Predicting efficacies of anticancer drugs using single cell HaloChip assay.

Single cell halo assay (HaloChip) is used to quantify DNA repair ability and predict the efficacy of anticancer drugs. After exposure to drugs, cells are patterned onto a substrate to form an ordered single cell array, then embedded inside an agarose gel, and fluorescently stained to generate a characteristic halo surrounding each cell. The extent of DNA repair is quantified by using a relative nuclear diffusion factor (rNDF) derived from the surface areas of nuclei and halos.

Preventing bacterial growth on implanted device with an interfacial metallic film and penetrating X-rays.

Device-related infections have been a big problem for a long time. This paper describes a new method to inhibit bacterial growth on implanted device with tissue-penetrating X-ray radiation, where a thin metallic film deposited on the device is used as a radio-sensitizing film for bacterial inhibition. At a given dose of X-ray, the bacterial viability decreases as the thickness of metal film (bismuth) increases.

Single cell array based assay for in vitro genotoxicity study of nanomaterials.

This paper describes the use of a single cell array based assay for genotoxicity study of nanomaterials using normal human fetal fibroblast cells obtained from two-dimensional (2D) monolayer cultures and three-dimensional (3D) microtissue. After being exposed to a suspension of nanomaterials, cells are attached onto microfabricated patches with proper modification through electrostatic attraction and embedded in hydrogel. The damaged DNAs diffuse in gel matrix and form observable halo structures, where the level of DNA damage is quantified from the dimensions of core and halo.

Targeted nanoparticles for enhanced X-ray radiation killing of multidrug-resistant bacteria.

This paper describes a nanoparticle enhanced X-ray irradiation based strategy that can be used to kill multidrug resistant (MDR) bacteria. In the proof-of-concept experiment using MDR Pseudomonas aeruginosa (P. aeruginosa) as an example, polyclonal antibody modified bismuth nanoparticles are introduced into bacterial culture to specifically target P.

Three-dimensional microtissue assay for high-throughput cytotoxicity of nanoparticles.

Traditional in vitro nanotoxicity researches are conducted on cultured two-dimensional (2D) monolayer cells and thereby cannot reflect organism response to nanoparticle toxicities at tissue levels. This paper describes a new, high-throughput approach to test in vitro nanotoxicity in three-dimensional (3D) microtissue array, where microtissues are formed by seeding cells in nonsticky microwells, and cells are allowed to aggregate and grow into microtissues with defined size and shape. Nanoparticles attach and diffuse into microtissues gradually, causing radial cytotoxicity among cells, with more cells being killed on the outer layers of the microtissue than inside.