Search results for "bioengineering"
showing 10 items of 1963 documents
Development of a self-pumping extracorporeal blood oxygenation device characterized by a rotating shaft with embedded fiber packages.
2019
Introduction: To offer respiratory support for patients with lung disease, a novel technological solution for blood pumping and oxygenation is being developed. The pump–lung system was designed to integrate fiber membranes into six packages radially embedded in a rotating hollow shaft placed along the longitudinal axis of the device. Fiber packages are inclined with respect to the rotation axis so that the rotational motion of the rotating shaft allows a self-pumping system to be obtained. Method: Both hemodynamic and gas transfer performances were investigated using both in vitro experiments and in silico flow analyses. Results: The predicted flow velocity in the pump chamber was smooth an…
Synthesis and In Vitro Evaluation of Defined HPMA Folate Conjugates: Influence of Aggregation on Folate Receptor (FR) Mediated Cellular Uptake
2010
In this article we report the synthesis and in vitro evaluation of well-defined, folate functionalized and fluorescently labeled polymers based on the clinically approved N-(2-hydroxypropyl)-methacrylamide (HPMA). The polymers were prepared applying the RAFT polymerization method as well as the reactive ester approach. The molecular weights of the polymers synthesized were around 15 and 30 kDa. The total content of conjugated folate varied from 0, 5, and 10 mol %. The cellular uptake of these polymers was investigated in the folate receptor (FR)-positive human nasopharyngeal epidermal carcinoma (KB-3-1) and FR-negative human lung epithelial carcinoma (A549) cancer cell lines. In FR-positive…
The therapeutic impact of PET-FDG scanning in broncho-pulmonary cancer
2005
Because of the expected high performances of scintigraphic scans with [18F]-fluorodeoxyglucose (FDG) not only in diagnostics and but also in therapeutic impact, especially in thoracic oncology, there are a lot of French nuclear medicine departments which will soon be equipped with a positron emission tomograph (PET).The Nuclear Medicine Department of the Hôpital d'Instructions des Armées du Val-de-Grâce, Paris, led a retrospective study among physicians interested in 338 FDG-PET exams performed between may 2000 and march 2002 in order to compare its own results with international literature concerning four indications for lung cancer: pulmonary nodule or mass malignancy diagnostic, lung car…
3D printing novel in vitro cancer cell culture model systems for lung cancer stem cell study
2021
Two-dimensional (2D) in vitro cell cultures and laboratory animals have been used traditionally as the gold-standard preclinical cancer model systems. However, for cancer stem cell (CSC) studies, they exhibit notable limitations on simulating native environment, which depreciate their translatability for clinical development purposes. In this study, different three-dimensional (3D) printing platforms were used to establish novel 3D cell cultures enriched in CSCs from non-small cell lung cancer (NSCLC) patients and cell lines. Rigid scaffolds with an elevated compressive modulus and uniform pores and channels were produced using different filaments. Hydrogel-based scaffolds were printed with…
RGD motifs on the surface of baculovirus enhance transduction of human lung carcinoma cells.
2006
Baculovirus vectors have been shown to enter a variety of mammalian cell lines and gene transfer with wild-type baculovirus (WT) has been demonstrated both in vitro and in vivo. Different protein motifs have been displayed on the viral surface to serve as ligands for cell-specific receptor molecules. We have generated recombinant baculovirus vectors displaying an RGD-motif, recognized by alphaV integrin, on the viral surface. The RGD motifs within the C-terminus of coxsackie virus A9 and human parechovirus 1 VP1 proteins were fused to the N-terminus of the major envelope glycoprotein, gp64, of Autographa californica multiple nucleopolyhedrovirus. The recombinant RGD-presenting viruses bound…
Metabolic fluxes and l-lysine synthesis by Corynebacterium glutamicum in relation to cellular total reducing activity
2001
Abstract The total reducing activity (TRA) of cells was used to estimate the physiological activity of Corynebacterium glutamicum under conditions of l -lysine synthesis. This was estimated as the rate of reduction of 2,3,5- triphenyltetrazolium chloride by intact cells. TRA of cells was linearly correlated with the intracellular concentrations of RNA and the bacterial growth rate. It was concluded that this activity reflected the rate of energy generation in cells. A decrease in TRA of growing cells was related to an increase in bacterial lysine synthesis activity. Alteration in metabolic pathway functioning and an increase in the intracellular concentrations of lysine precursors favoured …
Biodegradable Protein Nanocontainers
2015
The application of synthetic polymers for drug delivery often requires tremendous efforts to ensure biocompatibility and -degradation. To use the body's own substances can help to overcome these problems. Herein, we present the first synthesis of nanocontainers entirely composed of albumin proteins. These protein nanocontainers (PNCs) were loaded with hydrophilic compounds and release of the payload is triggered through natural lysis in vitro in human monocyte-derived dendritic cells (moDCs). No aggregation of PNCs in human blood plasma was observed, indicating stability for blood circulation. As the PNCs were readily taken up by moDCs, they are considered as a promising delivery platform f…
Use of Saccharomyces cerevisiae as a whole cell system for aldol condensation in organic medium: Study of the factors affecting the biotransformation
2011
Abstract Saccharomyces cerevisiae has been employed as a whole cell catalyst for a number of asymmetric transformations. This work explores the ability of this microorganism to carry out the asymmetric aldol condensation between 4-nitrobenzaldehyde and acetone. For this purpose, lyophilized cells of the FY86 laboratory strain from stationary phase cultures were employed. This reaction shows stereoselectivity, and its progress is affected by the water concentration in the medium, temperature and the growth stage of the yeast culture. Cell lysis experiments indicate that activity responsible for this biotransformation is located in the soluble fraction.
Lysis of yeast cells by Oenococcus oeni enzymes
2000
exhibited extracellular β (1→3) glucanase activity. This activity increased when cells were cultivated with glycosidic cell-wall macromolecules. In addition, the culture supernatant of the organism effectively lysed viable or dead cells of Saccharomyces cerevisiae. This lytic activity appeared in the early stationary phase of bacterial growth. Yeast cells at the end of the log phase of growth were the most sensitive. The optimum temperature for lysis of viable yeast cells was 40°C, which is very different from the temperatures observed in enological conditions (15–20°C). Moreover, the rate of the lytic activity was significantly lower in comparison with yeast cell wall-degrading activities …
Protein-induced, previously unidentified twin form of calcite.
2007
Using single-crystal x-ray diffraction, we found a formerly unknown twin form in calcite crystals grown from solution to which a mollusc shell-derived 17-kDa protein, Caspartin, was added. This intracrystalline protein was extracted from the calcitic prisms of the Pinna nobilis shells. The observed twin form is characterized by the twinning plane of the (108)-type, which is in addition to the known four twin laws of calcite identified during 150 years of investigations. The established twin forms in calcite have twinning planes of the (001)-, (012)-, (104)-, and (018)-types. Our discovery provides additional evidence on the crucial role of biological macromolecules in biomineralization.