Search results for "alginate"

Kinetic and equilibrium studies for uranyl removal from aqueous solution by adsorption onto alginate gel beads. DPV and ICP measurements

2014

Enhancing Biocompatibility and Antibacterial Activity of Ti6Al4V by Entrapping Ag and Hydroxyapatite Inside Alginate Filled Pores of TiO 2 Layer Grow…

2022

A three-step electrochemical process is developed to grow a coating on Ti6Al4V alloy for biomedical applications aimed to enhance its bioactivity. The coating is composed by a porous titanium oxide filled with Ag, alginic acid, and hydroxyapatite to provide antibacterial properties and, at the same time, osteointegration capability. Anodized and treated with the electrochemical process samples are characterized by Scanning Electron Microscopy (SEM), Energy-Dispersive X-ray Spectroscopy (EDX), X-Ray Diffraction, and Raman Spectroscopy to have information about morphology and composition soon after the fabrication and after immersion in Hanks' solution. Bioactivity of the samples is also prov…

A way to follow the viability of encapsulated Bifidobacterium bifidum subjected to a freeze-drying process in order to target the colon: Interest of …

2012

The aim of this work was to apply flow cytometry in order to assess and compare the viability of freeze-dried entrapped bacteria with an usual technique by quantification by plate count techniques. It also aimed at studying the effect of various cryoprotectants on the viability of an entrapped Bifidobacterium bifidum subjected to freeze-drying to check their ability to be delivered all along the gastro-intestinal tract. The alginate-pectinate beads were chosen as the encapsulation matrix added with different protectants. The beads were characterized by scanning electron microscopy and the viability was checked by both methods. The best combination to improve viability of entrapped bacteria …

Perspectives of the encapsulation technology in the nursery activity of Citrus

2007

The genetic and phytosanitary certification has to guarantee the quality of the propagation material also in Citrus. Traditional methods can be assisted by the techniques of in vitro culture, which are fundamental for the mass production of high quality plants. The encapsulation technology represents an innovative tool to combine the advantages of micropropagation with handling ease, storability, reduced size of the propagules, mechanization potentiality, transportability of the gamic seeds. In this work somatic embryos obtained from in vitro anther culture of the cultivar Mandarino Tardivo di Ciaculli (Citrus reticulata Blanco) were encapsulated in a sodium alginate matrix and synthetic se…

Preliminary research on conversion of encapsulated somatic embryos of Citrus reticulata Blanco, cv. Mandardino Tardivo di Ciaculli.

2006

Somatic embryogenesis was obtained through anther culture of Citrus reticulata, cv. Mandarino Tardivo di Ciaculli. The work was carried out to evaluate the response of somatic embryos inside a sodium alginate coating to different storage periods, and to the effects of the germicide PPM (1 ml l(-1) stop) and the fungicide Thiophanate-methyl (100 mg l(-1) stop). The effect of these alone or in combination, added to the artificial endosperm on the performance of the encapsulated somatic embryos was tested. After 45 days of culturing, sprouting, root development and conversion were recorded. The encapsulated somatic embryos can be conveniently stored at 4 degrees C, but not for a period longer …

The Marine Sponge-Derived Inorganic Polymers, Biosilica and Polyphosphate, as Morphogenetically Active Matrices/Scaffolds for the Differentiation of …

2014

The two marine inorganic polymers, biosilica (BS), enzymatically synthesized from ortho-silicate, and polyphosphate (polyP), a likewise enzymatically synthesized polymer consisting of 10 to >100 phosphate residues linked by high-energy phosphoanhydride bonds, have previously been shown to display a morphogenetic effect on osteoblasts. In the present study, the effect of these polymers on the differential differentiation of human multipotent stromal cells (hMSC), mesenchymal stem cells, that had been encapsulated into beads of the biocompatible plant polymer alginate, was studied. The differentiation of the hMSCs in the alginate beads was directed either to the osteogenic cell lineage by …

Cryopreservation of white mulberry (Morus alba L.) by encapsulation-dehydration and vitrification

2011

Shoot apices of in vitro-grown plantlets of white mulberry, Morus alba L. cv Florio, were cryopreserved using either encapsulation-dehydration or vitrification. For encapsulation-dehydration, alginate beads containing apices were dehydrated for 1, 3, 5 or 7 days in a liquid medium containing various sucrose concentrations (0.5, 0.75, 1.0 or 1.25 M). Bead desiccation was performed using silica gel for either 0, 4, 6, 8, 9 or 14 h. For vitrification, apices were directly immersed for either 5, 15, 30 or 60 min in a vitrification solution (PVS2). Following encapsulation-dehydration, treatment of alginate beads with 0.75 M sucrose was more effective in promoting re-growth of explants after imme…

The Schroeder paradox or how the state of water affects the moisture transfer through edible films

2012

The objective of this work was to better understand the water permeation through edible films when water is either in its vapour or in its liquid state related to their physico-chemical properties. Film based on iota-carrageenans or sodium alginate, containing or not fat, and encapsulating or not an aroma compound (n-hexanal) have been prepared. Films were conditioned at three different relative humidities, 0%, 43% and 84%. The incorporation of the n-hexanal in both types of biopolymer modifies the mechanical properties of film matrix and has a synergistic effect when associated to fat. Increasing the moisture content induces film plasticization by decreasing the glass transition of the gly…

Lifetime predictions of non-ionic and ionic biopolymers: kinetic studies by non-isothermal thermogravimetric analysis

2021

AbstractIn this paper, films based on sustainable polymers with variable charge have been investigated by non-isothermal thermogravimetry in order to predict their lifetime, which is a key parameter for their potential use in numerous technological and biomedical applications. Specifically, chitosan has been selected as positively charged biopolymer, while alginate has been chosen as negatively charged biopolymer. Among non-ionic polymers, methylcellulose has been investigated. Thermogravimetric measurements at variable heating rates (5, 10, 15 and 20 °C min−1) have been performed for all the polymers to study their degradation kinetics by using isoconversional procedures combined with ‘Mas…

Multilayer capsules: a promising microencapsulation system for transplantation of pancreatic islets

2001

In 1980, Lim and Sun introduced a microcapsule coated with an alginate/polylysine complex for encapsulation of pancreatic islets. Characteristic to this type of capsule is, that it consists of a plain membrane which is formed during a single procedural step. With such a simple process it is difficult to obtain instantly a membrane optimized with respect to all the properties requested for islet transplantation. To overcome these difficulties, it is recommended to build up the membrane in several consecutive steps, each optimized for a certain property. In this study, we have analysed such a multilayer microcapsule for the encapsulation of pancreatic islets. Therefore, empty and islet contai…