Posts tagged medicine

Drug-smuggling nanoparticles target tumours

Drug-smuggling nanoparticles could be the latest recruits in the fight againstcancer. The first results from early-stage trials show that cancer drugs couriered by nanoparticles may reduce the size of tumours in humans.

Researchers from BIND Biosciences in Boston filled nanoparticles with the cancer drug docetaxel and injected them into the blood of 17 people who had cancers that are normally resistant to the drug. Forty-two days later, two of the volunteers’ tumours had shrunk in size significantly, and the rest of the volunteers’ tumours had not grown.

Research wrests partial control of a memory

Scripps Research Institute scientists and their colleagues have successfully harnessed neurons in mouse brains, allowing them to at least partially control a specific memory. Though just an initial step, the researchers hope such work will eventually lead to better understanding of how memories form in the brain, and possibly even to ways to weaken harmful thoughts for those with conditions such as schizophrenia and post traumatic stress disorder.

The results are reported in the March 23, 2012 issue of the journal Science.

Researchers have known for decades that stimulating various regions of the brain can trigger behaviors and even memories. But understanding the way these brain functions develop and occur normally—effectively how we become who we are—has been a much more complex goal.

"The question we’re ultimately interested in is: How does the activity of the brain represent the world?" said Scripps Research neuroscientist Mark Mayford, who led the new study. "Understanding all this will help us understand what goes wrong in situations where you have inappropriate perceptions. It can also tell us where the brain changes with learning."

The team is now making progress toward more precise control that will allow the scientists to turn one memory on and off at will so effectively that a mouse will in fact perceive itself to be in Box A when it’s in Box B.

Should Science Pull the Trigger on Antiviral Drugs—That Can Blast the Common Cold?

We do currently have “antiviral” drugs, but they’re a pale shadow of their bacteria-fighting counterparts. People infected with HIV, for example, can avoid developing AIDS by taking a cocktail of antiviral drugs. But if they stop taking them, the virus will rebound to its former level in a matter of weeks. Patients have to keep taking the drugs for the rest of their lives to prevent the virus from wiping out their immune system.

Photo: Stan Musilek

Filoviridae (Ebola)
Photo: Stan Musilek

Viruses mutate much faster than bacteria, and so our current antivirals have a limited shelf life. And they all have a narrow scope of attack. You might treat your flu with Tamiflu, but it won’t cure you of dengue fever orJapanese encephalitis. Scientists have to develop antivirals one disease at a time—a labor that can take many years. As a result, we still have no antivirals for many of the world’s nastiest viruses, like Ebola andNipah virus. We can expect more viruses to leap from animals to our own species in the future, and when they do, there’s a good chance we’ll be powerless to stop them from spreading.

Virologists, in other words, are still waiting for their Penicillin Moment. But they might not have to wait forever. Buoyed by advances in molecular biology, a handful of researchers in labs around the US and Canada are homing in on strategies that could eliminate not just individual viruses but any virus, wiping out viral infections with the same wide-spectrum efficiency that penicillin and Cipro bring to the fight against bacteria. If these scientists succeed, future generations may struggle to imagine a time when we were at the mercy of viruses, just as we struggle to imagine a time before antibiotics.

Three teams in particular are zeroing in on new antiviral strategies, with each group taking a slightly different approach to the problem. But at root they are all targeting our own physiology, the aspects of our cell biology that allow viruses to take hold and reproduce. If even one of these approaches pans out, we might be able to eradicate any type of virus we want. Someday we might even be faced with a question that today sounds absurd: Are there viruses that need protecting?

Our bodies are rife not just with bacteria but with viruses too. Even when we’re perfectly healthy, we have trillions of viruses inside of us. Scientists are only beginning to survey this viral ecology, but some suspect that it may actually be essential to our health. Many animals depend on viruses. Aphids, for example, need a virus that makes a toxin that prevents wasps from laying eggs inside their bodies. Scientists have found that infecting mice with lymphotrophic viruses protects them from developing diabetes. Other viruses attack cancer cells.

We may have such beneficial viruses inside our own bodies as well, waiting to be discovered. These viruses may not even infect our own cells but could instead be inside the bacteria that colonize us. Some species might keep the populations of their microbial hosts in check, like predators thinning a herd. Some viruses merge with bacteria rather than killing them, providing their hosts with useful genes for feeding or fighting off competitors. All of these microbe-infecting viruses may ultimately help us stay healthy.

How to Mend a Broken Heart

Four-year-old Angela Irizarry was born with a single pumping chamber in her heart, a potentially lethal defect. To fix the problem, Angela is growing a new blood vessel in her body in an experimental treatment that could advance the burgeoning field of regenerative medicine. Doctors at Yale University here implanted in Angela’s chest in August a bioabsorbable tube that is designed to dissolve over time. The tube was seeded with cells, including stem cells, that had been harvested from Angela’s bone marrow. Since then, the doctors say, the tube has disappeared, leaving in its place a conduit produced by Angela’s cells that functions like a normal blood vessel.

Scientists have long been captivated by the ability of animals such as salamanders and starfish to regrow body parts lost to injury. It was long assumed that developmental forces that create a human being in the womb are lost at birth. But recent advances in stem-cell research and tissue engineering suggest that regenerative forces can be reawakened with strategically implanted stem cells and other tissue.

This notion is fueling research at many academic laboratories and dozens of start-up companies where scientists are hoping to identify effective ways to treat maladies including heart muscle damaged from heart attacks, paralysis due to spinal cord injuries and poor-functioning kidneys and bladders.

Nanopills Release Drugs Directly from the Inside of Cells

Researchers at Universitat Autonoma de Barcelona (UAB) have created nanoparticles which could release drugs directly from the cells’ interior. The technology, which has been named “nanopills,” was licensed to the firm Janus Developments of the Barcelona Scientific Park, which verified its tolerance by administering it in vivo.

UAB researchers developed a new vehicle to release proteins with therapeutic effects. This is known as “bacteria-inclusion bodies,” stable insoluble nanoparticles which normally are found in recombinant bacteria. Even though these inclusion bodies traditionally have been an obstacle in the industrial production of soluble enzymes and biodrugs, they were recently recognised as having large amounts of functional proteins with direct values in industrial and biomedical applications.

Printing Muscle
Organovo’s 3-D printer creates human tissues that could help speed drug discovery.
So far, Organovo has made only small pieces of tissue, but its  ultimate  goal is to use its 3-D printer to make complete organs for   transplants. Because the organs would be printed from a patient’s own   cells, there would be less danger of rejection.

Printing Muscle

Organovo’s 3-D printer creates human tissues that could help speed drug discovery.

So far, Organovo has made only small pieces of tissue, but its ultimate goal is to use its 3-D printer to make complete organs for transplants. Because the organs would be printed from a patient’s own cells, there would be less danger of rejection.

Sending DNA robot to do the job

Researchers at the Wyss Institute for Biologically Inspired Engineering at Harvard University have developed a robotic device made from DNA that could potentially seek out specific cell targets within a complex mixture of cell types and deliver important molecular instructions, such as telling cancer cells to self-destruct. Inspired by the mechanics of the body’s own immune system, the technology might one day be used to program immune responses to treat various diseases. The research findings appear today in Science.

Successful human tests for first wirelessly controlled drug-delivery chip

Medication via remote-control instead of a shot? Scientists implanted a microchip in seven women that did just that, oozing out the right dose of a bone-strengthening drug once a day without them even noticing. Implanted medicine is a hot field, aiming to help patients better stick to their meds and to deliver those drugs straight to the body part that needs them.

"You could literally have a pharmacy on a chip," says Langer, the David H. Koch Institute Professor at MIT. "You can do remote control delivery, you can do pulsatile delivery, and you can deliver multiple drugs.”

Compound May Help in Fight Against Antibiotic-Resistant Superbugs

North Carolina State University chemists have created a compound that makes existing antibiotics 16 times more effective against recently discovered antibiotic-resistant “superbugs.”

These so-called superbugs are actually bacterial strains that produce an enzyme known as New Delhi metallo-β-lactamase (NDM-1). Bacteria that produce this enzyme are practically impervious to antibiotics because NDM-1 renders certain antibiotics unable to bind with their bacterial targets. Since NDM-1 is found in Gram-negative bacteria like K. pneumoniae, which causes pneumonia, urinary tract, and other common hospital-acquired infections, it is of particular concern.

"We’ve demonstrated that we have the ability to take out the scariest superbug out there," Melander says. "Hopefully further research will allow us to make the compound even more effective, and make these infections little more than a nuisance."