Search results for " hyaluronic acid"
showing 10 items of 61 documents
HYDROGELS OF HYALURONIC ACID AND alpha, beta-POLYASPARTYLHYDRAZIDE AND THEIR BIOMEDICAL AND PHARMACEUTICAL USES
2005
Compositions and products based on the chemical crosslinking of hyaluronic acid with a polyfunctional polymer having a protein-like structure, bearing hydrazido pendent groups along the polymeric chain. The polymer is preferably, alpha-beta-polyaspartylhydrazide, a biocompatible macromolecule. The materials obtained after crosslinking, specifically hydrogels, undergo a reduced chemical and enzymatic degradation, unlike the starting hyaluronic acid, and they can be used to prepare systems for applications in the biomedical and pharmaceutical field.
A new hyaluronic acid pH sensitive derivative obtained by ATRP for potential oral administration of proteins
2013
Atom transfer radical polymerization (ATRP) has been successfully employed to obtain a new derivative of hyaluronic acid (HA) able to change its solubility as a function of external pH and then to be potentially useful for intestinal release of bioactive molecules, included enzymes and proteins. In particular, a macroinitiator has been prepared by linking 2-bromo-2-methypropionic acid (BMP) to the amino groups of ethylenediamino derivative of tetrabutyl ammonium salt of HA (HA-TBA-EDA). This macroinititor, named HA-TBA-EDA-BMP has been used for the ATRP of sodium methacrylate (MANa) using a complex of Cu(I) and 2,2'-bipyridyl (Byp) as a catalyst. The resulting copolymer, named HA-EDA-BMP-MA…
SELF-ASSEMBLED AMPHIPHILIC HYALURONIC ACID GRAFT COPOLYMERS FOR TARGETED RELEASE OF ANTITUMORAL DRUG
2009
Polymeric micelles obtained by self-assembling of amphiphilic hyaluronic acid (HA) graft copolymers have been prepared and characterized. In particular, hyaluronic acid (HA) has been grafted to polylactic acid (PLA) and polyethylenglycol chains (PEG), then the copolymers able to form micelles in aqueous medium have been chosen to entrap the antitumoral drug Doxorubicin. The critical aggregation concentration of HA-g-PLA or HA-g-PLA-g-PEG micelles has been determined by using pyrene as a fluorescent probe, whereas their shape and size have been evaluated by light scattering measurements, scanning and transmission electron microscopies. The selective cytotoxicity of drug loaded micelles towar…
Self-assembling and auto-crosslinkable hyaluronic acid hydrogels with a fibrillar structure
2008
Abstract A hyaluronic acid derivative bearing pendant l -benzoyl-cysteine portions (with a derivatization degree equal to 10 mol.%) was synthesized by linking N,N′-dibenzoyl- l -cystine to the polysaccharide and then reducing its disulfide bridge to thiol groups. The formation of π–π stacking interactions between the benzoyl moieties was studied by fluorescence spectroscopy as a function of polymer concentration and oxidation time. The efficiency of oxidation of thiol groups to disulfide bridges occurring in phosphate buffer pH 7.4, was determined by colorimetric assays. The hydrogel formed by means of oxidative crosslinking has shown the presence of fibrillar aggregates as detected by ligh…
MATRICES OF A HYDROPHOBICALLY FUNCTIONALIZED HYALURONIC ACID DERIVATIVE FOR THE LOCOREGIONAL TUMOUR TREATMENT
2015
A hyaluronic acid (HA) derivative bearing octadecylamine and acylhydrazine functionalities has been here employed for the production of a paclitaxel delivering matrix for locoregional chemotherapy. Through a strategy consisting in a powder compression and a plasticization with a mixture water/ethanol, a physically assembled biomaterial, stable in solutions with physiologic ionic strengths, has been produced. Two different drug loading strategies have been adopted, by using paclitaxel as chemotherapic agent, and obtained samples have been assayed in terms of release in enhanced solubility conditions and in vitro and in vivo tumoural cytotoxicity. In particular sample with the best releasing …
Intra-articular hyaluronic acid injections for hip osteoarthritis
2018
Although viscosupplementation has been used in the past few years both for knee and hip osteoarthritis (OA), the number of intra-articular injections and the interval between doses still remains an undetermined subject. The aim of this open retrospective study was to evaluate the clinical and functional outcome in patients with mild-moderate hip OA treated with a course of 1, 2 or 3 Hyaluronic Acid (HA) intra-articular injections. Ninety-six patients were included: 19 patients received only one injection, 24 received two injections, and 44 received three injections. Age, sex, VAS for pain and WOMAC score before each intra-articular injection, number of intra-articular injections, reasons fo…
Broncalt®, class II medical device, in patients with chronic upper airways disease: a survey in clinical practice
2019
Inflammation and infection are common pathogenic mechanisms involved in many otorhinolaryngological (ORL) chronic diseases. Broncalt® is a class II Medical Device containing: thermal water (Medesano, PR, Italy), hyaluronic acid, and grapefruit seed extract. It could exert a safe and effective anti-inflammatory, washing, and antimicrobial activity by virtue of these components. Therefore, the aim of the current survey, conducted in clinical practice of 84 Italian ORL centers, was to evaluate its safety and efficacy in the treatment of patients with chronic upper airways disease. The 1,817 (958 males, mean age 49 years) patients were evaluated at baseline (T0) and after one (T1) and two (T2) …
Broncalt®, class II medical device, in patients with chronic relapsed upper airways disease: a survey in clinical practice.
2019
Inflammation and infection are common pathogenic mechanisms involved in many otorhinolaryngological (ORL) chronic diseases. Broncalt® is a class II Medical Device containing: thermal water (Medesano, PR, Italy), hyaluronic acid, and grapefruit seed extract. It could exert a safe and effective anti-inflammatory, washing, and antimicrobial activity by virtue of these components. Therefore, the aim of the current survey, conducted in clinical practice of 84 Italian ORL centers, was to evaluate its safety and efficacy in the treatment of patients with chronic upper airways disease. The 1,817 (958 males, mean age 49 years) patients were evaluated at baseline (T0) and after one (T1) and two (T2) …
A New Hyaluronic Acid Derivative Obtained from Atom Transfer Radical Polymerization as a siRNA Vector for CD44 Receptor Tumor Targeting.
2015
Two derivatives of hyaluronic acid (HA) have been synthesized by atom transfer radical polymerization (ATRP), starting from an ethylenediamino HA derivative (HA-EDA) and by using diethylaminoethyl methacrylate (DEAEMA) as a monomer for polymerization. Both samples, indicated as HA-EDA-pDEAEMA a and b, are able to condense siRNA, as determined by gel retardation assay and resulting complexes show a size and a zeta potential value dependent on polymerization number, as determined by dynamic light scattering measurements. In vitro studies performed on HCT 116 cell line, that over express CD44 receptor, demonstrate a receptor mediated uptake of complexes, regardless of their surface charge. New…
CROSSLINKED HYALURONAN WITH A PROTEIN-LIKE POLYMER: NOVEL BIORESORBABLE FILMS FOR BIOMEDICAL APPLICATIONS
2007
In this work, novel hydrogel films based on hyaluronan (HA) chemically crosslinked with the alpha,beta-poly(N-2-hydroxyethyl) (2-aminoethylcarbamate)-D,L-aspartamide (PHEA-EDA) were produced by solution casting method. The goal was to exploit both the biological key role of HA in tissue repair and regeneration, and the versatility of a synthetic protein-like polymer as the PHEA-EDA, in order to obtain biomaterials with physicochemical and biological properties suitable for a clinical use. By varying the molar ratio between the PHEA-EDA amino groups and HA carboxyl groups, three different films were obtained and characterized. Particularly FTIR, swelling, hydrolysis, and enzymatic degradatio…