To understand them well, look to the past.
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Category: bioengineering – Page 163
Genetically modified virus may shrink incurable brain cancers
By Michael Le Page
People with incurable melanomas and brain or breast cancers are to get injections of tumour-fighting viruses.
The trial will test the safety of a virus that has been engineered to shrink tumours – an approach that holds promise for a range of cancers, including deadly brain tumours.
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A first in medical robotics: Autonomous navigation inside the body
Bioengineers at Boston Children’s Hospital report the first demonstration of a robot able to navigate autonomously inside the body. In an animal model of cardiac valve repair, the team programmed a robotic catheter to find its way along the walls of a beating, blood-filled heart to a leaky valve—without a surgeon’s guidance. They report their work today in Science Robotics.
Surgeons have used robots operated by joysticks for more than a decade, and teams have shown that tiny robots can be steered through the body by external forces such as magnetism. However, senior investigator Pierre Dupont, Ph.D., chief of Pediatric Cardiac Bioengineering at Boston Children’s, says that to his knowledge, this is the first report of the equivalent of a self-driving car navigating to a desired destination inside the body.
Dupont envisions autonomous robots assisting surgeons in complex operations, reducing fatigue and freeing surgeons to focus on the most difficult maneuvers, improving outcomes.
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Secret to lab-on-a-chip breakthrough: Matte black nail polish
BYU electrical engineering students have stumbled upon a very unconventional method that could speed up lab-on-a-chip disease diagnosis.
When someone goes to the hospital for a serious illness, if a bacterial infection is suspected, it can take up to three days to get results from a bacteria culture test. By then, it is often too late to adequately treat the infection, especially if the bacteria are resistant to common antibiotics.
BYU students are working on a project to diagnose antibiotic resistant bacteria, or superbugs, in less than an hour. Their method relies on extracting bacteria from a blood sample and then pulling DNA from that bacteria. If specific genetic codes indicating antibiotic resistance are present in the DNA, fluorescent molecules can be attached to these sites. Laser light can then be shined on the DNA samples and the molecules will light up.
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Welding with stem cells for next-generation surgical glues
Scientists at the University of Bristol have invented a new technology that could lead to the development of a new generation of smart surgical glues and dressings for chronic wounds. The new method, pioneered by Dr. Adam Perriman and colleagues, involves re-engineering the membranes of stem cells to effectively ‘weld’ the cells together.
Cell membrane re-engineering is emerging as a powerful tool for the development of next generation cell therapies, as it allows scientists to provide additional functions in the therapeutic cells, such as homing, adhesion or hypoxia (low oxygen) resistance. At the moment, there are few examples where the cell membrane is re-engineered to display active enzymes that drive extracellular matrix production, which is an essential process in wound healing.
In this research, published in Nature Communications today, the team modified the membrane of human mesenchymal stem cells (hMSCs) with an enzyme, known as thrombin, which is involved in the wound healing process. When the modified cells were placed in a solution containing the blood protein fibrinogen, they automatically welded together through the growth of a natural hydrogel from the surface of the cells. The researchers have also shown that the resulting 3D cellular structures could be used for tissue engineering.
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Light-based, 15-second scan aims to replace painful mammograms
Up to 50% of women skip potentially life-saving mammograms often because the procedure can cause extreme discomfort and pain. Now researchers have developed a painless, light-based, non-radioactive, 15-second procedure that could revolutionize breast cancer screening and save lives.
Although early detection of breast cancer can significantly increase survival, the radioactive X-ray that requires painful squeezing of the breast to get a good picture is an event that women do not look forward to. Now Caltech researcher Lihong Wang, Ph.D., Bren Professor of Medical and Electrical Engineering, and his colleagues are using their expertise in imaging tissues with light and sound to address this problem. Their development of a revolutionary breast scanning system known as photoacoustic computed tomography (PACT) is reported in the June issue of Nature Communications.2
“The technique developed by Wang and his colleagues combines light and sound to peer noninvasively into tissues without the radioactivity of an X-ray,” explained Behrouz Shabestari, Ph.D., director of the Program in Optical Imaging at the National Institute of Biomedical Imaging and Bioengineering, which funded the study. “PACT is also superior to MRI, which is expensive and sometimes requires the injection of contrast agents, commonly gadolinium. Gadolinium cannot be used in individuals with kidney disease and has recently been shown to accumulate in the bones and brain with unknown long-term effects.”
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Could humans ever regenerate limbs?
Circa 2016
Just lopped off your ring finger slicing carrots (some time in the future)? No problem. Just speed-read this article while you’re waiting for the dronebulance. …
“Epimorphic regeneration” — growing digits, maybe even limbs, with full 3D structure and functionality — may one day be possible. So say scientists at Tulane University, the University of Washington, and the University of Pittsburgh, writing in a review article just published in Tissue Engineering, Part B, Reviews (open access until March 8).
The process of amphibian epimorphic regeneration may offer hints for humans. After amputation, the wound heals to form an epidermal layer, the underlying tissues undergo matrix remodeling, and cells in the region secrete soluble factors. A heterogeneous cell mass, or blastema, forms from the proliferation and migration of cells from the adjacent tissues. The blastema then gives rise to the various new tissues that are spatially patterned to reconstruct the original limb structure. (credit: Lina M. Quijano et al./Tissue Engineering Part B)
A biosynthetic dual-core cell computer
ETH researchers have integrated two CRISPR-Cas9-based core processors into human cells. This represents a huge step towards creating powerful biocomputers.
Controlling gene expression through gene switches based on a model borrowed from the digital world has long been one of the primary objectives of synthetic biology. The digital technique uses what are known as logic gates to process input signals, creating circuits where, for example, output signal C is produced only when input signals A and B are simultaneously present.
To date, biotechnologists had attempted to build such digital circuits with the help of protein gene switches in cells. However, these had some serious disadvantages: they were not very flexible, could accept only simple programming, and were capable of processing just one input at a time, such as a specific metabolic molecule. More complex computational processes in cells are thus possible only under certain conditions, are unreliable, and frequently fail.
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