, nanoparticles are cleared before accomplishing their purpose, and at worst, the onset of dangerous allergic reaction. A University of Colorado Cancer Center paper published today [Dec. 19, 2016] in the journal Nature Nanotechnology details how the immune system recognizes nanoparticles, potentially paving the way to counteract or avoid this detection.

Specifically, the study worked with dextran-coated iron oxide nanoparticles, a promising and versatile class of particles used as drug-delivery vehicles and MRI contrast enhancers in many studies. As their name implies, the particles are tiny flecks of iron oxide encrusted with sugar chains.

“We used several sophisticated microscopy approaches to understand that the particles basically look like caterpillars,” says Dmitri Simberg, PhD, investigator at the CU Cancer Center and assistant professor in the Skaggs School of Pharmacy and Pharmaceutical Sciences, the paper’s senior author.

The comparison is striking: the iron oxide particle is the caterpillar’s body, which is surrounded by fine hairs of dextran.

Caption: University of Colorado Cancer Study shows how nanoparticles activate the complement system, potentially paving the way for expanded use of these technologies.
Credit: University of Colorado Cancer Center

A Dec. 19, 2016 University of Colorado news release on EurekAlert, which originated the news item, describes the work in more detail,

If Simberg’s dextran-coated iron oxide nanoparticles are caterpillars, then the immune system is a fat crow that would eat them – that is, if it can find them. In fact, the immune system has evolved for exactly this purpose – to find and “eat” foreign particles – and rather than one homogenous entity is actually composed of a handful of interrelated systems, each specialized to counteract a specific form of invading particle.

Simberg’s previous work shows that it is the immune subcomponent called the complement system that most challenges nanoparticles. Basically, the complement system is a group of just over 30 proteins that circulate through the blood and attach to invading particles and pathogens. In humans, complement system activation requires that three proteins come together on a particle -C3b, Bb and properdin – which form a stable complex called C3-convertase.

“The whole complement system activation starts with the assembly of C3-convertase,” Simberg says. “In this paper, we ask the question of how the complement proteins actually recognize the nanoparticle surface. How is this whole reaction triggered?”

First, it was clear that the dextran coating that was supposed to protect the nanoparticles from human complement attack was not doing its job. Simberg and colleagues could see complement proteins literally invade the barrier of dextran hairs.

“Electron microscopy images show protein getting inside the particle to touch the iron oxide core,” Simberg says.

In fact, as long as the nanoparticle coating allowed the nanoparticle to absorb proteins from blood, the C3 convertase was assembled and activated on these proteins. The composition of the coating was irrelevant – if any blood protein was able to bind to nanoparticles, it always led to complement activation. Moreover, Simberg and colleagues also showed that complement system activation is a dynamic and ongoing process – blood proteins and C3 convertase constantly dissociate from nanoparticles, and new proteins and C3 convertases bind to the particles, continuing the cascade of immune system activation. The group also demonstrated that this dynamic assembly of complement proteins occurs not only in the test tubes but also in living organisms as particles circulate in blood.

Simberg suggests that the work points to challenges and three possible strategies to avoid complement system activation by nanoparticles: “First, we could try to change the nanoparticle coating so that it can’t absorb proteins, which is a difficult task; second, we could better understand the composition of proteins absorbed from blood on the particle surface that allow it to bind complement proteins; and third, there are natural inhibitors of complement activation – for example blood Factor H – but in the context of nanoparticles, it’s not strong enough to stop complement activation. Perhaps we could get nanoparticles to attract more Factor H to decrease this activation.”

At one point, the concept of nanomedicine seemed as if it would be simple – engineers and chemists would make a nanoparticle with affinity for tumor tissue and then attach a drug molecule to it. Or they would inject nanoparticles into patients that would improve the resolution of diagnostic imaging. When the realities associated with the use of nanoparticles in the landscape of the human immune system proved more challenging, many researchers realized the need to step back from possible clinical use to better understand the mechanisms that challenge nanoparticle use.

“This basic groundwork is absolutely necessary,” says Seyed Moein Moghimi, PhD, nanotechnologist at Durham University, UK, and the coauthor of the Simberg paper. “It’s essential that we learn to control the process of immune recognition so that we can bridge between the promise that nanoparticles demonstrate in the lab and their use with real patients in the real world.”

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

Complement proteins bind to nanoparticle protein corona and undergo dynamic exchange in vivo by Fangfang Chen, Guankui Wang, James I. Griffin, Barbara Brenneman, Nirmal K. Banda, V. Michael Holers, Donald S. Backos, LinPing Wu, Seyed Moein Moghimi, & Dmitri Simberg. Nature Nanotechnology  (2016) doi:10.1038/nnano.2016.269 19 December 2016

This paper is behind a paywall.

I have a few previous postings about nanoparticles as drug delivery systems which have yet to fulfill their promise. There’s the April 27, 2016 posting (How many nanoparticle-based drugs does it take to kill a cancer tumour? More than 1%) and the Sept. 9, 2016 posting (Discovering how the liver prevents nanoparticles from reaching cancer cells).

Using melanin in bioelectronic devices

Brazilian researchers are working with melanin to make biosensors and other bioelectronic devices according to a Dec. 20, 2016 news item on,

Bioelectronics, sometimes called the next medical frontier, is a research field that combines electronics and biology to develop miniaturized implantable devices capable of altering and controlling electrical signals in the human body. Large corporations are increasingly interested: a joint venture in the field has recently been announced by Alphabet, Google’s parent company, and pharmaceutical giant GlaxoSmithKline (GSK).

One of the challenges that scientists face in developing bioelectronic devices is identifying and finding ways to use materials that conduct not only electrons but also ions, as most communication and other processes in the human organism use ionic biosignals (e.g., neurotransmitters). In addition, the materials must be biocompatible.

Resolving this challenge is one of the motivations for researchers at São Paulo State University’s School of Sciences (FC-UNESP) at Bauru in Brazil. They have succeeded in developing a novel route to more rapidly synthesize and to enable the use of melanin, a polymeric compound that pigments the skin, eyes and hair of mammals and is considered one of the most promising materials for use in miniaturized implantable devices such as biosensors.

A Dec. 14, 2016 FAPESP (São Paulo Research Foundation) press release, which originated the news item, further describes both the research and a recent meeting where the research was shared (Note: A link has been removed),

Some of the group’s research findings were presented at FAPESP Week Montevideo during a round-table session on materials science and engineering.

The symposium was organized by the Montevideo Group Association of Universities (AUGM), Uruguay’s University of the Republic (UdelaR) and FAPESP and took place on November 17-18 at UdelaR’s campus in Montevideo. Its purpose was to strengthen existing collaborations and establish new partnerships among South American scientists in a range of knowledge areas. Researchers and leaders of institutions in Uruguay, Brazil, Argentina, Chile and Paraguay attended the meeting.

“All the materials that have been tested to date for applications in bioelectronics are entirely synthetic,” said Carlos Frederico de Oliveira Graeff, a professor at UNESP Bauru and principal investigator for the project, in an interview given to Agência FAPESP.

“One of the great advantages of melanin is that it’s a totally natural compound and biocompatible with the human body: hence its potential use in electronic devices that interface with brain neurons, for example.”

Application challenges

According to Graeff, the challenges of using melanin as a material for the development of bioelectronic devices include the fact that like other carbon-based materials, such as graphene, melanin is not easily dispersible in an aqueous medium, a characteristic that hinders its application in thin-film production.

Furthermore, the conventional process for synthesizing melanin is complex: several steps are hard to control, it can last up to 56 days, and it can result in disorderly structures.

In a series of studies performed in recent years at the Center for Research and Development of Functional Materials (CDFM), where Graeff is a leading researcher and which is one of the Research, Innovation and Dissemination Centers (RIDCs) funded by FAPESP, he and his collaborators managed to obtain biosynthetic melanin with good dispersion in water and a strong resemblance to natural melanin using a novel synthesis route.

The process developed by the group at CDMF takes only a few hours and is based on changes in parameters such as temperature and the application of oxygen pressure to promote oxidation of the material.

By applying oxygen pressure, the researchers were able to increase the density of carboxyl groups, which are organic functional groups consisting of a carbon atom double bonded to an oxygen atom and single bonded to a hydroxyl group (oxygen + hydrogen). This enhances solubility and facilitates the suspension of biosynthetic melanin in water.

“The production of thin films of melanin with high homogeneity and quality is made far easier by these characteristics,” Graeff said.

By increasing the density of carboxyl groups, the researchers were also able to make biosynthetic melanin more similar to the biological compound.

In living organisms, an enzyme that participates in the synthesis of melanin facilitates the production of carboxylic acids. The new melanin synthesis route enabled the researchers to mimic the role of this enzyme chemically while increasing carboxyl group density.

“We’ve succeeded in obtaining a material that’s very close to biological melanin by chemical synthesis and in producing high-quality film for use in bioelectronic devices,” Graeff said.

Through collaboration with colleagues at research institutions in Canada [emphasis mine], the Brazilian researchers have begun using the material in a series of applications, including electrical contacts, pH sensors and photovoltaic cells.

More recently, they have embarked on an attempt to develop a transistor, a semiconductor device used to amplify or switch electronic signals and electrical power.

“Above all, we aim to produce transistors precisely in order to enhance this coupling of electronics with biological systems,” Graeff said.

I’m glad to have gotten some information about the work in South America. It’s one of FrogHeart’s shortcomings that I have so little about the research in that area of the world. I believe this is largely due to my lack of Spanish language skills. Perhaps one day there’ll be a universal translator that works well. In the meantime, it was a surprise to see Canada mentioned in this piece. I wonder which Canadian research institutions are involved with this research in South America.

A biocompatible (implantable) micromachine (microrobot)

I appreciate the detail and information in this well written Jan. 4, 2017 Columbia University news release (h/t Jan. 4, 2016 Nanowerk; Note: Links have been removed),

A team of researchers led by Biomedical Engineering Professor Sam Sia has developed a way to manufacture microscale-sized machines from biomaterials that can safely be implanted in the body. Working with hydrogels, which are biocompatible materials that engineers have been studying for decades, Sia has invented a new technique that stacks the soft material in layers to make devices that have three-dimensional, freely moving parts. The study, published online January 4, 2017, in Science Robotics, demonstrates a fast manufacturing method Sia calls “implantable microelectromechanical systems” (iMEMS).

By exploiting the unique mechanical properties of hydrogels, the researchers developed a “locking mechanism” for precise actuation and movement of freely moving parts, which can provide functions such as valves, manifolds, rotors, pumps, and drug delivery. They were able to tune the biomaterials within a wide range of mechanical and diffusive properties and to control them after implantation without a sustained power supply such as a toxic battery. They then tested the “payload” delivery in a bone cancer model and found that the triggering of release of doxorubicin from the device over 10 days showed high treatment efficacy and low toxicity, at 1/10 of the standard systemic chemotherapy dose.

“Overall, our iMEMS platform enables development of biocompatible implantable microdevices with a wide range of intricate moving components that can be wirelessly controlled on demand and solves issues of device powering and biocompatibility,” says Sia, also a member of the Data Science Institute. “We’re really excited about this because we’ve been able to connect the world of biomaterials with that of complex, elaborate medical devices. Our platform has a large number of potential applications, including the drug delivery system demonstrated in our paper which is linked to providing tailored drug doses for precision medicine.”

I particularly like this bit about hydrogels being a challenge to work with and the difficulties of integrating both rigid and soft materials,

Most current implantable microdevices have static components rather than moving parts and, because they require batteries or other toxic electronics, have limited biocompatibility. Sia’s team spent more than eight years working on how to solve this problem. “Hydrogels are difficult to work with, as they are soft and not compatible with traditional machining techniques,” says Sau Yin Chin, lead author of the study who worked with Sia. “We have tuned the mechanical properties and carefully matched the stiffness of structures that come in contact with each other within the device. Gears that interlock have to be stiff in order to allow for force transmission and to withstand repeated actuation. Conversely, structures that form locking mechanisms have to be soft and flexible to allow for the gears to slip by them during actuation, while at the same time they have to be stiff enough to hold the gears in place when the device is not actuated. We also studied the diffusive properties of the hydrogels to ensure that the loaded drugs do not easily diffuse through the hydrogel layers.”

The team used light to polymerize sheets of gel and incorporated a stepper mechanization to control the z-axis and pattern the sheets layer by layer, giving them three-dimensionality. Controlling the z-axis enabled the researchers to create composite structures within one layer of the hydrogel while managing the thickness of each layer throughout the fabrication process. They were able to stack multiple layers that are precisely aligned and, because they could polymerize a layer at a time, one right after the other, the complex structure was built in under 30 minutes.

Sia’s iMEMS technique addresses several fundamental considerations in building biocompatible microdevices, micromachines, and microrobots: how to power small robotic devices without using toxic batteries, how to make small biocompatible moveable components that are not silicon which has limited biocompatibility, and how to communicate wirelessly once implanted (radio frequency microelectronics require power, are relatively large, and are not biocompatible). The researchers were able to trigger the iMEMS device to release additional payloads over days to weeks after implantation. They were also able to achieve precise actuation by using magnetic forces to induce gear movements that, in turn, bend structural beams made of hydrogels with highly tunable properties. (Magnetic iron particles are commonly used and FDA-approved for human use as contrast agents.)

In collaboration with Francis Lee, an orthopedic surgeon at Columbia University Medical Center at the time of the study, the team tested the drug delivery system on mice with bone cancer. The iMEMS system delivered chemotherapy adjacent to the cancer, and limited tumor growth while showing less toxicity than chemotherapy administered throughout the body.

“These microscale components can be used for microelectromechanical systems, for larger devices ranging from drug delivery to catheters to cardiac pacemakers, and soft robotics,” notes Sia. “People are already making replacement tissues and now we can make small implantable devices, sensors, or robots that we can talk to wirelessly. Our iMEMS system could bring the field a step closer in developing soft miniaturized robots that can safely interact with humans and other living systems.”

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

Additive manufacturing of hydrogel-based materials for next-generation implantable medical devices by Sau Yin Chin, Yukkee Cheung Poh, Anne-Céline Kohler, Jocelyn T. Compton, Lauren L. Hsu, Kathryn M. Lau, Sohyun Kim, Benjamin W. Lee, Francis Y. Lee, and Samuel K. Sia. Science Robotics  04 Jan 2017: Vol. 2, Issue 2, DOI: 10.1126/scirobotics.aah6451

This paper appears to be open access.

The researchers have provided a video demonstrating their work (you may want to read the caption below before watching),

Magnetic actuation of the Geneva drive device. A magnet is placed about 1cm below and without contact with the device. The rotating magnet results in the rotational movement of the smaller driving gear. With each full rotation of this driving gear, the larger driven gear is engaged and rotates by 60º, exposing the next reservoir to the aperture on the top layer of the device.

—Video courtesy of Sau Yin Chin/Columbia Engineering

You can hear some background conversation but it doesn’t seem to have been included for informational purposes.