Three hypotheses were tested relating to Wyoming big sagebrush (Artemisia tridentata Nutt. ssp. wyomingensis (Beetle and Young) revegetation on coal-mined land in Wyoming: (1) that fourwing saltbush (Atriplex canescens (Pursh) Nutt.) seeded > 2.2 kg pure live seed (pls)/ha would exclude sagebrush, (2) the contrasting view that the saltbush, as a "pioneer plant", facilitated sagebrush stand deve...

In vitro expansion of endothelial progenitor cells (EPCs) remains a challenge in stem cell research and its application. We hypothesize that high density culture is able to expand EPCs from bone marrow by mimicking cell-cell interactions of the bone marrow niche. To test the hypothesis, rat bone marrow cells were either cultured in high density (2 × 10(5) cells/cm(2)) by seeding total 9 × 10(5)...

The purpose of this study was to evaluate the biological effects of guided tissue regeneration (GTR) membrane materials, per se, on the periodontal tissue regeneration. Rat periodontal ligament (PDL)-derived cells were used to study the attachment, proliferation and differentiation, in vitro, on various GTR membranes. Five commercially available membranes bovine type I collagen (BioMend; BM), b...

The use of biopolymers as a three dimensional (3D) support structure for cell growth is a leading tissue engineering approach in regenerative medicine. Achieving consistent cell seeding and uniform cell distribution throughout 3D scaffold culture in vitro is an ongoing challenge. Traditionally, 3D scaffolds are cultured within tissue culture plates to enable reproducible cell seeding and ease o...

In natural heart tissue, cell density is about 1.0 x 108/cm3, and the cell metabolism is very active. Therefore, culturing heart cells in 3-dimensions at high density and construction of engineered cardiac tissue in vitro is very difficult. The aim of this study was to simulate 3-dimensional culturing of cardiac cells and pursue a novel method to construct engineered cardiac tissue in vitro. Th...

The concept of using tissue density as a mechanism to diagnose a tumor has been around for centuries. However, this concept has not been sufficiently explored in a laboratory setting. Therefore, in this paper, we observed the effects of cell density and extracellular matrix (ECM) density on colon cancer invasion and proliferation using SW620 cells. We also attempted to inhibit ROCK-I to determi...

Research into biomaterials and tissue engineering often includes cell-based in vitro investigations, which require initial knowledge of the starting cell number. While researchers commonly reference their seeding density this does not necessarily indicate the actual number of cells that have adhered to the material in question. This is particularly the case for materials, or scaffolds, that do ...

Bone marrow-derived mesenchymal stromal stem cells (BMSCs) are a promising cell source for treating articular cartilage defects. The objective of this study was to assess the impact of cell seeding density within a collagen I scaffold on in vitro BMSC chondrogenesis following isolation and expansion in two-dimensional (2D) and three-dimensional (3D) environments. It was hypothesized that both e...

In this paper, a direct experimental comparison is made between scanning and tomo-PIV, on an unsteady wake flow behind a half-cylinder. Several seeding densities are used in order to demonstrate the capacities and limitations of both techniques. For the scanning technique, the effect of particles elongation is investigated and the influence of the seeding density on the volume reconstruction fo...