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At least 19 recordsLinked to original sources
PubMed1999

Developmental toxicities of methacrylic acid, ethyl methacrylate, n-butyl methacrylate, and allyl methacrylate in rats following inhalation exposure.

The developmental toxicities of 4 methacrylates were studied in Sprague-Dawley rats after inhalation exposure for 6 h/day, during days 6 to 20 of gestation. The exposure concentrations were, for methacrylic acid, 0, 50, 100, 200, or 300 ppm; for ethyl methacrylate, 0, 600, 1200, 1800, or 2400 ppm; for n-butyl methacrylate, 0, 100, 300, 600, or 1200 ppm; and for allyl methacrylate, 0, 12, 25, 50, or 100 ppm. No significant increases in embryo/fetal lethality or fetal malformations were observed after exposure to any of these methacrylates. Fetal toxicity evidenced by statistically significant decreases in fetal body weights was observed at exposure levels > or = 1200 ppm ethyl methacrylate, > or = 600 ppm n-butyl methacrylate, and at 100 ppm allyl methacrylate. Statistically significant increases in the incidence of fetuses with skeletal variations and of fetuses with any variations were noted at 1200 ppm n-butyl methacrylate. These developmental effects were observed in the presence of overt signs of maternal toxicity. While maternal toxicity was observed, methacrylic acid caused no evidence of developmental toxicity up to 300 ppm.

Administration, Inhalation↗
PubMed1979

Controlled drug dissolution by radiation-induced polymerization in the presence of dimethylaminoethyl methacrylate-methyl methacrylate copolymer or methacrylic acid-methyl acrylate copolymer.

Polymer-containing tablet preparation was studied using radiation-induced polymerization of glass-forming monomers at low temperatures in the presence of dimethylaminoethyl methacrylate-methyl methacrylate copolymer or methyl acrylate-methacrylic acid copolymer. Drug dissolution from tablets was in the pH 3.0-8.0 range. A copolymer contained in the tablets dissolved in the dissolution medium at a specific pH. Drug dissolution from tablets took place rapidly at pH greater than 6.0 in the presence of methyl acrylate-methacrylic acid copolymer and at pH less than 5.0 in the presence of dimethylaminoethyl methacrylate-methyl methacrylate copolymer. The polymers had fibrous or capillary pore structures in contrast to the spherical pore structures formed in the presence of polyethylene glycol 600.

Acrylic Resins↗
PubMed2002

Study of the miscibility of poly(styrene-co-4-vinylbenzoic acid) with poly(ethyl methacrylate) or with poly[ethyl methacrylate-co-(2-N,N-dimethylaminoethyl) methacrylate] by inverse gas chromatography.

Poly(styrene) is immiscible with poly(ethyl methacrylate). The introduction of a small amount of 4-vinylbenzoic acid units along poly(styrene) chains (PS-VBA) enhanced its miscibility with poly(ethyl methacrylate) (PEMA) or with poly[ethyl methacrylate-co-(2-N,N-dimethylaminoethyl) methacrylate] (PEMA-DAE), as observed from the appearance of a single composition dependent glass transition temperature for each binary system using inverse gas chromatography. The negative values of the apparent polymer-polymer interaction parameter, chi(23)app, determined with different families of molecular probes, for three blend compositions and over a range of temperature confirm quantitatively the miscibility of these blends. The chi(23)app values for PEMA(PS-VBA) and (PEMA-DAE)-(PS-VBA) blends are dependent of the chemical nature of the probes, the temperature and the blend composition.

Chromatography, Gas↗
PubMed2006

SP-PLP-EPR study of chain-length-dependent termination in free-radical polymerization of n-dodecyl methacrylate, cyclohexyl methacrylate, and benzyl methacrylate: evidence of "composite" behavior.

The chain-length dependence of the termination rate coefficient in n-dodecyl methacrylate (DMA), cyclohexyl methacrylate (CHMA), and benzyl methacrylate (BzMA) bulk free-radical homopolymerizations at ambient pressure and at temperatures from -20 to 0 degrees C is deduced using the recently developed technique of SP-PLP-EPR: pulsed-laser polymerization (PLP) in which time-resolved EPR measurement of radical concentration, cR, is made following each single pulse (SP) of an excimer laser. The decay of cR results from termination of radicals of almost identical size. Their chain length, i, increases linearly with time, t, after applying a SP. The rate coefficient, kt(i,i), for termination of two radicals of size i is determined by fitting the experimental cR vs t data. This process demonstrates that (at least) two power-law exponents are necessary to describe kt(i,i) over the extended chain-length range of i = 1 to 1000. This is consistent with the so-called "composite model" , which uses power-law exponents alpha(S) and alpha(L) to describe termination of radicals either shorter or longer, respectively, than a crossover chain length, ic. The fourth parameter obtained from fitting the SP-PLP-EPR data with this model is kt(1,1), the termination rate coefficient for two radicals of degree of polymerization 1. Previous DMA experiments are reanalyzed while new experimental results are reported and analyzed for CHMA and BzMA. The parameter values for CHMA and BzMA termination at 0 degrees C are almost identical-kt(1,1) approximately 3 x 10(7) L mol(-1) s(-1), alpha(S) approximately 0.50, ic approximately 90, and alpha(L) approximately 0.21-and they are close to those for DMA at 0 degrees C: kt(1,1) approximately 1 x 10(7) L mol(-1) s(-1), alpha(S) approximately 0.64, ic approximately 50, and alpha(L) approximately 0.18. The results fully support the composite model in that the chain-length dependence is more pronounced for shorter than for longer radicals, i.e., alpha(S) > alpha(L). Moreover, the power-law exponent that characterizes termination of long-chain radicals is close to the theoretical value of alpha(L) = 0.16. In fact all parameter values-including the small differences between DMA and CHMA/BzMA-are more-or-less in accord with expectations based on polymer dynamics. Furthermore, our results suggest that termination of methacrylate radicals with large cyclic or long n-alkyl substituents may be affected by steric shielding of the radical functionality.

Journal Article↗
PubMed1998

Studies on blood compatibility of terpolymers composed of methyl methacrylate, methoxypolyethyleneglycol methacrylate, and dimethylsiloxane methacrylate.

Terpolymers composed of methyl methacrylate (MMA), polydimethylsiloxane methacrylate (PDMSMA), and methoxypolyethyleneglycol methacrylate (MPEGMA), having different compositions were synthesized. Platelets were not adsorbed onto terpolymer surfaces composed of 50 wt% MMA, 25 wt% PDMSMA and 25 wt% MPEGMA, while on terpolymers with the other compositions, platelet adsorption and fibrin clot were observed. It was shown that PDMS segment was predominant on these terpolymer surfaces via XPS. Receding contact angles of terpolymers, on which no platelet was observed, showed intermediate values between PDMS- and MPEG-rich surfaces. It was suggested that these terpolymers had blood compatibility.

Adult↗
PubMed1997

Effect of methacrylic acid:methyl methacrylate monomer ratios on polymerization rates and properties of polymethyl methacrylates.

Five binary formulations were prepared from methyl methacrylate (MMA) and methacrylic acid (MAA) monomers, and six ternary formulations were prepared from polysols of 30% wt polymethyl methacrylate (PMMA)/MMA and MAA. Using thermal analyses (DSC and TGA) the polymerization kinetics, condition of postcuring, relative amount of residual monomers, and glass transition temperature (Tg) were determined. From bar-shaped samples, 25 x 5 x 0.9 mm in dimensions, mechanical properties [flexural moduli (E) and maximum strengths (sigma)] were measured in three-point bending. Polymerization kinetics of binary formulations improved over pure PMMA (from 15 to 4 min) as a result of over a 60-fold increase in propagation-to-termination constants (Kp/Kt) of MAA/MMA. The further addition of PMMA increased the viscosity, slowed down termination, and, consequently, improved the polymerization kinetics twofold. These enhancements occurred without a substantive change in the Tg of the ternary system (ca. 107 degrees C) over pure PMMA (ca. 112 degrees C). Moreover, the Es of the four ternary formulations averaged 2.94 GPa, which was comparable with many values reported in the literature. In contrast the sigma s of these same formulations averaged 97 MPa, which was about 25% better than earlier investigations of pure acrylic. When a thermoplastic material is required for pultruding profiles that cure fast and have good thermal-mechanical properties, ternaries of PMMA/MMA/MAA should be considered.

Biocompatible Materials↗
PubMed1995

Composite poly(methyl methacrylate-methacrylic acid-2-hydroxyethyl methacrylate) latex for immunoassay. The case of plasminogen.

Poly(methyl methacrylate-methacrylic acid-2-hydroxyethyl methacrylate) latex (ACRYLAT) was synthesized by radical precipitation polymerization. The mass median diameter (MMD) and the geometrical standard deviation (GSD) of the ACRYLAT particles were 138 nm and 1.2, respectively. The concentration of the titrable carboxylic groups in the surface layer of latex particles was equal to 8.41 x 10(-6) mol m-2. Latex was able to bind up to 2.82 x 10(-7) mol of 1-aminopyrene per 1 m2 of the surface of the latex particles due to the ionic interactions between carboxylate anions and ammonium cations of protonated 1-aminopyrene. ACRYLAT was able to immobilize covalently human serum albumin in amounts up to 0.23 mg m-2. Aggregation of ACRYLAT with immobilized HSA, induced with specific antibodies (anti-HSA), was investigated turbidimetrically. The results indicated that in the model turbidimetric immunoassay, ACRYLAT coated with HSA can be used for the detection of anti-HSA in the goat anti-HSA serum diluted from 50 to 7000-fold. Immobilization of rabbit antibodies to plasminogen (anti-Plg) to ACRYLAT via the epsilon-aminocaproic acid linkers provided particles which were used for the development of the turbidimetric immunoassay for plasminogen. In this assay plasminogen could be detected in concentration ranging from 0.75 to 75 micrograms ml-1 in the blood plasma.

Acrylic Resins↗
PubMed1995

Assessment of structurally related chemicals: toxicity and ecotoxicity of acrylic acid and acrylic acid alkyl esters (acrylates), methacrylic acid and methacrylic acid alkyl esters (methacrylates).

BUA compiled the available data on toxicity and ecotoxicity for several acrylic and methacrylic acid esters and their corresponding acids. A comparison of these data revealed a qualitative similarity in the toxicological and ecotoxicological properties of the compounds considered. The data indicate that methacrylates are less reactive than the corresponding acrylates.

Acrylates↗
PubMed1987

Intraocular biocompatibility of hydroxyethyl methacrylate and methacrylic acid copolymer/partially hydrolyzed poly(2-hydroxyethyl methacrylate).

A strip of partially hydrolyzed poly (2-hydroxyethyl methacrylate) containing 65%-75% H2O was implanted into the anterior eye chamber of 11 Chinchilla rabbits. No pathological changes were found in the iris or in the ciliary body. The pathological findings in the cornea accompanying implantation of a hydrogel strip to the anterior chamber were rare and not significant. The low occurrence of the foreign body giant multinucleate cells was observed on the implant surface 6 months after the implantation. Favorable properties of this hydrogel depend probably on its high water and acidic groups content.

Acrylates↗
PubMed1981

[Studies of dental methacrylic resin. (Part 8) Flexural and impact adhesive strength of self-curing methacrylic resin to cross-linked polymethyl methacrylate resins (author's transl)].

Heat-curing methacylic resins cross-linked with three kinds of dimethacrylates, i.e. EDMA, tri-EDMA and nona-EDMA, were prepared, and the flexural and the impact adhesive strength of the dough moulding type and the pour type self-curing methacrylic resins to them were examined. The results obtained were as follows. (1) The flexural and the impact adhesive strength of the pour type self-curing resin were higher and more stable than those of the dough moulding type one. (2) The flexural and the impact adhesive strength of self-curing resins to cross-linked adherent resins rised in order of nona-EDMA greater than tri-EDMA greater than EDMA in the range of higher concentration of cross-linking agents. This tendency was marked for the pour type resin. (3) When the dough moulding type resin was used as adhesive resin, to adherent resin cross-linked with EDMA or tri-EDMA which had relatively short chain, the respective adhesive strength of that decreased with increasing the concentration of cross-linking agent. While, to adherent resin cross-linked with nona-EDMA, which had relatively long and more flexible chain, the respective adhesive strength of the dough moulding type resin increased with increasing the concentration of cross-linking agent. (4) When the pour type resin was used as adhesive resin, to adherent resin cross-linked with EDMA or tri-EDMA, the respective adhesive strength of that showed the maximum at the concentration near 2 to 5 mole% and decreased with increasing the concentration. While, to adherent resin cross-linked with nona-EDMA, the flexural adhesive strength of the pour type resin was approximately constant without the effect of the concentration, but the impact adhesive strength of that increased with increasing the concentration. (5) The flexural adhesive strength of the dough moulding and the pour type resin under the wet condition decreased about 30 to 60% compared with under the dry condition, but the percentage of the falling for the impact adhesive strength was about 15 to 30% and relatively small. (6) The flexural adhesive strength showed a similar adhesive tendency to the tensile adhesive strength, but the impact adhesive strength showed a different adhesive tendency from those.

Adhesiveness↗
PubMed1998

Review of the biological response to a novel bone cement containing poly(ethyl methacrylate) and n-butyl methacrylate.

This review describes work published independently elsewhere in which the biological reactions to poly(ethyl methacrylate) n-butyl methacrylate (PEMBMA) have been studied. This material has been compared throughout with conventional poly(methyl methacrylate) (PMMA). Butyl methacrylate monomer used in PEMBMA was slightly less toxic than methyl methacrylate monomer used in PMMA when injected intraperitoneally in mice. No differences in cardiorespiratory effects were found between n-butyl and methyl monomer infused intravenously into anaesthetized rabbits. The tissue reaction to the beaded polymers of poly(methyl methacrylate) and poly(ethyl methacrylate) implanted subcutaneously was identical. The surface appearance of the two materials differed significantly when viewed by scanning electron microscopy, showing a series of elevations resembling tightly packed spheres in the case of PMMA, but a smooth surface with only occasional smooth elevations in the case of PEMBMA. Intramuscular implantation showed more fibrous tissue and tissue damage in relation to PMMA cured in situ compared with PEMBMA and there was more bone necrosis and a thicker fibrous tissue layer adjacent to PMMA than PEMBMA when cured intraosseously.

Animals↗
PubMed2006

Synthesis, characterization, properties, and drug release of poly(alkyl methacrylate-b-isobutylene-b-alkyl methacrylate).

Polyisobutylene (PIB)-based block copolymers have attracted significant interest as biomaterials. Poly(styrene-b-isobutylene-b-styrene) (SIBS) has been shown to be vascularly compatible and, when loaded with paclitaxel (PTx) and coated on a coronary stent, has the ability to deliver the drug directly to arterial walls. Modulation of drug release from this polymer has been achieved by varying the drug/polymer ratio, by blending SIBS with other polymers, and by derivatizing the styrene end blocks to vary the hydrophilicity of the copolymer. In this paper, results are reported on the synthesis, physical properties, and drug elution profile of PIB-based block copolymers containing methacrylate end blocks. The preparation of PIB-poly(alkyl methacrylate) block copolymers has been accomplished by a new synthetic methodology using living cationic and anionic polymerization techniques. 1,1-Diphenylethylene end-functionalized PIB was prepared from the reaction of living PIB and 1,4-bis(1-phenylethenyl)benzene, followed by the methylation of the resulting diphenyl carbenium ion with dimethylzinc (Zn(CH(3))(2)). PIB-DPE was quantitatively metalated with n-butyllithium in tetrahydrofuran, and the resulting macroinitiator could initiate the polymerization of methacrylate monomers, yielding block copolymers with high blocking efficiency. Poly(methyl methacrylate-b-isobutylene-b-methyl methacrylate) (PMMA-b-PIB-b-PMMA) and poly(hydroxyethyl methacrylate-b-isobutylene-b-hydroxyethyl methacrylate) (PHEMA-b-PIB-b-PHEMA) triblock copolymers were synthesized and used as drug delivery matrixes for coatings on coronary stents. The PMMA-b-PIB-b-PMMA/PTx system displayed zero-order drug release, while stents coated with PHEMA-b-PIB-b-PHEMA/PTx formulations exhibited a significant initial burst release of PTx. Physical characterization using atomic force microscopy and differential scanning calorimetry of the formulated PMMA-b-PIB-b-PMMA coating matrix indicated the partial miscibility of PTx with the PMMA microphase of the matrix.

Calorimetry, Differential Scanning↗
PubMed2005

Dendrimer/methyl methacrylate co-polymers: residual methyl methacrylate and degree of conversion.

Dendrimer/methyl methacrylate co-polymers were studied for use in dental composites. The aim was to determine the effects of methyl methacrylate concentration in the resin mixture and polymerization method on the degree of conversion and residual monomer content of the copolymers. Two dendrimers were studied, D12 with 12 reactive methacrylate groups and D24 with 24 reactive groups. The concentration of methyl methacrylate varied from 20 wt% to 50 wt% of monomers. Camphorquinone (CQ) was used as the light-activation initiator and 2-(N,N-dimethylamino)ethyl methacrylate (DMAEMA) as the activator, both in the quantity of 3.0 wt%. Three polymerization methods were used: photo-polymerization, photo-polymerized immediately followed by post-polymerization at 120 degrees C for 15 min, and photo-polymerization followed by postpolymerization after 7 days. The degree of conversion was determined using FT-IR. Residual monomers were extracted with tetrahydrofuran and methanol and analyzed with HPLC. The highest degrees of conversion were 65 and 62%, and the lowest residual monomer contents 1.0 and 1.5% for D12 and D24, respectively. These were measured after heat-induced post-polymerization. For D12, increasing the proportion of methyl methacrylate decreased the degree of conversion and increased the residual monomer content after photo-polymerization. Post-polymerization enhanced the polymerization of the dendrimer co-polymers in respect of degree of conversion and residual monomer content. The present study suggested that the tested dendrimer/methyl methacrylate copolymers require heat-induced polymerization to reach the generally accepted levels of degree of conversion and residual monomers.

Chromatography, High Pressure Liquid↗
PubMed1979

Controlled release of tetracycline I: In vitro studies with a trilaminate 2-hydroxyethyl methacrylate-methyl methacrylate system.

A membrane-controlled drug delivery device was developed to release tetracycline at zero-order rates. The tetracycline delivery vehicle is a trilaminate disk consisting of core and coating membranes fabricated from a series of 2-hydroxyethyl methacrylate and methyl methacrylate copolymers. Appropriate adjustment of the monomer composition ratio imparts a hydrophobic nature to the copolymer outer coating membrane (relative to the core material), which serves as the rate-limiting membrane in drug diffusion. The trilaminate disks demonstrated a zero-order tetracycline release over 4 months in vitro. The zero-order release rate was a function of the general device geometry, coating membrane thickness, disk surface, area, level of core reservoir drug loading, and membrane coating copolymer composition. Permeability parameters of tetracycline diffusion through a series of 2-hydroxyethyl methacrylate-methyl methacrylate copolymer membranes were determined by a flux-lag time method. Equilibrium hydration values of these membranes also were determined. The ability of trilaminate 2-hydroxyethyl methacrylate-methyl methacrylate devices to release tetracycline at constant rates over a prolonged period offers unique therapeutic and investigational possibilities.

Acrylates↗
PubMed1988

Genotoxicity of acrylic acid, methyl acrylate, ethyl acrylate, methyl methacrylate, and ethyl methacrylate in L5178Y mouse lymphoma cells.

A series of monomeric acrylate/methacrylate esters (methyl acrylate, ethyl acrylate, methyl methacrylate, and ethyl methacrylate) as well as acrylic acid were examined for genotoxic activity in L5178Y mouse lymphoma cells without exogenous activation. All five compounds induced concentration-dependent increases in mutant frequency. Small-colony, trifluorothymidine-resistant mutants were primarily induced, which suggests that these compounds may act via a clastogenic mechanism. This prediction was confirmed by the finding that all five compounds produced gross chromosome aberrations in mouse lymphoma cells. The two acrylates were much more potent in their response than acrylic acid. Methyl acrylate (22 micrograms/ml, survival = 18%) induced 385 mutants/10(6) survivors (total mutant frequency less the spontaneous mutant frequency) and 45 chromosome aberrations/100 cells analyzed (total aberrations less the spontaneous background). Ethyl acrylate (37.5 micrograms/ml, survival = 15%) induced 683 mutants/10(6) survivors and 48 aberrations/50 cells analyzed. Acrylic acid (500 micrograms/ml, survival = 22%) induced 245 mutants/10(6) survivors and 37 aberrations/100 cells analyzed. The two methacrylates required higher concentrations to induce a positive response. Methyl methacrylate (2,799 micrograms/ml, survival = 11%) induced 230 mutants/10(6) survivors and 29 aberrations/200 cells analyzed. Ethyl methacrylate was extremely difficult to test because of a plateau in the dose response, over which the toxicity fluctuated from 2% to 37% survival. Positive responses (twice the spontaneous background) were only obtained at toxicity levels with less than approximately 20% survival. A concentration of 1,626 micrograms/ml (survival = 16%) induced 83 mutants/10(6) survivors and 11 aberrations/200 cells analyzed. The evidence suggests that the genotoxicity of these compounds is most likely due to a clastogenic mechanism.

Acrylates↗
PubMed2002

Synthesis and properties of amphiphilic networks 2: a differential scanning calorimetric study of poly(dodecyl methacrylate-stat-2,3 propandiol-1-methacrylate-stat-ethandiol dimethacrylate) networks and adhesion and spreading of dermal fibroblasts on these materials.

A series of amphiphilic networks was prepared by radical copolymerisation of dodecyl methacrylate, 2,3-propandiol-1-methacrylate and ethandiol dimethacrylate. DSC studies on these materials, swollen in water. revealed that only materials containing more than 27 wt% of water displayed melting endotherms due to the melting of ice-like structures of water (freezing water). In materials that did produce a melting endotherm the peak was generally bimodal. Changing thermal history and heating rate did not effect the shape of the two peaks, nor the relative contribution of each peak to the total endothermic response. These observations and the narrow peak width of the low temperature endotherm suggested that the bimodality was an artefact of the DSC experiment and may be due to the promotion of the glass transition once a fraction of the water has frozen. The morphology of transformed human dermal fibroblasts grown on these materials was then examined by scanning electron microscopy. Compositions that contained only non-freezing water were found to allow cell adhesion and spreading. Cells with well-spread morphologies were obtained on materials containing small fractions of freezing water and dodecyl methacrylate. These fibroblasts displayed surface features such as microvilli and filapodia. However, all compositions of poly(2,3-propandiol-1-methacrylate-co-ethandiol dimethacrylate) (i.e. hydrogels that do not contain dodecyl methacrylate repeat units) were poor substrates for cell growth and examination of these materials showed that very few cells had adhered and those that did were highly rounded.

Biocompatible Materials↗