Breast cancer cells on the move: Monitoring migration speed
Shebanova and Hammer, Biotechnol. J. 2012, 7, 397–408.
Detailed knowledge of cell migration and cell-cell interactions are key to understanding cell invasion, a critical step in the progression of breast cancer. In this issue, Olga Shebanova and Daniel Hammer (University of Pennsylvania, USA) evaluate the combined influence of biochemical and mechanical paramters of the extracellular matrix to gain insight into cell motility, force generation, cell-cell interaction, and assembly in an in vitro breast cancer model. MCF-10A non-tumorigenic mammary epithelial cells were seeded on surfaces with varying fibronectin ligand concentration and polyacrylamide gel rigidity. The results show that the migration velocity and the assembly of breast cancer epithelial cells is optimal at intermediate concentrations of fibronectin and substrate compliance. On low compliance polyacrylamide gels (400 Pa), cells assemble into clusters, whereas on stiffer gels, cells remain dispersed.
In vitro cell culture models of the blood-brain barrier are important tools to study cellular physiology and therapeutics for neurological disorders. While many models exist, it is not clear whether any of these have been effectively optimized. In this issue, Diane Wuest and Kelvin Lee (University of Delaware, USA) present a sequential-screening study to find the optimal conditions for primary murine endothelial cells in such a model. They compare co-cultures with primary mouse or rat astrocytes at different densities as well as three distinct media-feeding strategies to evaluate different biochemical agent exposure times. The optimized conditions increased transendothelial electrical resistance by over 200%percnt; compared to an initial model and established a suitable in vitro model for brain disease application studies.
Many recent advances in bioprocessing were made possible by developments in miniaturization and microfluidics. A continuing challenge, however, is integrating multiple unit operations that require distinct spatial boundaries, especially those that include labile biological components. In this issue, William Bentley (University of Maryland, USA) and collaborators present the concept of “in-film biofabrication” in which a production address, e.g. antibody-producing cells, and a capture address, where secreted antibody is specifically retained and assayed, are assembled on one chip. Polysaccharide films of chitosan and alginate present smart interfaces that mediate communication between the biological systems and microfabricated devices. Scalability is shown by reducing electrode sizes to a 1 mm scale without compromising film biofabrication or bioprocessing performance. The presented approach has diverse application potential such as in drug screening and biopsy analysis.