We mentioned in class some time ago that micelles could be potential drug carriers in their aqueous core. Since my research from the past two years has been on drug and vaccine delivery (“controlled-release”), I perked up a bit at this concept, and thought I might share with you my research. I make micro- and nanoparticles out of polymers using a water-oil-water double emulsion. In my current project, this means I mix a small amount of water (plus iron oxide particles and fluorescent dye) in with polymer (PLGA-PEG) dissolved in an organic phase (DCM). The water phase “hides” from the organic phase by clumping together into little pseudo-particles. Then, I drop this mixture into an outer aqueous phase, PVA, which forms “bubbles” of polymer due to the hydrophobic effect. However, if I was good about homogenizing the first mixture, the polymer will encapsulate most of the water with the Fe2O3 and dye in aqueous phase inside the polymer shell. The resulting particles are thus water (PVA) on the outside, oil (polymer) for the shell, and water (Fe2O3 and dye) on the inside. The same principles apply to micelles, if we replaced our synthetic organic phase with a natural lipid.
In Week 4, we also talked about biological symmetries. Didem mentioned that the poliovirus has icosahedral symmetry. This past fall, I actually spent a fair amount of time testing the efficiency of self-assembly and strength of different shapes for a gastrointestinal “pill” that would self-assemble in the gut and get caught in the intestines to slowly release drug as the polymer delivery system degraded over the course of a month or more. In reality, I glued magnets to a lot of plastic shapes and flipped them around together in a cup. Living the dream! I can’t share my results here (or else we might not get the patent!), but we did find that cubes, dodecahedrons and icosahedrons are all more stable than tetrahedrons and octahedrons. So, yes, I have scientific evidence that the poliovirus is efficiently built!
Also, I hope that you enjoyed my pun!