Search results for "self-heal"
showing 10 items of 223 documents
CONTROLLED RELEASE OF IgG BY NOVEL UV INDUCED POLYSACCHARIDE/POLY(AMINO ACID)HYDROGELS
2009
The development of new protein and peptide drugs needs new delivery systems able to entrap such drugs in safe conditions without affecting their structure and biological activity. In this context, the present work reports a new approach to load IgG, used as a model of therapeutic proteins such as anti-TNF-alpha monoclonal antibodies, into a polymeric system able to release the entrapped IgG in a controlled manner. In particular, new polysaccharide/poly(amino acid) UV induced hydrogels are proposed as colon delivery systems for human IgG. The poly(amino acid), alpha,beta-poly[N-(2-hydroxyethyl)-D,L-aspartamide], has been functionalized with methacrylic anhydride, while the polysaccharide, in…
Smart hydrogels for novel optical functions
2007
Nanocomposites of inherently conductive polyaniline (PANT) within a highly hydrophilic polyvinyl alcohol (PVA) based hydrogel have been produced by coupling a conventional dispersion chemical oxidative polymerization to a subsequent high energy irradiation step, in order to convert the polymer stabilizing the aqueous dispersion, namely the PVA, into a highly water swollen hydrogel incorporating the PANT particles. The incorporation of the electroactive and "pH-sensitive" polymer into a transparent and highly permeable hydrogel matrix has been pursued as a route to the development of a novel class of potentially biocompatible, smart hydrogels that can respond to changes of the surrounding en…
Tunable and Large-Scale Model Network StarPEG-DNA Hydrogels
2021
The use of DNA as a building block in synthetic polymer hydrogels promises high levels of programmability regarding sol/gel temperatures, tunable bond lifetimes, biocompatibility, and interaction w...
Self-reporting hydrogels rapidly differentiate among enterohemorrhagic Escherichia coli (EHEC) and non-virulent Escherichia coli (K12)
2016
Abstract We report on the development of an autonomously reporting indicator hydrogel for the rapid and selective detection of enzymes secreted by the food-borne biosafety level 3 pathogen enterohemorrhagic Escherichia coli (E. coli) O157:H7 (EHEC) and the differentiation of this pathogen from the non-virulent E. coli strain K12. To introduce the sensing functionality, chitosan hydrogel films were equipped with fluorogenic substrates for the detection of α-galactosidase (α-Gal) and β-galactosidase (β-Gal), which are secreted by E. coli O157:H7, and β-glucuronidase (β-GUS), which is produced by the non-virulent E. coli K12 strain, but not by E. coli O157:H7, respectively. In the presence of …
Naphthalimide imidazolium-based supramolecular hydrogels as bioimaging and theranostic soft materials
2020
1,8-Naphthalimide-based imidazolium salts differing for the alkyl chain length and the nature of the anion were synthesized and characterized to obtain fluorescent probes for bioimaging applications. First, their self-assembly behavior and gelling ability were investigated in water and water/dimethyl sulfoxide binary mixtures. Only salts having longer alkyl chains were able to give supramolecular hydrogels, whose properties were investigated by using a combined approach of fluorescence, resonance light scattering, and rheology measurements. Morphological information was obtained by scanning electron microscopy. In addition, conductive properties of organic salts in solution and gel state we…
Perfluorocarbon functionalized hyaluronic acid derivatives as oxygenating systems for cell culture
2014
A set of new hyaluronic acid (HA) derivatives was obtained by binding fluorinated oxadiazole (OXA) moieties to an amino derivative of the polysaccharide (HA-EDA). The obtained HA-EDA-OXA biomaterials are potentially able to improve oxygenation into a scaffold for tissue engineering purposes. The oxygen solubility in aqueous dispersions of the obtained derivatives showed that polymers were able to improve oxygen uptake and maintenance in the medium. The HA-EDA-OXA was employed to form a hydrogel in situ by reaction with a vinyl sulphone derivative of inulin, under physiological conditions. The influence of the presence of OXA moieties on the mechanical properties of the obtained hydrogels as…
Bridging rigidity and flexibility : modulation of supramolecular hydrogels by metal complexation
2021
The combination of complementary, noncovalent interactions is a key principle for the design of multistimuli responsive hydrogels. In this work, an amphiphilic peptide, supramacromolecular hydrogelator which combines metal-ligand coordination induced gelation and thermoresponsive toughening is reported. Following a modular approach, the incorporation of the triphenylalanine sequence FFF into a structural (C3EG ) and a terpyridine-functionalized (C3Tpy ) C3 -symmetric monomer enables their statistical copolymerization into self-assembled, 1D nanorods in water, as investigated by circular dichroism (CD) spectroscopy and transmission electron microscopy (TEM). In the presence of a terpyridine …
A Multi-Component Reaction towards the Development of Highly Modular Hydrogelators
2018
Herein we report a multi‐component reaction approach for the development of a new class of hydrogelators based on the OxoTriphenylHexanOate (OTHO) backbone. A focused library of OTHOs has been synthesized and their hydrogelation features evaluated. The two most potent hydrogelators were studied by rheology revealing different stiffness, appearances and thixotropic behavior of the gels. The new gelators showcase the versatility of the OTHO backbone as a platform for the design of functionalized hydrogels with tunable gel properties. peerReviewed
Hyaluronic acid and beta cyclodextrins films for the release of corneal epithelial cells and dexamethasone
2016
In this work we prepared hydrogels based on hyaluronic acid and β-cyclodextrins to sustain the release of both corneal epithelial cells and dexamethasone. This steroid is administered as eye drops several times per day to reduce the risk of rejection in the post operative period after the cornea transplantation and cell release techniques. Hydrogels were produced by crosslinking an amino derivative of hyaluronic acid, with the divinyl sulfone derivative of β-cyclodextrins, this last employed as a crosslinker and solubilizing agent. Drug release studies revealed that dexamethasone containing samples are able to extend the release of this drug for at least five days. Biological studies, condu…
Phosphorylation triggered growth of metal phosphate on halloysite and sepiolite nanoparticles: preparation, entrapment in chitosan hydrogels and appl…
2020
The rational design of porous, biomass-derived eco-friendly adsorbents instead of costly synthetic, petroleum-based resins stands as a promising approach to resolving the thorny issue of sewage treatment (for example, by supplying safe water for drinking and irrigation). Herein we explore a straightforward transformation of abundant clay and polysaccharides into highly-reactive water-cleaning adsorbents. Surface-functionalization of sepiolite and halloysite by phosphoryl chloride triggered metal dissolution from the framework (inside of the lumen for halloysite and on the external surface for sepiolite) and the concomitant growth of well-truncated crystalline metal phosphates. These unprece…