Nano-forests to reveal secrets of cells

Vertical nanowires could be used for detailed studies of what happens on the surface of cells. The findings are important for pharmaceuticals research, among other applications. A group of researchers from Lund University in Sweden have managed to make artificial cell membranes form across a large number of vertical nanowires, known as a ‘nano-forest’.

                                                            

Nano-forest (Photo: Aleksandra Dabkowska)

All communication between the interior of a cell and its surroundings takes place through the cell membrane. The membrane is a surface layer that holds the cell together and that largely comprises lipids, built of fatty acids. Inside the cell there are also various types of membrane, all with their own specific role.

Studies of cell membranes using nanotechnology have up to now mainly involved studying artificial membranes on flat surfaces, but because many membranes in the body have a curved shape, a different type of nano-surface is needed. In a new scientific study, researchers from Lund University have used vertical nanowires to create more varied surfaces on which artificial membranes can form. The Lund researchers have built an entire forest of upright nanowires on a one millimetre squared surface, on which they have succeeded in forming artificial membranes that are curved in the same way as many natural cell membranes.

“Our research demonstrates that artificial membranes can follow the curved surface formed by the nanowires, which creates unique opportunities to study membranes in a curved state”, said Aleksandra Dabkowska from the Department of Chemistry at Lund University. 

The nanowires also act as fine feelers that can measure how the membrane works. For instance, the vertical nanowires can be used to study different proteins that are active in the body’s cell membranes. Because of their barrier function on the surface of the cell, these proteins are the target of a range of different drugs. The nano-forest could therefore be of great importance for pharmaceutical research, as well as for basic cell research, partly because the nano-surfaces are very precisely controlled as regards the length, thickness and spacing of the nanowires, and partly because the nano-forest multiplies the total study surface compared with a flat nano-landscape.

The present study is a close collaboration between researchers within the Nanometre Structure Consortium at Lund University who come from the Divisions of Physical Chemistry and Solid State Physics at the faculties of Science and Engineering

 

 

 

source:  LAUND UNIVERSITY
Aleksandra Dabkowska, postdoctoral research fellow in physical chemistry
Department of Chemistry, Lund University
+46 46 222 81 48
aleksandra.dabkowska@fkem1.lu.se

A 'Nano Vaccine' That Combats Dust Mite Allergies

Scientists at the University of Iowa have developed a vaccine that combats dust mite allergies by naturally switching off the body's immune response. It's welcome news for the millions of people who suffer from mite-induced breathing difficulties.

Nearly 84% of households in the United States contain dust mites — microscopic organisms that feed on organic leftovers like flakes of human skin. 

       

They're a common cause of asthma and allergic symptoms; their guts contain potent digestive enzymes that hang-out in their feces — a major contributor to allergic reactions such as wheezing.

But in animal tests, researchers demonstrated that a nano-sized vaccine package can lower lung inflammation by 83% despite repeated exposure to the allergens. The response happens because the vaccine package contains a booster that alters the body's inflammatory response to dust-mite allergens.

"Our research explores a novel approach to treating mite allergy in which specially-encapsulated miniscule particles are administered with sequences of bacterial DNA that direct the immune system to suppress allergic immune responses," noted co-author Peter Thorne in a statement. "This work suggests a way forward to alleviate mite-induced asthma in allergy sufferers."

                                               

                                                       

The UI-developed vaccine takes advantage of the body's natural inclination to defend itself against foreign bodies. A key to the formula lies in the use of an adjuvant—which boosts the potency of the vaccine—called CpG. The booster has been used successfully in cancer vaccines but never had been tested as a vaccine for dust-mite allergies. Put broadly, CpG sets off a fire alarm within the body, springing immune cells into action. Those immune cells absorb the CpG and dispose of it.

This is important, because as the immune cells absorb CpG, they're also taking in the vaccine, which has been added to the package, much like your mother may have wrapped a bitter pill around something tasty to get you to swallow it. In another twist, combining the antigen (the vaccine) and CpG causes the body to change its immune response, producing antibodies that dampen the damaging health effects dust-mite allergens generally cause.

In lab tests, the CpG-antigen package, at 300 nanometers in size, was absorbed 90 percent of the time by immune cells, the UI-led team reports. The researchers followed up those experiments by giving the package to mice and exposing the animals to dust-mite allergens every other day for nine days total. In analyses conducted at the UI College of Public Health, packages with CpG yielded greater production of the desirable antibodies, while lung inflammation was lower than particles that did not contain CpG, the researchers report.

 Read the entire study at AAPS Journal: "Development of a Poly (lactic-co-glycolic acid) Particle Vaccine to Protect Against House Dust Mite Induced Allergy".

Nano-sized chip picks up scent of explosives molecules

The groundbreaking nanotechnology-inspired sensor, devised by Prof. Fernando Patolsky of Tel Aviv University's School of Chemistry and Center for Nanoscience and Nanotechnology, and developed by the Herzliya company Tracense, picks up the scent of explosives molecules better than a detection dog's nose. Research on the sensor was recently published in the journal Nature Communications.

Existing explosives sensors are expensive, bulky and require expert interpretation of the findings. In contrast, the new sensor is mobile, inexpensive, and identifies in real time -- and with great accuracy -- explosives in the air at concentrations as low as a few molecules per 1,000 trillion.

                                                                 

nanosensor

A nano-nose to compete with a dog's

"Using a single tiny chip that consists of hundreds of supersensitive sensors, we can detect ultra low traces of extremely volatile explosives in air samples, and clearly fingerprint and differentiate them from other non-hazardous materials," said Prof. Patolsky, a top researcher in the field of nanotechnology. "In real time, it detects small molecular species in air down to concentrations of parts-per-quadrillion, which is four to five orders of magnitude more sensitive than any existing technological method, and two to three orders of magnitude more sensitive than a dog's nose.

"This chip can also detect improvised explosives, such as TATP (triacetone triperoxide), used in suicide bombing attacks in Israel and abroad," Prof. Patolsky added.

The clusters of nano-sized transistors used in the prototype are extremely sensitive to chemicals, which cause changes in the electrical conductance of the sensors upon surface contact. When just a single molecule of an explosive comes into contact with the sensors, it binds with them, triggering a rapid and accurate mathematical analysis of the material.

"Animals are influenced by mood, weather, state of health and working hours, the oversaturation of olfactory system, and much more," said Prof. Patolsky. "They also cannot tell us what they smell. Automatic sensing systems are superior candidates to dogs, working at least as well or better than nature. This is not an easy task, but was achieved through the development of novel technologies such as our sensor."

A technology for a safer world

The trace detector, still in prototype, identifies several different types of explosives several meters from the source in real time. It has been tested on the explosives TNT, RDX, and HMX, used in commercial blasting and military applications, as well as peroxide-based explosives like TATP and HMTD. The latter are commonly used in homemade bombs and are very difficult to detect using existing technology.

"Our breakthrough has the potential to change the way hazardous materials are detected, and of course should provide populations with more security," said Prof. Patolsky. "The faster, more sensitive detection of tiny amounts of explosives in the air will provide for a better and safer world."

Tracense has invested over $10M in research and development of the device since 2007, and expects to go to market next year. Prof.Patolsky and his team of researchers are currently performing multiple and extensive field tests of prototype devices of the sensor.

Source: science daily, www.aftau.org/nano

Computer simulations show how two knots on a DNA strand can interchange their positions

                                                                             

Physicists of Johannes Gutenberg University Mainz (JGU) and the Graduate School of Excellence "Materials Science in Mainz" (MAINZ) have been able with the aid of computer simulations to confirm and explain a mechanism by which two knots on a DNA strand can interchange their positions. For this, one of the knots grows in size while the other diffuses along the contour of the former. Since there is only a small free energy barrier to swap, a significant number of crossing events have been observed in molecular dynamics simulations, i.e., there is a high probability of such interchange of positions.
                                                             

"We assume that this swapping of positions on a DNA strand may also happen in living organisms," explained Dr. Peter Virnau of the JGU Institute of Physics, who performed the computer simulation together with his colleagues Benjamin Trefz and Jonathan Siebert. The scientists expect that the mechanism may play an important role in future technologies such as nanopore sequencing, where long DNA strands are sequenced by being pulled though pores. Long DNA strands of more than 100,000 base pairs have an increasing chance of knots, which is relevant for sequencing.

source:  Institute of Physics 

Johannes Gutenberg University 

Biomimetic nano-environments as templates for skin regeneration

Cellular functions within living organisms are extremely complex processes and researchers have been using nanopatterned substrates to control and monitor cellular functions in order to design and fabricate nanoscale biotechnological systems. Especially stem cell research has benefitted from nanopatterned surfaces to maintains stem cells' long-term viability and phenotype during experiments. Nevertheless, despite the intense scientific efforts to achieve precise control of stem cell fates with engineered nanopatterned substrates, reliable and cost effective control of stem cell behavior remains a challenge.Most of the tissues and organs in the human body, with their distinct three-dimensional structures, require support – scaffold/substrate, template, and artificial extracellular matrix or niche – for their formation from diverse cells.Researchers have now fabricated biomimetic substrates that are similar to that of the native extracellular matrix (ECM) in the epidermis which assists proliferation, differentiation, and biosynthesis of the keratinocyte (i.e. human outer skin) cells."Although sophisticated technologies and protocols have been employed for the fabrication of chemical functional substrates, our proposed methodology is simple and reproducible and, thus, may have good potential to be used in commercial processes," Morteza Mahmoudi, a professor at Tehran University of Medical Sciences, who heads the Laboratory of Nano-Bio Interactions, explains to Nanowerk. "In this work, we have introduced a shape-/pattern-induced stem cell differentiation phenomenon as an overlooked-factor in the substrate/scaffold designing procedure, which may represent a new concept on regeneration of skins from cells with the support of biomaterials with no chemical agents (e.g., growth factors)."                                  
                                                                      

               The detailed architecture of the basal-to-spinous layer transition together with illustration of the experimental set-up and artificial skin niche study steps. (click on image to enlarge) A) The program of epidermal differentiation is illustrated in this schematic, exposing the basement membrane at the base, the proliferative basal layer, and the four differentiation stages: stratum spinosum layer, stratum granulosum layer, stratum lucidum layer and outermost stratum corneum. The key molecular markers which are shown in this schematic are described in detail in the paper. The proliferative basal cells, as a multipotent progenitor of the epidermis layer, adhere to an underlying basement membrane (separating the dermis from the epidermis), and can differentiate into the spinous cells in the suprabasal layer. Quiescent human epidermal stem cells and their transient amplifying cell progeny give rise to a column of differentiated keratinocytes in diverse layers was depicted. The transit-amplifying cells constantly produce progeny which move upward as they terminally differentiate and are ultimately lost from the skin surface (superficial). B) The cultivated keratinocyte cells on different well plates at different passage levels are shown in this figure. C) In order to fabricate the PDMS-based substrate which mimics the natural stratum spinosum layer’s function, the keratinocyte cells were grown on a cell culture plate and their complete morphologies at different stages were transferred to a silicone replica by a mold casting procedure. After the removal of damaged cells and cell debris from the substrates, a negative PDMS-based replica (i.e., non-coated and gold coated heterostructure substrates with varied thicknesses) with an imprinted pattern of the cell surfaces was achieved. This unique structure was utilized as an efficient platform to manipulate the stem cells in order to achieve production of the keratinocyte-like cells. (Reprinted with permission from American Chemical Society) (click on image to enlarge)Mahmoudi and his collaborators have published their findings as a 'Just Accepted Manuscript' in the June 26, 2014 online edition of ACS Applied Materials & Interfaces ("Cell-Imprinted Substrates Act as Artificial Niche for Skin Regeneration").Initially, the researchers hypothesized that induction of specific mature adult cell shapes to stem cells – which were isolated from different sources – can result in differentiation of stem cells to specific mature cells. In their current work, they have focused on skin, as a classical example of a tissue, which is supported by stem cells; the skin needs to be regenerated constantly during normal homeostasis and after wounding."In this context, we have found that a 3D surface imitating the morphology of the keratinocyte plasma membrane could be used as a biomimetic template for differentiation of adipose-derived stem cells (ADSCs) into keratinocyte-like cells (KLCs)," says Mahmoudi. "It is worth noting that our artificial biomimetic micro/nano-environments were fabricated by a cell-imprinted procedure based on mature human keratinocyte morphological templates."Since the shape and geometry of the cell nucleus could alter the gene expression patterns, the researchers utilized a molecular dynamics approach to probe the effect of confining geometry on the chain arrangement of simulated chromatin fibers in the stem cell nucleus.
           As they point out, the obtained data could imply an obvious role of direct mechanotransduction to the nucleus and, consequently, to biochemical mechanotransduction.The main goal of this research is to design a novel cell-based therapeutical technology that results in efficient medical treatments – e.g., tissue-engineered skin substitutes – for diseases."Based on the obtained results, one can expect that our cell-imprinted substrates might pave the way for a reliable, efficient, and cheap controlling of stem cell differentiation toward skin cells for wound healing and skin tissue engineering applications," says Mahmoudi.The team found that, besides the cells themselves and external conditions, the physico-mechanical properties of the substrates are very important factors for controlling stem cell fate. As a result, the physico-mechanical properties of the native niche – such as adhesivity, stiffness, and topography – for different types of stem cells should be considered by researchers in their biomimetic approaches fabrication."Our work proves conclusively that stem cell function does follow form," notes Mahmoudi. "Make a stem cell look like you want it to act like – and it does so."The artificial niche introduced by this work may ultimately lead to advances in tissue engineering towards implants integrating bioprinting, nano-biosensors and advanced biomaterials.

source: nanowerk

DNA chimeras help assemble protein nanodevices

In 2008, Hermann Gaub and colleagues at the University of Munich developed a single-molecule cut-and-paste (SMC&P) technique that involves using an atomic force microscope (AFM) tip to pick up "sticky" DNA molecules, which bind only selectively to certain other complementary DNA molecules. The AFM works rather like a “nanocrane” that lifts up biomolecules, just like a normal, everyday crane lifts up life-sized objects. The molecules can then be brought to a target “construction site”, where they may be arranged at will. 

                                                          
                                     

In recent years, the researchers have considerably improved their method and can now even use it to transport DNA-coupled proteins, which are complex molecules. Such protein-DNA chimeras, as they are known, are also very useful in immunobiology applications as well as in nanobiotechnology – in particular for so-called DNA origami.

Gaub’s team has now taken its technique even further by employing the 11 amino acid ybbR-tag, helped along by the enzyme phospopantetheinyl transferase Sfp, to selectively attach co-enzyme A-modified DNA to proteins (see figure). 

Transporting single protein molecules

“By means of the ybbR-tag/CoA/Sfp system, we can efficiently and specifically couple proteins and DNA, and obtain robust protein-DNA chimeras that can be used in SMC&P,” says team member Diana Pippig. “Since the protein-DNA chimeras are so well defined and behaved we have succeeded in efficiently and precisely transporting actual single protein molecules, something hitherto only possible for mere DNA molecules.”

The researchers began by assembling the transfer complex comprising a protein (in this case “GFP”) and a covalently attached short-DNA-transfer strand. “We genetically modified the GFP to harbour encoded short peptide tags (an 11 amino acid ybbR-tag at one end and a 12 amino acid ‘GCN4-tag’ at the other),” explains Pippig. “We also modified the DNA oligomer with a co-enzyme A group so that it selectively attaches to the protein.”

What happens next is that the phospopantetheinyl transferase Sfp acts as a catalyst to couple the co-enzyme A to the hydroxyl group of a Serine residue in the ybbR-tag. “We then store the transfer complex in a predefined depot area on a functionalized glass surface by hybridizing the complex with a surface-bound, complementary DNA oligomer,

Picking up and pasting

The “cut” part of the process then involves the DNA molecule being unzipped at its bound end. The GFP-DNA complex is picked up by the AFM-tip transport crane and pasted in the depot area. In fact, the AFM tip contains a single-chain antibody fragment that specifically binds to the GCN4 peptide tag in the protein.

“In each SMC&P transfer cycle, we pick up one of the protein-DNA complexes stored in the depot area using the AFM tip and then deposit it where we want in the target area,” says Pippig. “The antibody AFM tip then becomes free again to move to the depot area and pick up a new transfer complex.”

Our process is precise to a scale of 10 nm, and we can pick up and arrange proteins from an arbitrary number of spatially separated depot regions, by, for example, employing a multichannel microfluidic device, she adds. “Indeed, such precision should enable us to position a protein in a confined compartment, such as a ‘zero-mode’ waveguide, for instance, which would allow us to observe single-molecule protein reactions using fluorescence spectroscopy. And that is not all: we might even be able to place proteins close to one another in a target area and study how they interact.”

The team describes its work in ACS Nano DOI: 10.1021/nn501644w.


source: nanoweb.org,written by Belle Dumé i

Scientists develop a 'nanosubmarine' that delivers complementary molecules inside cells

With the continuing need for very small devices in therapeutic applications, there is a growing demand for the development of nanoparticles that can transport and deliver drugs to target cells in the human body.
Recently, researchers created nanoparticles that under the right conditions, self-assemble – trapping complementary guest molecules within their structure. Like tiny submarines, these versatile nanocarriers can navigate in the watery environment surrounding cells and transport their guest molecules through the membrane of living cells to sequentially deliver their cargo.
Although the transport of molecules inside cells with nanoparticles has been previously achieved using various methods, researchers have developed nanoparticles capable of delivering and exchanging complementary molecules. For practical applications, these nanocarriers are highly desirable, explains Francisco Raymo, professor of chemistry in the University of Miami College of Arts and Sciences and lead investigator of this project.

                       

"The ability to deliver distinct species inside cells independently and force them to interact, exclusively in the intracellular environment, can evolve into a valuable strategy to activate drugs inside cells," Raymo says.
The new nanocarriers are15 nanometers in diameter. They are supramolecular constructs made up of building blocks called amphiphilic polymers. These nanocarriers hold the guest molecules within the confines of their water-insoluble interior and use their water-soluble exterior to travel through an aqueous environment. As a result, these nanovehicles are ideal for transferring molecules that would otherwise be insoluble in water, across a liquid environment.
             "Once inside a living cell, the particles mix and exchange their cargo. This interaction enables the energy transfer between the internalized molecules," says Raymo, director of the UM laboratory for molecular photonics. "If the complementary energy donors and acceptors are loaded separately and sequentially, the transfer of energy between them occurs exclusively within the intracellular space," he says. "As the energy transfer takes place, the acceptors emit a fluorescent signal that can be observed with a microscope."
Essential to this mechanism are the noncovalent bonds that loosely hold the supramolecular constructs together. These weak bonds exist between molecules with complementary shapes and electronic properties. They are responsible for the ability of the supramolecules to assemble spontaneously in liquid environments. Under the right conditions, the reversibility of these weak noncovalent contacts allows the supramolecular constructs to exchange their components as well as their cargo.
The experiments were conducted with cell cultures. It is not yet known if the nanoparticles can actually travel through the bloodstream.
"That would be the dream, but we have no evidence that they can actually do so," Raymo says. "However, this is the direction we are heading."
The next phase of this investigation involves demonstrating that this method can be used to do chemical reactions inside cells, instead of energy transfers.
"The size of these nanoparticles, their dynamic character and the fact that the reactions take place under normal biological conditions (at ambient temperature and neutral environment) makes these nanoparticles an ideal vehicle for the controlled activation of therapeutics, directly inside the cells," Raymo says.

		IMAGE: The sequential transport of donors and acceptors across cell membranes with independent and dynamic nanocarriers enables energy transfer exclusively in the intracellular space with concomitant fluorescence activation.

The current study is titled "Intracellular guest exchange between dynamic supramolecular hosts." It's published in theJournal of the American Chemical Society. Other authors are John F. Callan, co-corresponding author of the study, from the School of Pharmacy and Pharmaceutical Sciences at the University of Ulster; Subramani Swaminathan and Janet Cusido from the UM's Laboratory for Molecular Photonics, Department of Chemistry in the College of Arts and Sciences; and Colin Fowley and Bridgeen McCuaghan, School of Pharmacy and Pharmaceutical Sciences at the University of Ulster.

source:  University of Miami.

Nanoshell Shields Foreign Enzymes Used to Starve Cancer Cells from Immune System

Nanoengineers at the University of California, San Diego have developed a nanoshell to protect foreign enzymes used to starve cancer cells as part of chemotherapy.

                        Enzymes are naturally smart machines that are responsible for many complex functions and chemical reactions in biology. However, despite their huge potential, their use in medicine has been limited by the immune system, which is designed to attack foreign intruders. For example, doctors have long relied on an enzyme called asparaginase to starve cancer cells as a patient undergoes chemotherapy. But because asparaginase is derived from a nonhuman organism, E. Coli, it is quickly neutralized by the patient’s immune system and sometimes produces an allergic reaction. In animal studies with asparaginase, and other therapeutic enzymes, the research team found that their porous hollow nanoshell effectively shielded enzymes from the immune system, giving them time to work.

                                        

                                The shell’s pores are too small for the enzyme to escape but big enough for diffusion of amino acids that feed cancer cells in and out of the particle. The enzymes remain trapped inside where they deplete any amino acids that enter.  Photo courtesy of Inanc Ortac.

             Asparaginase works by reacting with amino acids that are an essential nutrient for cancer cells. The reaction depletes the amino acid, depriving the abnormal cells from the nutrients they need to proliferate.

“Ours is a pure engineering solution to a medical problem,” said Inanc Ortac (Ph.D. '13), who developed the technology as part of his doctoral research in the laboratory of nanoengineering professor Sadik Esener at UC San Diego Jacobs School of Engineering.

            The nanoshell acts like a filter in the bloodstream. The enzymes are loaded into the nanoparticle very efficiently through pores on its surface and later encapsulated with a shell of nanoporous silica. The shell’s pores are too small for the enzyme to escape but big enough for diffusion of amino acids that feed cancer cells in and out of the particle. The enzymes remain trapped inside where they deplete any amino acids that enter.  "This is a platform technology that may find applications in many different fields. Our starting point was solving a problem for cancer therapeutics,” said Ortac.

source:   Catherine Hockmuth
Jacobs School of Engineering
chockmuth@ucsd.edu

Nanodiamonds as bacterial killers

Nanodiamonds are a class of carbon-based nanoparticles that are rapidly gaining attention, particularly for biomedical applications, i.e., as drug carriers, for bioimaging, or as implant coatings. Nanodiamonds have generally been considered biocompatible with a broad variety of eukaryotic cells. We show that, depending on their surface composition, nanodiamonds kill Gram-positive and -negative bacteria rapidly and efficiently. We investigated six different types of nanodiamonds exhibiting diverse oxygen-containing surface groups that were created using standard pretreatment methods for forming nanodiamond dispersions. Our experiments suggest that the antibacterial activity of nanodiamond is linked to the presence of partially oxidized and negatively charged surfaces, specifically those containing acid anhydride groups. Furthermore, proteins were found to control the bactericidal properties of nanodiamonds by covering these surface groups, which explains the previously reported biocompatibility of nanodiamonds. Our findings describe the discovery of an exciting property of partially oxidized nanodiamonds as a potent antibacterial agent.

  
                                                  

The colored particles display different types of nanodiamonds that bind to bacterial cells (grey) and kill them. (Image: University of Bremen)

Exhibiting a diameter of 5 nanometers, nanodiamonds are 200-times smaller than a bacterium. Nanodiamonds are produced by the explosion of carbon-containing compounds in high-pressure storage tanks. Here, the tiny detonation diamonds are formed besides large amounts of soot. The material scientists Dr. Michael Maas, Julia Wehling and Professor Kurosch Rezwan from the University of Bremen (Germany) have now identified the strong antibacterial properties of these nanodiamonds. Besides silver and copper, nanodiamonds might be used as a new effective agent against bacterial contaminations and infections

             Discovered in the 1960s by Russian scientists, nanodiamonds only recently came into the spotlight, caused by current breakthroughs in processing and pretreatments that enabled their use in laboratories. Heat treatment of the grayish brown diamond powder can be used to generate different chemical groups on the nanodiamond surface. Biologist Julia Wehling and chemist and project leader Dr. Michael Maas discovered that some types of nanodiamonds kill bacterial cells rapidly and efficiently. Seeking to understand the reason for the antibacterial properties, both material scientists from the Advanced Ceramics Group of Prof. Dr.-Ing. Kurosch Rezwan puzzled out the cause: some oxygen-containing groups on the surface of nanodiamonds, such as acid anhydrides, seem to be responsible for the antibacterial effect of the diamonds.“The discovery that nanodiamonds kill bacterial cells as effectively as silver, which has been already used for 7000 years, opens a multitude of possible applications in biomedicine and material science. Furthermore, the concentrations that we used are proven to be nontoxic for human cells. This enables the use of nanodiamonds for surface coatings or as additives for disinfectants. In the era of antibiotic resistances, the discovery of a new antibacterial material can be seen as a breakthrough”, says Julia Wehling.The only scarcely explored diamonds were brought to the attention of Dr. Michael Maas by Prof. Richard N. Zare during a visit at Stanford University in California. “After my return, we directly started using nanodiamonds in the different nanosystems that we are working with in Bremen. We were quite surprised by how efficiently nanodiamonds killed bacteria and we are convinced that our discovery will be of great impact for further research. It can be expected that nanodiamonds will play a key role in different areas dealing with bacterial infection. Our next goal is to equip implant materials with nanodiamonds to provide them with antibacterial properties. At the same time, we want to further analyze the diamond surface”, Michael Maas says.

Source: University of Bremen

Graphene Contact Lenses Let You See in the Dark

                                                                                 

Thanks to graphene contact lenses, we all might be able to experience soon the super hero ability of having night vision. According to Zhaohui Zhong, an assistant professor of electrical and computer engineering at the University of Michigan, contact lenses one day in the near future will be able to register the entire infrared spectrum as well as visible and ultraviolet light.

There have been previous attempts to use graphene on contact lenses for this purpose, but they were unsuccessful, because of graphene’s insensitivity to certain parts of the light spectrum.

Zhong and the rest of his research team from Michigan solved this problem by creating a sandwich of layers. There would be an insulating barrier between two extremely thin slices of graphene, and an electrical current would then be sent through the bottom layer. The design would, according to Zhong, be “super-thin,” and it could, he added: “be stacked on a contact lens or integrated with a cell phone.”

What use would anyone have for graphene contact lenses?

Why would anyone want a pair of graphene contact lenses, you might well ask; just how useful would having night vision be, unless you were in the military?

There are many, many reasons why a person would want to have graphene contact lenses. They would be very useful to hunters of fishermen at night, policemen, firemen, and any other job where people have to sometimes work in almost total darkness. Ghost hunters like Zak Bagans, Nick Groff, and Aaron Goodwin, of the TV series “Ghost Adventures,” would love using this sort of technology.

The graphene contact lenses would be great for use by everyone else who has ever stumbled over a child’s toy in the middle of the night, or who has had to walk back to his/her car after a late-night movie or concert. They could also be useful for driving at night in places where there are not lit up by street lights.

How are graphene contact lenses better than current night-vision devices?

Graphene contact lenses are better than current night-vision devices because they are not nearly as bulky; they don’t require cooling equipment so that the heat detectors won’t get confused by the heat radiation that they, themselves, emit; and they can do “the same thing by using only a few layers of the atom-thick material,” according to a report in the Business Standard.

Current night-vision technology involves capturing the light spectrum’s infrared portion. The infrared portion is the heat that objects, humans, and animals emit, as opposed to light reflected off of objects.

The best night vision technology works by capturing the infrared portion of the light spectrum. Infrared is the part that is emitted as heat by objects, instead of reflected as light.

Other Uses for the Graphene Technology

Zhong mentioned other possible uses for the new graphene technology. For instance, he suggested that it could be used by doctors to monitor the blood flow of a patient without the necessity of moving them or subjecting them to being scanned. Also, art historians could be able to detect layers of paint and possibly entire paintings hidden underneath the surface of paintings.

Graphene contact lenses are just one of many uses that scientists and researchers have been developing. Some others include being able to charge your smartphone up in just 5 seconds; clumping together radioactive waste, making cleanup of it much easier and safer; in the manufacture of tennis racquets; creating filters to make even salt water drinkable; and it could be used to create super-thin, unbreakable touchscreens for your iPhones.

The potential uses for graphene are almost limitless, but what can beat the sensation you could have wearing graphene contact lenses that would enable you to see at night? One day you might be able to do just that, and unleash your inner Batman or Batwoman!

Written by: Douglas Cobb from nonotechnology now

Boston.com
DesignnTrend.com
BusinessStandard.com
Nature Nanotechnology journal article
Gizmodo.com