This study aimed to study the effects of initial cell density and in vitro culture method on the construction of tissue-engineered bone grafts and osteogenic activities. Human mesenchymal stem cells (hMSCs) were seeded onto cubic scaffolds prepared from demineralized bone matrix (DBM) by three methods - static, hydrodynamic, or fibrin hydrogel-assisted seeding. The resulting cell-scaffold const...

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...

Background: Monolayer electrospun scaffolds have already been used in bone tissue engineering due to their high surface-to-volume ratio, interconnectivity, similarity to natural bone extracellular matrix (ECM), and simple production. Objectives: The aim of this study was to evaluate the dynamic culture effect on osteogenic differentiation and mineralizationi into a compact cellular multilayer ...

Human embryonic stem cells (hESCs) have the ability to form cells derived from all three germ layers, and as such have received significant attention as a possible source for insulin-secreting pancreatic beta-cells for diabetes treatment. While considerable advances have been made in generating hESC-derived insulin-producing cells, to date in vitro-derived glucose-responsive beta-cells have rem...

We report development of a model of retroviral gene transduction in high-density limb bud cell micromass culture. The replication competent avian retrovirus RCAS BP (A) carrying the human placental alkaline phosphatase gene (RCAS AP) was used as a marker for retroviral infection and spread. The final protocol balances the need to allow time for retroviral integration and gene transduction again...

Raman spectrum based predictive models provide a process analytical technology (PAT) tool for monitoring and control of culture parameters in bioprocesses. Steady-state perfusion cultures generate relatively stable metabolite profile, which is not conducive to modeling due the absence variations parameters. Here we present an approach where different steady-states obtained by variation cell spe...

A multi-wavelength based optical density sensor unit was designed, developed, and evaluated to monitor microalgae growth in real time. The system consisted of five main components including: (1) laser diode modules as light sources; (2) photodiodes as detectors; (3) driver circuit; (4) flow cell; and (5) sensor housing temperature controller. The sensor unit was designed to be integrated into a...

1. A simple technique of 'rosette' formation by low-density-lipoprotein-coated erythrocytes around human lymphoblastoid cells, stimulated to generate specific high affinity low-density lipoprotein receptors, is described. 2. Rosette formation is specific for high-affinity surface binding alone and the properties of the low-density lipoprotein receptors defined by it are identical with those fou...