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).

Effect of cell origin and timing of delivery for stem cell-based bone tissue engineering using biologically functionalized hydrogels.

Despite progress in bone tissue engineering, the healing of critically sized diaphyseal defects remains a clinical challenge. A stem cell-based approach is an attractive alternative to current treatment techniques. The objective of this study was to examine the ability of adult stem cells to enhance bone formation when co-delivered with the osteoinductive factor bone morphogenetic protein-2 (BMP-2) in a biologically functionalized hydrogel.

Mineralization of three-dimensional osteoblast cultures is enhanced by the interaction of 1α,25-dihydroxyvitamin D3 and BMP2 via two specific vitamin D receptors.

1α,25-Dihydroxyvitamin D3 [1α,25(OH)2D3] and bone morphogenetic protein-2 (BMP2) are both used to stimulate osteoblastic differentiation. 1α,25(OH)2D3 regulates osteoblasts through classical steroid hormone receptor mechanisms and through rapid responses that are mediated by two receptors, the traditional vitamin D receptor (VDR) and protein disulphide isomerase family A member 3 (Pdia3). The interaction between 1α,25(OH)2D3 and BMP2, especially in three-dimensional (3D) culture, and the roles of the two vitamin D receptors in this interaction are not well understood.

Resveratrol effect on osteogenic differentiation of rat and human adipose derived stem cells in a 3-D culture environment.

The goal of this study was to investigate the effect of resveratrol treatment on the osteogenic potential of human and rat adipose derived stem cells in a 3-D culture environment. Adipose derived stem cells (ADSCs) have been widely studied and have shown promise as a potential source of osteogenic progenitor cells. Previous work had investigated the effect of 25 μM resveratrol on the osteogenic differentiation of rat ADSCs in a 3-D environment and found that pre-treating cells for one passage prior to seeding on the scaffold yielded significantly more mineralization than untreated cells.

Effects of resveratrol on enrichment of adipose-derived stem cells and their differentiation to osteoblasts in two-and three-dimensional cultures.

The goal of this study was to develop a method for increasing the yield of multipotent adipose-derived mesenchymal stem cells (ASCs) and osteoprogenitor cells (OPCs) from subcutaneous fat. After removing mature adipocytes and haematopoietic cells from rat inguinal fat, ASCs in the remaining cell population were verified by their attachment to plastic, surface marker profile (CD271(+), CD73(+) and CD45(-)) and ability to differentiate into adipocytes, chondrocytes and osteoblasts. OPCs were defined as E11(+) and OCN(+).

Stimulated calcium entry and constitutive RhoA kinase activity cause stretch-induced detrusor contraction.

Urinary bladder wall muscle (i.e., detrusor smooth muscle; DSM) contracts in response to a quick-stretch, but this response is neither fully characterized, nor completely understood at the subcellular level.

Adjustable passive length-tension curve in rabbit detrusor smooth muscle.

Until the 1990s, the passive and active length-tension (L-T) relationships of smooth muscle were believed to be static, with a single passive force value and a single maximum active force value for each muscle length. However, recent studies have demonstrated that the active L-T relationship in airway smooth muscle is dynamic and adapts to length changes over a period of time. Furthermore, our prior work showed that the passive L-T relationship in rabbit detrusor smooth muscle (DSM) is also dynamic and that in addition to viscoelastic behavior, DSM displays strain-softening behavior characterized by a loss of passive stiffness at shorter lengths following a stretch to a new longer length.

A mechanical model for adjustable passive stiffness in rabbit detrusor.

Strips of rabbit detrusor smooth muscle (DSM) exhibit adjustable passive stiffness characterized by strain softening: a loss of stiffness on stretch to a new length distinct from viscoelastic behavior. At the molecular level, strain softening appears to be caused by cross-link breakage and is essentially irreversible when DSM is maintained under passive conditions (i.e.