For years, researchers have been using fluorescent proteins in bacteria and animals to study everything from gene therapy and neural development to cancer and limb regeneration (and create some very pretty pictures). The concept is fairly simple: by inserting the gene for GFP (green fluorescent protein, originally found in jellyfish) at the end of another gene—say the gene for hemoglobin—its glow can be used to measure how much hemoglobin is produced and where it is produced in the cell.
Inspired by the success of GFP as a research tool (it earned its discoverers the Nobel Prize in Chemistry in 2008), scientists have adopted a similar approach to identify and locate transplanted stem cells in animal models. Except in their case, they’ve begun to use the gene for luciferase, the enzyme responsible for the mesmerizing glow of the firefly. And if this method works, it could make stem cells a potent tool for addressing heart disease.
The engineered ovary after 48 hours.
For many cancer patients, treatment can be a double-edged sword. While recent advances in chemotherapy, radiation therapy, and surgery have brought relief to millions of sufferers, a significant fraction have had to sacrifice their ability to have children in return. Going under the knife or being bombarded by high-energy rays—though often critical for therapy—can sometimes irreparably damage a woman’s eggs or man’s testes, robbing them of their fertility. To say that this leaves young patients pondering therapy with an unenviable set of choices would be something of an understatement.
Fortunately, thanks to some groundbreaking work by researchers from Brown University, female patients may soon never have to make this most difficult of decisions. A team led by Sandra Carson, a professor of obstetrics and gynecology, has built the first synthetic human ovary from scratch by cobbling together the three cell lines involved in egg development—the theca cells, granulosa cells, and egg cells themselves—into a fully three-dimensional honeycomb-shaped structure.
When William McDonough and other pioneers of the sustainable architecture movement first envisioned the concept of living, breathing buildings, it’s safe to say that they probably didn’t have structures teeming with actual living, breathing bacteria in mind. But don’t tell that to Henk Jonkers of Delft University of Technology in the Netherlands. What he and his colleagues have developed—a self-fixing bacteria-concrete hybrid—may do more to propel sustainable architecture into the mainstream than McDonough could have ever hoped for.
While it may sound unheard of, scientists have been pressing bacteria into service in construction for years. The use of mineral-producing bacteria has already been explored in a variety of applications, including the hardening of sand and in repairing cracks in concrete. But there are two problems inherent to this approach. First, the reaction that these bacteria undergo to synthesize calcium carbonate results in the production of ammonium, which is toxic at even moderate concentrations. The other problem is a more prosaic one. Since the bacteria have to be applied manually, a worker or team of workers would have to go out every few weeks to patch up every little crack on every slab of concrete—nearly defeating the purpose of making the repair process simpler and more cost-effective.
Jonkers’ solution was to track down a different bacterial strain that could live happily buried in the concrete for prolonged periods of time. Because the bacteria would be mixed into the concrete from the start, they could immediately nip small cracks in the bud before they had a chance to expand and become exposed to water, rendering them vulnerable to further wear and tear. (Concrete structures are typically reinforced with steel bars, but these can easily become corroded when water seeps into the cracks.) Such a strain would have to endure the high pH environment of concrete and churn out copious amounts of calcium carbonate without also producing large quantities of ammonium. Read More
In a few years’ time, recharging your handheld PC may be as easy as just slipping it into your back pocket. That is, as long as you don’t mind having a virus cocktail woven into your pair of slacks. Yes, the humble virus–that tiny protein-coated bag of genetic material that we more commonly associate with global pandemics–could replace graphite and lithium iron phosphate as the material of choice with which to build the next generation of customizable, high-powered, lithium-ion batteries.
Despite what you may think, this isn’t actually such an unusual pairing. By virtue of their simple design (most only contain enough genes to encode a few dozen proteins) and infinite capacity for manipulation, viruses have become the favored go-to tool for scientists seeking to explore cellular systems and tinker with their underlying components. Gene therapists have been infecting bacterial, plant, and animal cells with viruses for years in order to shuttle in new genes and repair malfunctioning ones. In one recent application, a team of researchers led by University of Pennsylvania ophthalmologist Arthur Cideciyan restored sight to two blind individuals by injecting a virus equipped with a retinal gene into their eyes. Read More
The neurons of a patient suffering from Alzheimer’s.
You may not be consciously aware of it, but at any given time your brain is playing host to billions of simultaneous conversations (and no, I’m not talking about those voices). I speak, of course, of the conversations between your neurons—the incessant neural jabbering that makes it possible for you to move your limbs, learn, remember, and feel pain. Every time we experience a new sensation or form a memory, millions of electrical and chemical signals are propagated across dense networks of axons and jump from one synapse to the next, building new neuronal connections or strengthening existing ones. And they are constantly changing—forming and reforming associations with other neurons in response to how the brain perceives and processes new bits of information.
Despite being central to our understanding of how the brain functions, these neural chats remain largely a mystery to scientists. What exactly are the individual neurons “saying” to each other? And how do these electrical and chemical “messages” become translated into actions, memories, or a range of other complex behaviors? To help decipher these discussions, a team of researchers from the University of Calgary led by bioengineer Naweed Syed have built a silicon microchip embedded with large networks of brain cells. The idea is to get the brain cells to “talk” to the millimeter-square chip—and then have the chip talk to the scientists through a computer interface.