Search results for " hydrogel"
showing 10 items of 277 documents
Dielectric characterization of biocompatible hydrogels for application to Epidermal RFID devices
2015
Functionalized skin-like membranes are currently under investigation for the design of a new class of Epidermal Electronics devices for sensing and healing applications. The dynamic response of epidermal antennas in presence of absorption and release of fluids is a key-point to design RFID radio-sensors and actuators. This paper addresses the characterization of the dielectric property of PVA-based biocompatible hydrogel membranes in the UHF RFID band by means of a modified ring resonator. Samples having different compositions are measured in the dry state as well as when exposed to a progressive release of body fluids emulating perspirations or wound exudates. It was found that the permitt…
Development and characterization of xyloglucan-poly(vinyl alcohol) hydrogel membrane for Wireless Smart wound dressings
2018
Abstract Hydrogel-based smart wound dressings that combine the traditional favourable properties of hydrogels as skin care materials with sensing functions of relevant biological parameters for the remote monitoring of wound healing are under development. In particular, lightweight, ultra-high frequency radiofrequency identification (UHF RFID) sensor are adjoined to xyloglucan-poly(vinyl alcohol) hydrogel films to battery-less monitor moisture level of the bandage in contact with the skin, as well as wireless transmit the measured data to an off-body reader. This study investigates the swelling behavior of the hydrogels in contact with simulated biological fluids, and the modification of th…
A methacrylic hyaluronic acid derivative for potential application in oral treatment of celiac disease.
2017
Objective: Aim of this work was the synthesis of a methacrylic hyaluronic acid (HA) derivative and the production, via photocrosslinking, of related hydrogels loaded with an endopeptidase intended for a potential oral treatment of celiac disease. Methods: The methacrylic derivative of HA was prepared through a one-pot procedure involving the reaction with ethylenediamine (EDA) and methacrylic anhydride (MA). The obtained derivative, named HA-EDA-MA, was used to prepare photocrosslinked hydrogels loaded with a prolyl endopeptidase derived from Flavobacterium meningosepticum (PEP FM) able to detoxify gliadin. Obtained hydrogels were recovered as gels or freeze-dried powders. Results: Hydrogel…
Iontophoretic in Vitro Release of Antimycotics from Hydrogels
1993
A new in vitro model for iontophoretic release from hydrogels was developed. It represents a modification of the rotary disk cell developed by Moll/Bender and can be used in a normal dissolution tester. The iontophoretic release from antimycotic hydrogels through an artificial membrane was investigated and different types of antimycotics were tested. The influence of current density, drug concentration and vehicle was determined.
Core-Shell Microgels with Switchable Elasticity at Constant Interfacial Interaction.
2016
Hydrogels based on poly(N-isopropylacrylamide) (pNIPAAm) exhibit a thermo-reversible volume phase transition from swollen to deswollen states. This change of the hydrogel volume is accompanied by changes of the hydrogel elastic and Young's moduli and of the hydrogel interfacial interactions. To decouple these parameters from one another, we present a class of submillimeter sized hydrogel particles that consist of a thermosensitive pNIPAAm core wrapped by a nonthermosensitive polyacrylamide (pAAm) shell, each templated by droplet-based microfluidics. When the microgel core deswells upon increase of the temperature to above 34 °C, the shell is stretched and dragged to follow this deswelling i…
Nanoencapsulation in Lipid-Core Nanocapsules Controls Mometasone Furoate Skin Permeability Rate and Its Penetration to the Deeper Skin Layers
2013
<b><i>Aims:</i></b> The influence of nanoencapsulation of mometasone furoate (MF) in poly(ε-caprolactone) lipid-core nanocapsules (LNC) on its in vitro human skin permeation and penetration was evaluated. <b><i>Methods:</i></b> Semisolid formulations were prepared by increasing the viscosity of LNC using a carbomer (Carbopol® Ultrez at 0.5% w/v). Two complementary techniques (the static Franz diffusion cell model and the Saarbrücken penetration model) were used to evaluate skin permeation/penetration. <b><i>Results:</i></b> The drug release rate was decreased by nanoencapsulation. The skin permeability of MF was control…
Ciprofloxacin releasing gellan gum/polydopamine based hydrogels with near infrared activated photothermal properties.
2021
Abstract In this work, with the aim to obtain a wound dressing hydrogel, an amine derivative of gellan gum was crosslinked in the presence of 4arm-polyethylenglycole-vinylsulfone. Through this easy and reproducible chemical procedure, a hydrogel with advanced elastic properties and hydrolytic resistance under physiological conditions was obtained. The incorporation of different quantities of polydopamine in the gelling solutions allows to obtain different hydrogels with marked photothermal properties when irradiated with a laser in the near infrared at 810 nm. The organic nanoparticles, reacting with the amino groups of the polysaccharide derivative, contribute to increase the storage modul…
Crosslinked α,β-Polyasparthydrazide Micromatrices for Controlled Release of Anticancer Drugs
1995
The preparation of new hydrogels by the reaction of α,β- polyasparthydrazide and glutaraldehyde is reported. A different crosslinking degree was obtained by varying the ratio crosslinking agent/polymer which influenced the swelling behavior of the gel. 5-Fluorouracil, was incorporated into the matrices during the crosslinking reaction and in vitro release studies were performed in simulated gastric juice (pH 1.1) and pH 7.4 buffer solution. The hydrogels prepared were chemically stable in the dissolution media. The observed data show the potential application of these new matrices for peroral administration of anticancer agents.
Biodegradable and pH-sensitive hydrogels for potential colon-specific drug delivery: Characterization and in vitro release studies
2008
A novel pH-sensitive and biodegradable composite hydrogel, based on a methacrylated and succinic derivative of dextran, named Dex-MA-SA, and a methacrylated and succinic derivative of alpha,beta-poly( N-2-hydroxyethyl)- DL-aspartamide (PHEA), named PHM-SA, was produced by photocross-linking. The goal was to obtain a colon-specific drug delivery system, exploiting both the pH-sensitive behavior and the colon-specific degradability. The hydrogel prepared with a suitable ratio between the polysaccharide and the polyaminoacid was characterized regarding its swelling behavior in gastrointestinal simulated conditions, chemical and enzymatic degradability, interaction with mucin, and cell compatib…
Operational Procedures in the Theory of the Drug Release from Chitosan Hydrogels
2018
We build a theoretical model based on a generalization of harmonic applications of Misner-type. It results a sine-Gordon type fractal differential equation whose elliptical solutions can describe, through a convenient choice of fractal dynamic constants, various modes of drug release. Thus, the entire class of empirical models (Higuchi, Korsmeyer-Peppas, Peppas-Sahlin) describing the drug release processes can be dispensed with.