"Chip-on-a-Transwell" Devices for User-Friendly Control of the Microenvironment of Cultured Cells.

We present microfabricated poly(dimethylsiloxane) templates assembled atop Transwell membranes ("Chip-on-a-Transwell") for focal delivery of soluble reagents to cells. This modified Transwell operates based on area-selective diffusion of soluble species to the basal side of cells. The device was capable of addressing small groups of cells, with a maximum spatial resolution of 20 μm, while sustaining focal signal for up to 48 hours.

Analysis of the Myc-induced pancreatic cell islet tumor microenvironment using imaging ToF-SIMS.

Solid tumors are a structurally complex system, composed of many different cell types. The tumor microenvironment includes nonmalignant cell types that participate in complex interactions with tumor cells. The cross talk between tumor and normal cells is implicated in regulating cell growth, metastatic potential, and chemotherapeutic drug resistance.

Effect of substrate storage conditions on the stability of "Smart" films used for mammalian cell applications.

When poly(-isopropyl acrylamide) (pNIPAM) is tethered to a surface, it can induce the spontaneous release of a sheet of mammalian cells. The release of cells is a result of the reversible phase transition the polymer undergoes at its lower critical solution temperature (LCST). Many techniques are used for the deposition of pNIPAM onto cell culture substrates.

An unsupervised MVA method to compare specific regions in human breast tumor tissue samples using ToF-SIMS.

Imaging time-of-flight secondary ion mass spectrometry (ToF-SIMS) and principal component analysis (PCA) were used to investigate two sets of pre- and post-chemotherapy human breast tumor tissue sections to characterize lipids associated with tumor metabolic flexibility and response to treatment. The micron spatial resolution imaging capability of ToF-SIMS provides a powerful approach to attain spatially-resolved molecular and cellular data from cancerous tissues not available with conventional imaging techniques. Three ca.