Motion of interfaces in biological systems

Interfaces might be characterised by properties such as energy per area, speed, width and interaction with inhomogeneities which may impede or accelerate their motion. We consider advancing tumour and apoptosis fronts as examples.

We present a simple stability analysis for an interface between a tumour and surrounding tissue. We consider how the sizes of escaping metastatic clusters and the work required to form protrusions of critical size might depend on interfacial energy.

We show how a pinning site which is impeding passage of an advancing membrane can be enveloped within a liposome and left in the membrane's wake.

We suggest how an advancing apoptosis front might initially advance fast enough to suppress disease, but slow beneath the threshold when its progress is curtailed by a need to generate replacement cells.

We consider boundaries which separate regions where cells cycles are synchronised from regions where they are unsynchronised, or regions where they are synchronised albeit with different phases or angular speeds.