Search results for "VITRO"

Toxic Tau Oligomers Modulated by Novel Curcumin Derivatives

2019

AbstractThe pathological aggregation and accumulation of tau, a microtubule-associated protein, is a common feature amongst more than 18 different neurodegenerative diseases that are collectively known as tauopathies. Recently, it has been demonstrated that the soluble and hydrophobic tau oligomers are highly toxic in vitro due to their capacity towards seeding tau misfolding, thereby propagating the tau pathology seen across different neurodegenerative diseases. Modulating the aggregation state of tau oligomers through the use of small molecules could be a useful therapeutic strategy to target their toxicity, regardless of other factors involved in their formation. In this study, we screen…

Toxicity and cell density monitoring in monolayer and three-dimensional cultures with the XTT assay

1998

The application of viability criteria (MTT and XTT tests) to monolayer cultures and immobilised cells in three-dimensional systems was investigated in order to assess cell viability and cell proliferation. The suitability and accuracy of these tests were compared with the conventional criteria (cellular protein and DNA content) used in monolayer cultures for the same purpose. The colorimetric assay based on the metabolic reduction of the tetrazolium salt XTT to a water-soluble formazan proved to be very useful, rapid and sensitive. This automated spectrophotometric enzymatic method, due to its lack of toxicity, also permits repeated nondestructive assays on a single cellular culture for the…

Alkaline phosphatase dual-binding sites for collagen dictate cell migration and microvessel assembly in vitro

2020

Interactions between cell types, growth factors, and extracellular matrix components involved in angiogenesis are crucial for new vessel formation leading to tissue regeneration. This study investigated whether cocultures of fibroblasts and endothelial cells (ECs; from macro- or microvasculature) play a role in the formation of microvessel-like structures by ECs, as well as modulate fibroblast differentiation and growth factors production (vascular endothelial cell growth factor, basic fibroblast growth factor, active transforming growth factor-beta 1, and interleukin-8), which are important for vessel sprouting and maturation. Data obtained revealed that in vitro coculture systems of fibro…

Exosomes derived from stimulated monocytes promote endothelial dysfunction and inflammation in vitro

2017

During the last few years, the scientific community interest on the role of extracellular vesicles (EVs) in physiology and pathophysiology of several human diseases has increased exponentially (1). These vesicles present the capability of transferring different kind of molecules (lipids, RNAs, DNA, protein…) between cells and may exert some effects on the cell phenotype. The content of these vesicles can vary depending on the cell type of origin (2). Although nowadays there is no consensus regarding the appropriate nomenclature, three well-known types of vesicles can be categorized on the basis of size and biogenesis: apoptotic bodies (>1 µm), microvesicles (150 nm–1 µm, budding from plasma…

Candida albicansis able to use M cells as a portal of entry across the intestinal barrierin vitro

2015

Candida albicans is the most frequent yeast responsible for systemic infections in humans. These infections mainly originate from the gastrointestinal tract where C. albicans can invade the gut epithelial barrier to gain access to the bloodstream. Along the gut, pathogens can use Microfold (M) cells as a portal of entry to cross the epithelial barrier. M cells are specialized cells mainly located in the follicule-associated epithelium of Peyer patches. In this study, we used scanning electron and fluorescence microscopy, adhesion and invasion assays and fungal mutants to investigate the interactions of C. albicans with M cells obtained in an established in vitro model whereby enterocyte-lik…

Visualizing In Vitro Type I Collagen Fibrillogenesis by Transmission Electron Microscopy

2017

Techniques and protocols for the in vitro formation of collagen type I fibrils and the extensive biochemical variation of the fibrillogenesis conditions are presented. In all cases, the incubation and fibrillogenesis product can be readily monitored by transmission electron microscopic study of negatively stained specimens. Representative TEM data is presented and discussed within the context of the products of the fibrillogenesis protocols, from which the extensive biochemical and structural possibilities of this integrated approach can be appreciated.

Impact of high-pressure processing on the stability and bioaccessibility of bioactive compounds in Clementine mandarin juice and its cytoprotective e…

2020

Mandarin juice is a rich source of antioxidant bioactive compounds. While the content and profile of bioactives are known, the impact of high-pressure processing (HPP) on their stability and bioaccessibility (BA) is unknown, but may allow obtaining safe, nutritious, and fresh-tasting juices with highly extractable bioactive compounds. The stability and BA of bioactive antioxidant compounds in untreated and HPP-treated (400 MPa/40 °C/1 min) Clementine mandarin juices, and the cytoprotective effect of its bioaccessible fractions (BF) obtained after simulated gastrointestinal digestion against H2O2-induced oxidative stress in differentiated Caco-2 cells were investigated. The BF of HPP-treated…

2017

Although a lot of research has been performed, large segmental bone defects caused by trauma, infection, bone tumors or revision surgeries still represent big challenges for trauma surgeons. New and innovative bone substitutes are needed. Three-dimensional (3D) printing is a novel procedure to create 3D porous scaffolds that can be used for bone tissue engineering. In the present study, solid discs as well as porous cage-like 3D prints made of polylactide (PLA) are coated or filled with collagen, respectively, and tested for biocompatibility and endotoxin contamination. Microscopic analyses as well as proliferation assays were performed using various cell types on PLA discs. Stromal-derived…

Antibacterial properties and reduction of MRSA biofilm with a dressing combining polyabsorbent fibres and a silver matrix

2016

Objective: This study was designed to evaluate the antibacterial activity of a wound dressing which combines polyacrylate fibres and a silver lipido-colloid matrix (UrgoClean Ag, silver polyabsorbent dressing), against biofilm of methicillin-resistant Staphylococcus aureus (MRSA). Method: Samples of silver polyabsorbent dressing and the neutral form of this dressing (UrgoClean) were applied to biofilms of MRSA formed on a collagen I-coated surface, cultured for 24 hours. Different exposure times were tested (1, 2, 4 and 7 days) without dressing change. The biofilm reduction was quantified by using culture methods and by confocal laser scanning microscopy experiments. Results: The applicatio…

Uptake of polyphosphate microparticles in vitro (SaOS-2 and HUVEC cells) followed by an increase of the intracellular ATP pool size

2017

Recently two approaches were reported that addressed a vitally important problem in regenerative medicine, i. e. the successful treatment of wounds even under diabetic conditions. Accordingly, these studies with diabetic rabbits [Sarojini et al. PLoS One 2017, 12(4):e0174899] and diabetic mice [Müller et al. Polymers 2017, 9, 300] identified a novel (potential) target for the acceleration of wound healing in diabetes. Both studies propose a raise of the intracellular metabolic energy status via exogenous administration either of ATP, encapsulated into lipid vesicles, or of polyphosphate (polyP) micro-/nanoparticles. Recently this physiological polymer, polyP, was found to release metabolic …