Randall T. Butler

Vacuum-assisted cell seeding in a microwell cell culture system.

We present a simple method to actively pattern individual cells and groups of cells in a polymer-based microdevice using vacuum-assisted cell seeding. Soft lithography is used to mold polymer microwells with various geometries on top of commercially available porous membranes. Cell suspensions are placed in a vacuum filtration setup to pull culture medium through the microdevice, trapping the cells in the microwells. The process is evaluated by determining the number of cells per microwell for a given cell seeding density and microwell geometry. This method is tested with adherent and nonadherent cells (NIH 3T3 fibroblasts, PANC-1 pancreatic ductal epithelial-like cells, and THP-1 monocytic leukemia cells). These devices could find applications in high-throughput cell screening, cell transport studies, guided formation of cell clusters, and tissue engineering.

Alveolar variant of invasive lobular carcinoma in a fibroadenoma.

by intense parenchymal background enhancement. Our histopathological findings of invasive adenoid cystic carcinoma confirm the importance of pathological examination of reduction mammoplasty specimens for breast carcinoma screening. It is also clear that a more extensive evaluation should be performed in patients with a history of breast carcinoma. Adequate sampling of reduction specimens is essential for accurate diagnosis and is vital for optimal clinical management.

Controlled silica deposition on soft-lithography fabricated poly-L-lysine templates

We describe the combination of soft-lithographic patterning and biomolecule-induced deposition to create microscale patterns of silica on a diverse array of substrates. A soft lithographic technique was used to create a sacrificial layer of the polymer poly(n-propyl methacrylate) (PPMA) on the desired substrate. Subsequently, poly-L-lysine was deposited on the substrate, after which removal of the PPMA yielded a pattern of PLL on the substrate. Exposure of the PLL template to a silicic acid solution resulted in silica deposition in the pattern spatially and geometrically controlled by the PLL. With this procedure, we have created both continuous and discontinuous silica patterns on metallic, ceramic, and polymer substrates. While morphology of the deposited silica varied between substrates, the ability to pattern silica through this templated growth was demonstrated on all investigated substrates. EDS, optical micrography, and SEM analysis verified the controlled deposition of silica on the PLL template patterns. This PLL template-mediated induction of silica formation may facilitate the incorporation of silica in new microdevices and serve as a prototype process for controlled deposition with other biomolecule-material systems.