Search results for "Biomedical"
showing 10 items of 2328 documents
Polyphosphate, the physiological metabolic fuel for corneal cells: a potential biomaterial for ocular surface repair
2019
The regeneration of the epithelium, covering the avascular cornea, involves the processes of differentiation, proliferation and migration of cells originating from the corneal epithelial stem cells. We ask the question if these energy-consuming processes can be fueled by the physiological, inorganic polyphosphate (polyP), the main energy storage/donor molecule in the extracellular space. The ex vivo results reveal that addition of polyP, in the form of soluble Na-polyP, to the culture medium elicits a strong stimulatory effect on cell viability/growth and migration of corneal epithelial cells. Microscopic analyses of partially denuded cornea specimens show that in the presence of polyP, but…
Hyaluronic acid based nanohydrogels fabricated by microfluidics for the potential targeted release of Imatinib: Characterization and preliminary eval…
2019
Abstract Microfluidics is emerging as an innovative technique for the “on chip” fabrication of nanoparticles for drug delivery applications. Here, by using an amphiphilic derivative of hyaluronic acid as a starting macromolecule, nanohydrogels loaded with Imatinib were produced by the microfluidic procedure in order to develop an innovative therapeutic tool for the treatment of retinal neovascularization. Both cyRGDC functionalized and non-functionalized nanohydrogels were designed and fabricated by using the same technique. The targeting efficiency of the obtained nanosystems was studied in vitro on human retinal pigment epithelial cells (HRPEpiC) and human umbilical vein endothelial cells…
The effects of shock wave stimulation of mesenchymal stem cells on proliferation, migration, and differentiation in an injectable gelatin matrix for …
2020
The treatment of a variety of defects in bony sites could benefit from mitogenic stimulation of osteoprogenitor cells, including endogenous bone marrow-derived mesenchymal stem cells (bMSCs), and from provision of such cells with a matrix permissive of their migration, proliferation, and osteogenic differentiation. That such MSC stimulation could result from treatment with noninvasive (extracorporeal) shock waves (ESWs), and the matrix delivered by injection could enable this therapeutic approach to be employed for applications in which preformed scaffolds and growth factor therapy are difficult to deploy. The objectives of the present study were to investigate focused ESWs for their effect…
Dynamic processes involved in the pre-vascularization of silk fibroin constructs for bone regeneration using outgrowth endothelial cells
2009
For successful bone regeneration tissue engineered bone constructs combining both aspects, namely a high osteogenic potential and a rapid connection to the vascular network are needed. In this study we assessed the formation of pre-vascular structures by human outgrowth endothelial cells (OEC) from progenitors in the peripheral blood and the osteogenic differentiation of primary human osteoblasts (pOB) on micrometric silk fibroin scaffolds. The rational was to gain more insight into the dynamic processes involved in the differentiation and functionality of both cell types depending on culture time in vitro. Vascular tube formation by OEC was assessed quantitatively at one and 4 weeks of cul…
OPETH: Open Source Solution for Real-Time Peri-Event Time Histogram Based on Open Ephys
2019
Single cell electrophysiology remains one of the most widely used approaches of systems neuroscience. Decisions made by the experimenter during electrophysiology recording largely determine recording quality, duration of the project and value of the collected data. Therefore, online feedback aiding these decisions can lower monetary and time investment, and substantially speed up projects as well as allow novel studies otherwise not possible due to prohibitively low throughput. Real-time feedback is especially important in studies that involve optogenetic cell type identification by enabling a systematic search for neurons of interest. However, such tools are scarce and limited to costly co…
Spot compliant neuronal networks by structure optimized micro-contact printing
2001
Neuronal cell growth in vitro can be controlled with micropatterned structures of extracellular matrix proteins such as laminin. This technique is a powerful tool for studying neuronal cell function in order to increase experimental reproducibility and to specifically design innovative experimental setups. In this paper the correlation between the structural dimensions of the ECM pattern and the shape of the resulting cellular network is analyzed. The aim of the present study was to position neuronal cell bodies as precisely as possible and to induce directed cell differentiation. PCC7-MzN cells were cultured on laminin patterns. The line width, node size and gap size in-between cell adhesi…
Murine muscle engineered from dermal precursors: an in vitro model for skeletal muscle generation, degeneration and fatty infiltration.
2013
Skeletal muscle can be engineered by converting dermal precursors into muscle progenitors and differentiated myocytes. However, the efficiency of muscle development remains relatively low and it is currently unclear if this is due to poor characterization of the myogenic precursors, the protocols used for cell differentiation, or a combination of both. In this study, we characterized myogenic precursors present in murine dermospheres, and evaluated mature myotubes grown in a novel three-dimensional culture system. After 5-7 days of differentiation, we observed isolated, twitching myotubes followed by spontaneous contractions of the entire tissue-engineered muscle construct on an extracellul…
On the Interaction between 1D Materials and Living Cells
2020
One-dimensional (1D) materials allow for cutting-edge applications in biology, such as single-cell bioelectronics investigations, stimulation of the cellular membrane or the cytosol, cellular capture, tissue regeneration, antibacterial action, traction force investigation, and cellular lysis among others. The extraordinary development of this research field in the last ten years has been promoted by the possibility to engineer new classes of biointerfaces that integrate 1D materials as tools to trigger reconfigurable stimuli/probes at the sub-cellular resolution, mimicking the in vivo protein fibres organization of the extracellular matrix. After a brief overview of the theoretical models r…
Hydration Chemistry of Cement Studied by Near Infrared Spectroscopy
2018
Cement is a complex mixture of inorganic compounds which mainly composed of calcium silicates and calcium aluminates. Cement is mixed with water to form concrete. During the mixing calcium silicate hydrate (CSH) and calcium hydroxide are formed. The ratio of water/cement (w/c ratio) is important to obtain a mixture that gives optimum strength to the concrete. In this work, three different cement samples were mixed with water in four different ratios, including 0.35, 0.40, 0.45 and 0.55, respectively. The hydration process of cement was investigated by using near infrared (NIR) spectroscopy over a period of 28 days. The combination frequency of OH stretching and bending of water molecules gi…
Influence of thickness and translucency of lithium disilicate ceramic on degree of conversion of resinous materials
2020
Background In this study was assessed the degree of conversion (DC) of amine-free resin cements light cured through lithium disilicate-reinforced ceramics at different thicknesses and translucency. Material and Methods Specimens were divided into 21 groups (n = 5) according to luting agent used: Variolink Esthetic LC (Light shade), RelyX Ultimate (A1 shade), and Filtek Z350 XT Flow (A1 shade); the ceramic translucency: low (LT) and high (HT); and the ceramic thickness: no ceramic (control), 0.5 mm, 1 mm, and 2 mm. A Teflon mold with (5 x 5 x 0.5 mm) was used to standardize the cement and over it the ceramic block from each group was placed. Set was cured using a polywave LED light (1200 mW/…