My biological physics is mainly on the two linked topics of phase separation in cells, and the dynamics of proteins, RNA, etc, inside cells.
Liquid droplets phase separation inside cells
The complex viscous energy-consuming fluid inside cells is very far from uniform, as this schematic attempts to show. The P granules (purple) and TRIM5alpha (orange) are both examples of liquid-droplet-like structures inside cells. In other words it looks like (functional) liquid/liquid phase separation occurs inside cells.
Modelling diffusion inside cells of the protein whose absence causes Duchenne muscular dystrophy
I have collaborated with muscle cell biologists on modelling the dynamics of the protein Dystrophin inside live muscle cells. Dystrophin is a medically important protein, the absence of this protein causes the genetic disease Duchenne Muscular Dystrophy. This work was published in eLife in October 2015. This site hosts the app used there. There is a news release on this work.