Chapter 7: Cells in Gels: NMR Studies

Cells growing or suspended in gels of various types, whether biological or synthetic, have been studied over many decades, using light microscopy and biochemical analyses. More recently, NMR spectroscopy has also been applied to these systems, beginning with exploring perfused cells in solid blocks and later with the cells supported in small spheres or threads of alginate and agarose gels. Pulsed magnetic field gradient spin-echo (PGSE) NMR has been used to understand the factors that affect nutrient diffusion in gel threads and spheres, and more recently gelatin gel has been used as a variably distortable medium in which to manipulate the cell shape. The latter studies exposed a link (for the first time) between the red blood cell shape and rates of glycolysis and transmembrane cation flux. The experimental technology and results of these studies are described here along with hypotheses to give a mechanistic basis to the findings, which entail several macromolecular participants, including the mechanosensitive cation channel Piezo1.