How To Trap DNA molecules With Your Smartphone

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

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

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

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

The research study has been published  in Nature Communications.

Source: https://cse.umn.edu/

Shape-shifting Molecular Robots

A research group at Tohoku University and Japan Advanced Institute of Science and Technology has developed a molecular robot consisting of biomolecules, such as DNA and protein. The molecular robot was developed by integrating molecular machines into an artificial cell membrane. It can start and stop its shape-changing function in response to a specific DNA signal.

This is the first time that a molecular robotic system has been able to recognize signals and control its shape-changing function. What this means is that molecular robots could, in the near future, function in a way similar to living organisms.

Using sophisticated biomolecules such as DNA and proteins, living organisms perform important functions. For example, white blood cells can chase bacteria by sensing chemical signals and migrating toward the target. In the field of chemistry and synthetic biology, elemental technologies for making various molecular machines, such as sensors, processors and actuators, are created using biomolecules. A molecular robot is an artificial molecular system that is built by integrating molecular machines. The researchers believe that realization of such a system could lead to a significant breakthrough – a bio-inspired robot designed on a molecular basis.

molecular robot

The molecular robot developed by the research group is extremely small – about one millionth of a meter – similar in size to human cells. It consists of a molecular actuator, composed of protein, and a molecular clutch, composed of DNA. The shape of the robot’s body (artificial cell membrane) can be changed by the actuator, while the transmission of the force generated by the actuator can be controlled by the molecular clutch. The research group demonstrated through experiments that the molecular robot could start and stop the shape-changing behavior in response to a specific DNA signal.

The findings were published in Science Robotics.

Source: http://www.tohoku.ac.jp/

Medical Nanorobots

Researchers from the Institute of General Physics, the Institute of Bioorganic Chemistry (Russia, Academy of Sciences) and MIPT have made an important step towards creating medical nanorobots. They discovered a way of enabling nano– and microparticles to produce logical calculations using a variety of biochemical reactions.
biological nanorobotsThe scientists draw on the idea of computing using biomolecules. In electronic circuits, for instance, logical connectives use current or voltage (if there is voltage, the result is 1, if there is none, it’s 0). In biochemical systems, the result can a given substance. For example, modern bioengineering techniques allow for making a cell illuminate with different colors or even programming it to die, linking the initiation of apoptosis to the result of binary operations.

Scientists say logical operations inside cells to be a way of controlling biological processes and creating nano-robots, which can deliver drugs on schedule. Calculations using biomolecules inside cells, a.k.a. biocomputing, are a very promising and rapidly developing branch of science, according to the leading author of the study, Maxim Nikitin, a 2010 graduate of MIPT’s Department of Biological and Medical Physics. Biocomputing uses natural cellular mechanisms.

The study paves the way for a number of biomedical technologies and differs significantly from previous works in biocomputing binary operations in DNA, RNA and proteins for over a decade now, but Maxim Nikitin and his colleagues were the first to propose and experimentally confirm a method to transform almost any type of nanoparticle or microparticle into autonomous biocomputing structures that are capable of implementing a functionally complete set of Boolean logic gates (YES, NOT, AND and OR) and binding to a target (such as a cell) as result of a computation.

The prefix “nano” in this case is not a fad or a mere formality. A decrease in particle size sometimes leads to drastic changes in the physical and chemical properties of a substance. The smaller the size, the greater the reactivity; very small semiconductor particles, for example, may produce fluorescent light. The new research project used nanoparticles (i.e. particles of 100 nm) and microparticles (3000 nm or 3 micrometers).

The new work was published on the website of the journal Nature Nanotechnology.
Source: http://mipt.ru/

DNA, Tool To Detect Cancer At Early Stage

Bioengineers at the University of Rome Tor Vergata and the University of Montreal have used DNA to develop a tool that detects and reacts to chemical changes caused by cancer cells and that may one day be used to deliver drugs to tumor cells.
The researchers’ nanosensor measures pH variations at the nanoscale – –how acidic (a higher pH level) or alkaline (a lower pH level) it is. Many biomolecules, such as enzymes and proteins, are strongly regulated by small pH changes. These changes affect in turn biological activities such as enzyme catalysis, protein assembly, membrane function and cell death. There is also a strong relation between cancer and pH.
Cancer cells often display a lower pH compared to normal cells: the pH level inside cancer cells is higher than it is outside.

DNA-based nanosensor that allows to measure pH variation at the nanoscale

In living organisms, these small pH changes typically occur in tiny areas measuring only few hundred nanometers,” says Prof. Francesco Ricci. “Developing sensors or nanomachines that can measure pH changes at this scale should prove of utility for several applications in the fields of in-vivo imaging, clinical diagnostics and drug-delivery.
DNA represents an ideal material to build sensors or nanomachines at the nanometer scale” adds Prof. Vallée-Bélisle. “By taking advantage of a specific DNA sequences that form pH-sensitive triple helix, we have designed a versatile nanosensor that can be programmed to fluoresce only at specific pH values.” Fluorescence is the emission of radiation, including visible light, caused by an exchange of energy.
This programming ability represents a key feature for clinical applications –we can design a specific sensor to send a fluorescent signal only when the pH reaches a specific value which is, for example, characteristic of a specific disease,” concludes first author Andrea Idili.
In the future, this recently patented nanotechnology may also find applications in the development of novel drug-delivery platforms that release chemio-therapeutic drugs only in the vicinity of tumor cells..

Source: http://www.newswise.com/

New Tool for Imaging Biomolecules

At the heart of the immune system that protects our bodies from disease and foreign invaders is a vast and complex communications network involving millions of cells, sending and receiving chemical signals that can mean life or death. At the heart of this vast cellular signaling network are interactions between billions of proteins and other biomolecules. These interactions, in turn, are greatly influenced by the spatial patterning of signaling and receptor molecules.   Biology is a game of nanometers, where spatial differences of only a few nanometers can determine the fate of a cell – whether it lives or dies, remains normal or turns cancerousA scientific team led by chemist Jay Groves (Berkeley Lab and the University of California – UC- Berkeleyhas used supported membranes to demonstrate that living cells not only interact with their environment through chemical signals but also through physical force.

click here to enjoy the video demonstration

The ability to observe signaling spatial patterns in the immune and other cellular systems as they evolve, and to study the impact on molecular interactions and, ultimately, cellular communication, would be a critical tool in the fight against immunological and other disorders that lead to a broad range of health problems including cancer.  
Such a tool is now at hand
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Source: http://newscenter.lbl.gov/feature-stories/2012/03/23/a-shiny-new-tool-for-imaging-biomolecules/