Search results for "hydrogels"
showing 10 items of 299 documents
pH-responsive physically and chemically cross-linked glutamic-acid-based hydrogels and nanogels
2018
Abstract Given the great demand for polymers prepared from renewable materials, the synthesis of a glutamic-acid-based hydrogel by solution and inverse miniemulsion polymerization is herein presented. Free radical initiated homopolymerizations of N-acryloyl- l -glutamic acid (l- AGA) resulted in either a readily water-soluble polymer or a physically cross-linked hydrogel, being the formation of physical cross-linking junctions closely related to monomer concentration and mixture viscosity. Chemically cross-linked poly( l -AGA-co-BIS) hydrogels were also synthesized by copolymerization of l -AGA and N,N′-methylenebis(acrylamide) (BIS). Both poly (l- AGA) and poly( l -AGA-co-BIS) swelling beh…
Novel hydrogels based on a polyasparthydrazide. Synthesis and characterization
2000
α,β-polyasparthydrazide (PAHy), a synthetic water-soluble biocompatible polymer, was chemically crosslinked with ethyleneglycol diglycidylether (EGDGE), in order to obtain water swellable microparticies. These were characterized by means of FT-IR spectrophotometry and by means of particle size distribution analysis. The mean pore size of the prepared gels as various crosslinking ratios and the fractal dimensions were determined by light scattering measurements. Swelling measurements gave evidence of the high affinity of PAHy-EGDGE microparticles towards aqueous media at different pH values. The physical state of the prepared networks was evaluated by means of X-rays diffractometry and therm…
A bioinspired metal–organic approach to cross-linked functional 3D nanofibrous hydro- and aero-gels with effective mixture separation of nucleobases …
2020
The direct reaction between Cu(CH3COO)2 and uracil-1-acetic acid in water gives rise to the formation of a hydrogel consisting of entangled nanometric ribbons of a crystalline antiferromagnetic 1D Cu(ii) coordination polymer (CP) decorated with biocompatible uracil nucleobases. This hydrogel is the precursor for the preparation of a meso/macroporous ultralight aerogel that shows a remarkable Young's modulus. As a proof-of-concept of the molecular recognition capability of the terminal uracil moieties anchored at Cu(ii) CP chains, this material has been tested as the selective stationary phase for the separation of nucleobase derivatives in HPLC columns.
SiRNA-mediated in vivo gene knockdown by acid-degradable cationic nanohydrogel particles
2017
Cationic nanohydrogel particles have become an attractive tool for systemic siRNA delivery, but improvement of their in vivo tolerance is desirable, especially to prevent potential long term side effects by tissue and cellular accumulation. Here, we designed novel ketal cross-linked cationic nanohydrogel particles that were assessed for reduced tissue accumulation and robust siRNA delivery in vitro and in vivo. An oligo-amine cross-linker equipped with a ketal moiety in its core was synthesized and applied to nanohydrogel cross-linking of self-assembled reactive ester block copolymers in DMSO. The resulting acid-sensitive cationic nanoparticles spontaneously disassembled over time in acidic…
Synthesis and characterization of redox-sensitive polyurethanes based on L-glutathione oxidized and poly(ether ester) triblock copolymers
2021
Abstract Segmented polyurethanes, based on PCL-PEG-PCL copolymers, 1,4-diisocyanatobutane and l -glutathione oxidized, used as chain extender, were synthetized. Three different reactions conditions were investigated using three different copolymers having ɛ-CL/polyethylene glycol molar ratios equal to 12, 24 and 36 and three different reaction conditions. As investigated by size exclusion chromatography analyses and quantification of l -glutathione, the polymerization and the extension phase's efficiency depended on the ɛ-CL/PEG ratio and the extension phase's operating temperature. Three selected polyurethanes were characterized by spectroscopic, differential scanning calorimetry (DSC) and…
Bioengineered endometrial hydrogels with growth factors promote tissue regeneration and restore fertility in murine models
2021
Extracellular matrix (ECM) hydrogels obtained from decellularized tissues are promising biocompatible materials for tissue regeneration. These biomaterials may provide important options for endometrial pathologies such as Asherman's syndrome and endometrial atrophy, which lack effective therapies thus far. First, we performed a proteomic analysis of a decellularized endometrial porcine hydrogel (EndoECM) to describe the specific role of ECM proteins related to regenerative processes. Furthermore, we investigated the ability of a bioengineered system-EndoECM alone or supplemented with growth factors (GFs)-to repair the endometrium in a murine model of endometrial damage. For this model, the …
Signal-Processing and Adaptive Prototissue Formation in Metabolic DNA Protocells
2021
Abstract The fundamental life-defining processes in living cells, such as replication, division, adaptation, and tissue formation, take place via intertwined metabolic reaction networks orchestrating downstream signal processing in a confined, crowded environment with high precision. Hence, it is crucial to understand and reenact some of these functions in wholly synthetic cell-like entities (protocells) to envision designing soft-materials with life-like traits. Herein, we report on a programmable all-DNA protocell (PC) composed of a liquid DNA interior and a hydrogel-like shell, harboring DNAzyme active sites in the interior whose catalytic bond-cleaving activity leads to a downstream phe…
Poly(vinyl alcohol)/κ-Carrageenan-based hydrogels enriched with the adhesive mussel protein Pvfp5β as 3D cell culture scaffold for tissue engineering…
2021
Many marine organisms such as sandcastle worms, barnacles and mussels, produce natural adhesives to attach to wet surfaces in aqueous tidal environments. In mussels, the adhesion is possible through the secretion of a protein-based water-resistant glue, composed of a mixture of proteins called mussel adhesive proteins (MAPs) or mussel foot proteins (mfps), that allow anchoring to almost any kind of surface in wet conditions [1]. The proteins confined to adhesive plaques are mfp-2, -3, -4, -5, and -6. All these proteins contain an atypically high concentration of the catecholic amino acid 3,4- dihydroxy-l-phenylalanine (DOPA), obtained by the post-translational enzymatic hydroxylation of tyr…
Nanomolar pyrophosphate detection in water and in a self-assembled hydrogel of a simple terpyridine-Zn2+ complex.
2014
A simple terpyridine-Zn(II) complex is shown to act as an efficient and highly selective fluorescent sensor for pyrophosphate in water at physiological pH. The sensor complex showed an unprecedented fluorescence response (∼500 fold increase) and a record nanomolar sensitivity (detectable fluorescent response at 20 nM and LOD ∼ 0.8 nM). It has successfully been used to stain and record confocal fluorescence microscopy images of HeLa cells. Moreover, the complex was found to self-assemble into a hydrogel which was subsequently used to coat disposable paper strips for easy, low-cost detection of pyrophosphate.
Uptake of silica covered Quantum Dots into living cells: Long term vitality and morphology study on hyaluronic acid biomaterials
2015
Quantum Dots (QDs) are promising very bright and stable fluorescent probes for optical studies in the biological field but water solubility and possible metal bio-contamination need to be addressed. In this work, a simple silica-QD hybrid system is prepared and the uptake in bovine chondrocytes living cells without any functionalization of the external protective silica shield is demonstrated. Moreover, long term treated cells vitality (up to 14 days) and the transfer of silica-QDs to the next cell generations are here reported. Confocal fluorescence microscopy was also used to determine the morphology of the so labelled cells and the relative silica-QDs distribution. Finally, we employ sil…