Keywords: atomic force microscopy, AFM, soft lithography, exocytosis, dielectrophoresis, biochip, single cell imaging, endometrial cancer cells, pituitary cells, bioimprint replication, LH-secreting cells, gonadotrophs, biomaterials, nanotechnology, cell positioning
Single cell imaging with AFM using Biochip/Bioimprint technology
Atomic Force Microscopy has been used to investigate and characterise endometrial cancer cells and LH-secreting cells, namely gonadotrophs, of the pituitary. Using nanoscale resolution of the AFM features associated with exocytosis events in each cell type are imaged and presented as foundation for further development and understanding of exocytosis process. Membrane fusion and secretion are fundamental cellular mechanisms responsible for the regulation secretion in pituitary gonadotroph cells and endometrial cells. We will describe a new technique named Bioimprint that integrate soft lithography directly with bio-material to create replica cell impression in robust storage media designed to facilitate topographic analysis using AFM. Furthermore, to advance the integration of automated laboratory systems for single-cell identification and analysis it is useful to position cells into organised arrangements. An electrode array chip, known as the Biochip, has also been developed to trap cells within cavities for high resolution analysis. The Biochip is designed to position cells at known addressable locations using positive dielectrophoresis by creating intense areas of high field gradients exposed as isolated regions, in the form of micro-cavity incubators fabricated on the electrode face. An integrated approach using a Biochip for cell positioning combined with a Bioimprint replication technique is presented as a methodology facilitating single-cell analysis.