Here is an interesting paper that has arisen out of a collaboration with Gary Pielak’s group at UNC-CH.  “An upper limit for macromolecular crowding effects“, just published in BMC Biophysics, basically illustrates that even at very high microgel concentrations, there is little change in the observed stability of solvated proteins. In other words, microgels are pretty crummy macromolecular crowders. The proteins appear to localize in the aqueous space between the microgels, and perhaps within large pores in the microgels, thereby not “feeling” any macromolecular crowding effects.

These results perhaps point to a nice way to probe the heterogeneity of microgel dispersions at a length scale below optical microscopy by using protein or synthetic macromolecule conformation, dynamics, and stability as the physical observables. Thanks to Gary’s group for doing some excellent work here, and to ex-group member Dr. Courtney Sorrell for doing all the microgel synthesis, characterization, and for pushing this collaboration from the GT side.

Full citation:  Miklos, A.; Li, C.; Sorrell, C.; Lyon, L. A.; Pielak, G., An upper limit for macromolecular crowding effects BMC Biophysics 2011, 4, 13.