These luminous shapes are cardiac fibroblasts from a newborn rat, suspended in a collagen-thick film which is stimulating the environment around the cells. This makes them express a protein called DDR2, which scientists believe help cells to sense their surroundings and signal to the cells that they need to remodel themselves in response. The blue part is the cell nucleus, the green part is the cell's cytoskeleton and the red staining is the DDR2 at work. This image is just one of Chris Robinson's last-minute entries in the 21st. NanoArt competition, which have become my favorite entrants. Click through to view the others.
This looks like baby stars forming in a nebula of gas and dust, but it's actually a visualization of light being scattered by gold nanorods, which are embedded in a collagen gel populated by human cells. Researchers at the University of South Carolina NanoCenter used a dark field microscope to view the patterns of light coming off the nanorods.