Synthetic biologists are designing and manufacturing "complicated biological circuitry:" bacteria that blink on and off like Christmas tree lights, bacteria that reproduce photographic images, circuits of biological parts to sit in the body's cells and guard against cancer, microbes that produce hydrogen for use as fuel.
"We're talking about taking biology and building it for a specific purpose, rather than taking existing biology and adapting it," Professor Jay D. Keasling said. "We don't have to rely on what nature's necessarily created."
Also new is the desire to make the design of life forms more predictable, like the design of a bridge.
Drew Endy and colleagues at M.I.T. have started a Registry of Standard Biological Parts. The parts, called BioBricks, are strings of DNA that can perform certain functions like turning on a gene or causing a cell to light up.
Some scientists envision that biological engineers will one day sit at computers writing programs for cells, like software developers. But the code would be written in sequences of DNA.
Other scientists experimented with quorum sensing to control bacterial populations, by engineering the microbes to turn on a suicide gene if the concentration of the quorum-sensing chemical grew too high.
However, it might be difficult to make biological engineering as predictable as bridge construction. "There is no such thing as a standard component, because even a standard component works differently depending on the environment," Professor France Arnold said. "The expectation that you can type in a sequence and can predict what a circuit will do is far from reality and always will be."
The unpredictability could lead to safety risks. In addition, the same technology could be used to synthesize known pathogens based on their published DNA sequences. Scientists have already created a poliovirus from scratch and more recently recreated the 1918 pandemic flu virus.
"It's quite clear this technology could be dangerous" if misapplied, Mr. Endy of M.I.T. warned.
Via The New York Times.
A fully functional breast has been grown from a stem cell found in female mice, in a study that promises insights into recurring breast tumours and a fresh approach to plastic surgery.
A team led by Jane Visvader, of the Walter and Eliza Hall Institute in Melbourne, isolated mammary stem cells from the breast pads of female mice for the first time.
They transplanted one of these cells into the mammary fat pad of a living female mouse from which all breast tissue had been removed. The cell divided and gave rise to all the normal types of cell found in the mouse breast, and the gland worked normally to produce milk.
If the findings prove applicable to people, scientists hope to develop drugs that target abnormal breast stem cells to eliminate not only tumours but also the source tissue from which they arise. It may also be possible to use mammary stem cells to grow breast tissue for reconstructive surgery after a mastectomy, or even for use in breast enhancement operations.
Via The Times.
"This has the potential to change the way that chemical plants operate or even improve dialysis treatments," said James. "Solids which have microscopic holes (...) are used in everything from washing powders to large-scale chemical plants. This is because they can mop up or release other substances."
However, he said, one of the problems was that they worked quite slowly as many of the holes were buried deep inside the solid. "With a porous liquid it would flow because the holes would be continually moving around, allowing it to mop up or release other substances incredibly quickly."
A second project will focus on replacing silicon chips with the use of RNA, a biological compound similar to DNA.
The boffins hope to use the material to store information. "Instead of using silicon chips to do computations, as today's computers do, we will try and see if we can do the same thing by using a biological material called RNA," Dr Vyle explained.
Via BBC News.
The University of British Columbia is working on the first human-made species -- a microbe made from scratch. The project is being spearheaded by Craig Venter, who gained fame by completing a privately-owned map of the human genome in 2000.
Several groups are trying to make synthetic genes in hopes of constructing microbes that perform useful tasks, such as producing industrial chemicals, clean energy or drugs. The Columbia team is pushing the technology to its limits by trying to put together an entirely synthetic genome.
They are working to construct a simpler version of the bacteria known as Mycoplasma genitalium, a single-cell bacterium with just one chromosome and 517 genes. The researchers believe their version will be able to survive with only 250 to 400 genes -- each of which they are making themselves, one chemical piece at a time.
For sparking life in a lab-made genome, they plan to use high-voltage electricity to zap open a host bacteria and slowly infuse it with small pieces of new DNA.
Johns Hopkins researchers have devised a self-assembling cube-shaped perforated container, no larger than a dust speck, that could serve as a delivery system for medications and cell therapy.
Because of their metallic nature, the container's location in the body could easily be tracked by magnetic resonance imaging.
"We're talking about an entirely new encapsulation and delivery device that could lead to a new generation of smart pills," said David H. Gracias. "The long-term goal is to be able to implant a collection of these therapeutic containers directly at the site or an injury or an illness."
He believes the microcontainers could someday incorporate electronic components that would allow the cubes to act as biosensors within the body or to release medication on demand in response to a remote-controlled radio frequency signal.
The cubes are coated with a thin layer of gold, so that they are unlikely to pose toxicity problems within the body. They have not yet been implanted in humans or animals, but the researchers have conducted lab tests to demonstrate how they might work in medical applications.
Scientists at the Salk Institute in San Diego have created mice with human brain cells in an effort to make realistic models of neurological disorders such as Parkinson's disease. The researchers injected about 100,000 human embryonic stem cells per mouse into the brains of 14-day-old rodent foetuses.
Those mice were each born with about 0.1 per cent of human cells in each of their heads, a trace amount that the scientists say does not remotely come close to "humanising" the rodents. Mice are already 97.5% genetically identical to humans.
Three cloning researchers provoked controversy with applications for a patent that contemplates fusing a complete set of human DNA into animal eggs in order to manufacturer human embryonic stem cells.
Doctors have transplanted pig valves into human hearts for years, and scientists have injected human cells into lab animals for even longer.
In 1995, Charles Vacanti and Linda Griffith-Cima caused a furore when they grew an engineered human ear on the back of a mouse.
But experiments involving the brain pose an additional level of concern because some envision scenarios in which a human mind might be trapped in an animal head.
"Human diseases, such as Parkinson's disease, might be amenable to stem cell therapy, and it is conceivable, although unlikely, that an animal's cognitive abilities could also be affected by such therapy," said a report by the National Academies of Science. The report recommended that such work be allowed, but with strict ethical guidelines established.