| Metastasis is the event in which cancer cells spread from their site of origin and invade into other areas of the body. It is believed that cancer cells migrate chemotactically via a gradient of soluble factors. Up to now, cancer migration and metastasis has been studied extensively in 2D via tissue culture plates and transwell membrane assays (i.e. Boyden chambers). But to recapitulate in vivo behaviors 3D assays are required which can recreate tumor microenvironment (and gradients) which can be a powerful tool to study metastatic events as well as the migratory behaviors of cancer cells. In order to better understand the migratory and invasion processes of cancer cells we have developed and employed a microfluidic device to generate gradients across 3D environments. Microfluidic devices allow the gradients of soluble factors to be generated in a controlled fashion to observe chemotaxis. In this dissertation, we present the development and characterization of our microfluidic device along with studies using HT1080 (human fibrosarcomas) and MDA MB-231 cells (human breast adenocarcinomas). Gradients can be generated across the 3D gels via an array of micropillars. The device can be adapted to be used in conjunction with a syringe pump or hydrostatic pressure to generate complex stable gradients. In addition, this device is capable of supporting co-cultures in varying hydrogels. This platform presents a versatile microfluidic model which can be employed to study chemotaxis in addition to engineering different microenvironments for cell co-culture studies. |
