GOT TOXINS? SOAK ‘EM UP WITH SCIENCE!
Constance Heidel (3 PM Micro) found an article about nanosponges via the science blog Live Science. This technology has the possibility of adsorbing things like toxins, bacteria, and viruses from the body using artificial microscopic devices (nanosponges) directly from the bloodstream. Here is Constance’s take on this topic:
She blinded me with science!
There was a motion picture released in 1966 called “Fantastic Voyage” that is considered one of the best science-fiction films ever made. While the movie may not be visually stunning (compared to today’s CGI-driven films), it is a truly in a league of its own in terms of conceptual brilliance.
Plot: A failed assassination attempt leaves a scientist in a coma. In order to save him, a task force is assembled upon The Proteus, a submarine. Then the crew and submarine are reduced to microscopic size and injected into the scientist’s bloodstream in order to operate on the surgically inaccessible clot in his brain using a laser. This team travels throughout his bloodstream, marveling at the wonders of the human body at a microbiological level. They must reach the brain within 60 minutes or else the effect will wear off and they will return to full-size. To further complicate things, the voyage is being compromised by a crew member who is a saboteur and is prepared to risk everything to stop the mission.
While the concept of shrinking a crew and submarine down to a microscopic level is definitely better left to science-fiction books and films, there are concepts and themes in the movie that were way beyond its time and are relevant today. Analogously to this film, scientists continue to wage biochemical wars within the human body in order to diagnose, treat and cure. Alas, there is a new battle looming on the horizon!
Dammit Jim, I’m a doctor not a scientist!
Don’t worry about it, Bones. The researchers at the University of California, San Diego have it all under control. They have invented a nanosponge which is capable of safely removing a broad range of toxins from our blood stream. Most antidotes or treatments against venoms, bacteria or bioweapons are targeted to counteract a specific molecular structure, like a lock and key mechanism. These nanosponges are more like a like a skeleton key. They work by absorbing pore-forming toxins, regardless of the toxins’ molecular structure. So it doesn’t matter if it is a virus, bacteria or evil spirits… these nanosponges are coming in there to eradicate them.
Liangfang Zhang, a nanoengineering professor at the UCSD Jacobs School of Engineering stated, “Instead of creating specific treatments for individual toxins, we are developing a platform that can neutralize toxins caused by a wide range of pathogens.”
Nanosponges: Troops against toxins
The word “sponge” doesn’t exactly conjure up images worthy of villains as epic as Darth Vader, but trust me… these aren’t your average loofahs. These microscopic sponges are sheathed in a suit of armor made of red blood cells. It is this design that allows the nanosponges to act as decoys and destroy.
By using a centrifuge, Zhang’s team is able to separate red blood cells from a sample of blood. The cells are then put into a solution that causes them to lyse. This releases the hemoglobin and leaves the skin of the RBCs behind. At this point, the globular nanoparticles (which are made of a biocompatible polymer core) are mixed with the skins until they’re fully cloaked with the red blood cell membrane. This cloaking allows the nanosponges to be undetected to the immune system and serve as a decoy to absorb the toxins away from their cellular targets. Unlike a red blood cell, the nanosponge’s center is made of lactic acid. This organic material acts like a scaffold to keep the membrane from falling apart once the toxins are trapped.
Each nanosponge is approximately 85 nanometers in diameter and they are 3,000 times smaller than that of a red blood cell. Scientists only need the membrane from one red blood cell to synthesize thousands of nanosponges. This is the stuff science fiction films are made of: “In a single dose, an army of nanosponges will be deployed to conquer your bloodstream. They will evade your immune system, outnumber your red blood cells, intercept toxins and deliver them to your liver in order to save your life!” The coolest part is, this is science NON-fiction!
To see a nanosponge in action, check out this video:
The war wages on…
The efficacy of this treatment was demonstrated through a study in mice. A lethal dose of MRSA was given to the mice, which normally causes acute death. The control group didn’t receive any treatment and all of the mice died as expected. When nanosponges were injected two minutes before the toxin was administered, an overwhelming number of mice survived – 89 percent. When the nanosponges were administered two minutes after the lethal dose was administered, an impressive amount – 44 percent – survived. Surviving mice were studied further and it was shown that the nanosponges accumulated primarily in the liver and were safely metabolized without any damage. Studies also showed that the nanosponges also have a half-life of about 40 hours. These results were published in Nature Nanotechnology.
The most virulent toxins in MRSA were used in the experiments with great success. It can be deduced that toxins with lower virulence factors would have an even higher success rate. These nanosponges are capable of removing a broad class of dangerous substances from the bloodstream including toxins produced by E. coli, S. aureus, venom from snakes, bees, sea anemones and more. With more and more strains of bacteria becoming resistant to antibiotics, nanosponges could work with or in lieu of most antibiotic treatments that are being prescribed today.
The goal of these experiments is to lead to approved therapies on human patients as soon as possible. Before that can happen, the researchers’ must pursue clinical trials. Follow this “fantastic voyage” on Twitter @UCSD_Nanomed for the latest on this promising technology!
Posted on May 1, 2013, in Guest Post, Strange but True and tagged Methicillin-resistant Staphylococcus aureus, Nature Nanotechnology, Red blood cell. Bookmark the permalink. Comments Off on GOT TOXINS? SOAK ‘EM UP WITH SCIENCE!.