Category Archives: Biology

Researchers merge human tissue with nanoscale wire “scaffold”

Scientists at Harvard have created a new system for using nanoscale wires to create scaffolds upon which human cells can grow into tissue. The combined “cyborg tissue” will enable researchers to measure chemical or electrical changes in living tissue. From the Harvard Gazette:

The process of building the networks, Lieber said, is similar to that used to etch microchips.

Beginning with a two-dimensional substrate, researchers laid out a mesh of organic polymer around nanoscale wires, which serve as the critical sensing elements. Nanoscale electrodes, which connect the nanowire elements, were then built within the mesh to enable nanowire transistors to measure the activity in cells without damaging them. Once completed, the substrate was dissolved, leaving researchers with a netlike sponge, or a mesh, that can be folded or rolled into a host of three-dimensional shapes.

Once complete, the networks were porous enough to allow the team to seed them with cells and encourage those cells to grow in 3-D cultures.

Takeaway quote from Charles M. Lieber, Mark Hyman Jr. Professor of Chemistry at Harvard: “Ultimately, this is about merging tissue with electronics in a way that it becomes difficult to determine where the tissue ends and the electronics begin.”

“Superhuman” exhibition showcases human enhancement through history, into the future

“Superhuman” – an exhibit currently showing at The Wellcome Collection in London – is showcasing art and displays focused on human enhancement throughout our history. The undeniably transhumanist exhibition will also examine how technology “stretches our ability to perform in the world.” From the site:

Glasses, lipstick, false teeth, the contraceptive pill and even your mobile phone – we take for granted how commonplace human enhancements are. Current scientific developments point to a future where cognitive enhancers and medical nanorobots will be widespread as we seek to augment our beauty, intelligence and health.

Superhuman takes a broad and playful look at our obsession with being the best we can be. Items on display range from an ancient Egyptian prosthetic toe to a packet of Viagra, alongside contributions from artists such as Matthew Barney and scientists, ethicists and commentators working at the cutting edge of this most exciting, and feared, area of modern science.

“Superhuman” will run through October 16, 2012.

Physicians ponder the future of medical robotics

Robots like the da Vinci surgical robot have enabled humans to achieve a remarkable degree of precision when performing certain surgeries, but these technologies – while incredible – are really just an extension of a physician’s body, like a very high tech scalpel or forceps.

A new generation of tiny snake-like robots is actually capable of crawling through the body to perform surgery, but again, these are guided by a human physician, and tethered to a external machine.

Physicians may look forward to these developments, but many may not foresee a future in which the robot will perform tasks on its own, without the guiding hand of a doctor:

“It won’t be very long before we have robots that are nanobots, meaning they will actually be inside the body without tethers,” said Dr. Michael Argenziano, the Chief of Adult Cardiac Surgery at New York-Presbyterian Hospital and Columbia University Medical Center in New York.

Argenziano was involved with some of the first U.S. Food and Drug Administration clinical trials on robotic heart surgery more than 10 years ago. Now he says snake robots have become a commonly used tool that gives surgeons a whole new perspective.

“It’s like the ability to have little hands inside the patients, as if the surgeon had been shrunken, and was working on the heart valve,” he said.

But Argenziano and experts in robotics say the new creations work best when they’re designed for very specific tasks. “The robot is a tool. It is no different in that sense than a scalpel. It’s really a master-slave device,” he said.

Argenziano recognizes that medical robots will continue to shrink in size and expand in capability, but is careful to note they won’t be putting him out of a job any time soon. He’s correct – for now.

In a generation, however, we may very well loose tiny robots within our bodies to perform autonomous diagnostics and procedures, often before we’ve even become aware of any symptoms that something is wrong. The role of a physician could easily change to that of a manager, directing fleets of tiny robots within patients, similar to the way an engineer helps guide the actions of robots on a factory floor.

Are scientists closer to developing resveratrol-based drugs?

Resveratrol is one of those wonder supplements purported to have many beneficial health effects, including increased longevity, anti-inflammatory properties, cancer-fighting properties, and more. Although animal studies have provided some evidence for these claims, human studies have been mixed.

Even with somewhat thin existing evidence of its benefits in humans, resveratrol has proven to be very popular as a nutritional supplement. Recent studies, however, may have cracked the code of how resveratrol can benefit health, and may open the door for resveratrol-based drugs:

“Resveratrol has potential as a therapy for diverse diseases such as type 2 diabetes, Alzheimer’s disease and heart disease,” study author Dr. Jay Chung, chief of the Laboratory of Obesity and Aging Research at the National Heart, Lung and Blood Institute, said in an institute news release. “However, before researchers can transform resveratrol into a safe and effective medicine, they need to know exactly what it targets in cells.”

Resveratrol appears to inhibit proteins called phosphodiesterases (PDEs), which help regulate cell energy, according to the researchers.

Some previous studies suggested that resveratrol’s primary target is sirtuin 1, but the authors of this new study doubted that when they found that resveratrol activity required another protein called AMPK. This would not be the case if resveratrol directly interacted with sirtuin 1.

The researchers analyzed the metabolic activity in cells treated with resveratrol and identified the protein PDE4 in the skeletal muscle as the principal target for the health benefits of resveratrol.

Details of the study are published in the current edition of Cell – a summary can be found here.

Next step in fast evolution of tissue engineering: 3D-printed capillaries

A team of German researchers claims to have found success in creating artificial capillaries, the smallest blood vessels in the body, via a 3D printer. These capillaries could be used to provide blood to lab grown organs in the future. From the BBC:

To print something as small and complex as a blood vessel, the scientists combined the 3D printing technology with two-photon polymerisation – shining intense laser beams onto the material to stimulate the molecules in a very small focus point.

The material then becomes an elastic solid, allowing the researchers to create highly precise and elastic structures that would be able to interact with a human body’s natural tissue.

So that the synthetic tubes do not get rejected by the living organism, their walls are coated with modified biomolecules.

Such biomolecules are also present in the composition of the “inks” used for the blood vessel printer, combined with synthetic polymers.

The team that developed this technique will be showing off their new technology at Biotechnica 2011 in October.

Scientists have been looking toward 3D organ printing as a potential path forward for tissue engineering for years, and with researchers on the verge of figuring out how to replace filing kidneys with 3D-printed versions (and having already used similar technology to replace bladders), humans are close to a day where we don’t have to worry about organ donor shortages or take anti-rejection drugs to live with transplanted organs.

That day can’t come soon enough.

New process allows scientists to make stem cells from skin cells

Embryonic stem cell research has faced significant controversy in the United States. Although private embryonic stem cell research is legal and unrestricted, the federal government is not allowed to fund any stem cell research that results in the destruction of the embryo. This has led to researchers exploring alternatives to embryonic destruction or ways to create stem cells that would avoid using human embryos altogether.

Today researchers from Harvard Medical School reported they’ve discovered a “surprisingly quick and apparently safe” way to transform skin cells into stem cells, which have the ability to themselves transform into other cell types. The process involves using RNA to carry new genes into the existing stem cells. In the past, scientists have used viruses to carry the genes, but this had led to serious complications, including development of cancer.

The researchers note this process should not be expected to replace embryonic research, but do note they “believe that our approach has the potential to become a major and perhaps even central enabling technology for cell-based therapies and regenerative medicine.”

Results of their research are published in the journal Cell Stem Cell.

Researchers successfully test “artificial pancreas”

Back in February I posted about the development of an “artificial pancreas,” which automatically monitored blood sugar levels and could deliver insulin when necessary. Today we learned that the system, which is made up of a blood glucose monitor, two insulin pumps and a laptop computer, was successfully tested in 11 adults with type 1 diabetes:

After some adjustments to a sophisticated computer program that acts as the brain of the system, all 11 adults in the study had good blood sugar control without experiencing hypoglycemia, even after eating three high-carbohydrate meals.

“This is the first artificial pancreas device that has used both insulin and glucagon,” said Dr. Steven Russell of Massachusetts General Hospital in Boston, who helped lead the study.

The finding is the latest in what has become a race to develop a fully functioning artificial pancreas that can give patients with type 1 diabetes an automated way to control their blood sugar.

Now if they can only shrink it to an implantable size…

3D organ printing: coming soon to a hospital near you?

For a few years I’ve been reading about technology that enables doctors to “print” human organs for transplants. Unlike the traditional sources for transplant organs (willing donors and cadavers), 3D printers would enable patients in need to receive organs without having to wait on a list, as well as produce organs created from the patients’ own cells, which would eliminate the risk of rejection.

Now two companies have partnered to bring the first commercial organ printer to the market, which will retail for about $200,000:

To start with, only simple tissues, such as skin, muscle and short stretches of blood vessels, will be made, says Keith Murphy, Organovo’s chief executive, and these will be for research purposes. Mr Murphy says, however, that the company expects that within five years, once clinical trials are complete, the printers will produce blood vessels for use as grafts in bypass surgery. With more research it should be possible to produce bigger, more complex body parts. Because the machines have the ability to make branched tubes, the technology could, for example, be used to create the networks of blood vessels needed to sustain larger printed organs, like kidneys, livers and hearts.

The article notes that future applications of this technology may even enable doctors to engineer effective replacement organs that aren’t exact copies of the original, so long as they do the same job. Of course, if we can re-engineer organs, wouldn’t that enable us to improve their function over the originals, as well?