Tiny UPS… or something

You’ve learned about phage therapy, quorum sensing and quorum quenching, which means, hello PhD! I’m just kidding, no grad student has the time to jump from topic to topic like this. But for us curious nerds, the next topic in the fight against antibiotic resistant bacteria is nanoparticles. Specifically, using them to deliver drugs. Sometimes, antibiotics don’t reach the cell because of the biofilm, and this physical problem requires a physical solution: tiny delivery systems.


Nanoparticles are usually some sort of metal or carbon polymer. They have a positive charge so that they can interact with negatively charged cell walls. Once you have this delivery vehicle, you can stick some antibiotics do the surface. This process is called doping. Not the Lance Armstrong type, just the biology/chemistry kind (you can dope semiconductors). Sometimes, bacteria have defenses such as proteases and other enzyme that might destroy the antibiotic. No problem, you can stick some complementary molecules on top of the antibiotic and while the enzymes are busy. The drug is released and (hopefully) kills the bacteria.

Biofilms and Macrophages

Biofilms are sticky and gross. They are also, to an extent, rather hardy and impenetrable. Quorum quenching tries to prevent bacteria from even making biofilm, but what if biofilm has already formed? Nanoparticles are small enough to make their way through the gooey mess of extracellular macromolecules. Sometimes, the bacteria live inside macrophages. Nanoparticles can deliver antibiotics inside of these infected macrophages and kill the bacteria intracellularly!

Wrong Place, Right Time

Places in the world where antibiotic resistance is the biggest problem are developing countries. Unfortunately, these are also the places where nanoparticle use is usually unaffordable, unavailable, or both. This problem is quite common, you’ll see someone come up with a great solution, but the realities of getting that solution to those who need it is the greatest hurdle. So far, the cheapest solution is still, phage therapy. Can you tell I’m a bit biased towards phages?