Search results for "Hydrogel"

A highly selective, Hg2+ triggered hydrogelation: modulation of morphology by chemical stimuli

2014

We report the first Hg2+ selective hydrogelation by 4´-[4-(4- aminophenyl)phenyl]-2,2´:6´,2´´-terpyridine. The gel showed remarkable response towards specific chemical agents such as benzo-18-crown-6 ether and K+ which enabled extensive 10 modulation of the gel morphology. peerReviewed

Current Trends in Advanced Alginate-Based Wound Dressings for Chronic Wounds

2021

Chronic wounds represent a major public health issue, with an extremely high cost worldwide. In healthy individuals, the wound healing process takes place in different stages: inflammation, cell proliferation (fibroblasts and keratinocytes of the dermis), and finally remodeling of the extracellular matrix (equilibrium between metalloproteinases and their inhibitors). In chronic wounds, the chronic inflammation favors exudate persistence and bacterial film has a special importance in the dynamics of chronic inflammation in wounds that do not heal. Recent advances in biopolymer-based materials for wound healing highlight the performance of specific alginate forms. An ideal wound dressing shou…

Pharmaceutical compositions in the form of gel containing xyloglucan and alcohols for the controlled release of active ingredients

2020

The invention relates to gel compositions comprising pharmaceutical active ingredients. The composition comprises xyloglucan at concentration between 0.1% and 10.0% by total weight of the composition, together with a primary alcohol at a concentration between 20.0 and 50.0% by total weight of the composition. The invention also describes a process for the preparation of the composition and its use in the treatment of pathologies wherein a controlled release of the active principle is useful.

RADIATION CROSSLINKED ADVANCED WOUND DRESSING CONTAINING EGG WHITE PROTEINS

During the past decades, the use of antibiotics has grown worldwide in different fields, from medicine to agriculture, leading to antibiotic resistance of microbes, which is the cause of thousands of deaths every year worldwide. [1, 2] Finding new antibiotics is becoming more and more difficult because their development is no longer convenient in term of the cost–benefit ratio for the pharmaceutical industry. The interest in egg white proteins, such as ovoalbumin, ovotransferrin and lysozyme, has risen especially because of their demonstrated antimicrobial activities. [3] These antimicrobial proteins can then be used to enrich wound dressing films that requires a high level of control of mi…

Application of endometrial extracellular matrix hydrogels developed from decellularized uterus in reproductive medicine.

2021

El endometrio es la capa del útero encargada de recibir al embrión en el momento de la implantación. Sin embargo, algunas enfermedades endometriales, como la atrofia endometrial y el síndrome de Asherman, pueden afectar negativamente a su función y provocar infertilidad. La matriz extracelular (del inglés extracellular matrix, ECM) es una red macromolecular en la que residen todas las células. La composición de la ECM es específica de cada tejido y sirve para sostener la estructura tisular, modular la función celular y contribuir a la curación después de una lesión. En las últimas décadas, los avances en las técnicas de bioingeniería y descelularización han permitido producir hidrogeles de …

Fluorescent naphthalimide-imidazolium hydrogels for biomedical applications

2019

Bioimaging and in vivo imaging are cornerstone technologies in support of biomedical diagnosis. However, in some cases imaging methods have increased cancer risks for patients. Moreover, the most widely used diagnostic medical imaging technique, X-ray imaging, is the largest man-made source of radiation exposure to the general population. Thus, the research of new efficient and less invasive materials for imaging is quite urgent. Supramolecular hydrogels have recently proved to be promising biological carriers to load versatile bioimaging agents for in vitro or in vivo bioimaging, thanks to the ability to undergo reversible swelling and gel–sol transition in response to various physiologica…

Modular Small Diameter Vascular Grafts with Bioactive Functionalities.

2015

We report the fabrication of a novel type of artificial small diameter blood vessels, termed biomimetic tissue-engineered blood vessels (bTEBV), with a modular composition. They are composed of a hydrogel scaffold consisting of two negatively charged natural polymers, alginate and a modified chitosan, N,O-carboxymethyl chitosan (N,O-CMC). Into this biologically inert scaffold two biofunctionally active biopolymers are embedded, inorganic polyphosphate (polyP) and silica, as well as gelatin which exposes the cell recognition signal, Arg-Gly-Asp (RGD). These materials can be hardened by exposure to Ca(2+) through formation of Ca(2+) bridges between the polyanions, alginate, N,O-CMC, and polyP…

Engineering a morphogenetically active hydrogel for bioprinting of bioartificial tissue derived from human osteoblast-like SaOS-2 cells.

2014

Abstract Sodium alginate hydrogel, stabilized with gelatin, is a suitable, biologically inert matrix that can be used for encapsulating and 3D bioprinting of bone-related SaOS-2 cells. However, the cells, embedded in this matrix, remain in a non-proliferating state. Here we show that addition of an overlay onto the bioprinted alginate/gelatine/SaOS-2 cell scaffold, consisting of agarose and the calcium salt of polyphosphate [polyP·Ca 2+ -complex], resulted in a marked increase in cell proliferation . In the presence of 100 μ m polyP·Ca2+ -complex, the cells proliferate with a generation time of approximately 47–55 h. In addition, the hardness of the alginate/gelatin hydrogel substantially i…

Porous Gelatin Hydrogels:  2. In Vitro Cell Interaction Study

2007

We report on the feasibility of applying porous gelatin hydrogels, prepared by a novel and controlled cryogenic treatment, as cell-interactive scaffolds for tissue engineering applications. Despite the large number of publications on gelatin as a biomaterial, a detailed study of screening a limited number of gelatin scaffolds for their interaction with a panel of human cells has, to the best of our knowledge, not yet been published. In the present work, we have evaluated two types of porous gelatin scaffolds that differ in their pore geometry and pore size. Type I hydrogels contained top-to-bottom transverse channels (i.e. cones) with a decreasing diameter from the top (330 microm) to the b…

Maltose-conjugated chitosans induce macroscopic gelation of pectin solutions at neutral pH

2014

Injectable polymer scaffolds are particularly attractive for guided tissue growth and drug/cell delivery with minimally invasive intervention. In the present work, "all-polymeric" gelling systems based on pectins and water-soluble maltose-conjugated chitosans (CM) have been developed. Maltose-conjugated chitosan has been synthesized at three different molar ratios, as evaluated by FITR analysis and fluorimetric titration. A thorough rheological characterization of the blends and their parent solutions has been performed. Macroscopic gelation has been achieved by mixing the high esterification degree pectins with CM at higher maltose grafted to chitosan contents. Gels form in a few minutes a…