Automated leukocyte processing by microfluidic deterministic lateral displacement.

We previously developed a Deterministic Lateral Displacement (DLD) microfluidic method in silicon to separate cells of various sizes from blood (Davis et al., Proc Natl Acad Sci 2006;103:14779-14784; Huang et al., Science 2004;304:987-990).

Microfluidic chemical processing with on-chip washing by deterministic lateral displacement arrays with separator walls.

We describe a microfluidic device for on-chip chemical processing, such as staining, and subsequent washing of cells. The paper introduces "separator walls" to increase the on-chip incubation time and to improve the quality of washing. Cells of interest are concentrated into a treatment stream of chemical reagents at the first separator wall for extended on-chip incubation without causing excess contamination at the output due to diffusion of the unreacted treatment chemicals, and then are directed to the washing stream before final collections.

Inhibition of clot formation in deterministic lateral displacement arrays for processing large volumes of blood for rare cell capture.

Microfluidic deterministic lateral displacement (DLD) arrays have been applied for fractionation and analysis of cells in quantities of ~100 μL of blood, with processing of larger quantities limited by clogging in the chip. In this paper, we (i) demonstrate that this clogging phenomenon is due to conventional platelet-driven clot formation, (ii) identify and inhibit the two dominant biological mechanisms driving this process, and (iii) characterize how further reductions in clot formation can be achieved through higher flow rates and blood dilution. Following from these three advances, we demonstrate processing of 14 mL equivalent volume of undiluted whole blood through a single DLD array in 38 minutes to harvest PC3 cancer cells with ~86% yield.

Deterministic separation of cancer cells from blood at 10 mL/min.

Circulating tumor cells (CTCs) and circulating clusters of cancer and stromal cells have been identified in the blood of patients with malignant cancer and can be used as a diagnostic for disease severity, assess the efficacy of different treatment strategies and possibly determine the eventual location of metastatic invasions for possible treatment. There is thus a critical need to isolate, propagate and characterize viable CTCs and clusters of cancer cells with their associated stroma cells. Here, we present a microfluidic device for mL/min flow rate, continuous-flow capture of viable CTCs from blood using deterministic lateral displacement (DLD) arrays.

Compounding rifampin suspensions with improved injectability for nasogastric enteral feeding tube administration.

Often medications that have to be administered to patients via a nasogastric enteral feeding tubes are only available as tablets and capsules with no suitable commercial liquid alternatives. In such situations, pharmacists and nurses have to compound the tablets and capsule contents into liquid suspension formulations for dosing. The risk of occlusion of the enteral tubes during administration is reduced by employing liquid suspensions that are composed of small and uniform particles, not subject to rapid rates of settling, resistant to caking, and easily and uniformly re-suspended upon agitation.