Category Archives: medicine

Replicating brain’s neural networks with 3D nanoprinting

An announcement about European Union funding for a project to reproduce neural networks by 3D nanoprinting can be found in a June 10, 2016 news item on Nanowerk,

The MESO-BRAIN consortium has received a prestigious award of €3.3million in funding from the European Commission as part of its Future and Emerging Technology (FET) scheme. The project aims to develop three-dimensional (3D) human neural networks with specific biological architecture, and the inherent ability to interrogate the network’s brain-like activity both electrophysiologically and optically. It is expected that the MESO-BRAIN will facilitate a better understanding of human disease progression, neuronal growth and enable the development of large-scale human cell-based assays to test the modulatory effects of pharmacological and toxicological compounds on neural network activity. The use of more physiologically relevant human models will increase drug screening efficiency and reduce the need for animal testing.

A June 9, 2016 Institute of Photonic Sciences (ICFO) press release (also on EurekAlert), which originated the news item, provides more detail,

About the MESO-BRAIN project

The MESO-BRAIN project’s cornerstone will use human induced pluripotent stem cells (iPSCs) that have been differentiated into neurons upon a defined and reproducible 3D scaffold to support the development of human neural networks that emulate brain activity. The structure will be based on a brain cortical module and will be unique in that it will be designed and produced using nanoscale 3D-laser-printed structures incorporating nano-electrodes to enable downstream electrophysiological analysis of neural network function. Optical analysis will be conducted using cutting-edge light sheet-based, fast volumetric imaging technology to enable cellular resolution throughout the 3D network. The MESO-BRAIN project will allow for a comprehensive and detailed investigation of neural network development in health and disease.

Prof Edik Rafailov, Head of the MESO-BRAIN project (Aston University) said: “What we’re proposing to achieve with this project has, until recently, been the stuff of science fiction. Being able to extract and replicate neural networks from the brain through 3D nanoprinting promises to change this. The MESO-BRAIN project has the potential to revolutionise the way we are able to understand the onset and development of disease and discover treatments for those with dementia or brain injuries. We cannot wait to get started!”

The MESO-BRAIN project will launch in September 2016 and research will be conducted over three years.

About the MESO-BRAIN consortium

Each of the consortium partners have been chosen for the highly specific skills & knowledge that they bring to this project. These include technologies and expertise in stem cells, photonics, physics, 3D nanoprinting, electrophysiology, molecular biology, imaging and commercialisation.

Aston University (UK) Aston Institute of Photonic Technologies (School of Engineering and Applied Science) is one of the largest photonic groups in UK and an internationally recognised research centre in the fields of lasers, fibre-optics, high-speed optical communications, nonlinear and biomedical photonics. The Cell & Tissue Biomedical Research Group (Aston Research Centre for Healthy Ageing) combines collective expertise in genetic manipulation, tissue engineering and neuronal modelling with the electrophysiological and optical analysis of human iPSC-derived neural networks. Axol Bioscience Ltd. (UK) was founded to fulfil the unmet demand for high quality, clinically relevant human iPSC-derived cells for use in biomedical research and drug discovery. The Laser Zentrum Hannover (Germany) is a leading research organisation in the fields of laser development, material processing, laser medicine, and laser-based nanotechnologies. The Neurophysics Group (Physics Department) at University of Barcelona (Spain) are experts in combing experiments with theoretical and computational modelling to infer functional connectivity in neuronal circuits. The Institute of Photonic Sciences (ICFO) (Spain) is a world-leading research centre in photonics with expertise in several microscopy techniques including light sheet imaging. KITE Innovation (UK) helps to bridge the gap between the academic and business sectors in supporting collaboration, enterprise, and knowledge-based business development.

For anyone curious about the FET funding scheme, there’s this from the press release,

Horizon 2020 aims to ensure Europe produces world-class science by removing barriers to innovation through funding programmes such as the FET. The FET (Open) funds forward-looking collaborations between advanced multidisciplinary science and cutting-edge engineering for radically new future technologies. The published success rate is below 1.4%, making it amongst the toughest in the Horizon 2020 suite of funding schemes. The MESO-BRAIN proposal scored a perfect 5/5.

You can find out more about the MESO-BRAIN project on its ICFO webpage.

They don’t say anything about it but I can’t help wondering if the scientists aren’t also considering the possibility of creating an artificial brain.

Lungs: EU SmartNanoTox and Pneumo NP

I have three news bits about lungs one concerning relatively new techniques for testing the impact nanomaterials may have on lungs and two concerning developments at PneumoNP; the first regarding a new technique for getting antibiotics to a lung infected with pneumonia and the second, a new antibiotic.

Predicting nanotoxicity in the lungs

From a June 13, 2016 news item on Nanowerk,

Scientists at the Helmholtz Zentrum München [German Research Centre for Environmental Health] have received more than one million euros in the framework of the European Horizon 2020 Initiative [a major European Commission science funding initiative successor to the Framework Programme 7 initiative]. Dr. Tobias Stöger and Dr. Otmar Schmid from the Institute of Lung Biology and Disease and the Comprehensive Pneumology Center (CPC) will be using the funds to develop new tests to assess risks posed by nanomaterials in the airways. This could contribute to reducing the need for complex toxicity tests.

A June 13, 2016 Helmholtz Zentrum München (German Research Centre for Environmental Health) press release, which originated the news item, expands on the theme,

Nanoparticles are extremely small particles that can penetrate into remote parts of the body. While researchers are investigating various strategies for harvesting the potential of nanoparticles for medical applications, they could also pose inherent health risks*. Currently the hazard assessment of nanomaterials necessitates a complex and laborious procedure. In addition to complete material characterization, controlled exposure studies are needed for each nanomaterial in order to guarantee the toxicological safety.

As a part of the EU SmartNanoTox project, which has now been funded with a total of eight million euros, eleven European research partners, including the Helmholtz Zentrum München, want to develop a new concept for the toxicological assessment of nanomaterials.

Reference database for hazardous substances

Biologist Tobias Stöger and physicist Otmar Schmid, both research group heads at the Institute of Lung Biology and Disease, hope that the use of modern methods will help to advance the assessment procedure. “We hope to make more reliable nanotoxicity predictions by using modern approaches involving systems biology, computer modelling, and appropriate statistical methods,” states Stöger.

The lung experts are concentrating primarily on the respiratory tract. The approach involves defining a representative selection of toxic nanomaterials and conducting an in-depth examination of their structure and the various molecular modes of action that lead to their toxicity. These data are then digitalized and transferred to a reference database for new nanomaterials. Economical tests that are easy to conduct should then make it possible to assess the toxicological potential of these new nanomaterials by comparing the test results s with what is already known from the database. “This should make it possible to predict whether or not a newly developed nanomaterial poses a health risk,” Otmar Schmid says.

* Review: Schmid, O. and Stoeger, T. (2016). Surface area is the biologically most effective dose metric for acute nanoparticle toxicity in the lung. Journal of Aerosol Science, DOI:10.1016/j.jaerosci.2015.12.006

The SmartNanoTox webpage is here on the European Commission’s Cordis website.

Carrying antibiotics into lungs (PneumoNP)

I received this news from the European Commission’s PneumoNP project (I wrote about PneumoNP in a June 26, 2014 posting when it was first announced). This latest development is from a March 21, 2016 email (the original can be found here on the How to pack antibiotics in nanocarriers webpage on the PneumoNP website),

PneumoNP researchers work on a complex task: attach or encapsulate antibiotics with nanocarriers that are stable enough to be included in an aerosol formulation, to pass through respiratory tracts and finally deliver antibiotics on areas of lungs affected by pneumonia infections. The good news is that they finally identify two promising methods to generate nanocarriers.

So far, compacting polymer coils into single-chain nanoparticles in water and mild conditions was an unsolved issue. But in Spain, IK4-CIDETEC scientists developed a covalent-based method that produces nanocarriers with remarkable stability under those particular conditions. Cherry on the cake, the preparation is scalable for more industrial production. IK4-CIDETEC patented the process.

Fig.: A polymer coil (step 1) compacts into a nanocarrier with cross-linkers (step 2). Then, antibiotics get attached to the nanocarrier (step 3).

Fig.: A polymer coil (step 1) compacts into a nanocarrier with cross-linkers (step 2). Then, antibiotics get attached to the nanocarrier (step 3).

At the same time, another route to produce lipidic nanocarriers have been developed by researchers from Utrecht University. In particular, they optimized the method consisting in assembling lipids directly around a drug. As a result, generated lipidic nanocarriers show encouraging stability properties and are able to carry sufficient quantity of antibiotics.

Fig.: On presence of antibiotics, the lipidic layer (step 1) aggregates the the drug (step 2) until the lipids forms a capsule around the antibiotics (step 3).

Fig.: On presence of antibiotics, a lipidic layer (step 1) aggregates the drug (step 2) until the lipids forms a capsule around antibiotics (step 3).

Assays of both polymeric and lipidic nanocarriers are currently performed by ITEM Fraunhofer Institute in Germany, Ingeniatrics Tecnologias in Spain and Erasmus Medical Centre in the Netherlands. Part of these tests allows to make sure that the nanocarriers are not toxic to cells. Other tests are also done to verify that the efficiency of antibiotics on Klebsiella Pneumoniae bacteria when they are attached to nanocarriers.

A new antibiotic for pneumonia (PneumoNP)

A June 14, 2016 PneumoNP press release (received via email) announces work on a promising new approach to an antibiotic for pneumonia,

The antimicrobial peptide M33 may be the long-sought substitute to treat difficult lung infections, like multi-drug resistant pneumonia.

In 2013, the European Respiratory Society predicted 3 millions cases of pneumonia in Europe every year [1]. The standard treatment for pneumonia is an intravenous administration of a combination of drugs. This leads to the development of antibiotic resistance in the population. Gradually, doctors are running out of solutions to cure patients. An Italian company suggests a new option: the M33 peptide.

Few years ago, the Italian company SetLance SRL decided to investigate the M33 peptide. The antimicrobial peptide is an optimized version of an artificial peptide sequence selected for its efficacy and stability. So far, it showed encouraging in-vitro results against multidrug-resistant Gram-negative bacteria, including Klebsiella Pneumoniae. With the support of EU funding to the PneumoNP project, SetLance SRL had the opportunity to develop a new formulation of M33 that enhances its antimicrobial activity.

The new formulation of M33 fights Gram-negative bacteria in three steps. First of all, the M33 binds with the lipopolysaccharides (LPS) on the outer membrane of bacteria. Then, the molecule forms a helix and finally disrupts the membrane provoking cytoplasm leaking. The peptide enabled up to 80% of mices to survive Pseudomonas Aeruginosa-based lung infections. Beyond these encouraging results, toxicity to the new M33 formulation seems to be much lower than antimicrobial peptides currently used in clinical practice like colistin [2].

Lately, SetLance scaled-up the synthesis route and is now able to produce several hundred milligrams per batch. The molecule is robust enough for industrial production. We may expect this drug to go on clinical development and validation at the beginning of 2018.

[1] http://www.erswhitebook.org/chapters/acute-lower-respiratory-infections/pneumonia/
[2] Ceccherini et al., Antimicrobial activity of levofloxacin-M33 peptide conjugation or combination, Chem Med Comm. 2016; Brunetti et al., In vitro and in vivo efficacy, toxicity, bio-distribution and resistance selection of a novel antibacterial drug candidate. Scientific Reports 2016

I believe all the references are open access.

Brief final comment

The only element linking these news bits together is that they concern the lungs.

Luminescent upconversion nanoparticles could make imaging more efficient

Researchers at the University of Adelaide (Australia) have found a way to embed luminiscent nanoparticles in glass, according to a June 8, 2016 news item on Nanotechnology,

This new “hybrid glass” successfully combines the properties of these special luminescent (or light-emitting) nanoparticles with the well-known aspects of glass, such as transparency and the ability to be processed into various shapes including very fine optical fibres.

The research, in collaboration with Macquarie University and University of Melbourne, has been published online in the journal Advanced Optical Materials.

A June 7, 2016 University of Adelaide press release (also on EurekAlert), which originated the news item, offers more detail,

“These novel luminescent nanoparticles, called upconversion nanoparticles, have become promising candidates for a whole variety of ultra-high tech applications such as biological sensing, biomedical imaging and 3D volumetric displays,” says lead author Dr Tim Zhao, from the University of Adelaide’s School of Physical Sciences and Institute for Photonics and Advanced Sensing (IPAS).

“Integrating these nanoparticles into glass, which is usually inert, opens up exciting possibilities for new hybrid materials and devices that can take advantage of the properties of nanoparticles in ways we haven’t been able to do before. For example, neuroscientists currently use dye injected into the brain and lasers to be able to guide a glass pipette to the site they are interested in. If fluorescent nanoparticles were embedded in the glass pipettes, the unique luminescence of the hybrid glass could act like a torch to guide the pipette directly to the individual neurons of interest.”

Although this method was developed with upconversion nanoparticles, the researchers believe their new ‘direct-doping’ approach can be generalised to other nanoparticles with interesting photonic, electronic and magnetic properties. There will be many applications – depending on the properties of the nanoparticle.

“If we infuse glass with a nanoparticle that is sensitive to radiation and then draw that hybrid glass into a fibre, we could have a remote sensor suitable for nuclear facilities,” says Dr Zhao.

To date, the method used to integrate upconversion nanoparticles into glass has relied on the in-situ growth of the nanoparticles within the glass.

“We’ve seen remarkable progress in this area but the control over the nanoparticles and the glass compositions has been limited, restricting the development of many proposed applications,” says project leader Professor Heike Ebendorff-Heideprem, Deputy Director of IPAS.

“With our new direct doping method, which involves synthesizing the nanoparticles and glass separately and then combining them using the right conditions, we’ve been able to keep the nanoparticles intact and well dispersed throughout the glass. The nanoparticles remain functional and the glass transparency is still very close to its original quality. We are heading towards a whole new world of hybrid glass and devices for light-based technologies.”

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

Upconversion Nanocrystal-Doped Glass: A New Paradigm for Photonic Materials by Jiangbo Zhao, Xianlin Zheng, Erik P. Schartner, Paul Ionescu, Run Zhang, Tich-Lam Nguyen, Dayong Jin, and Heike Ebendorff-Heidepriem. Advanced Optical Materials DOI: 10.1002/adom.201600296 Version of Record online: 30 MAY 2016

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

This paper is behind a paywall.

Biodegradable films from cellulose nanofibrils

A team at Purdue University (Indiana, US) has developed a new process for biodegradable films based on cellulose according to a June 8, 2016 news item on phys.org,

Purdue University researchers have developed tough, flexible, biodegradable films from cellulose, the main component of plant cell walls. The films could be used for products such as food packaging, agricultural groundcovers, bandages and capsules for medicine or bioactive compounds.

Food scientists Srinivas Janaswamy and Qin Xu engineered the cellophane-like material by solubilizing cellulose using zinc chloride, a common inorganic salt, and adding calcium ions to cause the cellulose chains to become tiny fibers known as nanofibrils, greatly increasing the material’s tensile strength. The zinc chloride and calcium ions work together to form a gel network, allowing the researchers to cast the material into a transparent, food-grade film.

A June 7, 2016 Purdue University news release by Natalie van Hoose, which originated the news item, discusses the need for these films and provides a few more technical details about the work (Note: A link has been removed),

“We’re looking for innovative ways to adapt and use cellulose – an inexpensive and widely available material – for a range of food, biomedical and pharmaceutical applications,” said Janaswamy, research assistant professor of food science and principal author of the study. “Though plastics have a wide variety of applications, their detrimental impact on the environment raises a critical need for alternative materials. Cellulose stands out as a viable option, and our process lays a strong foundation for developing new biodegradable plastics.”

Cellulose’s abundance, renewability and ability to biodegrade make it a promising substitute for petroleum-based products. While a variety of products such as paper, cellophane and rayon are made from cellulose, its tightly interlinked structure and insolubility – qualities that give plants strength and protection – make it a challenging material to work with.

Janaswamy and Xu loosened the cellulose network by adding zinc chloride, which helps push cellulose’s closely packed sheets apart, allowing water to penetrate and solubilize it. Adding calcium ions spurs the formation of nanofibrils through strong bonds between the solubilized cellulose sheets. The calcium ions boost the tensile strength of the films by about 250 percent.

The production process preserves the strength and biodegradability of cellulose while rendering it transparent and flexible.

Because the zinc chloride can be recycled to repeat the process, the method offers an environmentally friendly alternative to conventional means of breaking down cellulose, which tend to rely on toxic chemicals and extreme temperatures.

“Products based on this film can have a no-waste lifecycle,” said Xu, research assistant professor of food science and first author of the study. “This process allows us to create a valuable product from natural materials – including low-value or waste materials such as corn stover or wood chips- that can eventually be returned to the Earth.”

The methodology could be adapted to mass-produce cellulose films, the researchers said.

The next step in the project is to find ways of making the cellulose film insoluble to water while maintaining its ability to biodegrade.

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

A facile route to prepare cellulose-based films by Qin Xu, Chen Chen, Katelyn Rosswurm, Tianming Yao, Srinivas Janaswamy. Carbohydrate Polymers Volume 149, 20 September 2016, Pages 274–281 doi:10.1016/j.carbpol.2016.04.114

This paper is behind a paywall.

Taking DNA beyond genetics with living computers and nanobots

You might want to keep a salt shaker with you while reading a June 7, 2016 essay by Matteo Palma (Queen Mary’s University of London) about nanotechnology and DNA on The Conversation website (h/t June 7, 2016 news item on Nanowerk).

This is not a ‘hype’ piece as Palma backs every claim with links to the research while providing a good overview of some very exciting work but the mood is a bit euphoric so you may want to keep the earlier mentioned salt shaker nearby.

Palma offers a very nice beginner introduction especially helpful for someone who only half-remembers their high school biology (from the June 7, 2016 essay)

DNA is one of the most amazing molecules in nature, providing a way to carry the instructions needed to create almost any lifeform on Earth in a microscopic package. Now scientists are finding ways to push DNA even further, using it not just to store information but to create physical components in a range of biological machines.

Deoxyribonucleic acid or “DNA” carries the genetic information that we, and all living organisms, use to function. It typically comes in the form of the famous double-helix shape, made up of two single-stranded DNA molecules folded into a spiral. Each of these is made up of a series of four different types of molecular component: adenine (A), guanine (G), thymine (T), and cytosine (C).

Genes are made up from different sequences of these building block components, and the order in which they appear in a strand of DNA is what encodes genetic information. But by precisely designing different A,G,T and C sequences, scientists have recently been able to develop new ways of folding DNA into different origami shapes, beyond the conventional double helix.

This approach has opened up new possibilities of using DNA beyond its genetic and biological purpose, turning it into a Lego-like material for building objects that are just a few billionths of a metre in diameter (nanoscale). DNA-based materials are now being used for a variety of applications, ranging from templates for electronic nano-devices, to ways of precisely carrying drugs to diseased cells.

He highlights some Canadian work,

Designing electronic devices that are just nanometres in size opens up all sorts of possible applications but makes it harder to spot defects. As a way of dealing with this, researchers at the University of Montreal have used DNA to create ultrasensitive nanoscale thermometers that could help find minuscule hotspots in nanodevices (which would indicate a defect). They could also be used to monitor the temperature inside living cells.

The nanothermometers are made using loops of DNA that act as switches, folding or unfolding in response to temperature changes. This movement can be detected by attaching optical probes to the DNA. The researchers now want to build these nanothermometers into larger DNA devices that can work inside the human body.

He also mentions the nanobots that will heal your body (according to many works of fiction),

Researchers at Harvard Medical School have used DNA to design and build a nanosized robot that acts as a drug delivery vehicle to target specific cells. The nanorobot comes in the form of an open barrel made of DNA, whose two halves are connected by a hinge held shut by special DNA handles. These handles can recognise combinations of specific proteins present on the surface of cells, including ones associated with diseases.

When the robot comes into contact with the right cells, it opens the container and delivers its cargo. When applied to a mixture of healthy and cancerous human blood cells, these robots showed the ability to target and kill half of the cancer cells, while the healthy cells were left unharmed.

Palma is describing a very exciting development and there are many teams worldwide working on ways to make drugs more effective and less side effect-ridden. However there does seem to be a bit of a problem with targeted drug delivery as noted in my April 27, 2016 posting,

According to an April 27, 2016 news item on Nanowerk researchers at the University of Toronto (Canada) along with their collaborators in the US (Harvard Medical School) and Japan (University of Tokyo) have determined that less than 1% of nanoparticle-based drugs reach their intended destination …

Less than 1%? Admittedly, nanoparticles are not the same as nanobots but the problem is in the delivery, from my April 27, 2016 posting,

… the authors argue that, in order to increase nanoparticle delivery efficiency, a systematic and coordinated long-term strategy is necessary. To build a strong foundation for the field of cancer nanomedicine, researchers will need to understand a lot more about the interactions between nanoparticles and the body’s various organs than they do today. …

I imagine nanobots will suffer a similar fate since the actual delivery mechanism to a targeted cell is still a mystery.

I quite enjoyed Palma’s essay and appreciated the links he provided. My only proviso, keep a salt shaker nearby. That rosy future is going take a while to get here.

pH dependent nanoparticle-based contrast agent for MRIs (magnetic resonance images)

This news about a safer and more effective contrast agent for MRIs (magnetic resonance images) developed by Japanese scientists come from a June 6, 2016 article by Heather Zeiger on phys.org. First some explanations,

Magnetic resonance imaging relies on the excitation and subsequent relaxation of protons. In clinical MRI studies, the signal is determined by the relaxation time of the hydrogen protons in water. To get a stronger signal, scientists can use contrast agents to shorten the relaxation time of the protons.

MRI is non-invasive and does not involve radiation, making it a safe diagnostic tool. However, its weak signal makes tumor detection difficult. The ideal contrast agent would select for malignant tumors, making its location and diagnosis much more obvious.

Nanoparticle contrast agents have been of interested because nanoparticles can be functionalized and, as in this study, can contain various metals. Researchers have attempted to functionalize nanoparticles with ligands that attach to chemical factors on the surface of cancer cells. However, cancer cells tend to be compositionally heterogeneous, leading some researchers to look for nanoparticles that respond to differences in pH or redox potential compared to normal cells.

Now for the research,

Researchers from the University of Tokyo, Tokyo Institute of Technology, Kawasaki Institute of Industry Promotion, and the Japan Agency for Quantum and Radiological Science and Technology have developed a contrast agent from calcium phosphate-based nanoparticles that release a manganese ion an acidic environment. …

Peng Mi, Daisuke Kokuryo, Horacio Cabral, Hailiang Wu, Yasuko Terada, Tsuneo Saga, Ichio Aoki, Nobuhiro Nishiyama, and Kazunori Kataoka developed a contrast agent that is comprised of Mn2+– doped CaP nanoparticles with a PEG shell. They reasoned that using CaP nanoparticles, which are known to be pH sensitive, would allow the targeted release of Mn2+ ions in the tumor microenvironment. The tumor microenvironment tends to have a lower pH than the normal regions to rapid cell metabolism in an oxygen-depleted environment. Manganese ions were tested because they are paramagnetic, which makes for a good contrast agent. They also bind to proteins creating a slowly rotating manganese-protein system that results in sharp contrast enhancement.

These results were promising, so Peng Mi, et al. then tested whether the CaPMnPEG contrast agent worked in solid tumors. Because Mn2+ remains confined within the nanoparticle matrix at physiological pH, CaPMnPEG demonstrate a much lower toxicity [emphasis mine] compared to MnCl2. MRI studies showed a tumor-to-normal contrast of 131% after 30 minute, which is much higher than Gd-DTPA [emphasis mine], a clinically approved contrast agent. After an hour, the tumor-to-normal ratio was 160% and remained around 170% for several hours.

Three-dimensional MRI studies of solid tumors showed that without the addition of CaPMnPEG, only blood vessels were visible. However, upon adding CaPMnPEG, the tumor was easily distinguishable. Additionally, there is evidence that excess Mn2+ leaves the plasma after an hour. The contrast signal remained strong for several hours indicating that protein binding rather than Mn2+ concentration is important for signal enhancement.

Finally, tests with metastatic tumors in the liver (C26 colon cancer cells) showed that CaPMnPEG works well in solid organ analysis and is highly sensitive to detecting millimeter-sized micrometastasis [emphasis mine]. Unlike other contrast agents used in the clinic, CaPMnPEG provided a contrast signal that lasted for several hours after injection. After an hour, the signal was enhanced by 25% and after two hours, the signal was enhanced by 39%.

This is exciting stuff. Bravo to the researchers!

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

A pH-activatable nanoparticle with signal-amplification capabilities for non-invasive imaging of tumour malignancy by Peng Mi, Daisuke Kokuryo, Horacio Cabral, Hailiang Wu, Yasuko Terada, Tsuneo Saga, Ichio Aoki, Nobuhiro Nishiyama, & Kazunori Kataoka. Nature Nanotechnology (2016) doi:10.1038/nnano.2016.72 Published online 16 May 2016

This paper is behind a paywall.

Encapsulation of proteins in nanoparticles no longer necessary for time release?

A team of researchers at the University of Toronto (Canada) have developed a technique for the therapeutic use of proteins that doesn’t require ‘nanoencapsulation’ although nanoparticles are still used according to a May 27, 2016 news item on ScienceDaily,

A U of T [University of Toronto] Engineering team has designed a simpler way to keep therapeutic proteins where they are needed for long periods of time. The discovery is a potential game-changer for the treatment of chronic illnesses or injuries that often require multiple injections or daily pills.

For decades, biomedical engineers have been painstakingly encapsulating proteins in nanoparticles to control their release. Now, a research team led by University Professor Molly Shoichet has shown that proteins can be released over several weeks, even months, without ever being encapsulated. In this case the team looked specifically at therapeutic proteins relevant to tissue regeneration after stroke and spinal cord injury.

“It was such a surprising and unexpected discovery,” said co-lead author Dr. Irja Elliott Donaghue, who first found that the therapeutic protein NT3, a factor that promotes the growth of nerve cells, was slowly released when just mixed into a Jello-like substance that also contained nanoparticles. “Our first thought was, ‘What could be happening to cause this?'”

A May 27, 2016 University of Toronto news release (also on EurekAlert) by Marit Mitchell, which originated the news item, provides more in depth explanation,

Proteins hold enormous promise to treat chronic conditions and irreversible injuries — for example, human growth hormone is encapsulated in these tiny polymeric particles, and used to treat children with stunted growth. In order to avoid repeated injections or daily pills, researchers use complicated strategies both to deliver proteins to their site of action, and to ensure they’re released over a long enough period of time to have a beneficial effect.

This has long been a major challenge for protein-based therapies, especially because proteins are large and often fragile molecules. Until now, investigators have been treating proteins the same way as small drug molecules and encapsulating them in polymeric nanoparticles, often made of a material called poly(lactic-co-glycolic acid) or PLGA.

As the nanoparticles break down, the drug molecules escape. The same process is true for proteins; however, the encapsulating process itself often damages or denatures some of the encapsulated proteins, rendering them useless for treatment. Skipping encapsulation altogether means fewer denatured proteins, making for more consistent protein therapeutics that are easier to make and store.

“This is really exciting from a translational perspective,” said PhD candidate Jaclyn Obermeyer. “Having a simpler, more reliable fabrication process leaves less room for complications with scale-up for clinical use.”

The three lead authors, Elliott Donoghue, Obermeyer and Dr. Malgosia Pakulska have shown that to get the desired controlled release, proteins only need to be alongside the PLGA nanoparticles, not inside them. …

“We think that this could speed up the path for protein-based drugs to get to the clinic,” said Elliott Donaghue.

The mechanism for this encapsulation-free controlled release is surprisingly elegant. Shoichet’s group mixes the proteins and nanoparticles in a Jello-like substance called a hydrogel, which keeps them localized when injected at the site of injury. The positively charged proteins and negatively charged nanoparticles naturally stick together. As the nanoparticles break down they make the solution more acidic, weakening the attraction and letting the proteins break free.

“We are particularly excited to show long-term, controlled protein release by simply controlling the electrostatic interactions between proteins and polymeric nanobeads,” said Shoichet. “By manipulating the pH of the solution, the size and number of nanoparticles, we can control release of bioactive proteins. This has already changed and simplified the protein release strategies that we are pursuing in pre-clinical models of disease in the brain and spinal cord.”

“We’ve learned how to control this simple phenomena,” Pakulska said. “Our next question is whether we can do the opposite—design a similar release system for positively charged nanoparticles and negatively charged proteins.”

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

Encapsulation-free controlled release: Electrostatic adsorption eliminates the need for protein encapsulation in PLGA nanoparticles by Malgosia M. Pakulska, Irja Elliott Donaghue, Jaclyn M. Obermeyer, Anup Tuladhar, Christopher K. McLaughlin, Tyler N. Shendruk, and Molly S. Shoichet. Science Advances  27 May 2016: Vol. 2, no. 5, e1600519 DOI: 10.1126/sciadv.1600519

This paper appears to be open access.

Dr. Molly Shoichet was featured here in a May 11, 2015 posting about the launch of her Canada-wide science communication project Research2.Reality.

Better blood vessel growth for regenerative medicine?

If the organs and tissues grown in labs are to be successfully transplanted into bodies, then growing the blood vessels needed to maintain them becomes very important. A May 24, 2016 news item on ScienceDaily describes a new technique for the growing the vessels,

Growing tissues and organs in the lab for transplantation into patients could become easier after scientists discovered an effective way to produce three-dimensional networks of blood vessels, vital for tissue survival yet a current stumbling block in regenerative medicine.

In addition the technique to grow the blood vessels in a 3D scaffold cuts down on the risk of transplant rejection because it uses cells from the patient. It was developed by researchers from the University of Bath’s Department of Pharmacy and Pharmacology, working with colleagues at Bristol Heart Institute.

A May 24 (?), 2016 University of Bath (UK) press release, which originated the news item, expands on the theme (Note: Links have been removed),

So far the shortage of adequate patient-derived scaffolds that can support blood vessel growth has been a major limitation for regenerative medicine and tissue engineering.

Other methods only allow limited formation of small blood vessels such as capillaries, which makes tissue less likely to successfully transplant into a patient. In addition other methods of tissue growth require the use of animal products, unnecessary in this technique which uses human platelet lysate gel (hPLG) and endothelial progenitor cells (EPCs) – a type of cell which helps maintain blood vessel walls.

Dr Giordano Pula, Lecturer in Pharmacology at the University of Bath and head of the research team making the discovery, said: “A major challenge in tissue engineering and regenerative medicine is providing the new tissue with a network of blood vessels, and linking this to the patient’s existing blood supply; this is vital for the tissue’s survival and integration with adjacent tissues.

Dr Paul De Bank, Senior Lecturer in Pharmaceutics at the University of Bath and co-author of the paper, said: “By embedding EPCs in a gel derived from platelets, both of which can be isolated from the patient’s blood, we have demonstrated the formation of a network of small vessels. What is more, the gel contains a number of different growth factors which can induce existing blood vessels to infiltrate the gel and form connections with the new structures. Combining tissue-specific cells with this EPC-containing gel offers the potential for the formation of fully vascularised, functional tissues or organs, which integrate seamlessly with the patient.

“This discovery has the potential to accelerate the development of regenerative medicine applications.”

Professor Peter Weissberg, Medical Director of the British Heart Foundation, said: “Over a half a million people in the UK are living with heart failure, a disabling condition which can leave people unable to carry out everyday activities such as climbing the stairs or even walking to the shops. This regenerative research brings the British Heart Foundation’s goal to mend a broken heart and beat heart failure one step closer.

“All living tissues, including new heart muscle, need a blood supply. One of the fundamental goals of regenerative medicine is to find ways to grow a new blood supply from scratch. Previous attempts at this using human cells and synthetic scaffolds have met with only limited success.

“The beauty of this new approach is that components of a person’s own blood could be manipulated to create a scaffold on which new blood vessels could grow. This increases the likelihood that the new tissue will be integrated into the patient’s body which, if proven successful with more research, could improve the lives of people affected by heart failure.”

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

Platelet lysate gel and endothelial progenitors stimulate microvascular network formation in vitro: tissue engineering implications by Tiago M. Fortunato, Cristina Beltrami, Costanza Emanueli, Paul A. De Bank & Giordano Pula. Scientific Reports 6, Article number: 25326 (2016)  doi:10.1038/srep25326 Published online: 04 May 2016

This is an open access paper.

One of the criticisms of Paolo Macchiarini’s work with synthetic tracheas centered around blood supply to the cells (from my April 19, 2016 posting; it was part 1 of a 2-part series),

This ground-breaking achievement consisted of bringing to life a dead windpipe from a donor, by putting it in a plastic box, a so-called ‘bioreactor’ together with bone marrow fluid (stem cells). A few weeks later, I [Pierre Delaere*]  wrote a letter to The Lancet, pointing out:

“The main drawback of the proposed reconstruction is the lack of an intrinsic blood supply to the trachea. We know that a good blood supply is the first requirement in all other tissue and organ transplantations. Therefore, the reported success of this technique is questionable” (correspondence by Delaere and Hermans, Lancet 2009).

The excerpt you’ve just seen features part of an open letter Pierre Delaere (a long time Macchiarini critic), published in Leonid Schneider’s blog ‘For Better Science’ in an April 2, 2016 posting.

Getting back to Bath, this is exciting stuff and I hope the research is reproducible.

English ivy’s stickiness may be useful

Researchers have discovered the secret to English ivy’s stickiness and they hope that secret will lead to improved wound healing and more according to a May 24, 2016 news item on Nanowerk,

English ivy’s natural glue might hold the key to new approaches to wound healing, stronger armor for the military and maybe even cosmetics with better staying power.

New research from The Ohio State University illuminates the tiny particles responsible for ivy’s ability to latch on so tight to trees and buildings that it can withstand hurricanes and tornadoes. (Not to mention infuriate those trying to rid their homes of the vigorous green climber.)

The researchers pinpointed the spherical particles within English ivy’s adhesive and identified the primary protein within them.

A May 23, 2016 Ohio State University news release (also on EurekAlert) by Misti Crane, which originated the news item, expands on the theme,

“By understanding the proteins that give rise to ivy’s strength, we can give rise to approaches to engineer new bio-inspired adhesives for medical and industry products,” said Mingjun Zhang, the biomedical engineering professor who led the work.

“It’s a milestone to resolve this mystery. We now know the secret of this adhesive and the underlying molecular mechanism,” said Zhang, who focuses his work on finding answers in nature for vexing problems in medicine.

“Ivy has these very tiny hairy structures that have a wonderful interaction with the surface as the plant climbs. One day I was looking at the ivy in the backyard and I was amazed at the force,” Zhang said.Like many scientists before him, Charles Darwin among them, Zhang found himself captivated by English ivy – the physics of it, the sheer strength of it. The study appears today in the journal Proceedings of the National Academy of Sciences.

“It’s very difficult to tear down, even in a natural disaster. It’s one of the strongest adhesive forces in nature.”

When he and his team took a look at the ivy’s glue with a powerful atomic-force microscope, they were able to identify a previously unknown element in its adhesive.

Zhang said particles rich in those proteins have exceptional adhesive abilities – abilities that could be used to the advantage of many, from biomedical engineers to paint makers.The tiny particles inside the glue on their laboratory slides turned out to be primarily made up of arabinogalactan proteins. And when the scientists investigated further, they discovered that the driving force behind the curing of the glue was a calcium-mediated interaction between the proteins and pectin in the gelatinous liquid that oozes from ivy as it climbs.

Zhang, a member of Ohio State’s Davis Heart and Lung Research Institute, is particularly interested in bioadhesives that could aid in wound healing after injury or surgeries. Others, notably the U.S. military, are interested in surface-coating applications for purposes that include strengthening armor systems, he said.

Many plants are excellent climbers, but scientists have had limited information about the adhesives that enable those plants to affix themselves to walls, fences and just about anything in their way, he said.

“When climbing, ivy secretes these tiny nanoparticles which make initial surface contact. Due to their high uniformity and low viscosity, they can attach to large areas on various surfaces,” Zhang said.

After the water evaporates, a chemical bond forms, Zhang said.

“It’s really a nature-made amazing mechanism for high-strength adhesion,” he said.

The glue doesn’t just sit on the surface of the object that the ivy is clinging to, he said. It finds its way into openings invisible to the naked eye, further solidifying its bond.

To confirm what they found, Zhang and his collaborators used the nanoparticles to reconstruct a simple glue that mimics ivy adhesive. Advanced bioadhesives based on this research will take more time and research.

In addition to its strength, ivy adhesive has other properties that make it appealing to scientists looking for answers to engineering quandaries, Zhang said.

“Under moisture or high or low temperatures, it’s not easily damaged,” he said. “Ivy is very resistant to various environmental conditions, which makes the adhesive a particularly interesting candidate for the development of armor coatings.”

Ivy also is considered a pest because it can be destructive to buildings and bridges. Knowing what’s at the heart of its sticking ability could help scientists unearth approaches to resist the plant, Zhang said.

Zhang and his work have been featured here before in a Jan. 7, 2013 posting about flesh-eating fungus and in a July 22, 2010 posting about English ivy and sunscreens.

Here’s a link to and a citation for Zhang’s latest paper,

Nanospherical arabinogalactan proteins are a key component of the high-strength adhesive secreted by English ivy by Yujian Huang, Yongzhong Wang, Li Tan, Leming Sun, Jennifer Petrosino, Mei-Zhen Cui, Feng Hao, and Mingjun Zhang. PNAS [Proceedings of the National Academy of Sciences] 2016 doi: 10.1073/pnas.1600406113 Published ahead of print May 23, 2016,

This paper is behind a paywall.

Device detects molecules associated with neurodegenerative diseases

It’s nice to get notice of research in South America, an area for which I rarely stumble across any news releases. Brazilian researchers have developed a device that could help diagnose neurodegenerative diseases such as Alzheimer’s and and Parkinson’s as well as some cancers according to a May 20, 2016 news item on Nanotechnology Now,

A biosensor developed by researchers at the National Nanotechnology Laboratory (LNNano) in Campinas, São Paulo State, Brazil, has been proven capable of detecting molecules associated with neurodegenerative diseases and some types of cancer.

The device is basically a single-layer organic nanometer-scale transistor on a glass slide. It contains the reduced form of the peptide glutathione (GSH), which reacts in a specific way when it comes into contact with the enzyme glutathione S-transferase (GST), linked to Parkinson’s, Alzheimer’s and breast cancer, among other diseases. The GSH-GST reaction is detected by the transistor, which can be used for diagnostic purposes.

The project focuses on the development of point-of-care devices by researchers in a range of knowledge areas, using functional materials to produce simple sensors and microfluidic systems for rapid diagnosis.

A May 19, 2016 Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP) press release, which originated the news item, provides more detail,

“Platforms like this one can be deployed to diagnose complex diseases quickly, safely and relatively cheaply, using nanometer-scale systems to identify molecules of interest in the material analyzed,” explained Carlos Cesar Bof Bufon, Head of LNNano’s Functional Devices & Systems Lab (DSF) and a member of the research team for the project, whose principal investigator is Lauro Kubota, a professor at the University of Campinas’s Chemistry Institute (IQ-UNICAMP).

In addition to portability and low cost, the advantages of the nanometric biosensor include its sensitivity in detecting molecules, according to Bufon.

“This is the first time organic transistor technology has been used in detecting the pair GSH-GST, which is important in diagnosing degenerative diseases, for example,” he explained. “The device can detect such molecules even when they’re present at very low levels in the examined material, thanks to its nanometric sensitivity.” A nanometer (nm) is one billionth of a meter (10-9 meter), or one millionth of a millimeter.

The system can be adapted to detect other substances, such as molecules linked to different diseases and elements present in contaminated material, among other applications. This requires replacing the molecules in the sensor with others that react with the chemicals targeted by the test, which are known as analytes.

The team is working on paper-based biosensors to lower the cost even further and to improve portability and facilitate fabrication as well as disposal.

The challenge is that paper is an insulator in its usual form. Bufon has developed a technique to make paper conductive and capable of transporting sensing data by impregnating cellulose fibers with polymers that have conductive properties.

The technique is based on in situ synthesis of conductive polymers. For the polymers not to remain trapped on the surface of the paper, they have to be synthesized inside and between the pores of the cellulose fibers. This is done by gas-phase chemical polymerization: a liquid oxidant is infiltrated into the paper, which is then exposed to monomers in the gas phase. A monomer is a molecule of low molecular weight capable of reacting with identical or different molecules of low molecular weight to form a polymer.

The monomers evaporate under the paper and penetrate the pores of the fibers at the submicrometer scale. Inside the pores, they blend with the oxidant and begin the polymerization process right there, impregnating the entire material.

The polymerized paper acquires the conductive properties of the polymers. This conductivity can be adjusted by manipulating the element embedded in the cellulose fibers, depending on the application for which the paper is designed. Thus, the device can be electrically conductive, allowing current to flow without significant losses, or semiconductive, interacting with specific molecules and functioning as a physical, chemical or electrochemical sensor.

There’s no mention of a published paper.