Search results for "Gels"

A multifuctional nanoplatform for drug targeted delivery based on radiation-engineered nanogels

2020

Abstract Under a rational design, combining biologically active molecules, ligands to specific cell receptors and fluorescent, radioactive or paramagnetic labels into a single nano-object can bridge the unique properties of the individual components and improve conventional sensing, imaging and therapeutic efficacies. The validation of these functional nano-objects requires careful testing both in terms of physico-chemical properties and biological behaviour in vitro and in vivo, prior to translation into the clinic. Ionising radiation of aqueous polymer solutions is a viable strategy to produce multifunctional nanogels from aqueous solutions of hydrophilic polymers. By proper selection of …

Hyaluronic Acid–Silica Nanohybrid Gels

2013

Excessive water sorption and low mechanical properties are a severe drawback in some biomedical applications of hyaluronic acid (HA). A way to improve these properties is here explored through the novel concept of nanohybrid hydrogels consisting of a HA matrix including different amounts of silica-derived species. This inorganic filler phase controls the mechanical and swelling properties of HA cross-linked matrices. Below a 2 wt % of silica in the systems, nanoparticle aggregates of tens of nanometers and silica oligomers are distributed more or less homogeneously throughout the organic matrix, without percolating. This morphology of the silica phase is accompanied by an increased swelling…

Biocompatibility studies of endothelial cells on a novel calcium phosphate/SiO 2 -xerogel composite for bone tissue engineering

2008

The bone biomaterial BONITmatrix®, a nanoporous, granular scaffold composed of hydroxylapatite, calcium phosphate and SiO2, linked by a dense collagen mesh, was tested for its biocompatibility using endothelial cells (EC) in the form of macrovascular HUVEC, microvascular HDMEC and the endothelial cell line ISOHAS-1. Cells were examined for their adherence and growth on the biomaterial and this was followed by confocal laser scanning microscopy after vital staining or immunocytochemical reactions, as well as by scanning electron microscopy. Macro- and microvascular ECs predominantly spread on BONITmatrix®-collagen mesh-covered surfaces and fibres and maintained their typical morphology. As E…

Composite Hydrogels of Alkyl Functionalized Gellan Gum Derivative and Hydroxyapatite/Tricalcium Phosphate Nanoparticles as Injectable Scaffolds for b…

2021

An alkyl functionalized gellan gum derivative was here used to produce hydrogels containing hydroxyapatite and tricalcium phosphate nanoparticles as injectable nanostructured scaffolds for bone regeneration. The amphiphilic nature of the polysaccharide derivative along with its thermotropic behavior and ionotropic crosslinking features made possible to produce injectable bone mimetic scaffolds that can be used to release viable cells and osteoinductive biomolecules. The influence of different nanoparticles concentration on the rheological and physicochemical properties of the injectable systems was studied. We found that the presence of inorganic nanoparticles reinforces the three-dimension…

Aqueous two-phase system cold-set gelation using natural and recombinant probiotic lactic acid bacteria as a gelling agent

2016

The present study aimed to entrap probiotic lactic acid bacteria (LAB) in a sodium alginate and sodium caseinate aqueous two-phase gel system. The natural acidifying properties of two therapeutic probiotic LAB were exploited to liberate calcium ions progressively from calcium carbonate (CaCO3), which caused the gelation of the co-existing phases. Bi-biopolymeric matrix gelation of GDL/CaCO3 or LAB/CaCO3 was monitored by dynamic rheological measurements, and the final gels were characterized by frequency dependence measurements and confocal laser scanning microscopy. Weak to strong gels were formed with an elastic modulus G' from 10 to 1.000Pa, respectively. After cold-set gelation of our sy…

A Calorimetric and Viscosimetric Study for the Characterization of Pectin Hydrogels. Application in the field of Cultural Heritage

2009

Carl Christian Vogel von Vogelstein: Dante e la Divina Commedia (1842-44)

2006

Catalogue entry concerning Vogel von Vogelstein's painting «Dante e la Divina Commedia» (1842-44).

Carl Christian Vogel von Vogelstein: Autoritratto (1857)

2006

Catalogue entry concerning Vogel von Vogelstein's self-portrait (1857).

Modulating carbohydrate-based hydrogels as viscoelastic lubricant substitute for articular cartilages

2017

Viscosupplementation is a therapeutic approach for osteoarthritis treatment, where the synovial fluid, the natural lubricant of the joints, is replaced by viscoelastic solutions with rheological properties comparable or better than the starting material. This study presents the development of an innovative platform for viscosupplementation, based on the optimization of polysaccharide-based colloidal hydrogel, aiming to reduce on-site enzyme degradation and enhance the possibility of hyaluronic acid substitution with alternative biomaterials. Catanionic vesicles are proposed as physical crosslinker that can guarantee the formation of a 'soft', tunable network, offering a dual-therapeutic app…

κ-Carrageenan and PVA blends as bioinks to 3D print scaffolds for cartilage reconstruction.

2022

3D printing of polymeric scaffolds and autologous stem cells is a promising tool for damaged facial cartilage reconstruction surgeries. To this end, suitable bioinks are needed to generate scaffolds with the required morphological and functional features. We formulated hydrogel bioinks using k-Carrageen (kC) and poly(vinyl alcohol) (PVA) in three different weight ratios. The kC gives the systems the ability to undergo rapid sol-to-gel transitions upon cooling from 60 °C and above to body temperature, while the PVA is used as rheology modifier and porogen. The latter is crosslinked after molding or printing by freeze-thaw cycling for 1 day (FT1) or 5 days (FT5). To select the most suitable f…