The “nanosponges” work by targeting so-called pore-forming toxins, which kill cells by poking holes in them.
One of the most common classes of protein toxins in nature, pore-forming toxins are secreted by many types of bacteria, including Staphylococcus aureus, of which antibiotic-resistant strains, called MRSA, are endemic in hospitals worldwide and cause tens of thousands of deaths annually. They are also present in many types of animal venom.
There are a range of existing therapies designed to target the molecular structure of pore-forming toxins and disable their cell-killing functions. But they must be customized for different diseases and conditions, and there are over 80 families of these harmful proteins, each with a different structure.
Using the new nanosponge therapy, says Zhang, “we can neutralize every single one, regardless of their molecular structure.”
Zhang and his colleagues wrapped real red blood cell membranes around biocompatible polymeric nanoparticles. A single red blood cell supplies enough membrane material to produce over 3,000 nanosponges, each around 85 nanometers (a nanometer is a billionth of a meter) in diameter.
Since red blood cells are a primary target of pore-forming toxins, the nanosponges act as decoys once in the bloodstream, absorbing the damaging proteins and neutralizing their toxicity. And because they are so small, the nanosponges will vastly outnumber the real red blood cells in the system, says Zhang. This means they have a much higher chance of interacting with and absorbing toxins, and thus can divert the toxins away from their natural targets.
(via Research Published in Nature Nanotechnology Shows That Biomimetic Nanoparticles Can Absorb Bacterially Produced Toxins | MIT Technology Review)