The Nano Intravital Device, or NANIVID, is under development as an optically transparent, implantable tool to study
the tumor microenvironment. Two etched glass substrates are sealed using a thin polymer membrane to create a reservoir
with a single outlet. This reservoir is loaded with a hydrogel blend that contains growth factors or other chemicals to be
delivered to the tumor microenvironment. When the device is implanted in the tumor, the hydrogel will swell and release
these entrapped molecules, forming a gradient. Validation of the device has been performed in vitro using epidermal
growth factor (EGF) and Mena<sub>INV</sub>, a highly invasive, rat mammary adenocarcinoma cell line. In both 2-D and 3-D
environments, cells migrated toward the gradient of EGF released from the device. The chorioallantoic membrane
(CAM) of White Leghorn chicken eggs is being utilized to grow xenograft tumors that will be used for ex vivo cell
collection. Device optimization is being performed for in vivo use as a tool to collect the invasive cell population.
Preliminary cell collection experiments in vivo were performed using a mouse model of breast cancer. As a second
application, the device is being explored as a delivery vehicle for chemicals that induce controlled changes in the tumor
microenvironment. H<sub>2</sub>O<sub>2</sub> was loaded in the device and generated intracellular reactive oxygen species (ROS) in cells
near the device outlet. In the future, other induction targets will be explored, including hypoglycemia and the
manipulation of extracellular matrix stiffness.
Nanoparticles of CeO<sub>2</sub> doped with 10 mol% Dy<sub>2</sub>O<sub>3</sub> have been synthesized via a homogeneous precipitation method, employing nitrates as the starting salts and hexamethylenetetramine (HMT) as the precipitant, which was achieved under ambient pressure and hydrothermal conditions, respectively. Characterizations of the powders were made by elemental analysis, differential thermal analysis/thermogravimetry (DTA/TG), X-ray diffractometry (XRD) and field-emission scanning electron microscopy (FESEM). The results show that an additional hydrothermal treatment affects significantly the powder properties, and well dispersed, nanocrystalline solid solution with expected dopant content was obtained under the reaction conditions.