Researchers at UC San Diego have built a bacterial light source of about 13,000 ‘biopixels’, as they call it. Their work on synchronized fluorescent protein expression was published in Nature last week. This is not only a new form of art but also a piece of high tech bioengineering. The light producing chips consist of more than 50 million bacteria that interact and synchronize with each other using a mechanism known as quorum sensing, a method in which bacteria communicate with their fellows and gives them group-like behavior. They can regulate gene expression according to the density of the population or to determine adaptation strategies to their local environment.

The researchers in San Diego coupled the expression of a fluorescent protein to a biological clock which is synchronized with other colonies using a quorum sensing mechanism. In this way the bacteria will periodically fluoresce in unison like blinking light bulbs.

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A collaboration of researchers from Wayne State University, the Mayo Clinic and Johns Hopkins Medicine has discovered a potential new treatment for macular degeneration and retinitis pigmentosa. The investigators managed to attach steroids to dendrimers nanoparticles and showed that the drugs only targeted the activated microglia, the damage-causing cells associated with neuroinflammation. The researchers published their article online in the journal Biomaterials.

Age-related macular degeneration and retinitis pigmentosa are leading causes of blindness worldwide. Neuroinflammation plays a big role in both diseases. Activated microglia release substances that damage certain cells in the retina, which eventually can lead to vision loss.

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Researchers at Purdue have developed a method of monitoring both metallic and semiconducting nanotubes within cells and blood plasma without using any kind of marking or dying labels. The method, called transient absorption, uses two near-infrared lasers to energize and detect the shining nanotubes.

The method should be useful for monitoring the effects of nano-based treatments during laboratory and clinical development.

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Last week, we announced that the second artificial trachea implant procedure had been performed under the leadership of Paolo Macchiarini, MD, PhD at the Karolinska Institutet (Stockholm, Sweden). To get some perspective on what this news means for the field of medicine and tissue engineering, Medgadget spoke with Dr. Macchiarini as well as David Green, president of Harvard Bioscience (Holliston, MA), a company that made the bioreactor used to create the tissue-engineered trachea implants.

“The most important thing to me is that we now have evidence that regenerative medicine has promise; we’ve proved that it works in the clinic,” says Macchiarini.

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A few months ago we reported about the first artificial trachea transplant performed at Karolinska Institutet in Sweden. A patient had a carinal tumor that extended to the lowest 5 cm of the trachea along with the bronchi, so removal alone couldn’t save the patient. The team of surgeons removed the affected area and replaced it with a synthetic engineered trachea. The project was headed by Professor Paolo Macchiarini. Now, five months later, the study and successful outcome has been published in The Lancet by the doctors who performed the procedure.

The successful outcome of this operation, involving a transplant made of stem-cell-seeded nanocomposite, provides proof of the viability of this approach. Macchiarini says this method offers advantages, like preventing rejection or use of immunosuppressive drugs by using the patient’s own cells. Also, the implant can be tailor-made for the patient, because it is artificially constructed.

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Research teams from Purdue University and the University of Oxford are collaboratively developing a system which can measure the mechanical properties of living cells. To study the different types of cells they make use of an atomic force microscope. Up until now methods using atomic force microscopes were either too slow or did not have a high enough resolution. Professor Arvind Raman and his team have overcome these limitations and they reported their findings online in Nature Nanotechnology.

Atomic force microscopes make use of a small vibrating probe to gather information about materials and surfaces on the scale of nanometers. It makes it possible to ‘see’ certain objects which cannot be visualized using light microscopes. Therefore such microscopes could prove to be very useful in creating a kind of ‘map’ of mechanical properties of the smallest cellular structures.

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A researcher collaboration between scientists at University of Colorado–Denver and Technion–Israel Institute of Technology has successfully tested a gold nanoparticle (GNP)-based sensor that can detect lung cancer (LC) markers in a patient’s breath. The technology, which we’ve been following at Medgadget for a few years now (see flashbacks below), is able to rapidly identify small molecule volatile organic compounds that might point to the presence of lung cancer.

The team compared the sensor to gas chromatography–mass spectrometry identification finding that the new device provided “significant discrimination between (i) LC and healthy states; (ii) small cell LC and non–small cell LC; and between (iii) two subtypes of non–small cell LC: adenocarcinoma and squamous cell carcinoma.”

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A chip to accurately count sperm and measure their motility has been developed by Loes Segerink, researcher at the Universiteit Twente in The Netherlands. And by inserting this chip into a compact device, an accurate at-home test kit for men to assess fertility might become possible soon.

Here how it works, according to the press release:

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As we near the end of the 2011 Breast Cancer Awareness Month, it is fitting to continue our coverage of new developments related to breast cancer diagnostics and treatments. We recently reported on GE Healthcare‘s newly FDA-approved SenoBright system that promises to greatly improve imaging of breast tissue over traditional mammograms. Though mammographies have tremendously enhanced patient care – in some cases detecting pre-cancerous lesions three years prior to any problems arising – they are not perfect.  Mammograms currently are incapable of distinguishing between benign and malignant lesions and are estimated to miss detecting 10-25 percent of breast cancers.

In the latest issue of Breast Cancer Research, a collaborative team of oncologists and nanotechnology researchers report using targeted magnetic nanoparticles and ultra-sensitive magnetic field sensors to accurately detect relatively small numbers of breast cancer cells. By conjugating iron-oxide nanoparticles (diameter < 30 nm) with antibodies for the aggressive breast cancer cell surface receptor, Her2, the team was able to attach hundreds of magnetic nanoparticles to each individual cancer cell. Then, using superconducting quantum interference device (SQUID) sensors, they could differentially distinguish cancerous cells from normal tissue. The authors refer to this as magnetic relaxometry, which they describe as:

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Nanoparticles tend to clump together, or “agglomerate,” in a solution. How clusters are formed and what shape they assume can influence a number of factors including their toxicity, how they interact with their environment, and their suitability for use in biosensors. To better understand  nanoparticle agglomeration, researchers at the National Institute of Standards and Technology (NIST) have developed a method of precisely measuring cluster-size distribution and the resulting characteristic light absorption.

The research could assist with the development of ultra-sensitive pregnancy tests, according to NIST biomedical engineer Justin Zook. Such tests could be created by coating gold nanoparticles with antibodies to a human chorionic gonadotropin (hCG), a hormone produced by an embryo following conception.

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