As technology advances, electronic implants may or may not make their way into our bodies. But sometimes your own cells can prove sensors enough. Red blood cells, say scientists presenting work at the American Chemical Society meeting this week, could eventually be transformed to send doctors messages about your blood chemistry, without ever needing to leave the body.
Light, specifically near-infrared light, plays a starring role in this message-sending system. Near-infrared can seep through skin and strike the blood below. Scientists hope to eventually put special dye molecules into patients’ bloodstreams that will, if the blood is at a particular pH, for instance, send out a fluorescent glow when light hits them. A monitor that can detect that glow could let doctors keep tabs on blood chemistry without requiring blood samples.
Human serum albumin is used in everything from vaccines to cell culture.
Human blood is in demand these days. Donor blood is required for transfusions, of course, but it also contains human serum albumin, a blood protein used to treat shock, severe burns, and liver injuries that also shows up in vaccines and in cell culture materials. Worldwide, we use about 500 tons of human serum albumin (abbreviated HSA) a year.
Shortages of the protein and the potential for contamination by blood-borne viruses have encouraged scientists to look beyond donor blood for sources. One promising approach, inserting the gene for HSA into plants and then harvesting the resulting protein, has always yielded too little for the method to make sense financially, but a new paper details a way to get around that: get the plant to make HSA in its seeds, which are lean, mean protein-concentrating machines. HSA made up 10% of the soluble protein in the rice seeds produced by the research team, one of the highest yields on record from a transgenic plant. And when the team put it through its chemical paces, it worked exactly like normal, human-grown HSA, indicating that its sojourn in the plant world hadn’t impaired its usefulness. If all goes as planned, the team will be testing rice-grown HSA in people in clinical trials in the next two years, with an eye towards supplanting donor blood as a source.
[via Nature News]
Image courtesy of Borislav Mitel / Wikimedia Commons
What’s the News: When vampire bats bite their victims, their saliva releases an enzyme called desmoteplase, or DSPA, into the bloodstream, which causes blood to flow more readily. Several years ago, scientists realized that the same enzyme that gives bats more blood for their bite may also help stroke victims by breaking down blood clots. Dubbed Draculin, this blood-clot-bashing drug has now entered a phase 2 study: In hospitals across the country, scientists are currently comparing Draculin with traditional anticoagulants to see if it increases the three-hour window doctors have to treat post-stroke blood clots. “This is one of the studies that actually extends that window up to 9 hours,” says lead researcher Michel Torbey. “We’re hoping the bat saliva, in itself, dissolves the clot with lower risk of bleeding in the brain afterwards.” Read More
What’s the News: Scientists found that periodic fasting may decrease the risk of coronary artery disease and diabetes, and also causes significant changes in heart-disease risk factors like cholesterol, blood-sugar, and triglyceride levels, which hadn’t been linked to fasting before. “We’ve shown it is not a chance finding. Fasting is not just an indicator for other healthy lifestyles,” says lead researcher Benjamin Horne of the Intermountain Medical Center Heart Institute. “It is actually the fasting that is working to reduce the risk of disease.”
What’s the News: Scientists have developed a new carbon nanotube device (pictured above) that’s capable of detecting single cancer cells. Once implemented in hospitals, this microfluidic device could let doctors more efficiently detect the spread of cancer, especially in developing countries that don’t have the money for more sophisticated diagnostic equipment. Any improvement in detecting cancer’s spread is important, says MIT associate professor of aeronautics and astronautics Brian Wardle, because “of all deaths from cancer, 90 percent are … from tumors that spread from the original site.”
What’s the Context:
Not So Fast: The process of commercializing a technology like this takes quite a while; the previous version from four years ago is being tested in hospitals now and is may be commercially available “within the next few years.”
Next Up: The scientists are currently tweaking the device to try to catch HIV.
Reference: Grace D. Chen et al. “Nanoporous Elements in Microfluidics for Multiscale Manipulation of Bioparticles.” Small. DOI: 10.1002/smll.201002076
Image: Brian Wardle/MIT
Talk about early intervention. One day, a fetus with a genetic disease may be able to get treatment before it even leaves the womb–and that treatment will come in the form of an extra gift from mom. While this scenario will only come to pass if new mouse research can be translated to humans, the finding are exciting.
The new work solves a medical mystery. When researchers realized they could diagnose a fetus with certain genetic illnesses as early as the first trimester, they plunged into the search for in utero treatments. Ailments like sickle cell anemia and some immune disorders might be treatable with blood stem cells taken from a donor’s bone marrow, researchers thought: the transplanted cells would multiply and populate the fetus’s bone marrow with healthy blood-forming cells, and the fetus’s immature immune system wouldn’t reject the foreign entities. But when researchers tried such transplants, they didn’t work.
“The fact that fetal stem cell transplantation has not been very successful has been puzzling, especially given the widely accepted dogma that the immature fetal immune system can adapt to tolerate foreign substances,” said co-senior author Qizhi Tang…. “The surprising finding in our study is that the mother’s immune system is to blame.” [press release]
Steroids. Human growth hormone. EPO. The cast of characters implicated in major athletic doping scandals are familiar to fans who follow major sports. Nor are accusations of doping anything new to Lance Armstrong, the seven-time champion of the Tour de France and most famous American participant in a sport constantly marred by scandal.
Armstrong has always denied the doping charges, and he continues to in the wake of a major investigation published this week by Sports Illustrated. But this time around, reporters Selena Roberts and David Epstein allege something new: That Armstrong illegally acquired and took an experimental drug called HemAssist, which never got beyond clinical trials.
So what is this stuff? HemAssist, developed by Baxter Pharmaceuticals, belongs to a group of drugs called hemoglobin-based oxygen carriers, or HBOC. Simply, they are blood substitutes, ones that mimic the structure of hemoglobin—the protein in red blood cells that transports oxygen. According to a scientific source we spoke to, who researched these drugs for years but preferred to provide background anonymously, the drugs mimic the structure of hemoglobin to more than 99 percent, and can deliver oxygen the way natural hemoglobin does.
Biotech researchers have been developing HBOCs for decades because of their exciting potential applications. For example, these blood substitutes could be taken out on a battlefield where stocks of real blood could not be refrigerated and preserved, and given to wounded soldiers to send a rush of oxygen to their critical organs like the brain and the heart. That ability to pack an oxygen punch is what makes HBOCs a tempting target for a doper.
Not everybody is a big fan of being poked with needles to have their blood drawn. But from a medical perspective, blood tests are far less invasive and carry less potential for harm than other diagnostic tools. That’s why medical researchers are increasingly hunting for reliable blood tests for serious diseases, like the experimental Alzheimer’s disease test we covered last week. And this week, researchers report progress on assessing a new condition: a promising blood test for determining Down syndrome in a fetus.
The technique involves a blood test for the mother and an ultrasound for the baby. From the combined results, doctors can estimate the chance that the baby has Down’s. [CBS News]
Down syndrome happens when a baby has an extra copy of chromosome 21. Because the fetus’ DNA can cross over into the plasma of the mother, doctors can seek out the extra chromosome in a blood sample taken from the mother.
The researchers reporting in the British Medical Journal say that in a pool of 753 women, their tests had no false negatives. It accurately found all 86 fetuses with Down (The women selected were all at high risk for down in their fetus; the prevalence among the general public is only about 1 in 800). That’s a larger pool of women sampled than in similar research we covered in 2008, and with a higher success rate. The test is not perfect, though: It also identified false positives for Down in 2 percent of the fetuses that did not have the syndrome, which is why even a test more accurate than this one must have a backup to verify positive results.
Research teams around the world are attempting to develop new tiny synthetic particles that will enter your bloodstream to act as red blood cells, to play the part of platelets and stop the bleeding, to latch onto damaged areas and deliver drugs there, and more. And to make these lab-created particles as effective as possible, they need to stay in one’s system and not get stuck. In this week’s Proceedings of the National Academy of Sciences, Joseph DiSimone and colleagues say they have figured out a way to mimic the twistable, turnable, bendable, foldable nature of red bloods cells to make long-lasting synthetic particles, and that they’ve tested those particles on a living system, a first.
Previous studies had focused on how size, shape and surface characteristics of particles affected their movement through the bloodstream, the team wrote, but flexibility’s role is less well understood. To test it out, the researchers built artificial cells out of a gel material with “tunable elasticity” — that is, the team could control how deformable the cells were. [Los Angeles Times]
Maximizing that elasticity could allow for particles that can wiggle through tiny blood vessels:
It has long been speculated that the deformability of particles influences how long they circulate and where they are distributed in the body. Red blood cells are equipped for longevity and have an average lifespan of 120 days. As they age, they become stiffer and less capable of passing through the tiny vascular structures in the spleen, where they’re ultimately removed. [Nature]
Suppose that Alzheimer’s disease, like a bacterial or viral infection, inspires the immune system to take action and defend the body. If this is true, then there must be antigen proteins that are specific to the disease, which the body recognizes as foreign and which triggers the mustering of a defense. Could doctors catch a glimpse of that process and diagnose the disease earlier? That’s the hope behind a study out this week in Cell, led by Thomas Kodadek.
Many new efforts to speed up diagnosis of Alzheimer’s are ongoing, with some, like Kodadek’s, looking for a signal in the bloodstream. The problem is, scientists don’t know what antigens are the signature of the disease, nor which antibodies the immune system raises to go after them. So they set a trap.
On a slide, Kodadek’s team assembled thousands of different shapes of peptoids—molecules that are slight variations of the peptide molecules found in our bodies—and exposed them to blood samples from people with Alzheimer’s and without. The idea was, if particular peptoids bound only to antibodies from people with Alzheimer’s and not to antibodies of people without, then those antibodies they snagged could be considered a signature of Alzheimer’s in the bloodstream.