SEARCH · PubMed Health

Results for “Polyhydroxyethyl Methacrylate”

Explore indexed PubMed citations for clinical trials, systematic reviews and public health research. Read source abstracts and follow each citation to its original PubMed record.

Quote a phrase for an exact phrase match. Source license links do not imply unrestricted reuse.

At least 163 records · Page 9Linked to original sources

PubMed1980

A novel method to improve immunofluorescence in histological specimens.

A new approach to immunofluorescent labeling of sectioned tissue is described. Small tissue fragments which have been fixed and rendered permeable are labeled with immune reagents by either the direct or indirect method, prior to embedding in glycol methacrylate (2-hydroxyethyl methacrylate) at 4 degrees. In this way, the well-known superiority of plastic embedding over paraffin embedding or cryo-sections can be used to compare cellular structure in tissues with that seen in cultured cells.

Animals↗

PubMed2003

Binding of D-mannose to poly(2-hydroxyethyl methacrylate) hydrogels by azo coupling.

Crosslinked hydrogels based on poly(2-hydroxyethyl methacrylate) poly(HEMA) were prepared and modified with tyramine [4-(2-aminoethyl)phenol] to enable azo coupling with mannosyl derivatives, copolymerization of HEMA with polymerizable activated esters and surface modification reaction with 4-nitrophenyl chlorocarbonate for activation of the hydrogels were used.

Biocompatible Materials↗

PubMed1999

Periodontal repair in dogs: histologic observations of guided tissue regeneration with a prostaglandin E1 analog/methacrylate composite.

This report describes observations of healing following guided tissue regeneration (GTR) including surgical implantation of the prostaglandin E1 analog misoprostol with calcium-layered methacrylate particles. Critical size, supra-alveolar periodontal defects were surgically created around the 3rd and 4th mandibular premolar teeth in 4 beagle dogs. Wound management included soaking with a 24 microg/ml misoprostol solution and implantation of the misoprostol/methacrylate composite. One jaw quadrant per animal was prepared for GTR using expanded polytetrafluoroethylene membranes. The gingival flaps were coronally advanced and sutured to submerge the teeth. The tissues covering the surgical sites daily received topical misoprostol in an oral adhesive over the 4-week healing interval. Upon euthanasia, tissue blocks were prepared for histometric analysis of regeneration of alveolar bone and cementum, root resorption and ankylosis. The defect area underneath the membrane and the density of methacrylate particles were recorded for the GTR defects. The methacrylate particles appeared encapsulated in a dense connective tissue without signs of an inflammatory reaction, some in contact to newly formed bone. Alveolar bone regeneration height averaged (+/-SD) 1.2+/-1.0 and 1.0+/-0.6 mm for GTR and non-GTR defects, respectively. Corresponding values for bone regeneration area were 1.3+/-1.0 and 0.7+/-0.5 mm2. Cementum regeneration was confined to the apical aspect of the defects. Small areas of root resorption and ankylosis were observed for all teeth. Bone regeneration area correlated positively to the defect area and negatively to the density of methacrylate particles in the GTR defects. The histologic observations suggest that the methacrylate composite has marginal potential to promote bone and cementum regeneration under provisions for GTR.

Alveolar Bone Loss↗

PubMed1981

Pressurized polymerization for reaction casting of poly(2-hydroxyethyl methacrylate).

Homopolymers of the hydrogel poly(2-hydroxyethyl methacrylate) are produced with no observable bubbles trapped in the lattice by performing the free radical initiated polymerization reaction under pressure (700 kPa). Implantable hydrogel structures of intricate and exact geometry, such as nipples for ureteral anastomoses in the prosthetic urinary bladder, can be made using this technique.

Animals↗

PubMed1981

The mechanism of interaction between chlorhexidine digluconate and poly(2-hydroxyethyl methacrylate).

The extent of the interaction between chlorhexidine digluconate and poly(2-hydroxyethyl methacrylate), (PHEMA), is independent of temperature between 22-50 degrees C which is consistent with an ion-ion interaction mechanism. Different contact lens materials exhibit different affinities for chlorhexidine digluconate, the extent of uptake correlating in rank order with the number of free carboxylic acid sites in the polymers. Esterification of the carboxyl groups with diazomethane, resulted in a reduction in the affinity of the treated polymers for chlorhexidine to a near basal level. The uptake of chlorhexidine in soaking solution experiments involving lenses made from PHEMA and the more ionic material, poly(2-hydroxyethyl methacrylate-co-isobutyl methacrylate-co-methacrylic acid), was consistent with their carboxylate content. However, the fraction of bound disinfectant released was lower from the terpolymer, suggesting there are differences in bonding strengths between chlorhexidine and different contact lens hydrogels.

Adsorption↗

PubMed2005

Staining of the Reinke crystalloids in the human testis--re-evaluation study.

Reinke crystalloid (CR)s are rod or corn shaped structures present in the interstitial cells (Leydig cell) of human testis. Due to existing controversies and because of their importance in histological studies, we decided to reevaluate their staining behavior with various dyes. Earlier it has been shown that hematoxylin and eosin dyes do not stain CRs even though their protein nature remains undisputed. In the present study, sections of testicular tissues embedded in glycol-methacrylate (GMA) showed that hematoxylin binds to CRs non-specifically and eosin stains them specifically. The reasons for stainability and/or non stainability of CRs with hematoxylin, eosin and other dyes are discussed.

Aged↗

PubMed1988

Sudan black B as a histological stain for polymeric biomaterials embedded in glycol methacrylate.

Sudan black B, usually a stain for all kinds of lipid, turned out to be an excellent histological stain for polymeric biomaterials embedded in glycol methacrylate. Staining the surrounding connective tissue with toluidine blue-basic fuchsin makes details of the polymer-tissue interface clearly visible. Sudan black B might be used to visualize the biodegradation process of polymeric biomaterials.

Animals↗

PubMed1997

Selected aspects of the microencapsulation of mammalian cells in HEMA-MMA.

Microencapsulation of live mammalian cells is one means of creating hybrid artificial organs, like an artificial pancreas or an artificial liver. In addition to creating and developing the methodologies for enclosing cells within the appropriate semipermeable and biocompatible membranes, novel techniques are needed to assess the various features of the resulting capsules. The small size of a capsule or its heterogeneity can lead to additional complexities that go beyond the problem of examining cell behavior in the presence of biomaterials. These problems are illustrated here by comparison of protein release by microencapsulated HepG2 cells within large and small HEMA-MMA (hydroxyethyl methacrylate-methyl methacrylate) capsules, by assessment of the effect of processing conditions on HEMA-MMA microcapsule permeability to horseradish peroxidase at the individual capsule level, and by a confocal microscopy technique for assessing intracapsule cell viability.

Animals↗

PubMed1980

Laminates of poly(2-hydroxyethyl methacrylate) and polybutadiene as potential burn covering.

The preparation and the physical characterization of poly(2-hydroxyethyl methacrylate) thermally grafted onto polybutadiene (PHEMA/PB) are reported. The presence of polybutadiene increases the tensile properties of the film and prevents water diffusion through it while it does not affect the oxygen permeability of the PHEMA. The potential use of this material as burn wound cover is suggested.

Bandages↗

PubMed1990

Intracerebral implantation of synthetic polymer/biopolymer matrix: a new perspective for brain repair.

Various poly (2-hydroxyethyl methacrylate)-collagen and poly (glyceryl methacrylate)-collagen composite hydrogels with varying porosities and cross-linking densities were implanted into the cortex of adult rat brains to provide mechanical guiding substrates for wound healing and tissue ingrowth. The hydrogels were well tolerated by the neural tissue. After 2 and 3 month, hyper- and macroporous hydrogels (poly(glyceryl methacrylate)) with interconnected channel systems were penetrated by neural tissue and elements of extracellular matrices, with differences in the degree and the topographic patterning of tissue ingrowth according to the type of samples. These differences were ascribed to the geometry, size of the pore interconnections and the mechanical properties of the polymers. Hyper- and microporous hydrogels (poly(2-hydroxyethyl methacrylate)) and hydrogels without collagen were not penetrated by the host tissue. The compatibility of the polymers with the neural tissue was also tested in vitro. This study suggests a new approach to repair brain lesions consisting of loss of tissue volume.

Animals↗

PubMed2004

Solid-phase ATRP synthesis of peptide-polymer hybrids.

A versatile methodology to prepare hybrid biomaterials by atom transfer radical polymerization from resin-supported peptides has been established. As an example, we have synthesized a GRGDS-functionalized poly(2-hydroxyethyl methacrylate). The peptide-polymer was characterized by solid-state (13)C NMR and GPC and found to have a number average molecular weight of 4420 and a polydispersity of 1.47. These values are comparable to those obtained from solution-phase syntheses, suggesting the ATRP reaction is successful from a peptide-conjugated solid support. Solid-state (13)C NMR was used to characterize multiple steps in the reaction, and the synthesis was found to be near quantitative. We have performed cell adhesion experiments and observed the GRGDS sequence-promoted cell adhesion, whereas unfunctionalized poly(2-hydroxyethyl methacrylate) did not. By incorporating cell-signaling moieties in materials with defined molecular architecture, it will be possible to control the interactions between polymeric materials and biological systems.

Animals↗

PubMed2000

Transarterial embolization with HEMA-MMA of variant convexity-superior sagittal sinus dural arteriovenous fistula--case report.

A 62-year-old male presented with a variant dural arteriovenous fistula (DAVF) within the wall of the convexity-superior sagittal sinus, fed by branches of the bilateral external carotid arteries and only cortical venous drainage despite the presence of a patent sinus. Transarterial embolization with poly(2-hydroxyethyl methacrylate-co-methyl methacrylate) (HEMA-MMA) was performed, resulting in complete obliteration of the DAVF. Embolization with HEMA-MMA is an effective and safe procedure for the treatment of DAVF.

Biocompatible Materials↗

PubMed1992

Polyhydroxy and polyethyleneglycol (meth)acrylate polymers: physical properties and general studies for their use as electrophoresis matrices.

A new series of materials have been tested for their suitability as electrophoresis matrices. The mechanical and optical properties of gels composed of polyethyleneglycol (meth)acrylate esters or polyhydroxy (meth)acrylate esters in water and in various concentrations of organic solvents are described. Several crosslinkers including polyethyleneglycol and polyhydroxy di(meth)acrylates, piperazine diacrylate, and bisacrylamide were used in these studies. Electrophoretic migration and separation of a series of protein standards through polyethyleneglycol methacrylate (PEGM) 200, PEGM 400, and glyceryl methacrylate is demonstrated. Further, copolymerization of all of the monomers with acrylamide was performed and the distribution of monomer incorporation into the polymer network calculated. All monomers and copolymers that were examined by IR spectroscopy showed greater than 99% polymerization. These results justify their further study for biomolecule separations.

Cross-Linking Reagents↗

PubMed1997

The expression of the molecular chaperone calnexin is decreased in cancer cells grown as colonies compared to monolayer.

Differential display was used to identify genes which were differentially expressed when HT-29 human colon adenocarcinoma cells were grown as monolayers attached to plastic or as colonies in soft agarose. One of the gel bands differentially displayed corresponded to a 171 bp fragment that showed 99% identity with a sequence of mRNA for human calnexin. The decrease in calnexin gene expression by HT-29 cells growing as colonies in soft agarose was confirmed by reverse transcriptase-PCR (RT-PCR) using calnexin-specific primers. We also used RT-PCR to show that the expression of calnexin was decreased in HT-29 cells and MCF-7 human breast adenocarcinoma cells growing in suspension in poly(hydroxyethyl methacrylate)-coated wells compared to cells growing as monolayers. The results suggest that there is a signal for the up-regulation of calnexin expression when cells contact a substrate which allows cell adhesion.

Adenocarcinoma↗

PubMed1985

A glycol methacrylate method for the routine histologic evaluation of rat inner ear.

A method has been developed for the histologic evaluation of rat inner ear using glycol methacrylate (GMA) and steel knife sectioning. The necropsy, fixation, and histologic techniques described are not so complex and difficult as to preclude their routine use. The method is particularly useful in studies in which the entire inner ear of a large number of animals must be evaluated histologically.

Animals↗

PubMed1978

Transport properties of hydrolyzed polyacrylonitrile.

Measurements of the permeability coefficients of various compounds up-to a molecular weight of about 70,000 have shown clearly that membranes prepared from hydrolyzed polyacrylonitrile are about 10 times more permeable than those made of poly(2-hydroxyethyl) methacrylate. The higher permeability is probably due more to the higher water content (about 75%) than to the type of network. The high mechanical strength of the membranes and their good permeability to compounds possessing a comparatively high molecular weight seem to designate the material for some new applications in medicine.

Acrylic Resins↗

PubMed1997

Nontoxic embolic liquids for treatment of arteriovenous malformations.

Interventional radiology is becoming one of the standard treatments of arteriovenous malformation (AVM). Cyanoacrylate derivatives and polymer solutions are widely used to occlude the AVM nidus by their injection through a catheter, but they are far from satisfactory embolic liquids. For instance, cyanoacrylate derivatives sometimes glue the catheter to the artery, resulting in serious complications; in addition, the organic solvents used to dissolve polymers cause damage to the surrounding brain tissue of the AVM. Therefore, we attempted to develop embolic liquids by dissolving poly(2-hydroxyethyl methacrylate-co-methyl methacrylate) in Iopamiron with an addition of a small amount of ethyl alcohol. This new embolic liquid is not cytotoxic and is easily injected into the AVM through a thin, long catheter to effectively occlude the AVM.

Animals↗

PubMed1988

Separation of B- and T-lymphocytes by cellular adsorption chromatography using poly(2-hydroxyethyl methacrylate)/polyamine graft copolymer as column adsorbent.

A series of poly(2-hydroxyethyl methacrylate)/polyamine graft copolymers (HA copolymers) were examined as an adsorbent for cellular adsorption chromatography in order to separate cell populations with high efficacy. The capability of each copolymer sample to selectively adsorb rat lymphocyte subpopulations (B-cells and T-cells) was evaluated by applying a lymphocyte suspension to a copolymer-coated glass bead column. A separation factor (AB/AT) greater than 5.0 was achieved for the HA copolymer, compared to 1.9 and 1.1 for homopolymers of poly(2-hydroxyethyl methacrylate) and of a polyamine (poly(N,N-diethylaminoethylstyrene], respectively. By loading a rat lymphocyte suspension containing B-cells (28%) and T-cells (72%) through the HA copolymer column, more than 60% of T-cells in 90% purity or more were recovered in the effluent.

Adsorption↗