University of Wisconsin-Madison
Enabling the study of circulating tumor cells.
Circulating tumor cells (CTCs), tumor cells found in the blood stream of cancer patients, have the potential to be a source of information that could greatly impact patient care. Currently, clinicians use repeated surgical biopsies of tumors to monitor the efficacy of a treatment protocol. The surgeries can be invasive, expensive, and difficult to coordinate. CTCs obtained in a simple blood draw offer an way to monitor the cancer in a way that would largely address these issues. However, only 100's or 1000's are typically obtained in a single blood draw. Rare cell populations such as these can be difficult to study using macroscale methods, specifically in assays of live cell function. In contrast, microscale methods are well suited for studying small numbers of cells per device, but require all the cells to be concentrated into a few ÁL prior to loading. For this reason, centrifugation is not well-suited for preparing samples of rare cells and actually impedes the use of rare cells in microscale studies.
We plan to enable microscale studies of rare cell populations by using a method that simultaneously concentrates the suspension and deposits the cells into a simple microfluidic channel that can be used for wide variety of downstream assays including cell culture and staining. This method provides a way to increase cell concentrations after centrifugation and lower the minimum number of cells needed to perform a particular assay. An important advantage of this method is that it avoids the use of impediments, electric charge, and adhesive surfaces in an attempt to minimize perturbation of the cells and microenvironment while providing a way to subsequently culture and gently apply treatments to cells. By facilitating the use of microscale devices for the study of rare cells we hope to increase the number of endpoints that can be performed per cell sample and leverage the increased sensitivity and functionality of microscale assays.