About the Seminar:
Cells are material objects with specific mechanical properties, which are important for proper function, but unlike passive substances, the material properties of cells are strongly affected by life processes. In this talk I will discuss two aspects of cells as active materials, which my lab has been interested in.
Firstly, cells are viscoelastic materials, and a phenomenological picture of the cellular cytoplasm is one of a viscoelastic material fluidized by active forces created by energy-consuming life processes. Characterizing viscoelasticity along with active force generation requires a combination of passive particle-tracking microrheology (PMR) and active microrheology using laser or magnetic tweezers. In this talk I will discuss our attempts to develop simpler single-cell assays of cellular mechanical properties based on PMR alone, using mitochondria as well as fluorescent beads as probe particles.
The second property I will talk about is morphology: cells acquire a specific morphology when spreading on surfaces. My group has been exploring the hypothesis that cell morphology or shape carries useful information about the state of the cell, and in particular it is a marker for tumor aggressiveness. In order to explore this hypothesis we culture osteosarcoma and breast cancer cell lines with different phenotypes, image them on two dimensional substrates, quantify their shape characteristics and use statistical analysis and neural networks to analyze shape differences and build predictive models for inferring cancer invasiveness based on morphology.