Bacteria are clever little buggers. Every time we hit them with a new drug that kills 99.9% of them, that left-over 0.01% regroups and breeds and we're back to square one. We're going to run out of drugs before the bacteria run out of evolution — which means we need some new weapons in our arsenal.
IBM Research and Singapore's Institute of Bioengineering and Nanotechnology have teamed up to develop a self-assembling nanoparticle that can selectively seek out and destroy even the most drug-resistant bacteria by not trying to do anything clever with chemicals or DNA and instead just ripping the bacterial walls to shreds. It's a bit like an old school Terminator's approach: show up in a human outpost with a bunch of guns and just start shooting everything.
They've been testing out these nanoparticles on MRSA, a highly drug-resistant bacteria that kills tens of thousands of people in hospitals every year, and, well, here's a before and after pic of what happens when the nanomedicine gets sent after the MRSA bacteria:
The nanoparticles are made of plastic, and when they're injected into the bloodstream, they self-assemble into blobs about 200 nanometers across. These blobs have a slight positive charge, and are attracted only to bacteria, which have a negative charge that differs from all the other cells in our bodies. The nanoblobs stick to bacterial membranes, and poke big holes in them, and then all those bacterial guts just spill out and bacterial DEATH ensues. Then, the nanoblob can move on to attack another bacteria.
Since each nanoblob can kill multiple bacterial cells, you don't need to use it in high concentrations. And after a few days, the nanoparticles naturally break down into little building blocks of alcohol and carbon dioxide, and your body removes them on its own with no toxic chemicals to worry about.
Now, I don't know if we can say that nanotech methods like this will spell the end for evil bacteria; there's always the threat of newly evolved defenses like stronger cell walls or maybe a change to electric charge that would make the bacteria blend in with our own cells. In any case, targeting and attacking the bacteria physically seems to be an extremely promising way of dealing with infections, and the next step is for IBM to figure out how to get their nanoparticles into human-safe testing.