Search results for "agarose"

Alginate-Agarose Hydrogels Improve the In Vitro Differentiation of Human Dental Pulp Stem Cells in Chondrocytes. A Histological Study

2021

[EN] Matrix-assisted autologous chondrocyte implantation (MACI) has shown promising results for cartilage repair, combining cultured chondrocytes and hydrogels, including alginate. The ability of chondrocytes for MACI is limited by different factors including donor site morbidity, dedifferentiation, limited lifespan or poor proliferation in vitro. Mesenchymal stem cells could represent an alternative for cartilage regeneration. In this study, we propose a MACI scaffold consisting of a mixed alginate-agarose hydrogel in combination with human dental pulp stem cells (hDPSCs), suitable for cartilage regeneration. Scaffolds were characterized according to their rheological properties, and their…

Mesoscopic gels at low agarose concentration: perturbation effects of ethanol

1997

Aqueous agarose solutions at low concentrations (0.5 g/liter) were temperature quenched below the spinodal line to form mutually disconnected mesoscopic gels. In the presence of 6% ethanol, these solutions, obtained by quenching at the same temperature depth as in pure water, appear much more fluid, as determined by probe diffusion experiments. We show by static and dynamic light scattering that this can be explained by the solvent-mediated effects of ethanol, leading to a globular shape of mesoscopic agarose gels, rather than to an extended rodlike structure observed in pure water. Our findings show the significant effects of solvent perturbations on particle condensation and, therefore, m…

Microgel regions in dilute agarose solutions: the notion of non-gelling concentration, and the role of spinodal demixing

1991

Abstract Freely drifting microgel regions are found in aqueous solutions of agarose, a representative biostructural polysaccharide, at concentrations between 0.01% and 0.05% w/v when quenched from 100°C to lower temperature. The size of these domains depends on the quench temperature and agarose concentration. The results agree with recent findings on the role that fluctuations within or close to the instability region of solution have as the initial step towards the self-assembly of supramolecular structures, and throw a new light on the notion of the lowest solute concentration needed for gelation.

Nuclear magnetic resonance relaxometry and imaging for dosimetry with agarose Fricke gel

2016

Gel dosimeters for radiotherapy applications

2014

Dependence of MRI sensitivity of Fricke gel dosimeters exposed to clinical photons beams on ferrous ammonium sulfate content

2014

Characterization of Fricke gel dosimeters exposed to clinical photons beams and of MRI dosimetrical applications

2014

PVA gel dosimeters for radiotherapy applications,

2015

Gel dosimeters for three-dimensional mapping of radiotherapy doses were introduced at Yale University in the mid-1980’s. Soon after, research and development in this field also started in Italy. Early work was done at the Istituto Superiore di Sanità, and at the Universities of Pisa and Milan. Several institutes now collaborate on this topic with the goal of developing new formulations of hydrogel matrices with improved characteristics of stability, sensitivity and spatial resolution compared to those of earlier Fricke-gel and polymer-gel systems. Contrary to earlier gels based on natural gelling agents, such as porcine skin gelatin and/or agarose, which suffer from limited batch -to-batch …

Investigation of relaxation times of irradiated Fricke gels by means of nuclear magnetic resonance relaxometry

2016

Fricke gel dosimeters are ideal candidates to provide 3D maps of dose distributions and are particularly useful in the plann ing and verification phase of radiotherapy treatments. One of the most effective experimental techniques to reconstruct dose maps is magnetic resonance imaging (MRI). This measures th e nuclear relaxation times variations induced by irradiation. In this work, we analyzed Fricke gels with and without Xylenol Orange by means of a single side-NMR relaxometer (which is abl e to provide information on both relaxation relaxation times T1 and T2 and is mainly used in the field of diagnostics for Cultural Heritage [1-2] to perform porosimetry meaurements). Our goal was to per…

Shigella sonnei biotype g carrying class 2 integrons in southern Italy: a retrospective typing study by pulsed field gel electrophoresis

2006

Abstract Background Emergence and global dissemination of multiresistant strains of enteric pathogens is a very concerning problem from both epidemiological and Public Health points of view. Shigella sonnei is the serogroup of Shigella most frequently responsible for sporadic and epidemic enteritis in developed countries. The dissemination is associated most often to human to human transmission, but foodborne episodes have also been described. In recent years the circulation of multiresistant strains of S. sonnei biotype g carrying a class 2 integron has been reported in many countries worldwide. In southern Italy a strain with similar properties has been responsible for a large community o…