Gold Nanowire Heart Patch Helps Cardiac Tissue Rebuild Itself

Ischaemic heart disease is one of the leading cause of death all over the world causing more than 7 million deaths every year according to WHO. So it's no wonder that scientist all over the world are trying to find ways to combat against it and now Scientists at MIT may be on the best track for the solution.

Fixing cardiac tissue damaged in a heart attack is one of the great current challenges in tissue engineering. Heart cells are particularly hard to make in the lab, requiring special care to develop into the proper type of beating cells. Once they’re made, it’s difficult to seed them into a broken heart. Other efforts have also been made that encourage surrounding heart cells to grow into Heart Muscle Cells.

Electrical signals shared among calcium ions dictate when cardiomyocytes contract, making the heart beat. But tissue scaffolds are often made with materials like polylactic acid or alginate, which act as insulators, so the signals are blocked. This makes it difficult to get all the cells in a piece of tissue to coordinate their signals and beat in time, which in turn makes it difficult to build a very big or very effective heart patch.

The Cambridge-based team, led by Daniel Kohane, a professor in the Harvard-MIT Division of Health Sciences and Technology, went around this problem by creating a sponge-like matrix made from alginate, a gummy organic substance that is frequently used for such tissue scaffolds. Mixed with that alginate, however, was a solution containing billions of tiny gold nanowires. As with "traditional" tissue scaffolds, it was then seeded with heart cells.

Although the alginate itself acted as an insulator, the nanowires were able to bridge the gaps between the cells, allowing electrical signals to pass between them. While heart tissue grown on pure alginate has been shown to have a conductivity of only a few hundred micrometers, the nanowire-enhanced tissue was able to conduct electricity over "many millimeters." Compared to a typical scaffold system, the gold nanowire cells’ conductivity improved by three orders of magnitude. Kohane said it was “night and day.”

The MIT researchers believe that the technology could be used not only for heart patches, but also for addressing problems with other types of muscle tissue, vascular constructs, or in neural systems.

The video below shows how tissue grown in the nanowire-alginate composite (right) is able to conduct electricity better than tissue grown using pure alginate (left).

World's Smallest Battery Yet is About as Thick as a Human Hair

Nanotechnology promises to enable tiny, intricate circuits powering devices on any surface. But unless they’re harvesting energy from something like a heartbeat, the devices can only be as small as the smallest battery.

Now researchers at Rice University have combined the two, packing an entire lithium-ion battery into a single nanowire. The developers say it’s as small as such a device can possibly get.

Researchers led by Rice professor Pulickel Ajayan built a hybrid energy storage device, which serves as a battery and a supercapacitor. The first version sandwiched an electrolyte between a nickel/tin anode and a cathode made of a polymer called polyaniline. The cathode also served as a supercapacitor, storing lithium ions in bulk, as this writeup by Rice University explains. The prototype proved that lithium ions would move through the electrolyte and into the cathode.

Then Ajayan and colleagues incorporated this structure into a single nanowire, through a complicated process of etching and chemical washing. The goal is to make nanowires with ultra-thin separation between electrodes, so the device can remain as small as possible.

The completed wire-batteries are about 50 microns tall, which is roughly the diameter of a human hair, according to Rice.

For now, they can only charge and discharge about 20 times before they die, but researchers are trying to optimize them to last longer. The research is published in the journal ACS Nano Letters.

[Popsci via PhysOrg]

Physicists Confirm Existence of New Particle

Physicists working at Fermilab’s particle accelerator have confirmed the observation of an entirely new particle — the the Xi-sub-b baryon.


Baryons are particles formed of three quarks, in different configurations. The proton is a baryon that consists of two up and one down quark, and the neutron is two down and one up. The Xi-sub-b has an up quark, a strange quark (yes, that’s its real name) and a heavy bottom quark (again, real name), meaning that it weighs around six times as much as a proton or neutron.

Its existence has been predicted for some time, but hadn’t previously been observed. It doesn’t stick around long, though — traveling a fraction of a millimeter before decaying into lighter particles.

Happily, Fermilab has smashed together almost 500 trillion sets of particles, so researchers were able to verify the particle’s existence multiple times over. The Xi-sub-b has been spotted 25 times.

Fermilab’s Tevatron, where the Xi-sub-b was discovered, is based in Illinois in the United States, and was the highest-energy particle accelerator in the world until the Large Hadron Collider opened below Geneva.

Source: Wired

The First Self-Powering Nano-Device That Can Also Transmit Wireless Data

Scientists working with DARPA and Department of Energy backing have cracked the code on a kind of technological milestone, for the first time developing a nano-device capable of powering itself by harvesting energy from vibrations while at the same time transmitting data wirelessly over long distances. That kind of technology could have huge implications for devices ranging from surveillance implements to airborne sensors to implantable medical devices.

Researchers Build the First Living Laser, Using Human Cells and Jellyfish Protein

Researchers at Harvard Medical School and Massachusetts General Hospital built a living laser partly to study interactions between electronic and biological systems, and partly out of sheer curiosity. The world’s first biological laser, made from a single living cell, could lead to better microscope imaging inside the body and even targeted light therapies, researchers say.

First 'practical nanogenerator' developed

Tiny devices that turn bodily movements — such as the snap of one's fingers — into electricity for a cellphone or MP3 player are now much closer to making the leap from the laboratory into everyday life.

Called nanogenerators, these devices are made of so-called piezoelectric materials that generate a current of electricity when stretched or strained. So far, however, nanogenerators have not been able to crank out enough power to be useful.