Polymer Nanosponges Suck Toxins Out Of Blood Stream
Written by Dale McGeehon
Say, in the near future you're going on a hike or a camping trip and you want to be nearly impervious to the harmful effects of bee stings or bites from poisonous snakes. It might be a good idea to get inoculated with "nanosponges" before you go.
These biocompatible polymer-based "sponges" - developed by engineers at the University of California, San Diego - are 3,000 times smaller than a red blood cell. But they are wrapped in red-blood-cell membranes and act a lot like red blood cells. They circulate in the bloodstream and slurp up a wide range of toxins before those toxins can do much damage to healthy tissue.
The nanosponges - about 85 nanometers in diameter - soak up toxins that damage healthy cells by poking holes in cell membranes. When the poking causes a pore to form, uncontrolled ions rush in and the cell dies.
Nanosponges Treat A Wide Variety Of Toxins
Other anti-toxin treatments need to be custom-synthesized for each specific type of toxin. But nanosponges can absorb pore-forming toxins regardless of their molecular structure. Each sponge can absorb tens or hundreds of toxin molecules before the sponge itself is absorbed and metabolized by the liver, with no ill effects.
"This is a new way to remove toxins from the bloodstream," says Liangfang Zhang, a nanoengineering professor at the University of California San Diego (UCSD) Jacobs School of Engineering and the senior author on the study. "Instead of creating specific treatments for individual toxins, we are developing a platform that can neutralize toxins caused by a wide range of pathogens, including MRSA [Methicillin-resistant Staphylococcus aureus] and other antibiotic-resistant bacteria."
The researchers claim that the sponges would potentially provide life-saving treatment to those who are allergic to bee stings or those bitten by poisonous snakes.
89 Percent Survival Rate For Mice
In the study, mice that had been pretreated with the nanosponges had a 89 percent survival rate when they were later injected with a lethal dose of a toxin from MRSA. Mice that received the nanosponges after being injected with the lethal dose had a 44 percent survival rate. Those mice that did not receive nanosponges had a 100 percent mortality rate.
Now the researchers need to make sure nanosponges can work as well in humans. So they are pursing clinical trials and making sure the research can translate into proven therapies.
Polymer Nanosponges Effective Against MRSA
"One of the first applications we are aiming for would be an anti-virulence treatment for MRSA," says "Jack" Che-Ming Hu, the first author on the paper that was published in Nature Nanotechnology in April. "That's why we studied one of the most virulent toxins from MRSA in our experiments."
The team at Zhang's lab makes nanosponges by separating red blood cells from a small sample of blood, then puts those cells into a solution that causes them to burst, releasing hemoglobin and leaving the cells' outer membrane behind. Then researchers stuff the ball-shaped polymer nanosponge into the membrane like a pimento is stuffed inside an olive.
A single blood cell membrane is large enough to make thousands of nanosponges because the polymer sponges are 3,000 times smaller than a blood cell. The amount of toxin a nanosponge can absorb depends on the toxin. For example, each nanosponge can only absorb 85 molecules of MRSA, but can suck up to 850 molecules of bee venom.
In mice, the nanosponges have a half-life of 40 hours. Eventually, they are metabolized by the liver, which brakes down both the sponges and the toxins and eliminates them from the body without any known harmful effects.
About the Author
Dale McGeehon is the head blogger for Polymer Solutions Incorporated(PSI), an independent plastics and polymer testing laboratory. Dale has been a journalist and editor for more than 25 years, and covers plastic testing and failure for the PSI Newsblog.
Peloton vulnerable to cyber attacks, McAfee research finds
Peloton, the popular exercise bikes, were found to be vulnerable to cyber attacks according to the latest research from McAfee.
For those still unfamiliar with Peloton, it is a brand of electric bikes that combines high end exercise equipment with cutting-edge technology. Its products use a wi fi connection to connect to a large tablet that interfaces with the components of the exercise device, and provides an easy way for physical activity enthusiasts to attend virtual workout classes over the internet several times a week.
“Behind the scenes is a standard Android tablet, and this hi-tech approach to the exercise bikes has not gone unnoticed. Viral marketing mishaps aside, Peloton has garnered attention recently regarding surrounding the privacy and security of its products. So McAfee decided to take a look for themselves and purchased a Peloton Bike+.
Researchers looked at Android devices, and uncovered a vulnerability that could allow an attacker with either physical access to the Bike+ or access during any point in the supply chain to gain remote access to the bike’s tablet, including the camera, microphone and personal data.
To the user there would be no indication the Bike+ has been tampered with, potentially putting Peloton’s 16.7 million users at risk of being hacked.
The flaw was found in the Android Verified Boot (AVB) process, leaving Peloton open to attackers.
They were able to bypass the Android Verified Boot process, which normally verifies all code and data within the system before booting. Researchers were able to get the device to boot bypassing this step.
This can lead to an Android OS being compromised by an attacker who is physically present. Even worse, the attacker could boot up the Peloton with a modified credential to gain privileges, granting them access to the bike remotely.
As the attacker never has to unlock the device to boot it up, there would be no trace of any access they achieved on the device. This type of attack could also happen at any point from construction to warehouse to delivery, by installing a backdoor into the Android tablet without the user ever knowing.
Given the simplicity and criticality of the flaw, McAfee informed Peloton even as auditing was ongoing. The vendor was sent full details, and shortly after, Peloton confirmed the issue and subsequently released a fix for it.
The patched image no longer allows for the “boot” command to work on a user build, mitigating this vulnerability entirely. Further conversations between McAfee and Peloton confirmed that this vulnerability is also present on the Peloton Tread exercise equipment.
Peloton’s Head of Global Information Security, Adrian Stone, commented on the research: “this vulnerability reported by McAfee would require direct, physical access to a Peloton Bike+ or Tread. Like with any connected device in the home, if an attacker is able to gain physical access to it, additional physical controls and safeguards become increasingly important.
"To keep our members safe, we acted quickly and in coordination with McAfee. We pushed a mandatory update in early June and every device with the update installed is protected from this issue.”