Day 23

January 4, 2012

I did not write a post for yesterday because I did not do anything because my mentor was not there.
Today we worked with polymers and experimented to find the best way to make a sphere shaped cell. Polymers are mulitple positively charged monomers put together.   Polymers have little legs on them called PEGs.  PEGs aprevent negatively charged nanoparticles from clinging to the polymer and clump together.  However, the more PEGs, the more worm-shaped the polymer is. We want to make the polymer sphere though because sphere shaped polymers last longer when injected into the blood. The sphere shape copes better with the flow of blood cells then the worm shape does. So the question is how many PEGs have to be cut off from the polymer in order to make it spherical but to keep enough PEGs on to prevent other particles from clinging with the polymer? This is what we are trying to find out. It will take several trials to finally figure it out. We just did one trial today. JM made a polymer  and then placed them into a syringe.  The syringe very rapidly spins the nanoparticles in order to change their shape.  After about a half hour, we placed the particles into a different machine that calculates the number and size of the nanoparticles. Apparently, the polymer nanoparticles ended up being a little too be. Each was 170 nanometers big but we were hoping for about 60 or 70 nanometers. This may have meant that the particles hadn't completely changed into a spherical shape yet and are still in the worm form. We didn't have enough time to do another trial, so we talked about the presentation for a few minutes. Even though I will not be presenting on this project, we discussed how he thinks we should make our powerpoints and how to prepare for the oral presentation.