Search results for "bioengineering"
showing 10 items of 1963 documents
Two-dimensional transthoracic echocardiographic normal reference ranges for proximal aorta dimensions: Results from the EACVI NORRE study
2017
International audience; AIMS: To report normal reference ranges for echocardiographic dimensions of the proximal aorta obtained in a large group of healthy volunteers recruited using state-of-the-art cardiac ultrasound equipment, considering different measurement conventions, and taking into account gender, age, and body size of individuals. METHODS AND RESULTS: A total of 704 (mean age: 46.0 ± 13.5 years) healthy volunteers (310 men and 394 women) were prospectively recruited from the collaborating institutions of the Normal Reference Ranges for Echocardiography (NORRE) study. A comprehensive echocardiographic examination was obtained in all subjects following pre-defined protocols. Aortic…
Balancing Passive and Active Targeting to Different Tumor Compartments Using Riboflavin-Functionalized Polymeric Nanocarriers
2017
Riboflavin transporters (RFTs) and the riboflavin carrier protein (RCP) are highly upregulated in many tumor cells, tumor stem cells, and tumor neovasculature, which makes them attractive targets for nanomedicines. Addressing cells in different tumor compartments requires drug carriers, which are not only able to accumulate via the EPR effect but also to extravasate, target specific cell populations, and get internalized by cells. Reasoning that antibodies are among the most efficient targeting systems developed by nature, we consider their size (-10-15 nm) to be ideal for balancing passive and active tumor targeting. Therefore, small, short-circulating (10 kDa, -7 nm, t1/2 - 1 h) and large…
HPMA-LMA copolymer drug carriers in oncology: an in vivo PET study to assess the tumor line-specific polymer uptake and body distribution.
2013
Polymeric drug carriers aim to selectively target tumors in combination with protecting normal tissue. In this regard polymer structure and molecular weight are key factors considering organ distribution and tumor accumulation of the polymeric drug delivery system. Four different HPMA based copolymer structures (random as well as block copolymers with lauryl methacrylate as hydrophobic block) varying in molecular weight, size and resulting architecture were analyzed in two different tumor models (AT1 prostate carcinoma and Walker-256 mammary carcinoma) in vivo. Polymers were labeled with (18)F and organ/tumor uptake was followed by μPET imaging and ex vivo biodistribution. Vascular permeabi…
Improving cytocompatibility of Co28Cr6Mo by TiO 2 coating: gene expression study in human endothelial cells
2013
Cobalt-based materials are widely used for coronary stents, as well as bone and joint implants. However, their use is associated with high corrosion incidence. Titanium alloys, by contrast, are more biocompatible owing to the formation of a relatively inactive titanium oxide (TiO 2 ) layer on their surface. This study was aimed at improving Co28Cr6Mo alloy cytocompatibility via sol–gel TiO 2 coating to reduce metal corrosion and metal ion release. Owing to their role in inflammation and tissue remodelling around an implant, endothelial cells present a suitable in vitro model for testing the biological response to metallic materials. Primary human endothelial cells seeded on Co28Cr6Mo showe…
Engineering a Microvascular Capillary Bed in a Tissue-Like Collagen Construct
2014
Previous studies have shown that plastic compression (PC) of collagen gels allows a rapid and controlled fabrication of matrix- and cell-rich constructs in vitro that closely mimic the structure and characteristics of tissues in vivo. Microvascular endothelial cells, the major cell type making up the blood vessels in the body, were added to the PC collagen to determine whether cells attach, survive, grow, and express endothelial cell characteristics when seeded alone or in coculture with other cells. Endothelial cells seeded on the PC collagen containing human foreskin fibroblasts (HFF) or human osteoblasts (HOS) formed vessel-like structures over 3 weeks in culture without the addition of …
Intravoxel incoherent motion diffusion-weighted imaging in nonalcoholic fatty liver disease: a 3.0-T MR study.
2012
International audience; PURPOSE: To compare pure molecular diffusion, D, perfusion-related diffusion, D*, and perfusion fraction, f, determined from diffusion-weighted (DW) magnetic resonance (MR) imaging on the basis of the intravoxel incoherent motion (IVIM) theory in patients with type 2 diabetes with and without liver steatosis. MATERIALS AND METHODS: This prospective study was approved by the appropriate ethics committee, and written informed consent was obtained from all patients. Between December 2009 and September 2011, 108 patients with type 2 diabetes (51 men, 57 women; mean age, 50 years) underwent 3.0-T single-voxel point-resolved proton MR spectroscopy of the liver (segment VII…
Synaptosomes: new vesicles for neuronal mitochondrial transplantation
2021
Abstract Background Mitochondrial dysfunction is a critical factor in the onset and progression of neurodegenerative diseases. Recently, mitochondrial transplantation has been advised as an innovative and attractive strategy to transfer and replace damaged mitochondria. Here we propose, for the first time, to use rat brain extracted synaptosomes, a subcellular fraction of isolated synaptic terminal that contains mitochondria, as mitochondrial delivery systems. Results Synaptosome preparation was validated by the presence of Synaptophysin and PSD95. Synaptosomes were characterized in terms of dimension, zeta potential, polydispersity index and number of particles/ml. Nile Red or CTX-FITCH la…
Fate of Linear and Branched Polyether-Lipids In Vivo in Comparison to Their Liposomal Formulations by 18F-Radiolabeling and Positron Emission Tomogra…
2015
In this study, linear poly(ethylene glycol) (PEG) and novel linear-hyperbranched, amphiphilic polyglycerol (hbPG) polymers with cholesterol (Ch) as a lipid anchor moiety were radiolabeled with fluorine-18 via copper-catalyzed click chemistry. In vivo investigations via positron emission tomography (PET) and ex vivo biodistribution in mice were conducted. A systematic comparison to the liposomal formulations with and without the polymers with respect to their initial pharmacokinetic properties during the first hour was carried out, revealing remarkable differences. Additionally, cholesterol was directly labeled with fluorine-18 and examined likewise. Both polymers, Ch-PEG27-CH2-triazole-TEG-…
Pattern of occult nodal relapse diagnosed with 18F-fluoro-choline PET/CT in prostate cancer patients with biochemical failure after prostate-only rad…
2014
Abstract Introduction The purpose of this study was to describe the pattern of nodal relapse with 18 F-fluoro-choline (FCH) Positron Emission Tomography/Computerized Tomography (PET/CT) in prostate cancer patients after radiotherapy. Materials and methods Eighty-three patients had a FCH PET/CT at time of biochemical failure. Of 65 patients with positive findings, 33 had positive nodes. This analysis included 31 patients who had undergone prior prostate-only radiotherapy with or without a prior radical prostatectomy. Each FCH positive node was assigned to a lymph node station with respect to the CTV defined by the RTOG guidelines (CTV RTOG ). 3D mapping was performed after each node was manu…
Fine-tuning DNA/albumin polyelectrolyte interactions to produce the efficient transfection agent cBSA-147.
2010
We present the preparation and isolation of different chemically modified BSA species with varying numbers of primary amino groups at the surface. Highly cationic albumin proteins with increased numbers of amino groups were achieved and complex formation with plasmid DNA was carefully investigated. We compare the transfection results, polyelectrolyte complexes morphologies with their impact on complex stabilities, cytotoxicities and DNA accessibility. This knowledge-driven approach led to the identification of the efficient non-viral DNA delivery agent cBSA-147, which showed high transfection efficacies and stability.