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Sample records for 2-hydroxypropyl methacrylate hpma

  1. N-(2-hydroxypropyl) methacrylamide based cryogels--synthesis and biomimetic modification for stem cell applications.

    PubMed

    Golunova, A; Jaroš, J; Jurtíková, V; Kotelnikov, I; Kotek, J; Hlídková, H; Streit, L; Hampl, A; Rypáček, F; Proks, V

    2015-01-01

    The design of favorable mechanical properties and suitable surface modifications of hydrogels in order to stimulate specific cell response is a great challenge. N-(2-Hydroxypropyl) methacryl-amide (HPMA) was utilized to form macroporous cryogel scaffolds for stem cell applications. Furthermore, one group of scaffolds was enhanced by copolymerization of HPMA with methacryloyl-GGGRGDS-OH peptide in an effort to integrate biomimetic adhesion sites. The cryogels were characterized by stiffness and equilibrium swelling measurements as well as by scanning electron microscopy. Cell culture experiments were performed with human adipose-derived stem cells and substrates were found completely non-toxic. Moreover, RGDS-enriched cryogels supported cell attachment, spreading and proliferation, so they can be considered suitable for designed aims.

  2. Efficient gene carriers composed of 2-hydroxypropyl-β-cyclodextrin, ethanolamine-functionalized poly(glycidyl methacrylate), and poly((2-dimethyl amino)ethyl methacrylate) by combination of ATRP and click chemistry.

    PubMed

    Zhu, Yun; Zheng, Xuefeng; Yu, Bingran; Yang, Wantai; Zhao, Nana; Xu, Fujian

    2014-08-01

    In this work, a simple one-step method is first employed to produce the bromoisobutyryl-terminated 2-hydroxypropyl-β-cyclodextrin (HPCD-Br). The pendant epoxy groups of poly(glycidyl methacrylate) block prepared via ATRP from HPCD-Br can be reacted with ethanolamine to produce HPCD-PGEA which exhibits much lower cytotoxicity and better gene transfection yield than polyethylenimine (25 kDa) in COS7 and HepG2 cell lines. Moreover, poly((2-dimethyl amino)ethyl methacrylate) blocks can be incorporated into low-molecular-weight HPCD-PGEA via "click" reaction to further enhance the gene transfection efficiency in HepG2 cell lines.

  3. Effect on in vitro cell response of the statistical insertion of N-(2-hydroxypropyl) methacrylamide on linear pro-dendronic polyamine's gene carriers.

    PubMed

    Redondo, Juan Alfonso; Martínez-Campos, Enrique; Navarro, Rodrigo; Reinecke, Helmut; Elvira, Carlos; López-Lacomba, José Luis; Gallardo, Alberto

    2015-06-01

    Statistical copolymers of N-(2-hydroxypropyl) methacrylamide (HPMA) and the dendronic methacrylic monomer 2-(3-(Bis(2-(diethylamino)ethyl)amino)propanamido)ethyl methacrylate (TEDETAMA, derived from N,N,N',N'-tetraethyldiethylenetriamine, TEDETA), were synthesized through radical copolymerization and evaluated in vitro as non-viral gene carriers. Three copolymers with nominal molar percentages of HPMA of 25%, 50% and 75% were prepared and studied comparatively to the positive controls poly-TEDETAMA and hyperbranched polyethyleneimine (PEI, 25kDa). Their ability to complex DNA at different N/P molar ratios, from 1/1 up to 8/1, was determined through agarose gel electrophoresis and Dynamic Light Scattering. The resulting complexes (polyplexes) were characterized and evaluated in vitro as possible non-viral gene carriers for Swiss-3T3 fibroblasts, using luciferase as reporter gene and a calcein cytocompatibility assay. All the copolymers, except the one with highest HPMA proportion (75 molar %) at the lowest N/P ratio, condensed DNA to a particle size between 100 and 300 nm. The copolymers with 25 and 50 molar % of HPMA displayed higher transfection efficiency and cytocompatibility than the positive controls poly-TEDETAMA and PEI. A higher proportion of HPMA (75 molar %) led to copolymers that displayed very low transfection efficiency, despite their full cytocompatibility even at the highest N/P ratio. These results indicate that the statistical combination of TEDETAMA and HPMA and its fine compositional tuning in the copolymers may fulfill the fine balance of transfection efficiency and cytocompatibility in a superior way to the control poly-TEDETAMA and PEI.

  4. A minimal hydrophobicity is needed to employ amphiphilic p(HPMA)-co-p(LMA) random copolymers in membrane research.

    PubMed

    Stangl, Michael; Hemmelmann, Mirjam; Allmeroth, Mareli; Zentel, Rudolf; Schneider, Dirk

    2014-03-11

    Because a polymer environment might be milder than a detergent micelle, amphiphilic polymers have attracted attention as alternatives to detergents in membrane biochemistry. The polymer poly[N-(2-hydroxypropyl)-methacrylamid] [p(HPMA)] has recently been modified with hydrophobic lauryl methacrylate (LMA) moieties, resulting in the synthesis of amphiphilic p(HPMA)-co-p(LMA) polymers. p(HPMA)-co-p(LMA) polymers with a LMA content of 5 or 15% have unstable hydrophobic cores. This, on one hand, promotes interactions of the hydrophobic LMA moieties with membranes, resulting in membrane rupture, but at the same time prevents formation of a hydrophobic, membrane mimetic environment that is sufficiently stable for the incorporation of transmembrane proteins. On the other hand, the p(HPMA)-co-p(LMA) polymer with a LMA content of 25% forms a stable hydrophobic core structure, which prevents hydrophobic interactions with membrane lipids but allows stable incorporation of membrane proteins. On the basis of our data, it becomes obvious that amphiphilic polymers have to have threshold hydrophobicities should an application in membrane protein research be anticipated.

  5. Synthesis and Characterization of Amphiphilic Graft Copolymers of Poly (1,3dioxolane) Macromonomers with Styrene and Methyl Methacrylate

    NASA Astrophysics Data System (ADS)

    Bendaikha, H.; Clisson, G.; Khoukh, A.; François, J.; Kada, S. Ould; Krallafa, A.

    2008-08-01

    Methacrylate-terminated Poly (1,3dioxolane) (PDXL) macromonomers were synthesized by cationic ring-opening polymerization in the presence of 2-hydroxypropyl methacrylate (2-HPMA) as transfer agent. Molecular weights and polydispersity index of the PDXL macromonomers were evaluated by size exclusion chromatography (SEC) and 1H-NMR. Copolymerizations of PDXL macromonomers with styrene (St) and methyl methacrylate (MMA) were carried out using various feed molar ratios. Monomer reactivity ratios between the macromonomers and the comonomers were estimated from the copolymerization results. Glass transition temperatures of the copolymers were found to decrease with an increase in the amount of PDXL in the copolymers.

  6. Complexation of anionic copolymers of acrylamide and N-(2-hydroxypropyl)methacrylamide with aminoglycoside antibiotics

    NASA Astrophysics Data System (ADS)

    Solovskii, M. V.; Tarabukina, E. B.; Amirova, A. I.; Zakharova, N. V.; Smirnova, M. Yu.; Gavrilova, I. I.

    2014-03-01

    The complexation of aminoglycoside antibiotics neomycin, gentamicin, kanamycin, and amikacin in the form of free bases with carboxyl- and sulfo-containing copolymers of acrylamide and N-(2-hydroxypropyl)methacrylamide (HPMA) in water and water-salt solutions is studied by means of viscometry, equilibrium dialysis, potentiometric titration, and molecular hydrodynamics. Factors influencing the stability of formed copolymer-antibiotic complexes and determinations of their toxicity are established.

  7. Biodegradable Multiblock Poly[N-(2-hydroxypropyl)methacrylamide] via Reversible Addition-Fragmentation Chain Transfer Polymerization and Click Chemistry.

    PubMed

    Luo, Kui; Yang, Jiyuan; Kopečková, Pavla; Kopeček, Jindřich

    2011-04-26

    A new bifunctional chain transfer agent (CTA) containing alkyne end groups was designed, synthesized and used for direct synthesis of clickable telechelic polymers. Good control of reversible addition-fragmentation chain transfer (RAFT) polymerization of N-(2-hydroxypropyl)methacrylamide (HPMA) was achieved by using the new CTA, as indicated by a linear increase of number average molecular weight (Mn) with conversion and low polydispersity (PDI) (<1.1). In particular, enzymatically degradable multiblock HPMA polymers were readily prepared by subsequent reaction with αω, -diazido oligopeptide (GFLG) sequence via Cu(I) catalyzed alkyne-azide cycloaddition. Upon exposure of high molecular weight fractions of multiblock polyHPMA to papain or cathepsin B, the polymer was degraded into segments of molecular weight and narrow polydispersity similar to those of the initial telechelic polyHPMA.

  8. Passive and active hepatoma tumor targeting of new N-(2-hydroxypropyl)methacrylamide copolymer conjugates: synthesis, characterization, and evaluation in vitro and in vivo.

    PubMed

    Yuan, Jianchao; Yuan, Bingnian; Guo, Hongyun; Zeng, Xianwu; Wang, Xiaoqi; Liao, Shiqi; Li, Jing; Jia, Zong; Song, Fengying; Wang, Fuzhou

    2013-01-01

    Human hepatocellular carcinoma (HCC) is one of the major causes of death worldwide. To investigate the relative importance of active and passive targeting strategies, the synthesis, characterization, in vitro uptake, and in vivo biodistribution of specific sulfapyridine HPMA (HPMA: N-(2-hydroxypropyl methacrylamide)) copolymer (sulfapyridine: SPD) conjugates, nonspecific HPMA copolymer conjugates, and DTPA are described in this study. The poly(HPMA)-SPD-DTPA (DTPA: diethylenetriaminepentaacetic acid), poly(HPMA)-DTPA, and DTPA conjugates were radiolabeled with the radionuclide (99m)Tc and tested for uptake by cultured H22 cells. The cellular accumulation of poly(HPMA)-SPD-DTPA-(99m)Tc complex was found to be time-dependent. The poly(HPMA)-SPD-DTPA-(99m)Tc tracer exhibited rapid uptake kinetics in cell culture with a t(1/2) of ~5 min. The uptake of poly(HPMA)-SPD-DTPA-(99m)Tc was significantly higher than that of poly(HPMA)-DTPA-(99m)Tc, indicating that the uptake of the poly(HPMA)-SPD-DTPA-(99m)T was active binding. The uptake of poly(HPMA)-DTPA-(99m)Tc was significantly higher than that of DTPA-(99m)Tc, suggesting that the uptake of the poly(HPMA)-DTPA-(99m)T was passive binding. Twenty-four hour necropsy data in the hepatocellular carcinoma tumor model showed significantly higher (p < 0.001) tumor localization for poly(HPMA)-SPD-DTPA-(99m)Tc (4.98 ± 0.48%ID/g [percentage injected dose per gram tissue]) compared with poly(HPMA)-DTPA-(99m)Tc (2.69 ± 0.15% ID/g) and DTPA-(99m)Tc (0.83 ± 0.03%ID/g). Moreover, higher T/B for poly(HPMA)-SPD-DTPA-(99m)Tc indicated reduced extravazation of the targeted polymeric conjugates in normal tissues. Specific molecular targeting and nonspecific vascular permeability are both significant in the relative tumor localization of poly(HPMA)-SPD-DTPA-(99m)Tc. Extravascular leak in nonspecific organs appears to be a major factor in reducing the T/B for the sulfapyridine molecules. Thus, the poly(HPMA)-SPD-DTPA is expected to be used

  9. Coating of DNA/poly(L-lysine) complexes by covalent attachment of poly[N-(2-hydroxypropyl)methacrylamide].

    PubMed

    Subr, Vladimír; Konák, Cestmír; Laga, Richard; Ulbrich, Karel

    2006-01-01

    N-(2-Hydroxypropyl)methacrylamide (HPMA) copolymers (pHPMA) containing 4-nitrophenyl ester (ONp) or thiazolidine-2-thione (TT) reactive groups in side chains and telechelic/semitelechelic pHPMA with TT groups were designed as highly hydrophilic biocompatible polymers suitable for chemical coating of polyelectrolyte-based DNA-containing nanoparticles bearing amino groups on the surface. The course of the coating reaction carried out in aqueous solution was evaluated on model self-assembling polyelectrolyte DNA/poly(L-lysine) (DNA/PLL) complexes either by monitoring the amount of residual polymer reactive groups by UV spectroscopy or by monitoring changes in the weight-average molecular weight and hydrodynamic size of the complexes using light scattering methods. Physicochemical stability of the coated complexes in buffered saline solution was also investigated. Contrary to uncoated particles, the coated complexes showed remarkable stability to aggregate in 0.15 M NaCl. Coating with pHPMA had practically no effect on the size distribution of the most stable complexes prepared by complexation of DNA with high-molecular-weight PLL (M(w) = 134 000) as shown by dynamic light scattering. The coating reaction was faster and more efficient with multivalent HPMA copolymers containing TT reactive groups than that with HPMA copolymers containing ONp groups.

  10. Biodistribution and pharmacokinetic studies of bone-targeting N-(2-hydroxypropyl)methacrylamide copolymer-alendronate conjugates.

    PubMed

    Pan, Huaizhong; Sima, Monika; Kopecková, Pavla; Wu, Kuangshi; Gao, Songqi; Liu, Jihua; Wang, Dong; Miller, Scott C; Kopecek, Jindrich

    2008-01-01

    The biodistribution and pharmacokinetics of bone-targeting N-(2-hydroxypropyl)methacrylamide (HPMA) copolymer-alendronate conjugates were evaluated following intravenous administration of radioiodinated conjugates to young healthy BALB/c mice. The synthesis of a polymerizable and cathepsin K cleavable alendronate derivative, N-methacryloylglycylglycylprolylnorleucylalendronate, enabled the preparation of HPMA copolymer-alendronate conjugates with varying composition. Using the RAFT (reversible addition-fragmentation chain transfer) polymerization technique, four conjugates with different molecular weight and alendronate content and two control HPMA copolymers (without alendronate) with different molecular weight were prepared. The results of biodistribution studies in mice demonstrated a strong binding capacity of alendronate-targeted HPMA copolymer conjugates to bone. Conjugates with low (1.5 mol%) alendronate content exhibited a similar bone deposition capacity as conjugates containing 8.5 mol % of alendronate. The molecular weight was an important factor in the biodistribution of the HPMA copolymer conjugates. More conjugate structures need to be evaluated, but the data suggest that medium molecular weights (50-100 kDa) might be effective drug carriers for bone delivery.

  11. Biodistribution and Pharmacokinetic Studies of Bone-Targeting N-(2-Hydroxypropyl)methacrylamide Copolymer–Alendronate Conjugates

    PubMed Central

    Pan, Huaizhong; Sima, Monika; Kopečková, Pavla; Wu, Kuangshi; Gao, Songqi; Liu, Jihua; Wang, Dong; Miller, Scott C.; Kopeček, Jindřich

    2015-01-01

    The biodistribution and pharmacokinetics of bone-targeting N-(2-hydroxypropyl)-methacrylamide (HPMA) copolymer–alendronate conjugates were evaluated following intravenous administration of radioiodinated conjugates to young healthy BALB/c mice. The synthesis of a polymerizable and cathepsin K cleavable alendronate derivative, N-methacryloylglycylglycylprolylnorleucylalendronate, enabled the preparation of HPMA copolymer–alendronate conjugates with varying composition. Using the RAFT (reversible addition–fragmentation chain transfer) polymerization technique, four conjugates with different molecular weight and alendronate content and two control HPMA copolymers (without alendronate) with different molecular weight were prepared. The results of biodistribution studies in mice demonstrated a strong binding capacity of alendronate-targeted HPMA copolymer conjugates to bone. Conjugates with low (1.5 mol%) alendronate content exhibited a similar bone deposition capacity as conjugates containing 8.5 mol % of alendronate. The molecular weight was an important factor in the biodistribution of the HPMA copolymer conjugates. More conjugate structures need to be evaluated, but the data suggest that medium molecular weights (50–100 kDa) might be effective drug carriers for bone delivery. PMID:18505266

  12. In vitro drug release studies from the polymeric hydrogels based on HEA and HPMA using 4-[(E)-[(3Z)-3-(4-(acryloyloxy)benzylidene)-2-hexylidene]methyl]phenyl acrylate as a crosslinker.

    PubMed

    Arun, A; Reddy, B S R

    2005-04-01

    Novel crosslinker, 4-[(E)-[(3Z)-3-(4-(acryloyloxy)benzylidene)-2-hexylidene]methyl]phenyl acrylate (AMA) was synthesized using (2Z, 6E)-2,6-bis(4-hydroxybenzylidene)cyclohexanone (HBC) and acryloyl chloride. Two types of crosslinked polymeric hydrogels were prepared from 2-hydroxyethyl acrylate (HEA) and 2-hydroxypropyl methacrylate (HPMA) monomers using AMA as a crosslinking agent. 2',4-dichloro-5'-fluoro-1-ene-2-(4-hydroxyphenyl)phenone (EHP) (J. Bio Active Compat. Polym. 18 (2003) 219) was used as a drug molecule for monitoring the releasing behaviour of the hydrogels. Morphology of the hydrogels was characterized using optical microscopy (OM) and Scanning Electron Microscopy (SEM) techniques. Several modifications were made in the experimental sections to study the effect of crosslinking percentage (CLP), drug loading percentage (DLP), monomer type (HEA and HPMA) and the pH. Totally 18 experiments were carried out to study the desired parameters in the hydrogels. The drug-releasing rate was monitored by the absorption appeared at 330.5 nm using UV spectrometer. It was found that the releasing rate of the drug from the polymeric hydrogels was dependent on the crosslinking density, drug loading percentage, monomer type and pH of the medium.

  13. The Potential of Poly[N-(2-hydroxypropyl)methacrylamide] via Reversible Addition-Fragmentation Chain Transfer Polymerization as Safe Nanocarrier.

    PubMed

    Zhang, Yanhong; Guo, Chunhua; Li, Shuo; Luo, Kui; Hu, Jiani; Gu, Zhongwei

    2016-06-01

    N-(2-hydroxypropyl)methacrylamide (HPMA) copolymers have been presented as nanoscale drug/gene delivery systems and imaging probes, and the well-defined HPMA copolymers prepared via reversible addition-fragmentation chain transfer (RAFT) polymerization promote their to clinical trials, as the significant enhanced anticancer efficacy. The biosafety is another issue associated with the carriers. In this study, we prepared the linear and branched HPMA copolymers labeled with Cy5.5 via RAFT polymerization and click chemistry, and their potential biosafety was studied. The linear copolymer was prepared via RAFT polymerization mediated by the ends-functionalized peptide chain transfer agent (peptide2CTA), resulting in well-defined and block linear HPMA copolymer with molecular weight (MW) of 98 kDa. Additionally, the branched HPMA copolymer was also prepared via RAFT polymerization. Followed by Cy5.5 labeling, the two copolymers showed negative zeta potential and their accumulation into tumor was studied by in vivo optical fluorescence imaging in the nude mice with breast tumors. The biosafety studies on in vitro cytotoxicity and hemocompatibility studies, including hemolysis tests, plasma coagulation and thromboelastography assay were carried out well, demonstrating that the linear HPMA copolymer-Cy5.5 with MW around 100 kDa and biodegradable moiety in the main chain might be utilized as safe nanoscale carrier.

  14. Water-soluble HPMA copolymer--prostaglandin E1 conjugates containing a cathepsin K sensitive spacer.

    PubMed

    Pan, Huaizhong; Kopecková, Pavla; Wang, Dong; Yang, Jiyuan; Miller, Scott; Kopecek, Jindrich

    2006-07-01

    A novel bone targeting, N-(2-hydroxypropyl)methacrylamide (HPMA) copolymer based, prostaglandin E1 (PGE1) delivery system was designed, synthesized and characterized. PGE1 was bound to the polymer backbone via a spacer, composed of a cathepsin K sensitive tetrapeptide (Gly-Gly-Pro-Nle) and a self-eliminating 4-aminobenzyl alcohol structure. The HPMA copolymer conjugates were prepared by photo-initiated free radical copolymerization of HPMA, PGE1-containing macromonomer, and optionally a comonomer containing a reactive p-nitrophenyl ester group. The latter group was used as attachment points for the D-aspartic acid octapeptide targeting moieties. Incubation of the PGE1-containing macromonomer and HPMA copolymer-PGE1 conjugates with cathepsin K resulted in release of unmodified PGE1. The rate of release depended on the composition of the conjugate. The higher the PGE1 content in the conjugate, the slower the PGE1 release. This appeared to be the result of association of hydrophobic side-chains in aqueous media, which rendered the formation of the enzyme substrate complex more difficult. The data seems to indicate that HPMA copolymer-PGE1 conjugates have a potential in the treatment of osteoporosis and other bone diseases.

  15. Targeting prostate carcinoma by G3-C12 peptide conjugated N-(2-hydroxypropyl)methacrylamide copolymers.

    PubMed

    Yang, Yang; Li, Lian; Zhou, Zhou; Yang, Qingqing; Liu, Chong; Huang, Yuan

    2014-10-06

    Prostate carcinoma is the second leading cause of cancer-related deaths. Increased expression of membrane-bound galectin-3 by prostate carcinoma cell has been found to correlate with more poorly differentiated and increased metastatic potential. In the present study, different amount of galectin-3-binding peptide, G3-C12 (the sequence ANTPCGPYTHDCPVKR), was attached to N-(2-hydroxypropyl)methacrylamide (HPMA) copolymers as targeting moiety. The results of qPCR and competitive binding test indicated that the expression level of galectin-3 in two metastatic prostate carcinoma cell lines (PC-3 and DU145 cells) could be significantly suppressed by the addition of G3-C12-modified HPMA copolymers (PG1 and PG2), demonstrating the high affinity of PG1 and PG2 to galectin-3. Due to the multivalent effects of moieties, the uptake of copolymers was remarkably enhanced with the increasing amount of conjugated G3-C12 peptide. A higher internalization of PG1 and PG2 occurred in PC-3 cells via caveolin- and clathrin-mediated endocytosis, whereas a clathrin-mediated uptake process was involved in DU145 cells. The in vivo biodistribution and pharmacokinetics of nonmodified ((131)I-pHPMA) and G3-C12-modified ((131)I-PG1 and (131)I-PG2) copolymers were estimated on a well-established mice model bearing PC-3 xenografts by (131)I-SPECT-imaging. Higher tumor accumulation of (131)I-PG1 (1.60 ± 0.08% ID/g, p < 0.05) and (131)I-PG2 (1.54 ± 0.06% ID/g, p < 0.05) was observed compared with (131)I-pHPMA (1.19 ± 0.04% ID/g) at 2 h post-intravenous injection. Although the amount of conjugated G3-C12 peptide performed a remarkable in vitro effect on the affinity and internalization of HPMA copolymers to the galectin-3 overexpressed prostate carcinoma cells, the molecular weight and ligand modification all play important roles on their in vivo tumor accumulation.

  16. Reducible HPMA-co-oligolysine copolymers for nucleic acid delivery

    PubMed Central

    Shi, Julie; Johnson, Russell N.; Schellinger, Joan G.; Carlson, Peter M.

    2011-01-01

    Biodegradability can be incorporated into cationic polymers via use of disulfide linkages that are degraded in the reducing environment of the cell cytosol. In this work, N-(2-hydroxypropyl)methacrylamide (HPMA) and methacrylamido-functionalized oligo-L-lysine peptide monomers with either a non-reducible 6-aminohexanoic acid (AHX) linker or a reducible 3-[(2-aminoethyl)dithiol]propionic acid (AEDP) linker were copolymerized via reversible addition-fragmentation chain transfer (RAFT) polymerization. Both of the copolymers and a 1:1 (w/w) mixture of copolymers with reducible and non-reducible peptides were complexed with DNA to form polyplexes. The polyplexes were tested for salt stability, transfection efficiency, and cytotoxicity. The HPMA-oligolysine copolymer containing the reducible AEDP linkers was less efficient at transfection than the non-reducible polymer and was prone to flocculation in saline and serum-containing conditions, but was also not cytotoxic at charge ratios tested. Optimal transfection efficiency and toxicity was attained with mixed formulation of copolymers. Flow cytometry uptake studies indicated that blocking extracellular thiols did not restore transfection efficiency and that the decreased transfection of the reducible polyplex is therefore not primarily caused by extracellular polymer reduction by free thiols. The decrease in transfection efficiency of the reducible polymers could be partially mitigated by the addition of low concentrations of EDTA to prevent metal-catalyzed oxidation of reduced polymers. PMID:21893178

  17. Reducible HPMA-co-oligolysine copolymers for nucleic acid delivery.

    PubMed

    Shi, Julie; Johnson, Russell N; Schellinger, Joan G; Carlson, Peter M; Pun, Suzie H

    2012-05-01

    Biodegradability can be incorporated into cationic polymers via use of disulfide linkages that are degraded in the reducing environment of the cell cytosol. In this work, N-(2-hydroxypropyl)methacrylamide (HPMA) and methacrylamido-functionalized oligo-l-lysine peptide monomers with either a non-reducible 6-aminohexanoic acid (AHX) linker or a reducible 3-[(2-aminoethyl)dithiol] propionic acid (AEDP) linker were copolymerized via reversible addition-fragmentation chain transfer (RAFT) polymerization. Both of the copolymers and a 1:1 (w/w) mixture of copolymers with reducible and non-reducible peptides were complexed with DNA to form polyplexes. The polyplexes were tested for salt stability, transfection efficiency, and cytotoxicity. The HPMA-oligolysine copolymer containing the reducible AEDP linkers was less efficient at transfection than the non-reducible polymer and was prone to flocculation in saline and serum-containing conditions, but was also not cytotoxic at charge ratios tested. Optimal transfection efficiency and toxicity were attained with mixed formulation of copolymers. Flow cytometry uptake studies indicated that blocking extracellular thiols did not restore transfection efficiency and that the decreased transfection of the reducible polyplex is therefore not primarily caused by extracellular polymer reduction by free thiols. The decrease in transfection efficiency of the reducible polymers could be partially mitigated by the addition of low concentrations of EDTA to prevent metal-catalyzed oxidation of reduced polymers.

  18. Overcoming the stromal barrier for targeted delivery of HPMA copolymers to pancreatic tumors.

    PubMed

    Buckway, Brandon; Wang, Yongjian; Ray, Abhijit; Ghandehari, Hamidreza

    2013-11-01

    Delivery of macromolecules to pancreatic cancer is inhibited by a dense extracellular matrix composed of hyaluronic acid, smooth muscle actin and collagen fibers. Hyaluronic acid causes a high intratumoral fluidic pressure which prevents diffusion and penetration into the pancreatic tumor. This study involves the breaking down of hyaluronic acid by treating CAPAN-1 xenograft tumors in athymic nu/nu mice with targeted N-(2-hydroxypropyl)methacrylamide (HPMA) copolymers radiolabeled with (111)In for single photon emission computerized tomography (SPECT) imaging. Two targeting strategies were investigated including αvβ3 integrin and HER2 receptors. HPMA copolymers were targeted to these receptors by conjugating short peptide ligands cRGDfK and KCCYSL to the side chains of the copolymer. Results demonstrate that tumor targeting can be achieved in vivo after treatment with hyaluronidase. This approach shows promise for enhanced delivery of polymer-peptide conjugates to solid tumors.

  19. HPMA-oligolysine copolymers for gene delivery: optimization of peptide length and polymer molecular weight.

    PubMed

    Johnson, Russell N; Chu, David S H; Shi, Julie; Schellinger, Joan G; Carlson, Peter M; Pun, Suzie H

    2011-10-30

    Polycations are one of the most frequently used classes of materials for non-viral gene transfer in vivo. Several studies have demonstrated a sensitive relationship between polymer structure and delivery activity. In this work, we used reverse addition-fragmentation chain transfer (RAFT) polymerization to build a panel of N-(2-hydroxypropyl)methacrylamide (HPMA)-oligolysine copolymers with varying peptide length and polymer molecular weight. The panel was screened for optimal DNA-binding, colloidal stability in salt, high transfection efficiency, and low cytotoxicity. Increasing polyplex stability in PBS correlated with increasing polymer molecular weight and decreasing peptide length. Copolymers containing K(5) and K(10) oligocations transfected cultured cells with significantly higher efficiencies than copolymers of K(15). Four HPMA-oligolysine copolymers were identified that met the desired criteria. Polyplexes formed with these copolymers demonstrated both salt stability and transfection efficiencies on-par with poly(ethylenimine) PEI in cultured cells.

  20. Synthesis of long-circulating, backbone degradable HPMA copolymer-doxorubicin conjugates and evaluation of molecular-weight-dependent antitumor efficacy.

    PubMed

    Pan, Huaizhong; Sima, Monika; Yang, Jiyuan; Kopeček, Jindřich

    2013-02-01

    Backbone degradable, linear, multiblock N-(2-hydroxypropyl)methacrylamide (HPMA) copolymer-doxorubicin (DOX) conjugates are synthesized by reversible addition-fragmentation chain transfer (RAFT) polymerization followed by chain extension via thiol-ene click reaction. The examination of molecular-weight-dependent antitumor activity toward human ovarian A2780/AD carcinoma in nude mice reveals enhanced activity of multiblock, second-generation, higher molecular weight conjugates when compared with traditional HPMA copolymer-DOX conjugates. The examination of body weight changes during treatment indicates the absence of non-specific adverse effects.

  1. Tumor-Targeted HPMA Copolymer-(RGDfK)-(CHX-A″-DTPA) Conjugates Show Increased Kidney Accumulation

    PubMed Central

    Borgman, Mark P.; Coleman, Tomika; Kolhatkar, Rohit B.; Geyser-Stoops, Sandra; Line, Bruce R.; Ghandehari, Hamidreza

    2008-01-01

    N-(2-hydroxypropyl) methacrylamide (HPMA) copolymer-RGDfK conjugates targeting the αvβ3 integrin have shown increased accumulation in solid tumors and promise for selective delivery of radiotherapeutics to sites of angiogenesis- or tumor-expressed αvβ3 integrin. An unresolved issue in targeting radiotherapeutics to solid tumors is toxicity to non-target organs. To reduce toxicity of radiolabeled conjugates, we have synthesized HPMA copolymer-RGDfK conjugates with varying molecular weight and charge content to help identify a polymeric structure that maximizes tumor accumulation while rapidly clearing from non-targeted organs. Endothelial cell binding studies showed that copolymer conjugates of approximately 43, 20 and 10 kD actively bind to the αvβ3 integrin. Scintigraphic images showed rapid clearance of indium-111 radiolabeled conjugates from the blood pool and high kidney accumulation within 1 h in tumor bearing mice. Biodistribution data confirms images with high accumulation in kidney (max 210% ID/g for 43 kD conjugate) and lower tumor accumulation (max 1.8% ID/g for 43kD conjugate). While actively binding to the αvβ3 integrin in vitro, HPMA copolymer-RGDfK conjugates with increased negative charge through increased CHX-A″-DTPA chelator content in the side chains causes increased kidney accumulation with a loss of tumor binding in vivo. PMID:18687371

  2. Anticancer and antiangiogenic activity of HPMA copolymer-aminohexylgeldanamycin-RGDfK conjugates for prostate cancer therapy.

    PubMed

    Greish, Khaled; Ray, Abhijit; Bauer, Hillevi; Larson, Nate; Malugin, Alexander; Pike, Daniel; Haider, Mohamed; Ghandehari, Hamidreza

    2011-05-10

    Tumor progression is dependent on neoangiogenesis for blood supply. Neovasculature over-express α(v)β(3) integrins which recognize the Arg-Gly-Asp (RGD) sequence in the extracellular matrix. N-(2-hydroxypropyl)methacrylamide (HPMA) copolymers containing side chains terminated in cyclic RGD analogs such as RGDfK show increased accumulation in prostate tumors. Geldanamycin and their derivatives (e.g., aminohexylgeldanamycin (AH-GDM)) are benzoquinone ansamycins that have both antiangiogenic and antitumor activity. In this work the antiangiogenic and antitumor activities of targetable HPMA copolymer-RGDfK-AH-GDM conjugates were compared with non-targetable systems in vitro and in vivo. Copolymer-drug conjugates containing RGDfK in the side chains showed superior activity against endothelial and prostate cancer cell lines in vitro, as well as higher inhibition of angiogenesis in vivo. At equimolar doses of the drug, the RGDfK containing conjugates showed significantly higher antitumor activity in nude mice bearing DU-145 human prostate cancer xenografts. These findings suggest the utility of HPMA copolymer-RGDfK conjugates for targeted delivery of geldanamycin analogs with a dual mode of action.

  3. Poly-L-Lysine-Poly[HPMA] Block Copolymers Obtained by RAFT Polymerization as Polyplex-Transfection Reagents with Minimal Toxicity.

    PubMed

    Tappertzhofen, Kristof; Weiser, Franziska; Montermann, Evelyn; Reske-Kunz, Angelika; Bros, Matthias; Zentel, Rudolf

    2015-08-01

    Herein we describe the synthesis of poly-L-lysine-b-poly[N-(2-hydroxypropyl)-metha-crylamide)] (poly[HPMA]) block copolymers by combination of solid phase peptide synthesis or polymerization of α-amino acid-N-carboxy-anhydrides (NCA-polymerization) with the reversible addition-fragmentation chain transfer polymerization (RAFT). In the presence of p-DNA, these polymers form polyplex micelles with a size of 100-200 nm in diameter (monitored by SDS-PAGE and FCS). Primary in vitro studies with HEK-293T cells reveal their cellular uptake (FACS studies and CLSM) and proof successful transfection with efficiencies depending on the length of polylysine. Moreover, these polyplexes display minimal toxicity (MTT-assay and FACS-measurements) featuring a p[HPMA] corona for efficient extracellular shielding and the potential ligation with antibodies.

  4. Influence of histidine incorporation on buffer capacity and gene transfection efficiency of HPMA-co-oligolysine brush polymers

    PubMed Central

    Shi, Julie; Schellinger, Joan G.; Johnson, Russell N.; Choi, Jennifer L.; Chou, Brian; Anghel, Ersilia L.; Pun, Suzie H.

    2013-01-01

    One of the major intracellular barriers to non-viral gene delivery is efficient endosomal escape. The incorporation of histidine residues into polymeric constructs has been found to increase endosomal escape via the proton sponge effect. Statistical and diblock copolymers of N-(2-hydroxypropyl)methacrylamide (HPMA), oligolysine, and oligohistidine were synthesized via reversible-addition fragmentation chain transfer (RAFT) polymerization, and tested for in vitro transfection efficiency, buffering ability, and polyplex uptake mechanism via the use of chemical endocytic inhibitors. Interestingly, histidine-containing statistical and diblock polymers exhibited increased buffer capacity in different endosomal pH ranges. Statistical copolymers transfected better than block copolymers that contained similar amounts of histidine. In addition, only the polymer containing the highest incorporation of oligohistidine residues led to increases in transfection efficiency over the HPMA-oligolysine base polymer. Thus, for these polymer architectures, high histidine incorporation may be required for efficient endosomal escape. Furthermore, uptake studies indicate that non-acidified caveolae-mediated endocytosis may be the primary route of transfection for these copolymers, suggesting that alternative approaches for increasing endosomal escape may be beneficial for enhancing transfection efficiency with these HPMA-oligolysine copolymers. PMID:23641942

  5. Melittin-grafted HPMA-Oligolysine Based Copolymers for Improved Gene Delivery

    PubMed Central

    Schellinger, Joan G.; Pahang, Joshuel A.; Johnson, Russell N.; Chu, David S.H.; Sellers, Drew L.; Maris, Don O.; Convertine, Anthony J.; Stayton, Patrick S.; Horner, Philip J.; Pun, Suzie H.

    2012-01-01

    Non-viral gene delivery systems capable of transfecting cells in the brain are critical in realizing the potential impact of nucleic acid therapeutics for diseases of the central nervous system. In this study, the membrane-lytic peptide melittin was incorporated into block copolymers synthesized by reversible addition-fragmentation chain transfer (RAFT) polymerization. The first block, designed for melittin conjugation, was composed of N-(2-hydroxypropyl)methacrylamide (HPMA) and pyridyl disulfide methacrylamide (PDSMA) and the second block, designed for DNA binding, was composed of oligo-L-lysine (K10) and HPMA. Melittin modified with cysteine at the C-terminus was conjugated to the polymers through the pyridyl disulfide pendant groups via disulfide exchange. The resulting pHgMelbHK10 copolymers are more membrane-lytic than melittin-free control polymers, and efficiently condensed plasmid DNA into salt-stable particles (~ 100–200 nm). The melittin-modified polymers transfected both HeLa and neuron-like PC-12 cells more efficiently than melittin-free polymers although toxicity associated with the melittin peptide was observed. Optimized formulations containing the luciferase reporter gene were delivered to mouse brain by intraventricular brain injections. Melittin-containing polyplexes produced about 35-fold higher luciferase activity in the brain compared to polyplexes without melittin. Thus, the melittin-containing block copolymers described in this work are promising materials for gene delivery to the brain. PMID:23261217

  6. Amphiphilic HPMA-LMA copolymers increase the transport of Rhodamine 123 across a BBB model without harming its barrier integrity.

    PubMed

    Hemmelmann, Mirjam; Metz, Verena V; Koynov, Kaloian; Blank, Kerstin; Postina, Rolf; Zentel, Rudolf

    2012-10-28

    The successful non-invasive treatment of diseases associated with the central nervous system (CNS) is generally limited by poor brain permeability of various developed drugs. The blood-brain barrier (BBB) prevents the passage of therapeutics to their site of action. Polymeric drug delivery systems are promising solutions to effectively transport drugs into the brain. We recently showed that amphiphilic random copolymers based on the hydrophilic p(N-(2-hydroxypropyl)-methacrylamide), pHPMA, possessing randomly distributed hydrophobic p(laurylmethacrylate), pLMA, are able to mediate delivery of domperidone into the brain of mice in vivo. To gain further insight into structure-property relations, a library of carefully designed polymers based on p(HPMA) and p(LMA) was synthesized and tested applying an in vitro BBB model which consisted of human brain microvascular endothelial cells (HBMEC). Our model drug Rhodamine 123 (Rh123) exhibits, like domperidone, a low brain permeability since both substances are recognized by efflux transporters at the BBB. Transport studies investigating the impact of the polymer architecture in relation to the content of hydrophobic LMA revealed that random p(HPMA)-co-p(LMA) having 10mol% LMA is the most auspicious system. The copolymer significantly increased the permeability of Rh123 across the HBMEC monolayer whereas transcytosis of the polymer was very low. Further investigations on the mechanism of transport showed that integrity and barrier function of the BBB model were not harmed by the polymer. According to our results, p(HPMA)-co-p(LMA) copolymers are a promising delivery system for neurological therapeutics and their application might open alternative treatment strategies.

  7. Traceless Bioresponsive Shielding of Adenovirus Hexon with HPMA Copolymers Maintains Transduction Capacity In Vitro and In Vivo

    PubMed Central

    Prill, Jan-Michael; Šubr, Vladimír; Pasquarelli, Noemi; Engler, Tatjana; Hoffmeister, Andrea; Kochanek, Stefan; Ulbrich, Karel; Kreppel, Florian

    2014-01-01

    Capsid surface shielding of adenovirus vectors with synthetic polymers is an emerging technology to reduce unwanted interactions of the vector particles with cellular and non-cellular host components. While it has been shown that attachment of shielding polymers allows prevention of undesired interactions, it has become evident that a shield which is covalently attached to the vector surface can negatively affect gene transfer efficiency. Reasons are not only a limited receptor-binding ability of the shielded vectors but also a disturbance of intracellular trafficking processes, the latter depending on the interaction of the vector surface with the cellular transport machinery. A solution might be the development of bioresponsive shields that are stably maintained outside the host cell but released upon cell entry to allow for efficient gene delivery to the nucleus. Here we provide a systematic comparison of irreversible versus bioresponsive shields based on synthetic N-(2-hydroxypropyl)methacrylamide (HPMA) copolymers. In addition, the chemical strategy used for generation of the shield allowed for a traceless bioresponsive shielding, i.e., polymers could be released from the vector particles without leaving residual linker residues. Our data demonstrated that only a bioresponsive shield maintained the high gene transfer efficiency of adenovirus vectors both in vitro and in vivo. As an example for bioresponsive HPMA copolymer release, we analyzed the in vivo gene transfer in the liver. We demonstrated that both the copolymer's charge and the mode of shielding (irreversible versus traceless bioresponsive) profoundly affected liver gene transfer and that traceless bioresponsive shielding with positively charged HPMA copolymers mediated FX independent transduction of hepatocytes. In addition, we demonstrated that shielding with HPMA copolymers can mediate a prolonged blood circulation of vector particles in mice. Our results have significant implications for the

  8. The Influence of Linker Length on the Properties of Cathepsin S Cleavable 177Lu-labeled HPMA Copolymers for Pancreatic Cancer Imaging

    PubMed Central

    Shi, Wen; Wagh, Nilesh K.; Zhou, Zhengyuan; Jia, Yinnong; Brusnahan, Susan K.

    2014-01-01

    N-(2-hydroxypropyl)-methacrylamide (HPMA) copolymers have shown promise for application in the detection and staging of cancer. However, non-target accumulation, particularly in the liver and spleen, hinders the detection of resident or nearby metastatic lesions thereby decreasing diagnostic effectiveness. Our laboratory has pursued the development of cathepsin S susceptible linkers (CSLs) to reduce the non-target accumulation of diagnostic/radiotherapeutic HPMA copolymers. In this study, we ascertain if the length of the linking group impacts the cleavage and clearance kinetics, relative to each other and a non-cleavable control, due to a reduction in steric inhibition. Three different CSLs with linking groups of various lengths (0, 6 and 13 atoms) were conjugated to HPMA copolymers. In vitro cleavage studies revealed that the longest linking group (13 atoms) led to more rapid cleavage when challenged with cathepsin S. The CSL incorporated HPMA copolymers demonstrated significantly higher levels of excretion and a significant decrease in long-term hepatic and splenic retention relative to the non-cleavable control. Contrary to in vitro observations, the length of the linking group did not substantially impact the non-target in vivo clearance. In the case of HPAC tumor retention, the CSL with the null (0 atom) linker demonstrated significantly higher levels of retention relative to the other CSLs. Given these results, we find that the length of the linking group of the CSLs did not substantially impact non-target clearance, but did influence tumor retention. Overall, these results demonstrate that the CSLs can substantially improve the non-target clearance of HPMA copolymers thereby enhancing clinical potential. PMID:24755528

  9. Comparison of active and passive targeting of doxorubicin for somatostatin receptor 2 positive tumor models by octreotide-modified HPMA copolymer-doxorubicin conjugates.

    PubMed

    He, Shuang; Zhou, Zhou; Li, Lian; Yang, Qingqing; Yang, Yang; Guan, Shan; Zhang, Jian; Zhu, Xi; Jin, Yun; Huang, Yuan

    2016-01-01

    Somatostatin receptor 2 (SSTR2), specifically over-expressed on many tumor cells, is a potential receipt for active targeting in cancer therapy. In the present study, octreotide (Oct), which had high affinity to SSTR2, was attached to N-(2-hydroxypropyl) methacrylamide (HPMA) polymeric system to enhance the antitumor efficiency of the anticancer drug doxorubicin (DOX). Two kinds of cell lines (HepG2 and A549), which overexpress SSTR2, were chosen as cell models. Compared with non-modified conjugates, Oct-modified conjugates exhibited superior cytotoxicity and intracellular uptake on both HepG2 and A549 cell lines. This might be due to the mechanism of receptor-mediated endocytosis. Subsequently, the in vivo biodistribution and antitumor activity evaluations showed that Oct modification significantly improved the tumor accumulation and antitumor efficacy of HPMA copolymer conjugates in SSTR2 over-expressed Kunming mice bearing H22 tumor xenografts. In summary, Oct-modified HPMA polymer-DOX conjugates might be a promising system for the treatment of SSTR2 over-expressed cancers.

  10. Comparison of Active and Passive Targeting of Docetaxel for Prostate Cancer Therapy by HPMA copolymer-RGDfK Conjugates

    PubMed Central

    Ray, Abhijit; Larson, Nate; Pike, Daniel B.; Grüner, Michele; Naik, Sachin; Bauer, Hillevi; Malugin, Alexander; Greish, Khaled; Ghandehari, Hamidreza

    2011-01-01

    N-(2-hydroxypropyl)methacrylamide (HPMA) copolymer-docetaxel-RGDfK conjugate was synthesized, characterized, and evaluated in vitro and in vivo in comparison with untargeted low and high molecular weight HPMA copolymer-docetaxel conjugates. The targeted conjugate was designed to have a hydrodynamic diameter below renal threshold to allow elimination post treatment. All conjugates demonstrated the ability to inhibit the growth of DU145 and PC3 human prostate cancer cells and the HUVEC at low nanomolar concentrations. The targeted conjugate showed active binding to αvβ3 integrins in both HUVEC and DU145 cells, whereas the untargeted conjugate demonstrated no evidence of specific binding. Efficacy at two concentrations (20 mg/kg and 40 mg/kg) was evaluated in nu/nu mice bearing DU145 tumor xenografts treated with a single dose of conjugates and compared with controls. RGDfK targeted and high molecular weight nontargeted conjugates exhibited the highest antitumor efficacy as evaluated by tumor regression. These results demonstrate that αvβ3 integrin targeted polymeric conjugates with improved water solubility, reduced toxicity and ease of elimination post treatment in vivo are promising candidates for prostate cancer therapy. PMID:21599008

  11. Pharmacokinetic and biodistribution studies of N-(2-hydroxypropyl)methacrylamide copolymer-dexamethasone conjugates in adjuvant-induced arthritis rat model.

    PubMed

    Quan, Ling-Dong; Yuan, Fang; Liu, Xin-Ming; Huang, Jian-Geng; Alnouti, Yazen; Wang, Dong

    2010-08-02

    N-(2-Hydroxypropyl)methacrylamide (HPMA) copolymer has been found to be arthrotropic (joint-targeting) in the adjuvant-induced arthritis (AA) rat model using magnetic resonance imaging (MRI). In this manuscript, we report the quantitative pharmacokinetics and biodistribution (PK/BD) of (125)I-labeled HPMA copolymer-dexamethasone conjugate (P-Dex) in AA rats. Structural parameters of the prodrug such as the molecular weight (MW) and Dex content were found to have strong impact on the PK/BD profiles of P-Dex. The increase of MW (14,000, 24,000, and 42,000 g/mol) and Dex content (0, 151, and 313 micromol/g) enhances the arthrotropism of P-Dex. For the conjugate with highest MW and Dex content (P-H-M(W)/Dex), the percentage of injected doses per gram (ID/g) of ankle synovial tissue at day seventh postadministration is 1% g(-1), which confirms P-Dex as an arthrotropic macromolecular prodrug. For liver and spleen, the ID/g values are 0.51 and 3.64% g(-1), respectively. As an antigen-presenting organ, the sequestration of the prodrug by spleen may be explained by its abnormal enlargement associated with the systemic inflammatory disease model. Gradual reduction of spleen weight due to the inflammation resolution effect of P-Dex may also contribute to the high ID/g values. Increase of Dex content and reduction of MW would increase P-Dex distribution to kidney. The highest ID/g value for kidney at day seventh postadministration (0.91% g(-1)) was found with P-L-M(w) (MW = 14,000 g/mol, Dex content =288 micromol/g), which may suggest kidney tubuli reabsorption of the conjugates. The P-Dex's distribution to heart and lung is minimum.

  12. The use of poly(N-[2-hydroxypropyl]-methacrylamide) hydrogel to repair a T10 spinal cord hemisection in rat: a behavioural, electrophysiological and anatomical examination.

    PubMed

    Pertici, Vincent; Amendola, Julien; Laurin, Jérôme; Gigmes, Didier; Madaschi, Laura; Carelli, Stephana; Marqueste, Tanguy; Gorio, Alfredo; Decherchi, Patrick

    2013-05-30

    There have been considerable interests in attempting to reverse the deficit because of an SCI (spinal cord injury) by restoring neural pathways through the lesion and by rebuilding the tissue network. In order to provide an appropriate micro-environment for regrowing axotomized neurons and proliferating and migrating cells, we have implanted a small block of pHPMA [poly N-(2-hydroxypropyl)-methacrylamide] hydrogel into the hemisected T10 rat spinal cord. Locomotor activity was evaluated once a week during 14 weeks with the BBB rating scale in an open field. At the 14th week after SCI, the reflexivity of the sub-lesional region was measured. We also monitored the ventilatory frequency during an electrically induced muscle fatigue known to elicit the muscle metaboreflex and increase the respiratory rate. Spinal cords were then collected, fixed and stained with anti-ED-1 and anti-NF-H antibodies and FluoroMyelin. We show in this study that hydrogel-implanted animals exhibit: (i) an improved locomotor BBB score, (ii) an improved breathing adjustment to electrically evoked isometric contractions and (iii) an H-reflex recovery close to control animals. Qualitative histological results put in evidence higher accumulation of ED-1 positive cells (macrophages/monocytes) at the lesion border, a large number of NF-H positive axons penetrating the applied matrix, and myelin preservation both rostrally and caudally to the lesion. Our data confirm that pHPMA hydrogel is a potent biomaterial that can be used for improving neuromuscular adaptive mechanisms and H-reflex responses after SCI.

  13. Combination chemotherapy using core-shell nanoparticles through the self-assembly of HPMA-based copolymers and degradable polyester.

    PubMed

    Jäger, Eliézer; Jäger, Alessandro; Chytil, Petr; Etrych, Tomáš; Ríhová, Blanka; Giacomelli, Fernando Carlos; Stěpánek, Petr; Ulbrich, Karel

    2013-01-28

    The preparation of core-shell polymeric nanoparticles simultaneously loaded with docetaxel (DTXL) and doxorubicin (DOX) is reported herein. The self-assembly of the aliphatic biodegradable copolyester PBS/PBDL (poly(butylene succinate-co-butylene dilinoleate)) and HPMA-based copolymers (N-(2-hydroxypropyl)methacrylamide-based copolymers) hydrophobically modified by the incorporation of cholesterol led to the formation of narrow-size-distributed (PDI<0.10) sub-200-nm polymeric nanoparticles suitable for passive tumor-targeting drug delivery based on the size-dependent EPR (enhanced permeability and retention) effect. The PHPMA provided to the self-assembled nanoparticle stability against aggregation as evaluated in vitro. The highly hydrophobic drug docetaxel (DTXL) was physically entrapped within the PBS/PBDL copolyester core and the hydrophilic drug doxorubicin hydrochloride (DOX·HCl) was chemically conjugated to the reactive PHPMA copolymer shell via hydrazone bonding that allowed its pH-sensitive release. This strategy enabled the combination chemotherapy by the simultaneous DOX and DTXL drug delivery. The structure of the nanoparticles was characterized in detail using static (SLS), dynamic (DLS) and electrophoretic (ELS) light scattering besides transmission electron microscopy (TEM). The use of nanoparticles simultaneously loaded with DTXL and DOX provided a more efficient suppression of tumor-cell growth in mice bearing EL-4 T cell lymphoma when compared to the effect of nanoparticles loaded with either DTXL or DOX separately. Additionally, the obtained self-assembled nanoparticles enable further development of targeting strategies based on the use of multiple ligands attached to an HPMA copolymer on the particle surface for simultaneous passive and active targeting and different combination therapies.

  14. Enhanced anti-tumor activity and safety profile of targeted nano-scaled HPMA copolymer-alendronate-TNP-470 conjugate in the treatment of bone malignances

    PubMed Central

    Segal, Ehud; Pan, Huaizhong; Benayoun, Liat; Kopečková, Pavla; Shaked, Yuval; Kopeček, Jindčrich; Satchi-Fainaro, Ronit

    2015-01-01

    Bone neoplasms, such as osteosarcoma, exhibit a propensity for systemic metastases resulting in adverse clinical outcome. Traditional treatment consisting of aggressive chemotherapy combined with surgical resection, has been the mainstay of these malignances. Therefore, bone-targeted non-toxic therapies are required. We previously conjugated the aminobisphosphonate alendronate (ALN), and the potent anti-angiogenic agent TNP-470 with N-(2-hydroxypropyl)methacrylamide (HPMA) copolymer. HPMA copolymer-ALN-TNP-470 conjugate exhibited improved anti-angiogenic and anti-tumor activity compared with the combination of free ALN and TNP-470 when evaluated in a xenogeneic model of human osteosarcoma. The immune system has major effect on toxicology studies and on tumor progression. Therefore, in this manuscript we examined the safety and efficacy profiles of the conjugate using murine osteosarcoma syngeneic model. Toxicity and efficacy evaluation revealed superior anti-tumor activity and decreased organ-related toxicities of the conjugate compared with the combination of free ALN plus TNP-470. Finally, comparative anti-angiogenic activity and specificity studies, using surrogate biomarkers of circulating endothelial cells (CEC), highlighted the advantage of the conjugate over the free agents. The therapeutic platform described here may have clinical translational relevance for the treatment of bone-related angiogenesis-dependent malignances. PMID:21429572

  15. Degree of conversion and leached monomers of urethane dimethacrylate-hydroxypropyl methacrylate-based dental resin systems.

    PubMed

    Zhang, Meng; Puska, Mervi A; Botelho, Michael G; Säilynoja, Eija S; Matinlinna, Jukka P

    2016-01-01

    The degree of conversion (DC) and monomer leaching of three experimental urethane dimethacrylate (UEDMA)-hydroxypropyl methacrylate (HPMA)-based resin systems were studied. Three experimental resins (E1: 70.6 wt% UEDMA + 27.4 wt% HPMA, E2: 80.6 wt% UEDMA + 17.4 wt% HPMA, E3: 90.6 wt% UEDMA + 7.4 wt% HPMA) and one control resin [C: 70.6 wt% bis-phenol A glycidyl methacrylate (bis-GMA) + 27.4 wt% methyl methacrylate (MMA)] were prepared. For the DC test, cylindrical specimens [1.5 mm (h) × 6 mm (d)] were scanned with an ATR-FTIR instrument before and after light-curing (n = 5). For the monomer leaching test, block-shaped specimens [5.67 mm (l) × 2.00 mm (w) × 2.00 mm (h)] were light-cured (n = 6), stored in a 75% ethanol:water solution for 3 days, and then analyzed with HPLC. The UEDMA-HPMA-based experimental groups showed higher DC (62-78%) than the bis-GMA-MMA-based control group (58-66%), and the DC decreased as the UEDMA content increased (P < 0.05). Amongst the four groups, E3 exhibited the lowest leaching of both mono methacrylate (0.1% HPMA) and dimethacrylate (<0.043% UEDMA) monomers after 30 or 40 s of curing. The UEDMA-HPMA-based resins, therefore, exhibited higher DC and less monomer leaching compared to the bis-GMA-MMA-based resin. (J Oral Sci 58, 15-22, 2016).

  16. Optimization of Tet1 ligand density in HPMA-co-oligolysine copolymers for targeted neuronal gene delivery

    PubMed Central

    Chu, David S.H.; Schellinger, Joan G.; Bocek, Michael J.; Johnson, Russell N.; Pun, Suzie H.

    2013-01-01

    Targeted gene delivery vectors can enhance cellular specificity and transfection efficiency. We demonstrated previously that conjugation of Tet1, a peptide that binds to the GT1b ganglioside, to polyethylenimine results in preferential transfection of neural progenitor cells in vivo. In this work, we investigate the effect of Tet1 ligand density on gene delivery to neuron-like, differentiated PC-12 cells. A series of statistical, cationic peptide-based polymers containing various amounts (1—5 mol%) of Tet1 were synthesized via one-pot reversible addition-fragmentation chain transfer (RAFT) polymerization by copolymerization of Tet1 and oligo-l-lysine macromonomers with N-(2-hydroxypropyl)methacrylamide (HPMA). When complexed with plasmid DNA, the resulting panel of Tet1-functionalized polymers formed particles with similar particle size as particles formed with untargeted HPMA–oligolysine copolymers. The highest cellular uptake in neuron-like differentiated PC-12 cells was observed using polymers with intermediate Tet1 peptide incorporation. Compared to untargeted polymers, polymers with optimal incorporation of Tet1 increased gene delivery to neuron-like PC-12 cells by over an order of magnitude but had no effect compared to control polymers in transfecting NIH/3T3 control cells. PMID:24041424

  17. Synthesis and Properties of Star HPMA Copolymer Nanocarriers Synthesised by RAFT Polymerisation Designed for Selective Anticancer Drug Delivery and Imaging.

    PubMed

    Chytil, Petr; Koziolová, Eva; Janoušková, Olga; Kostka, Libor; Ulbrich, Karel; Etrych, Tomáš

    2015-06-01

    High-molecular-weight star polymer drug nanocarriers intended for the treatment and/or visualisation of solid tumours were synthesised, and their physico-chemical and preliminary in vitro biological properties were determined. The water-soluble star polymer carriers were prepared by the grafting of poly(amido amine) (PAMAM) dendrimers by hetero-telechelic N-(2-hydroxypropyl)methacrylamide (HPMA) copolymers, synthesised by the controlled radical Reversible Addition Fragmentation chain Transfer (RAFT) polymerisation. The well-defined star copolymers with Mw values ranging from 2 · 10(5) to 6 · 10(5) showing a low dispersity (approximately 1.2) were prepared in a high yield. A model anticancer drug, doxorubicin, was bound to the star polymer through a hydrazone bond, enabling the pH-controlled drug release in the target tumour tissue. The activated polymer arm ends of the star copolymer carrier enable a one-point attachment for the targeting ligands and/or a labelling moiety. In this study, the model TAMRA fluorescent dye was used to prove the feasibility of the polymer carrier visualisation by optical imaging in vitro. The tailor-made structure of the star polymer carriers should facilitate the synthesis of targeted polymer-drug conjugates, even polymer theranostics, for simultaneous tumour drug delivery and imaging.

  18. Intermolecular interactions in rifabutin—2-hydroxypropyl-β-cyclodextrin—water solutions

    NASA Astrophysics Data System (ADS)

    Anshakova, A. V.; Yermolenko, Yu. V.; Konyukhov, V. Yu.; Polshakov, V. I.; Maksimenko, O. O.; Gelperina, S. E.

    2015-05-01

    The possibility of a intermolecular complex rifabutin (RB)-2-hydroxypropyl-β-cyclodextrin (HP-β-CD) formed as a result of the interaction of the piperidine fragment of the RB molecule and the hydrophobic cavity of the HP-β-CD molecule was found. The stability constant of the intermolecular complex was determined.

  19. 75 FR 35796 - Busan 74 (2-hydroxypropyl methanethiosulfonate); Chlorine Gas; and Dichromic Acid, et al...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2010-06-23

    ... AGENCY Busan 74 (2-hydroxypropyl methanethiosulfonate); Chlorine Gas; and Dichromic Acid, et al... harris.monisha@epa.gov Dichromic Acid EPA-HQ-OPP-2010-02 Rebecca VonDem- Disodium Salt 43 Hagen Dihydrate... Gas; Dichromic Acid, Disodium Salt, Dihydrate, Meta-Cresol (m-Cresol), and Xylenol. Dated: May...

  20. Effect of film thickness on the antifouling performance of poly(hydroxy-functional methacrylates) grafted surfaces.

    PubMed

    Zhao, Chao; Li, Lingyan; Wang, Qiuming; Yu, Qiuming; Zheng, Jie

    2011-04-19

    The development of nonfouling biomaterials to prevent nonspecific protein adsorption and cell/bacterial adhesion is critical for many biomedical applications, such as antithrombogenic implants and biosensors. In this work, we polymerize two types of hydroxy-functional methacrylates monomers of 2-hydroxyethyl methacrylate (HEMA) and hydroxypropyl methacrylate (HPMA) into polymer brushes on the gold substrate via surface-initiated atom transfer radical polymerization (SI-ATRP). We systematically examine the effect of the film thickness of polyHEMA and polyHPMA brushes on their antifouling performance in a wide range of biological media including single-protein solution, both diluted and undiluted human blood serum and plasma, and bacteria culture. Surface plasmon resonance (SPR) results show a strong correlation between antifouling property and film thickness. Too thin or too thick polymer brushes lead to large protein adsorption. Surfaces with the appropriate film thickness of ∼25-45 nm for polyHPMA and ∼20-45 nm for polyHEMA can achieve almost zero protein adsorption (<0.3 ng/cm(2)) from single-protein solution and diluted human blood plasma and serum. For undiluted human blood serum and plasma, polyHEMA brushes at a film thickness of ∼20-30 nm adsorb only ∼3.0 and ∼3.5 ng/cm(2) proteins, respectively, while polyHPMA brushes at a film thickness of ∼30 nm adsorb more proteins of ∼13.5 and ∼50.0 ng/cm(2), respectively. Moreover, both polyHEMA and polyHPMA brushes with optimal film thickness exhibit very low bacteria adhesion. The excellent antifouling ability and long-term stability of polyHEMA and polyHPMA brushes make them, especially for polyHEMA, effective and stable antifouling materials for usage in blood-contacting devices.

  1. Intermolecular interactions in rifabutin-2-hydroxypropyl-β-cyclodextrin-water solutions, according to solubility data

    NASA Astrophysics Data System (ADS)

    Anshakova, A. V.; Vinogradov, E. V.; Sedush, N. G.; Kurtikyan, T. S.; Zhokhov, S. S.; Polshakov, V. I.; Ermolenko, Yu. V.; Konyukhov, V. Yu.; Maksimenko, O. O.; Gelperin, S. E.

    2016-05-01

    The formulations of rifabutin (RB) and 2-hydroxypropyl-β-cyclodextrin (HP-β-CD), obtained using different preparation techniques, are studied by means of differential scanning calorimetry and molecular spectroscopy (FTIR, NMR, Raman scattering, and photon correlation light scattering). It is established that molecules of RB do not form inclusion complexes with the molecules of HP-β-CD, and an increase in the solubility of RB determined earlier is caused by the formation of weak intermolecular associates.

  2. Stabilization of thymopentin and preservation of its pharmacological properties by 2-hydroxypropyl-beta-cyclodextrin.

    PubMed

    Brown, N D; Butler, D L; Chiang, P K

    1993-07-01

    Thymopentin prepared in 5, 15, and 20% 2-hydroxypropyl-beta-cyclodextrin (HPCD) was able to inhibit guinea-pig ileum contraction stimulated by anatoxin-a (3 x 10(-6) M) after fourteen months of storage at room temperature. Thus, in contrast to the instability of thymopentin prepared without HPCD, the pharmacological activity was retained and could be stored in a ready-to-use solution for extended periods without refrigeration.

  3. Synergistic enhancement of cancer therapy using a combination of heat shock protein targeted HPMA copolymer-drug conjugates and gold nanorod induced hyperthermia

    PubMed Central

    Larson, Nate; Gormley, Adam; Frazier, Nick; Ghandehari, Hamidreza

    2013-01-01

    In the field of nanomedicine, selective delivery to cancer cells is a common goal, where active targeting strategies are often employed to increase tumor accumulation. In this study, tumor hyperthermia was utilized as a means to increase the active delivery of heat shock protein (HSP) targeted N-(2-hydroxypropyl)methacrylamide (HPMA) copolymer-drug conjugates. Following hyperthermia, induced expression of cell surface heat shock protein (HSP) glucose regulated protein 78 kDa (GRP78) was utilized for targeted drug therapy. Conjugates bearing the anticancer agents aminohexylgeldanamycin (AHGDM), docetaxel (DOC), or cisplatin and the GRP78 targeting peptide WDLAWMFRLPVG were synthesized and characterized. Binding to cell surface expressed heat shock protein GRP78 on the surface of human prostate cancer DU145 cells was evaluated. HSP targeted AHGDM and DOC conjugates demonstrated active binding comparable to native targeting peptide. They were then assessed in vitro for the ability to synergistically induce cytotoxicity in combination with moderate hyperthermia (43°C, 30 min.). HSP targeted DOC conjugates exhibited high potency against DU145 cells with an IC50 of 2.4 nM. HSP targeted AHGDM and DOC conjugates demonstrated synergistic effects in combination with hyperthermia with combination index values of 0.65 and 0.45 respectively. Based on these results, HSP targeted DOC conjugates were selected for in vivo evaluation. In DU145 tumor bearing mice, a single treatment of tumor hyperthermia, induced via gold nanorod mediated plasmonic photothermal therapy, and intravenous administration of HSP targeted HPMA copolymer-docetaxel at 10 mg/kg resulted in maintained tumor regression for a period of 30 days. These results demonstrate the potential for tumor hyperthermia to increase the delivery of HSP targeted macromolecular chemotherapeutics. PMID:23602864

  4. Direct Cytoplasmic Delivery and Nuclear Targeting Delivery of HPMA-MT Conjugates in a Microtubules Dependent Fashion.

    PubMed

    Zhong, Jiaju; Zhu, Xi; Luo, Kui; Li, Lian; Tang, Manlin; Liu, Yanxi; Zhou, Zhou; Huang, Yuan

    2016-09-06

    As the hearts of tumor cells, the nucleus is the ultimate target of many chemotherapeutic agents and genes. However, nuclear drug delivery is always hampered by multiple intracellular obstacles, such as low efficiency of lysosome escape and insufficient nuclear trafficking. Herein, an N-(2-hydroxypropyl) methacrylamide (HPMA) polymer-based drug delivery system was designed, which could achieve direct cytoplasmic delivery by a nonendocytic pathway and transport into the nucleus in a microtubules dependent fashion. A special targeting peptide (MT), derived from an endogenic parathyroid hormone-related protein, was conjugated to the polymer backbone, which could accumulate into the nucleus a by microtubule-mediated pathway. The in vitro studies found that low temperature and NaN3 could not influence the cell internalization of the conjugates. Besides, no obvious overlay of the conjugates with lysosome demonstrated that the polymer conjugates could enter the tumor cell cytoplasm by a nonendocytic pathway, thus avoiding the drug degradation in the lysosome. Furthermore, after suppression of the microtubule dynamics with microtubule stabilizing docetaxel (DTX) and destabilizing nocodazole (Noc), the nuclear accumulation of polymeric conjugates was significantly inhibited. Living cells fluorescence recovery after photobleaching study found that the nuclear import rate of conjugates was 2-fold faster compared with the DTX and Noc treated groups. These results demonstrated that the conjugates transported into the nucleus in a microtubules dependent way. Therefore, in addition to direct cytoplasmic delivery, our peptide conjugated polymeric platform could simultaneously mediate nuclear drug accumulation, which may open a new path for further intracellular genes/peptides delivery.

  5. Indium-based and iodine-based labeling of HPMA copolymer–epirubicin conjugates: Impact of structure on the in vivo fate

    PubMed Central

    Zhang, Libin; Zhang, Rui; Yang, Jiyuan; Wang, Jiawei; Kopeček, Jindřich

    2016-01-01

    Recently, we developed 2nd generation backbone degradable N-(2-hydroxypropyl)methacrylamide (HPMA) copolymer-drug conjugates which contain enzymatically cleavable sequences (GFLG) in both polymeric backbone and side-chains. This design allows using polymeric carriers with molecular weights above renal threshold without impairing their biocompatibility, thereby leading to significant improvement in therapeutic efficacy. For example, 2nd generation HPMA copolymer-epirubicin (EPI) conjugates (2P-EPI) demonstrated complete tumor regression in the treatment of mice bearing ovarian carcinoma. To obtain a better understanding of the in vivo fate of this system, we developed a dual-labeling strategy to simultaneously investigate the pharmacokinetics and biodistribution of the polymer carrier and drug EPI. First, we synthesized two different types of dual-radiolabeled conjugates, including 1) 111In-2P-EPI-125I (polymeric carrier 2P was radiolabeled with 111In and drug EPI with 125I), and 2) 125I-2P-EPI-111In (polymeric carrier 2P was radiolabeled with 125I and drug EPI with 111In). Then, we compared the pharmacokinetics and biodistribution of these two dual-labeled conjugates in female nude mice bearing A2780 human ovarian carcinoma. There was no significant difference in the blood circulation between polymeric carrier and payload; the carriers (111In-2P and 125I-2P) showed similar retention of radioactivity in both tumor and major organs except kidney. However, compared to 111In-labeled payload EPI, 125I-labeled EPI showed lower radioactivity in normal organs and tumor at 48 h and 144 h after intravenous administration of conjugates. This may be due to different drug release rates resulting from steric hindrance to the formation of enzyme-substrate complex as indicated by cleavage experiments with lysosomal enzymes (Tritosomes). A slower release rate of EPI(DTPA)111In than EPI(Tyr)125I was observed. It may be also due to in vivo catabolism and subsequent iodine loss as

  6. Characterization of new acrylic bone cement based on methyl methacrylate/1-hydroxypropyl methacrylate monomer.

    PubMed

    Pascual, B; Goñi, I; Gurruchaga, M

    1999-01-01

    New formulations of acrylic bone cement based on methyl methacrylate/1-hydroxypropyl methacrylate (MMA/HPMA) monomers were developed with the purpose of obtaining more ductile materials with reduced polymerization shrinkage. In this way, the ductility of such materials increased, but the introduction of high percentages of the hydrophilic component produced an important decrease in Young's modulus and strength. To ascertain the reason for the deterioration of the tensile parameters, an analysis by scanning electron microscopy of these formulations was carried out; it revealed poor adhesion between the matrix and poly(MMA) beads. We also observed that the polymerization shrinkage increased as the amount of hydrophilic monomer in the formulation decreased, and the 50% (v/v) HPMA modified bone cement compensated for this volume reduction with its water uptake swelling. Measurements taken on the setting time and polymerization exotherm showed a decrease in the former and an increase in the latter, because of the introduction of a more reactive monomer in the bone cement formulation.

  7. The transduction of Coxsackie and Adenovirus Receptor-negative cells and protection against neutralizing antibodies by HPMA-co-oligolysine copolymer-coated adenovirus

    PubMed Central

    Wang, Chung-Huei K.; Chan, Leslie W.; Johnson, Russell N.; Chu, David S.H.; Shi, Julie; Schellinger, Joan G.; Lieber, Andre; Pun, Suzie H.

    2011-01-01

    Adenoviral (AdV) gene vectors offer efficient nucleic acid transfer into both dividing and non-dividing cells. However issues such as vector immunogenicity, toxicity and restricted transduction to receptor-expressing cells have prevented broad clinical translation of these constructs. To address this issue, engineered AdV have been prepared by both genetic and chemical manipulation. In this work, a polymer-coated Ad5 formulation is optimized by evaluating a series of N-(2-hydroxypropyl) methacrylamide (HPMA)-co-oligolysine copolymers synthesized by living polymerization techniques. This synthesis approach was used to generate highly controlled and well-defined polymers with varying peptide length (K5, K10 and K15), polymer molecular weight, and degradability to coat the viral capsid. The optimal formulation was not affected by the presence of serum during transduction and significantly increased Ad5 transduction of several cell types that lack the Coxsackie and Adenovirus Receptor (CAR) by up to 6-fold compared to unmodified AdV. Polymer-coated Ad5 also retained high transduction capability in the presence of Ad5 neutralizing antibodies. The critical role of heparan sulfate proteoglycans (HSPGs) in mediating cell binding and internalization of polymer-coated AdV was also demonstrated by evaluating transduction in HSPG-defective recombinant CHO cells. The formulations developed here are attractive vectors for ex vivo gene transfer in applications such as cell therapy. In addition, this platform for adenoviral modification allows for facile introduction of alternative targeting ligands. PMID:21959008

  8. Physicochemical study and characterization of the trimethoprim/2-hydroxypropyl-γ-cyclodextrin inclusion complex

    NASA Astrophysics Data System (ADS)

    Macedo, Osmir F. L.; Andrade, George R. S.; Conegero, Leila S.; Barreto, Ledjane S.; Costa, Nivan B., Jr.; Gimenez, Iara F.; Almeida, Luis E.; Kubota, Daniela

    2012-02-01

    Here we report the preparation of a trimethoprim/2-hydroxypropyl-γ-cyclodextrin inclusion complex along with a physicochemical study, structural characterization, and molecular modeling of the complex. As main results, we observed from phase-solubility studies at two temperatures (20 °C and 35 °C) that the association constants decrease with increasing temperature. Values for K1:1 constant were of the same magnitude order of those found for the parent γ-CD. The inclusion orientation as evidenced by ROESY measurements involves the inclusion of the 3,4,5-trimethoxybenzyl ring in the CD cavity from the larger rim. This is in agreement with semiempirical molecular modeling calculation.

  9. The pK(a) values of N,N,N',N'-tetrakis-(2-hydroxypropyl)ethylenediamine.

    PubMed

    McMahon, R; Brennan, M; Glennon, J D

    1986-11-01

    Aqueous solutions of the industrially important chelating agent N,N,N',N'-tetrakis(2-hydroxypropyl)ethylenediamine exhibit basic properties. The proton dissociation constants were determined to be 8.99 +/- 0.04 (pK(1)) and 4.30 +/- 0.04 (pK(2)) by potentiometric titration at 25 degrees in 0.15M sodium chloride.

  10. 40 CFR 721.10054 - Phenol, polymer with formaldehyde, 3-[(2-aminocyclohexyl)amino]-2-hydroxypropyl ethers.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... 40 Protection of Environment 31 2011-07-01 2011-07-01 false Phenol, polymer with formaldehyde, 3... Significant New Uses for Specific Chemical Substances § 721.10054 Phenol, polymer with formaldehyde, 3- -2... substance identified generically as a phenol, polymer with formaldehyde, 3- -2-hydroxypropyl ethers (PMN...

  11. 40 CFR 721.10054 - Phenol, polymer with formaldehyde, 3-[(2-aminocyclohexyl)amino]-2-hydroxypropyl ethers.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 40 Protection of Environment 30 2010-07-01 2010-07-01 false Phenol, polymer with formaldehyde, 3... Significant New Uses for Specific Chemical Substances § 721.10054 Phenol, polymer with formaldehyde, 3- -2... substance identified generically as a phenol, polymer with formaldehyde, 3- -2-hydroxypropyl ethers (PMN...

  12. 40 CFR 721.10054 - Phenol, polymer with formaldehyde, 3-[(2-aminocyclohexyl)amino]-2-hydroxypropyl ethers.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... 40 Protection of Environment 32 2012-07-01 2012-07-01 false Phenol, polymer with formaldehyde, 3... Significant New Uses for Specific Chemical Substances § 721.10054 Phenol, polymer with formaldehyde, 3- -2... substance identified generically as a phenol, polymer with formaldehyde, 3- -2-hydroxypropyl ethers (PMN...

  13. Methyl methacrylate

    Integrated Risk Information System (IRIS)

    TOXICOLOGICAL REVIEW of METHYL METHACRYLATE ( CAS No . 80 - 62 - 6 ) In Support of Summary Information on the Integrated Risk Information System ( IRIS ) January 1998 U.S . Environmental Protection Agency Washington , DC TABLE OF CONTENTS DISCLAIMER . . . . . . . . . . . . . . . . . . . . . . . . .

  14. Investigating the mechanism of enhanced cytotoxicity of HPMA copolymer-Dox-AGM in breast cancer cells.

    PubMed

    Greco, Francesca; Vicent, María J; Gee, Siobhan; Jones, Arwyn T; Gee, Julia; Nicholson, Robert I; Duncan, Ruth

    2007-01-22

    Recently we have described an HPMA copolymer conjugate carrying both the aromatase inhibitor aminoglutethimide (AGM) and doxorubicin (Dox) as combination therapy. This showed markedly enhanced in vitro cytotoxicity compared to the HPMA copolymer-Dox (FCE28068), a conjugate that demonstrated activity in chemotherapy refractory breast cancer patients during early clinical trials. To better understand the superior activity of HPMA copolymer-Dox-AGM, here experiments were undertaken using MCF-7 and MCF-7ca (aromatase-transfected) breast cancer cell lines to: further probe the synergistic cytotoxic effects of AGM and Dox in free and conjugated form; to compare the endocytic properties of HPMA copolymer-Dox-AGM and HPMA copolymer-Dox (binding, rate and mechanism of cellular uptake); the rate of drug liberation by lysosomal thiol-dependant proteases (i.e. conjugate activation), and also, using immunocytochemistry, to compare their molecular mechanism of action. It was clearly shown that attachment of both drugs to the same polymer backbone was a requirement for enhanced cytotoxicity. FACS studies indicated both conjugates have a similar pattern of cell binding and endocytic uptake (at least partially via a cholesterol-dependent pathway), however, the pattern of enzyme-mediated drug liberation was distinctly different. Dox release from PK1 was linear with time, whereas the release of both Dox and AGM from HPMA copolymer-Dox-AGM was not, and the initial rate of AGM release was much faster than that seen for the anthracycline. Immunocytochemistry showed that both conjugates decreased the expression of ki67. However, this effect was more marked for HPMA copolymer-Dox-AGM and, moreover, only this conjugate decreased the expression of the anti-apoptotic protein bcl-2. In conclusion, the superior in vitro activity of HPMA copolymer-Dox-AGM cannot be attributed to differences in endocytic uptake, and it seems likely that the synergistic effect of Dox and AGM is due to the

  15. Synthesis and in vitro evaluation of defined HPMA folate conjugates: influence of aggregation on folate receptor (FR) mediated cellular uptake.

    PubMed

    Barz, Matthias; Canal, Fabiana; Koynov, Kaloian; Zentel, R; Vicent, María J

    2010-09-13

    In this article we report the synthesis and in vitro evaluation of well-defined, folate functionalized and fluorescently labeled polymers based on the clinically approved N-(2-hydroxypropyl)-methacrylamide (HPMA). The polymers were prepared applying the RAFT polymerization method as well as the reactive ester approach. The molecular weights of the polymers synthesized were around 15 and 30 kDa. The total content of conjugated folate varied from 0, 5, and 10 mol %. The cellular uptake of these polymers was investigated in the folate receptor (FR)-positive human nasopharyngeal epidermal carcinoma (KB-3-1) and FR-negative human lung epithelial carcinoma (A549) cancer cell lines. In FR-positive cells, the cellular uptake of polymers depended strongly on the folate content. The conjugates with the highest folate content led to the highest level of cell-associated fluorescence. Regarding influence of molecular weight, nonsignificant differences were observed when total cell uptake was analyzed. The cellular uptake is related to the aggregate formation of the polymer conjugates, which were studied by fluorescence correlation spectroscopy (FCS). For the conjugates, we found aggregates with a diameter ranging from 11-18 nm. Much to our surprise, we found aggregates of the same size for the 30 kDa polymer bearing 5 mol % folate and for the 15 and 30 kDa conjugates with a folate content of 10 mol %. Consequently, a different conformation in solution for the different conjugates was expected. By live cell confocal fluorescence microscopy the receptor-mediated endocytosis process was observed, as colocalization with lysosomal markers was achieved. In addition, cellular uptake was not observed in FR-negative cells (A549) and can be dramatically reduced by blocking the FR with free folic acid. Our findings clearly underline the need for a minimum amount of accessible folate units to target the FR that triggers specific cellular uptake. Furthermore, it has been demonstrated that

  16. 2-Hydroxypropyl-beta-cyclodextrin extracts 2-phenylphenol from silicone tubing.

    PubMed

    den Brok, Monique W J; van der Schoot, Sabien C; Nuijen, Bastiaan; Hillebrand, Michel J X; Beijnen, Jos H

    2004-07-08

    Cyclodextrins are capable to solubilise lipophilic drugs via (partial) inclusion in their lipophilic cavity. This, however, also provides the potential for the extraction of small molecules from production materials. In the present study, the potency of the commercially available and used cyclodextrin, 2-hydroxypropyl-beta-cyclodextrin (HPbetaCD) to extract the preservative 2-phenylphenol (2-PP) from platinum cured silicone tubing was tested. The presence of 2-PP was structurally confirmed with HPLC-UV and LC/MS/MS in HPbetaCD solutions after incubation with platinum cured silicone tubing. HPbetaCD concentration and prior tubing sterilisation were found not to influence the levels of 2-PP extracted. Interestingly, extraction to ethanol was 15-fold higher than observed for HPbetaCD solutions. 2-PP was extracted from silicone tubing during routine manufacture of a blank dosage form formulated with only HPbetaCD, resulting in detectable levels of 2-PP in the final product. In a freeze-dried dosage form containing HPbetaCD and an active pharmaceutical ingredient (exhibiting a stability constant for HPbetaCD/drug of 1045 L/mol), on the other hand, 2-PP was undetectable.

  17. Adsorption kinetics of 3-alkoxy-2-hydroxypropyl trimethyl ammonium chloride at oil-water interface

    NASA Astrophysics Data System (ADS)

    Wei, Xi-lian; Wang, Xiu-hong; Liu, Jie; Sun, De-zhi; Yin, Bao-lin; Wang, Xiu-jie

    2012-11-01

    Dynamic interfacial tension (DIT) between aqueous solution of 3-alkoxy-2-hydroxypropyl trimethyl ammonium chloride (RnHTAC) and n-octane was measured using spinning drop method. The effects of RnHTAC concentration (the concentration below the CMC) and temperature on DIT have been investigated. The cause of the change of DIT with time has been discussed. The effective diffusion coefficient, Da, and the adsorption barrier, ɛa, have been obtained with extended Word-Tordai equation. The results show that the higher the concentration of the surfactant is, the smaller the DIT will be and the lower the curve of the DIT, and the aqueous RnHTAC solutions follow a mixed diffusion-activation adsorption mechanism. With increase of RnHTAC concentration in the bulk solution, Da decreases and ɛa increases. Da of aqueous R14HTAC solution decreases from 0.090 × 10-13 m2 s-1 to 0.081 × 10-13 m2 s-1 and ɛa increases from 10.12 kJ mol-1 to 11.89 kJ mol-1, with the temperature increasing from 30 °C to 50 °C. This phenomenon indicates that the diffusion tendency becomes weak with the strengthening of the interaction between the surfactant molecules and that the thermo-motion of molecules benefits interface adsorption.

  18. Intrathecal 2-Hydroxypropyl-Beta-Cyclodextrin in a Single Patient with Niemann-Pick C1

    PubMed Central

    Maarup, Timothy J.; Chen, Agnes H.; Porter, Forbes D.; Farhat, Nicole Y.; Ory, Daniel S.; Sidhu, Rohini; Jiang, Xuntian; Dickson, Patricia I.

    2015-01-01

    Niemann-Pick C, Type 1 (NPC1) is a progressive autosomal recessive neurologic disease caused by defective intracellular cholesterol and lipid trafficking. There are currently no United States Food and Drug Administration approved treatments for NPC1. We undertook a study evaluating the safety, efficacy, and biomarker response of intrathecal 2-hydroxypropyl-β-cyclodextrin (HP-β-CD) in a 12-year old subject with mildly symptomatic NPC. The subject received 200mg intrathecal HP-β-CD administered biweekly via lumbar puncture. To date the subject has received 27 intrathecal HP-β-CD injections. Intrathecal HP-β-CD has been generally safe and well tolerated in this subject. There has been improvement in vertical gaze. The subject has developed subclinical hearing loss at high frequency that is likely HP-β-CD related. Plasma 24-(S)-hydroxycholesterol, a pharmacodynamic biomarker for cholesterol redistribution in the central nervous system, was significantly increased in response to each of the first 5 drug administrations. Further dosing as well as dose escalations are needed to more completely ascertain the safety and efficacy of intrathecal HP-β-CD. PMID:26189084

  19. Increasing solubility of red bell pepper carotenoids by complexation with 2-hydroxypropyl-β-cyclodextrin.

    PubMed

    de Lima Petito, Nicolly; da Silva Dias, Daiana; Costa, Valéria Gonçalves; Falcão, Deborah Quintanilha; de Lima Araujo, Kátia Gome

    2016-10-01

    Red bell pepper carotenoids were complexed with 2-hydroxypropyl-β-cyclodextrin (2-HPβCD) in different mass ratios (1:4, 1:6, 1:8 and 1:10) through ultrasonic homogenization in order to increase carotenoid solubility and their use as natural pigment in food. Inclusion complexes, red bell pepper extract and physical mixtures were analyzed by DSC, FT-IR, (1)H NMR and DLS. Solubility assay was performed to identify the effect of complexation on the solubility of carotenoids. From characterization assays, results showed that inclusion process occurred for all tested ratios. Results for water solubility assays demonstrated clear differences between solubility index of inclusion complexes (8.06±2.59-16.55±4.40mg/mL) and physical mixtures (3.53±1.44-7.3±1.88mg/mL), while carotenoid extract was no water soluble, as expected. These results indicated that molecular inclusion of carotenoids in 2-HPβCD was efficient to enhance their solubility in water, enabling application of red bell pepper carotenoid as natural pigment and/or bioactive substances in food.

  20. Reactivity pattern of bromonucleosides induced by 2-hydroxypropyl radicals: photochemical, radiation chemical, and computational studies.

    PubMed

    Zdrowowicz, Magdalena; Chomicz, Lidia; Miloch, Justyna; Wiczk, Justyna; Rak, Janusz; Kciuk, Gabriel; Bobrowski, Krzysztof

    2015-06-04

    The bromonucleosides (BrdX's) 5-bromo-2'-deoxyuridine (BrdU), 5-bromo-2'-deoxycytidine (BrdC), 8-bromo-2'-deoxyadenosine (BrdA), and 5-bromo-2'-deoxyguanosine (BrdG) may substitute for ordinary nucleosides in DNA. As indicated by electron-stimulated desorption experiments, such a modified biopolymer is greater than 2-3-fold more sensitive to damage induced by excess electrons. The other major product of water radiolysis, the (•)OH radical, may form a number of other radicals in chemical reactions with the complex content of the cell. Thus, the well-proved BrdU-labeled DNA radiosensitivity may be, at least in part, related to secondary organic radicals. Therefore, in the current study, the propensity of BrdX's to damage induced by 2-hydroxypropyl radical (OHisop(•))-a prototype radical species-was investigated. The HPLC and LC-MS analyses revealed the formation of two major products from the brominated pyrimidine nucleosides, a native nucleoside and an adduct of BrdX and OHisop(•) , and only an adduct of BrdX from the bromopurine nucleosides. Quantum chemical calculations ascribed this evident difference between purines and pyrimidines to the electron transfer from OHisop(•) to BrdX that is especially favorable in pyrimidines.

  1. Interaction of iodine with 2-hydroxypropyl-alpha-cyclodextrin and its bactericidal activity.

    PubMed

    Tomono, K; Goto, H; Suzuki, T; Ueda, H; Nagai, T; Watanabe, J

    2002-11-01

    To obtain an effective iodine solution, the use of 2-hydroxypropyl-alpha-cyclodextrin (2-HP-alpha-CD) as solubilizer was examined in comparison with alpha-cyclodextrin (alpha-CD), beta-cyclodextrin (beta-CD), potassium iodide (KI), and polyvinylpyrrolidone (PVP). The stability constants for inclusion of iodine with cyclodextrin and KI were ascertained by the solubility method. The apparent stability constants increased in the following order: KI < beta-CD < alpha-CD < 2-HP-alpha-CD. This order was nearly in accordance with that of the stabilization ability. The largest volatile depression effect was exhibited by 2HP-alpha-CD. The measurement of the minimum inhibitory concentration (MC) using Escherichia coli NIH-J-2 and Staphylococcus aureus FDA209P suggested that the bactericidal activity of the iodine/2-HP-alpha-CD system was the same as that of the iodine/alpha-CD, iodine/beta-CD, and iodine/PVP systems. The present results suggest that the combination of 2-HP-alpha-CD and iodine is useful for a stable and effective iodine solution.

  2. Formulation and In-vitro Evaluation of Orally Disintegrating Tablets of Olanzapine-2-Hydroxypropyl-β-Cyclodextrin Inclusion Complex

    PubMed Central

    Ajit Shankarrao, Kulkarni; Dhairysheel Mahadeo, Ghadge; Pankaj Balavantrao, Kokate

    2010-01-01

    The aim of this study was to design orally disintegrating tablets of Olanzapine and to complex Olanzapine with 2-hydroxypropyl-β- cyclodextrin with special emphasis on disintegration and dissolution studies. Phase solubility studies demonstrated the formation of 1:1 molar inclusion complex by kneading method. Tablets were prepared by using superdisintegrants namely, sodium starch glycolate, croscarmellose sodium, crospovidone, tulsion 339, and indion 414. Complex was characterized using infrared spectroscopy, drug content estimation, saturated solubility study, diffrerential scanning calorimetry and X-ray diffractometry. 5% w/w croscarmellose sodium showed the minimum disintegration time 39 ± 1.76 sec and in-vitro drug release 99.19 ± 0.18% within 6 min. In general, solubility of Olanzapine can be improved by complexing with 2-hydroxypropyl-β- cyclodextrin. Croscarmellose sodium can be used for faster disintegration of tablets. PMID:24381598

  3. New type of chitosan/2-hydroxypropyl-β-cyclodextrin composite membrane for gallic acid encapsulation and controlled release.

    PubMed

    Paun, Gabriela; Neagu, Elena; Tache, Andreia; Radu, G L

    2014-01-01

    A new type of chitosan/2-hydroxypropyl-β-cyclodextrin composite membrane have been developed for the encapsulation and controlled release of gallic acid. The morphology of the composite membrane was investigated by infrared spectroscopy (FT-IR) and scanning electron microscopy (SEM), whereas swelling gallic acid and release properties were investigated by UV-visible spectroscopy. The release behavior with pH changes was also explored. The composite membrane based on chitosan/2-hydroxypropyl-β-cyclodextrin with gallic acid included showed improved antioxidant capacities compared to plain chitosan membrane. The information obtained in this study will facilitate the design and preparation of composite membrane based on chitosan and could open a wide range of applications, particularly its use as an antioxidant in food, food packaging, biomedical (biodegradable soft porous scaffolds for enhance the surrounding tissue regeneration), pharmaceutical and cosmetics industries.

  4. In vitro stimulation of macrophages by quadrol [N,N,N',N'-tetrakis(2-hydroxypropyl)ethylenediamine].

    PubMed

    Bhide, M V; Patel, S; Rowland, E C; Smith, D J

    1985-01-01

    Mouse peritoneal macrophages, when exposed to Quadrol [N,N,N',N'-tetrakis(2-hydroxypropyl)ethylenediamine] in vitro, show a dose dependent enhanced spreading over a four-hour period. In vitro Quadrol induced phagocytosis of polystyrene beads was found to be time and concentration dependent. The rate and extent of the enhancement of phagocytosis was comparable to that observed for lipopolysaccharide and tuftsin.

  5. Ammonium methacrylate

    Integrated Risk Information System (IRIS)

    Ammonium methacrylate ; CASRN 16325 - 47 - 6 Human health assessment information on a chemical substance is included in the IRIS database only after a comprehensive review of toxicity data , as outlined in the IRIS assessment development process . Sections I ( Health Hazard Assessments for Noncarcin

  6. Induction of Dendritic Cell Maturation and Activation by a Potential Adjuvant, 2-Hydroxypropyl-β-Cyclodextrin

    PubMed Central

    Kim, Sun Kyung; Yun, Cheol-Heui; Han, Seung Hyun

    2016-01-01

    2-Hydroxypropyl-β-cyclodextrin (HP-β-CD) is a chemically modified cyclic oligosaccharide produced from starch that is commonly used as an excipient. Although HP-β-CD has been suggested as a potential adjuvant for vaccines, its immunological properties and mechanism of action have yet to be characterized. In the present study, we investigated the maturation and activation of human dendritic cells (DCs) treated with HP-β-CD. We found that DCs stimulated with HP-β-CD exhibited a remarkable upregulation of costimulatory molecules, MHC proteins, and PD-L1/L2. In addition, the production of cytokines, such as TNF-α, IL-6, and IL-10, was modestly increased in DCs when treated with HP-β-CD. Furthermore, HP-β-CD-sensitized DCs markedly induced the proliferation and activation of autologous T lymphocytes. HP-β-CD also induced a lipid raft formation in DCs. In contrast, filipin, a lipid raft inhibitor, attenuated HP-β-CD-induced DC maturation, the cytokine expression, and the T lymphocyte-stimulating activities. To determine the in vivo relevance of the results, we investigated the adjuvanticity of HP-β-CD and the modulation of DCs in a mouse footpad immunization model. When mice were immunized with ovalbumin in the presence of HP-β-CD through a hind footpad, serum ovalbumin-specific antibodies were markedly elevated. Concomitantly, DC populations expressing CD11c and MHC class II were increased in the draining lymph nodes, and the expression of costimulatory molecules was upregulated. Collectively, our data suggest that HP-β-CD induces phenotypic and functional maturation of DCs mainly mediated through lipid raft formation, which might mediate the adjuvanticity of HP-β-CD. PMID:27812358

  7. Cytotoxic effects of acrylates and methacrylates: relationships of monomer structures and cytotoxicity.

    PubMed

    Yoshii, E

    1997-12-15

    Thirty-nine acrylates and methacrylates that had been used in dental resin materials were evaluated by a cytotoxicity test, and the relationships between their structures and cytotoxicity were studied to predict cytotoxic levels of dental resin materials in order to develop new low-toxic resin materials. All the acrylates evaluated were more toxic than corresponding methacrylates. In both the acrylates and methacrylates, a hydroxyl group seemed to enhance cytotoxicity. Dimethacrylates with 14 or fewer oxyethylene chains showed similar cytotoxicity while dimethacrylates with 23 oxyethylene chains showed lower cytotoxicity. The cytotoxicity ranking of monomers widely used in dental resin materials was bisphenol A bis 2-hydroxypropyl methacrylate (bisGMA) > urethane dimethacrylate (UDMA) > triethyleneglycol dimethacrylate (3G) > 2-hydroxyethyl methacrylate (HEMA) > methyl methacrylate (MMA). In acrylates, methacrylates, and ethylmethacrylates with either substituents, the lipophilicity of substituents affected their cytotoxicity, and an inverse correlation between IC50 and logP was observed. These results will be useful in developing new resin materials with low toxic monomer compositions.

  8. 76 FR 69659 - Methacrylic Acid-Methyl Methacrylate-Polyethylene Glycol Monomethyl Ether Methacrylate Graft...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2011-11-09

    ... AGENCY 40 CFR Part 180 Methacrylic Acid-Methyl Methacrylate-Polyethylene Glycol Monomethyl Ether... residues of methacrylic acid-methyl methacrylate- polyethylene glycol monomethyl ether methacrylate graft... permissible level for residues of methacrylic acid-methyl methacrylate-polyethylene glycol monomethyl...

  9. Quantitation of N,N,N',N'-tetrakis (2-hydroxypropyl)-ethylenediamine in plasma by gas chromatography.

    PubMed

    Dunphy, M J; Smith, D J

    1989-03-24

    A wide-bore capillary gas chromatographic method with nitrogen-selective thermionic detection is described for the quantitative analysis of N,N,N',N'-tetrakis (2-hydroxypropyl)ethylenediamine (Quadrol) in plasma. N,N,N',N'-tetrakis (2-hydroxybutyl)ethylenediamine is used as an internal standard. Rat or human plasma samples (0.5 ml) are mixed with internal standard, adjusted to alkaline pH and subjected to a single extraction with dichloromethane. Quadrol recovery from plasma typically exceeds 90%. The method is linear over the range 1.0-50 micrograms/ml. The working detection limit is 0.5 microgram/ml and the analysis time is under 7 min. The procedure has been used to obtain plasma concentration versus time data for the evaluation of Quadrol pharmacokinetics in rats.

  10. A Case of Olfactory Neuroblastoma Induced in A Rat by N-Nitrosobis(2-hydroxypropyl)amine.

    PubMed

    Takagi, Mizuho; Shiraiwa, Kazumi; Kusuoka, Osamu; Tamura, Kazutoshi

    2010-06-01

    N-nitrosobis(2-hydroxypropyl)amine (BHP) is a well-known carcinogen and induces tumors in various tissues. In the present paper, a case of olfactory neuroblastoma (ONB) induced in a rat by BHP is described. The tumor was observed in one out of 25 male rats that received 2000 ppm of BHP in drinking water from 6 to 18 weeks of age and were sacrificed at 26 weeks of age. Histologically, the tumor arose in the posterior nasal cavity and consisted of small round cells and elongate cells with scant basophilic cytoplasm. The neoplastic cells proliferated with compartmentalization into the lobules by fibrovascular septa. True rosettes, pseudorosettes and an intercellular fibrillar matrix were occasionally observed. Immunohistochemically, the tumor cells were positive for NF120/200 and β III-tubulin. These results indicate that the present tumor is the first case of ONB induced in a rat by BHP treatment.

  11. Host-guest inclusion system of scutellarein with 2-hydroxypropyl-beta-cyclodextrin: preparation, characterization, and anticancer activity.

    PubMed

    Wang, Fen; Yang, Bo; Zhao, Yulin; Liao, Xiali; Gao, Chuanzhu; Jiang, Ruijian; Han, Bin; Yang, Jian; Liu, Man; Zhou, Rongguang

    2014-01-01

    The inclusion complexation behavior of scutellarein (SCUE) with 2-hydroxypropyl-β-cyclodextrin (HP-β-CD) has been investigated in both solution and in the solid state. SCUE/HP-β-CD solid system was prepared by suspension method. The formation of SCUE/HP-β-CD complex in aqueous solution was demonstrated by fluorescence spectroscopy, and the Job plot showed a maximum at a molar fraction of 0.5, indicating 1:1 inclusion complexation between SCUE and HP-β-CD. However, SCUE/HP-β-CD inclusion complex was characterized by means of XRD, DSC, (1)H, and two-dimensional NMR. Through the complexation between HP-β-CD and SCUE, the water solubility and antitumor activity of SCUE were obviously increased. This satisfactory water solubility and high antitumor activity of the SCUE/HP-β-CD complex will be potentially useful for its application on human colon cancer chemotherapies.

  12. 40 CFR 721.4040 - Glycols, polyethylene-, 3-sulfo-2-hydroxypropyl-p-(1,1,3,3-tetra-methylbutyl)phenyl ether, sodium...

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 40 Protection of Environment 30 2010-07-01 2010-07-01 false Glycols, polyethylene-, 3-sulfo-2... CHEMICAL SUBSTANCES Significant New Uses for Specific Chemical Substances § 721.4040 Glycols, polyethylene..., polyethylene-, 3-sulfo-2-hydroxypropyl-p-(1,1,3,3-tetramethyl butyl)phenyl ether, sodium salt (P-90-1565)...

  13. 40 CFR 721.4040 - Glycols, polyethylene-, 3-sulfo-2-hydroxypropyl-p-(1,1,3,3-tetra-methylbutyl)phenyl ether, sodium...

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... 40 Protection of Environment 31 2014-07-01 2014-07-01 false Glycols, polyethylene-, 3-sulfo-2... CHEMICAL SUBSTANCES Significant New Uses for Specific Chemical Substances § 721.4040 Glycols, polyethylene..., polyethylene-, 3-sulfo-2-hydroxypropyl-p-(1,1,3,3-tetramethyl butyl)phenyl ether, sodium salt (P-90-1565)...

  14. 40 CFR 721.4040 - Glycols, polyethylene-, 3-sulfo-2-hydroxypropyl-p-(1,1,3,3-tetra-methylbutyl)phenyl ether, sodium...

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... 40 Protection of Environment 32 2013-07-01 2013-07-01 false Glycols, polyethylene-, 3-sulfo-2... CHEMICAL SUBSTANCES Significant New Uses for Specific Chemical Substances § 721.4040 Glycols, polyethylene..., polyethylene-, 3-sulfo-2-hydroxypropyl-p-(1,1,3,3-tetramethyl butyl)phenyl ether, sodium salt (P-90-1565)...

  15. 40 CFR 721.4040 - Glycols, polyethylene-, 3-sulfo-2-hydroxypropyl-p-(1,1,3,3-tetra-methylbutyl)phenyl ether, sodium...

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... 40 Protection of Environment 32 2012-07-01 2012-07-01 false Glycols, polyethylene-, 3-sulfo-2... CHEMICAL SUBSTANCES Significant New Uses for Specific Chemical Substances § 721.4040 Glycols, polyethylene..., polyethylene-, 3-sulfo-2-hydroxypropyl-p-(1,1,3,3-tetramethyl butyl)phenyl ether, sodium salt (P-90-1565)...

  16. 40 CFR 721.4040 - Glycols, polyethylene-, 3-sulfo-2-hydroxypropyl-p-(1,1,3,3-tetra-methylbutyl)phenyl ether, sodium...

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... 40 Protection of Environment 31 2011-07-01 2011-07-01 false Glycols, polyethylene-, 3-sulfo-2... CHEMICAL SUBSTANCES Significant New Uses for Specific Chemical Substances § 721.4040 Glycols, polyethylene..., polyethylene-, 3-sulfo-2-hydroxypropyl-p-(1,1,3,3-tetramethyl butyl)phenyl ether, sodium salt (P-90-1565)...

  17. Cathepsin S-cleavable, multi-block HPMA copolymers for improved SPECT/CT imaging of pancreatic cancer.

    PubMed

    Fan, Wei; Shi, Wen; Zhang, Wenting; Jia, Yinnong; Zhou, Zhengyuan; Brusnahan, Susan K; Garrison, Jered C

    2016-10-01

    This work continues our efforts to improve the diagnostic and radiotherapeutic effectiveness of nanomedicine platforms by developing approaches to reduce the non-target accumulation of these agents. Herein, we developed multi-block HPMA copolymers with backbones that are susceptible to cleavage by cathepsin S, a protease that is abundantly expressed in tissues of the mononuclear phagocyte system (MPS). Specifically, a bis-thiol terminated HPMA telechelic copolymer containing 1,4,7,10-tetraazacyclododecane-1,4,7,10-tetraacetic acid (DOTA) was synthesized by reversible addition-fragmentation chain transfer (RAFT) polymerization. Three maleimide modified linkers with different sequences, including cathepsin S degradable oligopeptide, scramble oligopeptide and oligo ethylene glycol, were subsequently synthesized and used for the extension of the HPMA copolymers by thiol-maleimide click chemistry. All multi-block HPMA copolymers could be labeled by (177)Lu with high labeling efficiency and exhibited high serum stability. In vitro cleavage studies demonstrated highly selective and efficient cathepsin S mediated cleavage of the cathepsin S-susceptible multi-block HPMA copolymer. A modified multi-block HPMA copolymer series capable of Förster Resonance Energy Transfer (FRET) was utilized to investigate the rate of cleavage of the multi-block HPMA copolymers in monocyte-derived macrophages. Confocal imaging and flow cytometry studies revealed substantially higher rates of cleavage for the multi-block HPMA copolymers containing the cathepsin S-susceptible linker. The efficacy of the cathepsin S-cleavable multi-block HPMA copolymer was further examined using an in vivo model of pancreatic ductal adenocarcinoma. Based on the biodistribution and SPECT/CT studies, the copolymer extended with the cathepsin S susceptible linker exhibited significantly faster clearance and lower non-target retention without compromising tumor targeting. Overall, these results indicate that

  18. Polarographic investigation of Cu(II) complexes with N,N,N',N'-tetrakis-(2-hydroxypropyl)-ethylenediamine.

    PubMed

    Norkus, E; Vaskelis, A; Zakaité, I; Reklaitis, J

    1995-11-01

    During investigation of the formation of Cu(2+) ion complexes with N,N,N',N'-tetrakis-(2-hydroxypropyl)-ethylenediamine (Quadrol-Q) by means of constant current polarography (20 degrees C, ionic strength J = 3 mol l(-1)), the possibility of the formation of two complex compounds; CuQ(2+) and CuQ(2+)(2), was shown within the pH range from 6 to 8. The logarithms of the stability constants for these compounds are 10.6 +/- 0.5 and 14.6 +/- 0.4 respectively. Cu(II) complexation increases sharply when the pH increases from 8 to 10. It was shown that the data at a pH of greater than 10 are in accordance with the existence of the hydroxy complexes CuQ(OH)(2) and CuQ(2)(OH)(2), the logarithms of the stability constants being 26.9 +/- 0.5 and 29.1 +/- 0.3.

  19. UV-vis and FTIR-ATR characterization of 9-fluorenon-2-carboxyester/(2-hydroxypropyl)-beta-cyclodextrin inclusion complex.

    PubMed

    Stancanelli, R; Ficarra, R; Cannavà, C; Guardo, M; Calabrò, M L; Ficarra, P; Ottanà, R; Maccari, R; Crupi, V; Majolino, D; Venuti, V

    2008-08-05

    In this work, the usefulness of (2-hydroxypropyl)-beta-cyclodextrin (HP-beta-CyD) as a tool to form an inclusion complex with 9-fluorenonic derivative (AG11) has been investigated, in pure water, by UV absorption. Phase-solubility diagrams allowed the determination of the association constant between AG11 and HP-beta-CyD. At the same time, solid binary systems between AG11 and HP-beta-CyD have been prepared in 1:1 stoichiometry by co-precipitation method. In order to confirm the complexation, FTIR spectroscopy in ATR geometry measurements have been performed and the results have been compared with the free compounds and the corresponding physical mixture in the same molar ratio. The nature of the interactions between AG11 and HP-beta-CyD has been elucidated also by applying mathematical procedures such as deconvolution and curve fitting. Improvement of the aqueous solubility is expected to improve the bioavailability of the drug in oral administration.

  20. Inclusion complex of ITH12674 with 2-hydroxypropyl-β-cyclodextrin: Preparation, physical characterization and pharmacological effect.

    PubMed

    Michalska, Patrycja; Wojnicz, Aneta; Ruiz-Nuño, Ana; Abril, Sheila; Buendia, Izaskun; León, Rafael

    2017-02-10

    ITH12674 is a multitarget drug, designed to exert a dual "drug-prodrug" mechanism of action, able to induce the phase II antioxidant and anti-inflammatory response for the treatment of brain ischemia. However, its physicochemical properties limit its potential preclinical development due to its low water solubility and instability towards heat and pH variations. In order to improve its properties, we prepared the inclusion complex of ITH12674 with 2-hydroxypropyl-β-cyclodextrin (HP-β-CD) by the freeze-drying method. The formation of the inclusion complex was confirmed by FT-IR spectroscopy, PXRD, DSC, (1)H NMR and SEM techniques. Experimental results showed that the inclusion complex enhanced its water solubility and stability against heat, acidic and basic conditions. Furthermore, the inclusion complex, prepared in water solution, exerted the same potency to induce the phase II antioxidant response as the pure ITH12674. Thus the formation of the inclusion complex with HP-β-CD is a very effective method to stabilize and solubilize the active compound for its future preclinical development.

  1. Effects of intracerebroventricular administration of 2-hydroxypropyl-β-cyclodextrin in a patient with Niemann-Pick Type C disease.

    PubMed

    Matsuo, Muneaki; Shraishi, Koki; Wada, Koki; Ishitsuka, Yoichi; Doi, Hirohito; Maeda, Miyuki; Mizoguchi, Tatsuhiro; Eto, Junya; Mochinaga, Sakiko; Arima, Hidetoshi; Irie, Tetsumi

    2014-01-01

    Niemann-Pick Type C disease (NPC) is an autosomal recessive lysosomal storage disorder characterized by progressive neurological deterioration. Previously, we reported that intravenous administration of 2-hydroxypropyl-β-cyclodextrin (HPB-CD) in two patients with NPC had only partial and transient beneficial effects on neurological function. The most likely reason for HPB-CD not significantly improving the neurological deficits of NPC is its inability to cross the blood-brain barrier. Herein, we describe the effects of intrathecal HPB-CD in an eight-year-old patient with a perinatal onset of NPC, administered initially at a dose of 10 mg/kg every other week and increased up to 10 mg/kg twice a week. Clinically, the patient maintained residual neurological functions for two years, at which time nuclear magnetic resonance spectroscopy showed a decreased choline to creatine ratio and increased N-acetylaspartate to creatine ratio, and positron emission tomography revealed increased standardized uptake values. Total-tau in the cerebrospinal fluid (CSF) was also decreased after two years. No adverse effects were observed over the course of treatment. The CSF concentrations of HPB-CD during the distribution phase after the injections were comparable with those at which HPB-CD could normalize cellular cholesterol abnormality in vitro. Further studies are necessary to elucidate the mechanisms of action of HPB-CD in NPC, and to determine the optimal dose and intervals of HPB-CD injection.

  2. Selective adsorption of metoprolol enantiomers using 2-hydroxypropyl-β-cyclodextrin cross-linked multiwalled carbon nanotube.

    PubMed

    Farhadian, Nafiseh; Sharifi, Arezoo; Lashgari, Elmira

    2015-03-01

    This study investigates the ability of functionalized multiwalled carbon nanotubes (MWCNTs) for enantio-separation of metoprolol chiral forms. 2Hydroxypropyl-β-cyclodextrin (2HP-β-CD) was applied as a chiral selector to functionalize carbon nanotubes (CNTs). The modified multiwalled CNT samples were characterized using scanning electron microscopy and Fourier transform infrared spectroscopy. The results of analyses showed that CNTs were successfully cross-linked with 2HP-β-CD. To evaluate the enantio-separation property of the products, the separation of metoprolol chiral forms on the initial and final products was examined. Further, UV-visible spectroscopy and polarimeter analyses were used for characterization. The results indicate that MWCNT does not have any intrinsic enantio-separation ability, although its selectivity for enantio-separation can be enhanced by cross-linking it to 2HP-β-CD. Moreover, the optimal mass of adsorbent as well as optimal mass of functional groups is estimated to achieve maximum enantio-separation efficiency. The results indicate that applying large amounts of 2HP-β-CD to CNTs functionalization decreases the cross-linking efficiency, which consequently reduces enantio-separation efficiency.

  3. Encapsulation of plai oil/2-hydroxypropyl-β-cyclodextrin inclusion complexes in polyvinylpyrrolidone (PVP) electrospun nanofibers for topical application.

    PubMed

    Tonglairoum, Prasopchai; Chuchote, Tudduo; Ngawhirunpat, Tanasait; Rojanarata, Theerasak; Opanasopit, Praneet

    2014-06-01

    The aim of this study was to prepare electrospun polyvinylpyrrolidone (PVP)/2-hydroxypropyl-β-cyclodextrin (HPβCD) nanofiber mats and to incorporate plai oil (Zingiber Cassumunar Roxb.). The plai oil with 10, 20 and 30% wt to polymer were incorporated in the PVP/HPβCD solution and electrospun to obtain nanofibers. The morphology and structure of the PVP and PVP/HPβCD nanofiber mats with and without the plai oil were analyzed using scanning electron microscopy (SEM). The thermal behaviors of the nanofiber mats were characterized using differential scanning calorimeter (DSC). Terpinen-4-ol was used as a marker of the plai oil. The amount of plai oil remaining in the PVP/HPβCD nanofiber mats was determined using gas chromatography-mass spectoscopy (GC-MS). The SEM images revealed that all of the fibers were smooth. The average diameter of fibers was 212-450 nm, and decreased with the increasing of plai oil content. The release characteristics of plai oil from the fiber showed the fast release followed by a sustained release over the experimental time of 24 h. The release rate ranged was in the order of 10% > 20% ∼ 30% plai oil within 24 h. Electrospun fibers with 20% plai oil loading provided the controlled release and also showed the highest plai oil content. Hence, this electrospun nanofiber has a potential for use as an alternative topical application.

  4. Multi-step lung carcinogenesis model induced by oral administration of N-nitrosobis(2-hydroxypropyl)amine in rats.

    PubMed

    Tsujiuchi, Toshifumi; Nakae, Dai; Konishi, Yoichi

    2014-03-01

    N-Nitrosobis(2-hydroxypropyl)amine (BHP) was first synthesized by Krüger et al. (1974), and has been shown to primarily induce pancreatic duct adenocarcinomas by a subcutaneous injection in Syrian hamsters. By contrast, the carcinogenic effect of BHP has been indicated at the different target organs in rats, namely the lung. When rats are received by an oral administration of BHP in drinking water for 25 weeks, a high incidence of lung carcinomas are induced, which include adenocarcinomas, squamous cell carcinomas and combined squamous cell and adenocarcinomas. So many similarities are observed in terms of not only histological appearances but also gene alterations between human and BHP-induced rat lung cancers. Moreover, the step by step development of lung lesions, from preneoplastic lesions to cancers in rat lung carcinogenesis by BHP offers a good model to investigate the mechanisms underlying the pathogenesis of lung cancers. Because data for genetic and epigenetic alterations have indeed been accumulated during the BHP-induced rat lung carcinogenesis, we will introduce them in this review and hence demonstrate that this lung carcinogenesis model provides a useful opportunity for the research on the pathogenesis of lung cancers of both humans and rats.

  5. Collaborative Development of 2-Hydroxypropyl-β-Cyclodextrin for the Treatment of Niemann-Pick Type C1 Disease

    PubMed Central

    Ottinger, Elizabeth A.; Kao, Mark L.; Carrillo-Carrasco, Nuria; Yanjanin, Nicole; Shankar, Roopa Kanakatti; Janssen, Marjo; Brewster, Marcus; Scott, Ilona; Xu, Xin; Cradock, Jim; Terse, Pramod; Dehdashti, Seameen; Marugan, Juan; Zheng, Wei; Portilla, Lili; Hubbs, Alan; Pavan, William J.; Heiss, John; Vite, Charles H.; Walkley, Steven U.; Ory, Daniel S.; Silber, Steven A.; Porter, Forbes D.; Austin, Christopher P.; McKew, John C.

    2014-01-01

    In 2010, the National Institutes of Health (NIH) established the Therapeutics for Rare and Neglected Diseases (TRND) program within the National Center for Advancing Translational Science (NCATS), which was created to stimulate drug discovery and development for rare and neglected tropical diseases through a collaborative model between the NIH, academic scientists, nonprofit organizations, and pharmaceutical and biotechnology companies. This paper describes one of the first TRND programs, the development of 2-hydroxypropyl-β-cyclodextrin (HP-β-CD) for the treatment of Niemann-Pick disease type C1 (NPC1). NPC is a neurodegenerative, autosomal recessive rare disease caused by a mutation in either the NPC1 (about 95% of cases) or the NPC2 gene (about 5% of cases). These mutations affect the intracellular trafficking of cholesterol and other lipids, which leads to a progressive accumulation of unesterified cholesterol and glycosphingolipids in the CNS and visceral organs. Affected individuals typically exhibit ataxia, swallowing problems, seizures, and progressive impairment of motor and intellectual function in early childhood, and usually die in adolescence. There is no disease modifying therapy currently approved for NPC1 in the US. A collaborative drug development program has been established between TRND, public and private partners that has completed the pre-clinical development of HP-β-CD through IND filing for the current Phase I clinical trial that is underway. Here we discuss how this collaborative effort helped to overcome scientific, clinical and financial challenges facing the development of new drug treatments for rare and neglected diseases, and how it will incentivize the commercialization of HP-β-CD for the benefit of the NPC patient community. PMID:24283970

  6. Enhancement of curcumin wound healing ability by complexation with 2-hydroxypropyl-γ-cyclodextrin in sacran hydrogel film.

    PubMed

    Wathoni, Nasrul; Motoyama, Keiichi; Higashi, Taishi; Okajima, Maiko; Kaneko, Tatsuo; Arima, Hidetoshi

    2017-05-01

    Curcumin is one of promising agents to accelerate the wound-healing process. However, the efficacy of curcumin is limited due to its poor water solubility and stability. To enhance the properties of curcumin, 2-hydroxypropyl-γ-cyclodextrin (HP-γ-CyD) can be used through complexation. Recently, we revealed that sacran has the potential to form a hydrogel film (HGF) as a wound dressing material. Therefore, in the present study, we investigated the wound healing ability of curcumin/HP-γ-CyD (Cur/HP-γ-CyD) complex in sacran-based HGF (Sac-HGF). We prepared the Cur/HP-γ-CyD complex in Sac-HGF without surface roughness. Additionally, the amorphous form in the Cur/HP-γ-CyD complex in Sac-HGF were observed. In contrast, the curcumin in Sac-HGF and curcumin/HP-γ-CyD physical mixture in Sac-HGF formed inhomogeneous films due to crystallization of curcumin. Furthermore, HP-γ-CyD played an important role to increase the elastic modulus of the Sac-HGF with high re-swelling ability. The Cur/HP-γ-CyD complex in Sac-HGF maintained antioxidant properties of curcumin. Curcumin was gradually released from the HP-γ-CyD complex in Sac-HGF. Notably, the Cur/HP-γ-CyD complex in Sac-HGF provided the highest wound healing ability in hairless mice. These results suggest that the Cur/HP-γ-CyD complex in Sac-HGF has the potential for use as a new transdermal therapeutic system to promote the wound-healing process.

  7. Collaborative development of 2-hydroxypropyl-β-cyclodextrin for the treatment of Niemann-Pick type C1 disease.

    PubMed

    Ottinger, Elizabeth A; Kao, Mark L; Carrillo-Carrasco, Nuria; Yanjanin, Nicole; Shankar, Roopa Kanakatti; Janssen, Marjo; Brewster, Marcus; Scott, Ilona; Xu, Xin; Cradock, Jim; Terse, Pramod; Dehdashti, Seameen J; Marugan, Juan; Zheng, Wei; Portilla, Lili; Hubbs, Alan; Pavan, William J; Heiss, John; Vite, Charles H; Walkley, Steven U; Ory, Daniel S; Silber, Steven A; Porter, Forbes D; Austin, Christopher P; McKew, John C

    2014-01-01

    In 2010, the National Institutes of Health (NIH) established the Therapeutics for Rare and Neglected Diseases (TRND) program within the National Center for Advancing Translational Sciences (NCATS), which was created to stimulate drug discovery and development for rare and neglected tropical diseases through a collaborative model between the NIH, academic scientists, nonprofit organizations, and pharmaceutical and biotechnology companies. This paper describes one of the first TRND programs, the development of 2-hydroxypropyl-β-cyclodextrin (HP-β-CD) for the treatment of Niemann-Pick disease type C1 (NPC1). NPC is a neurodegenerative, autosomal recessive rare disease caused by a mutation in either the NPC1 (about 95% of cases) or the NPC2 gene (about 5% of cases). These mutations affect the intracellular trafficking of cholesterol and other lipids, which leads to a progressive accumulation of unesterified cholesterol and glycosphingolipids in the CNS and visceral organs. Affected individuals typically exhibit ataxia, swallowing problems, seizures, and progressive impairment of motor and intellectual function in early childhood, and usually die in adolescence. There is no disease modifying therapy currently approved for NPC1 in the US. A collaborative drug development program has been established between TRND, public and private partners that has completed the pre-clinical development of HP-β-CD through IND filing for the current Phase I clinical trial that is underway. Here we discuss how this collaborative effort helped to overcome scientific, clinical and financial challenges facing the development of new drug treatments for rare and neglected diseases, and how it will incentivize the commercialization of HP-β-CD for the benefit of the NPC patient community.

  8. Direct administration of 2-Hydroxypropyl-Beta-Cyclodextrin into guinea pig cochleae: Effects on physiological and histological measurements.

    PubMed

    Lichtenhan, J T; Hirose, K; Buchman, C A; Duncan, R K; Salt, A N

    2017-01-01

    2-Hydroxypropyl-Beta-Cyclodextrin (HPβCD) can be used to treat Niemann-Pick type C disease, Alzheimer's disease, and atherosclerosis. But, a consequence is that HPβCD can cause hearing loss. HPβCD was recently found to be toxic to outer hair cells (OHCs) in the organ of Corti. Previous studies on the chronic effects of in vivo HPβCD toxicity did not know the intra-cochlear concentration of HPβCD and attributed variable effects on OHCs to indirect drug delivery to the cochlea. We studied the acute effects of known HPβCD concentrations administered directly into intact guinea pig cochleae. Our novel approach injected solutions through pipette sealed into scala tympani in the cochlear apex. Solutions were driven along the length of the cochlear spiral toward the cochlear aqueduct in the base. This method ensured that therapeutic levels were achieved throughout the cochlea, including those regions tuned to mid to low frequencies and code speech vowels and background noise. A wide variety of measurements were made. Results were compared to measurements from ears treated with the HPβCD analog methyl-β-cyclodextrin (MβCD), salicylate that is well known to attenuate the gain of the cochlear amplifier, and injection of artificial perilymph alone (controls). Histological data showed that OHCs appeared normal after treatment with a low dose of HPβCD, and physiological data was consistent with attenuation of cochlear amplifier gain and disruption of non-linearity associated with transferring acoustic sound into neural excitation, an origin of distortion products that are commonly used to objectively assess hearing and hearing loss. A high dose of HPβCD caused sporadic OHC losses and markedly affected all physiologic measurements. MβCD caused virulent destruction of OHCs and physiologic responses. Toxicity of HPβCD to OHC along the cochlear length is variable even when a known intra-cochlear concentration is administered, at least for the duration of our acute

  9. The interaction of radiation-generated radicals with myoglobin in aqueous solution—V. The indirect action of 2-methyl-2-hydroxypropyl radicals on oxymyoglobin

    NASA Astrophysics Data System (ADS)

    Whitburn, Kevin D.; Hoffman, Morton Z.

    The interaction of radiation-generated 2-methyl-2-hydroxypropyl radicals (derived from t-butyl alcohol) with oxymyoglobin has been examined at pH 7.3. In N 2O-saturated solutions, oxymyoglobin is converted to the ferri and ferryl derivatives of myoglobin; the production of ferrylmyoglobin is essentially eliminated when catalase is present in solution during irradiation. In deaerated solutions containing catalase, oxymyoglobin is converted to both ferro- and ferrimyoglobin during irradiation. When added O 2 is initially present, all compositional changes occur after irradiation; the presence of catalase diminishes, but does not eliminate, the extent of these postirradiation conversions of oxymyoglobin to the ferri and ferryl derivatives. These observations are interpreted in terms of the scavenging of the 2-methyl-2-hydroxypropyl radicals by O 2 to generate their peroxy analogs, which causes a displacement of the equilibrium between oxy- and ferromyoglobin. The peroxy radicals decay to produce H 2O 2, an organic peroxide, and other products. These peroxides subsequently react with ferromyoglobin to produce the ferryl form; the rate of the reaction increases with decreasing [O 2] as [ferromyoglobin] increases. This reaction is sufficiently fast in deaerated solution that substantial conversion of ferromyoglobin to ferrylmyoglobin occurs during the time of irradiation. The formation of the ferryl derivative in the presence of unconverted ferromyoglobin drives a concurrent synproportion reaction which produces ferrimyoglobin. Overall, no direct interaction of 2-methyl-2-hydroxypropyl radicals, nor their peroxy analogs, with myoglobin is indicated; all reactivity is accountable by the peroxide products of these radicals.

  10. Acrylates and Methacrylates,

    DTIC Science & Technology

    1987-09-15

    of ethylene and hydrocyanic acid through ethylene cyanohydrin. In the presence of basic catalysts ethylene oxide easily adds hydrocyanic acid with the...of synthesis of methacrylates. At present methacrylates are obtained in the industry by continuous method from acetone and hydrocyanic acid through...acetone cyanohydrin. The addition/connection to it of hydrocyanic acid with the formation of acetone cyanohydrin is one of the most important reactions

  11. Synthesis of a reactive polymethacrylate capillary monolith and its use as a starting material for the preparation of a stationary phase for hydrophilic interaction chromatography.

    PubMed

    Kip, Çiğdem; Erkakan, Damla; Gökaltun, Aslıhan; Çelebi, Bekir; Tuncel, Ali

    2015-05-29

    Poly(3-chloro-2-hydroxypropyl methacrylate-co-ethylene dimethacrylate), poly(HPMA-Cl-co-EDMA) capillary monolith was proposed as a reactive starting material with tailoring flexibility for the preparation of monolithic stationary phases. The reactive capillary monolith was synthesized by free radical copolymerization of 3-chloro-2-hydroxypropyl methacrylate (HPMA-Cl) and ethylene dimethacrylate (EDMA). The mean pore size, the specific surface area and the permeability of poly(HPMA-Cl-co-EDMA) monoliths were controlled by adjusting porogen/monomer volume ratio, porogen composition and polymerization temperature. The porogen/monomer volume ratio was found as the most effective factor controlling the porous properties of poly(HPMA-Cl-co-EDMA) monolith. Triethanolamine (TEA-OH) functionalized polymethacrylate monoliths were prepared by using the reactive chloropropyl group of poly(HPMA-Cl-co-EDMA) monolith via one-pot and simple post-functionalization process. Poly(HPMA-Cl-co-EDMA) monolith reacted with TEA-OH was evaluated as a stationary phase in nano-hydrophilic interaction chromatography (nano-HILIC). Nucleotides, nucleosides and benzoic acid derivatives were satisfactorily separated with the plate heights up to 20μm. TEA-OH attached-poly(HPMA-Cl-co-EDMA) monolith showed a reproducible and stable retention behaviour in nano-HILIC runs. However, a decrease in the column performance (i.e. an increase in the plate height) was observed with the increasing retention factor. Hence "retention-dependent column efficiency" behaviour was shown for HILIC mode using the chromatographic data collected with the polymer based monolith synthesized.

  12. Aggregation behavior of amphiphilic p(HPMA)-co-p(LMA) copolymers studied by FCS and EPR spectroscopy.

    PubMed

    Hemmelmann, Mirjam; Kurzbach, Dennis; Koynov, Kaloian; Hinderberger, Dariush; Zentel, Rudolf

    2012-12-10

    A combined study of fluorescence correlation spectroscopy and electron paramagnetic resonance spectroscopy gave a unique picture of p(HPMA)-co-p(LMA) copolymers in aqueous solutions, ranging from the size of micelles and aggregates to the composition of the interior of these self-assembled systems. P(HPMA)-co-p(LMA) copolymers have shown high potential as brain drug delivery systems, and a detailed study of their physicochemical properties can help to elucidate their mechanism of action. Applying two complementary techniques, we found that the self-assembly behavior as well as the strength of hydrophobic attraction of the amphiphilic copolymers can be tuned by the hydrophobic LMA content or the presence of hydrophobic molecules or domains. Studies on the dependence of the hydrophobic lauryl side chain content on the aggregation behavior revealed that above 5 mol % laury side-chain copolymers self-assemble into intrachain micelles and larger aggregates. Above this critical alkyl chain content, p(HPMA)-co-p(LMA) copolymers can solubilize the model drug domperidone and exhibit the tendency to interact with model cell membranes.

  13. Thermoforming polymethyl methacrylate.

    PubMed

    Jagger, R G; Okdeh, A

    1995-11-01

    This study characterized a range of commercially available polymethyl methacrylate sheets with respect to molecular weight, residual monomer content, and glass transition temperature and then developed a thermoforming procedure that produced visually satisfactory thermoformed polymethyl methacrylate specimens. Molecular weight values of Perspex material were considerably greater than those of the other materials. All materials but Diakon had residual monomer concentrations of less than 1% and glass transition temperature values greater than 100 degrees C. Perspex material was selected for further investigation. It was necessary to preheat Perspex sheets in an oven at 160 degrees C for at least 30 minutes before heating and forming on the thermoforming apparatus to obtain acceptable specimens.

  14. Synthesis and characterization of theranostic poly(HPMA)-c(RGDyK)-DOTA-64Cu copolymer targeting tumor angiogenesis: tumor localization visualized by positron emission tomography.

    PubMed

    Yuan, Jianchao; Zhang, Haiyuan; Kaur, Harpreet; Oupicky, David; Peng, Fangyu

    2013-05-01

    Poly(HPMA)-c(RGDyK)-DOTA-64Cu copolymers were synthesized and characterized for tumor localization in vivo as a theranostic scaffold for cancer imaging and anticancer drug delivery targeting tumor angiogenesis. Tumor localization of the poly(HPMA)-c(RGDyK)-DOTA-64Cu copolymers was visualized in mice bearing human prostate cancer xenografts by positron emission tomography (PET) using a microPET scanner. PET quantitative analysis demonstrated that tumor 64Cu radioactivity (2.75 ± 0.34 %ID/g) in tumor-bearing mice 3 hours following intravenous injection of the poly(HPMA)-c(RGDyK)-DOTA-64Cu copolymers was significantly higher than the tumor 64Cu radioactivity (1.29 ± 0.26 %ID/g) in tumor-bearing mice injected with the nontargeted poly(HPMA)-DOTA-64Cu copolymers (p = .004). The poly(HPMA)-c(RGDyK)-DOTA-64Cu copolymers hold potential as a theranostic scaffold for cancer imaging and radiochemotherapy of prostate cancer targeting tumor angiogenesis by noninvasive tracking with PET.

  15. Synthesis and Characterization of Biodegradable HPMA-Oligolysine Copolymers for Improved Gene Delivery

    PubMed Central

    Burke, Rob S.; Pun, Suzie H.

    2009-01-01

    Bioactive peptides, including DNA-binding, endosomal release and cell targeting peptides, have been integrated into synthetic gene carriers to improve delivery efficiencies by enabling the vectors to overcome barriers to gene delivery. Our overall goal is to develop multifunctional, peptide-based polymers that incorporate motifs to condense DNA and facilitate sequential trafficking steps. One approach is to polymerize vinyl-terminated peptides by radical polymerization. In this work, cationic oligolysine peptides were designed to contain vinyl termini with internal reducible linkers. These peptides were copolymerized with HPMA to form biodegradable, DNA-condensing copolymers for gene delivery. The polymerization conditions were optimized by varying the initiator to monomer ratios, macromonomer to comonomer ratios, and reactant concentrations. The synthesized copolymers were shown to possess several important properties required for in vivo gene delivery applications, including (i) efficient DNA binding and condensation, (ii) the ability to stabilize particles against salt-induced aggregation, (iii) the ability to resist extracellular polyplex unpackaging, (iv) biocompatibility and the potential to be degraded into nontoxic components after cellular uptake, and (v) efficient delivery of plasmid to cultured cells. PMID:19968270

  16. Resolution of diastereomers of N,N,N',N'-tetrakis(2-hydroxypropyl)ethylenediamine (quadrol) by reversed-phase high-performance liquid chromatography.

    PubMed

    Fulton, J A; Pokharna, H K; Dunphy, M J; Smith, D J

    1988-11-25

    Quadrol, N,N,N',N'-tetrakis(2-hydroxypropyl)ethylenediamine, has been recently observed to display biological activity. It is an immunostimulant and has been implicated as a potentially useful agent in accelerated wound healing. Quadrol exists as a mixture of four unique diastereomers, each of which may, upon further investigation, display differences in biological activity. This paper describes an high-performance liquid chromatographic procedure (both analytical and prep) for the separation of the Quadrol diastereomers. Gas-liquid chromatography and NMR data are presented which corroborate the high-performance liquid chromatographic results. This procedure may be used to obtain pure Quadrol diastereomers, to monitor the progress of Quadrol synthesis from propylene oxide and ethylenediamine or to develop a quantitative assay for Quadrol diastereomers.

  17. Cytoprotection of pancreatic β-cells and hypoglycemic effect of 2-hydroxypropyl-β-cyclodextrin: sertraline complex in alloxan-induced diabetic rats.

    PubMed

    Buko, Vyacheslav; Zavodnik, Ilya; Lukivskaya, Oxana; Naruta, Elena; Palecz, Bartlomiej; Belica-Pacha, Silwia; Belonovskaya, Elena; Kranc, Robert; Abakumov, Vladimir

    2016-01-25

    Sertraline, a selective inhibitor of serotonin reuptake, is widely used as antidepressant in diabetic patients for improvement of depression and glycemic control. Sertraline is poorly soluble in water, which limits its oral applicability. In this work we tried to improve the pharmaceutical properties of sertraline by complexation with 2-hydroxypropyl-β-cyclodextrin (HPβCD) and evaluated the efficacy of the HPβCD:sertraline complex in prevention of alloxan-induced lesions in rats. The solubility of sertraline increased in the presence of HPβCD and the association constant for sertraline and HPβCD was equal to 4000 ± 1000 M(-1). Two-week treatment of diabetic animals with the HPβCD:sertraline complex improved pancreatic islet morphology and β-cell survival, which, in turn, reduced the severity of diabetes, as evidenced by lowering of blood glucose and glycated hemoglobin contents as well as normalization of serum insulin level and insulin sensitivity (HOMA-IR). The effect of the HPβCD:sertraline complex was strongly expressed in comparison with the antidiabetic effect of both the monopreparations, HPβCD and sertraline. It is suggested that the cyclodextrin derivative increased the pharmacological effect of sertraline, probably due to enhanced drug bioavailability.

  18. BCM-95 and (2-hydroxypropyl)-β-cyclodextrin reverse autophagy dysfunction and deplete stored lipids in Sap C-deficient fibroblasts.

    PubMed

    Tatti, Massimo; Motta, Marialetizia; Scarpa, Susanna; Di Bartolomeo, Sabrina; Cianfanelli, Valentina; Tartaglia, Marco; Salvioli, Rosa

    2015-08-01

    Saposin (Sap) C deficiency is a rare variant form of Gaucher disease caused by impaired Sap C expression or accelerated degradation, and associated with accumulation of glucosylceramide and other lipids in the endo/lysosomal compartment. No effective therapies are currently available for the treatment of Sap C deficiency. We previously reported that a reduced amount and enzymatic activity of cathepsin (Cath) B and Cath D, and defective autophagy occur in Sap C-deficient fibroblasts. Here, we explored the use of two compounds, BCM-95, a curcumin derivative, and (2-hydroxypropyl)-β-cyclodextrin (HP-β-CD), to improve lysosomal function of Sap C-deficient fibroblasts. Immunofluorescence and biochemical studies documented that each compound promotes an increase of the expression levels and activities of Cath B and Cath D, and efficient clearance of cholesterol (Chol) and ceramide (Cer) in lysosomes. We provide evidence that BCM-95 and HP-β-CD enhance lysosomal function promoting autophagic clearance capacity and lysosome reformation. Our findings suggest a novel pharmacological approach to Sap C deficiency directed to treat major secondary pathological aspects in this disorder.

  19. Development of a competitive immunoassay for the determination of N-(2-hydroxypropyl)valine adducts in human haemoglobin and its application in biological monitoring.

    PubMed

    Ball, L; Jones, A; Boogaard, P; Will, W; Aston, P

    2005-01-01

    Propylene oxide (PO) is an important industrial compound and a directly acting mutagen. Human exposure to PO can be monitored by the determination of haemoglobin adducts. An immunoassay that quantifies the N-terminal adduct N-(2-hydroxypropyl)valine in whole haemoglobin was developed and its potential usefulness as a tool for biologically monitoring occupational exposure was demonstrated. Analytical reliability was confirmed in a comparative study with GC-MS (range 3.7-992 nmol g-1 haemoglobin (Hb), correlation coefficient 0.99, n=10). The assay has been configured as a competitive enzyme-linked immunosorbent assay to facilitate the rapid throughput of samples. The assay employs a whole blood matrix and has a working range of 2-250 pmol g-1 Hb. It does not appear to be affected by structurally similar metabolites and has been used to determine adducts in human blood samples. The first results in potentially exposed workers indicate the assay's high potential usefulness in routine occupational biomonitoring of exposure to PO.

  20. Efficacy of 2-Hydroxypropyl-β-cyclodextrin in Niemann-Pick Disease Type C Model Mice and Its Pharmacokinetic Analysis in a Patient with the Disease.

    PubMed

    Tanaka, Yuta; Yamada, Yusei; Ishitsuka, Yoichi; Matsuo, Muneaki; Shiraishi, Koki; Wada, Koki; Uchio, Yushiro; Kondo, Yuki; Takeo, Toru; Nakagata, Naomi; Higashi, Taishi; Motoyama, Keiichi; Arima, Hidetoshi; Mochinaga, Sakiko; Higaki, Katsumi; Ohno, Kousaku; Irie, Tetsumi

    2015-01-01

    Niemann-Pick type C disease (NPC), an autosomal recessive lysosomal storage disorder, is an inherited disease characterized by the accumulation of intracellular unesterified cholesterol. A solubilizing agent of lipophilic compounds, 2-hydroxypropyl-β-cyclodextrin (HPBCD), is an attractive drug candidate against NPC disease. However, establishment of the optimum dosage of HPBCD remains to be determined. In this study, we evaluated the effective dosage of HPBCD in NPC model (Npc1(-/-)) mice, and determined serum HPBCD concentrations. Subcutaneous injection of 1000-4000 mg/kg HPBCD improved the lifespan of Npc1(-/-) mice. In addition, liver injury and cholesterol sequestration were significantly prevented by 4000 mg/kg HPBCD in Npc1(-/-) mice. Serum HPBCD concentrations, when treated at the effective dosages (1000-4000 mg/kg), were approximately 1200-2500 µg/mL at 0.5 h after subcutaneous injection, and blood HPBCD concentrations were immediately eliminated in Npc1(-/-) mice. Furthermore, we examined serum HPBCD concentrations when treated at 40000 mg (approximately 2500 mg/kg) in a patient with NPC. We observed that the effective concentration in the in vivo study using Npc1(-/-) mice was similar to that in the patient. In the patient, systemic clearance and the volume of distribution of HPBCD were in accordance with the glomerular filtration rate and extracellular fluid volume, respectively. These results could provide useful information for developing the optimal dosage regimen for HPBCD therapy when administered intravenously to NPC patients.

  1. Nano-precipitated curcumin loaded particles: effect of carrier size and drug complexation with (2-hydroxypropyl)-β-cyclodextrin on their biological performances.

    PubMed

    Serri, Carla; Argirò, Mario; Piras, Linda; Mita, Damiano Gustavo; Saija, Antonina; Mita, Luigi; Forte, Maurizio; Giarra, Simona; Biondi, Marco; Crispi, Stefania; Mayol, Laura

    2017-03-30

    In this work, curcumin (CURC)-encapsulating nanoparticles (NPs), made up of an amphiphilic blend of poloxamers and PLGA (PPC NPs) at different polymer concentrations, were prepared by nanoprecipitation. CURC was preliminarily complexed with (2-hydroxypropyl)-β-cyclodextrin (HPβCD) to improve its loading efficiency. The formation of host-guest complexes of CURC with HPβCD (CD-CURC) was confirmed by means of (1)HNMR studies and differential scanning calorimetry (DSC). Nanoprecipitation allowed to obtain NPs with a small size (90-120nm depending on the polymer concentration), a narrow size distribution and stable in water for 30days at 4°C and in RPMI-1640 cell culture medium up to 72h at 37°C. The in vitro release of CD-CURC, sustained up to 5days, was governed mainly by a diffusive mechanism. It was also found that the produced NPs were efficiently internalized by mesothelioma cells (MSTO-211H) in the cytoplasmic space, at an extent strongly dependent on NP size and polydispesity index, therefore pointing at the importance of NP preparation method in improving their uptake.

  2. Acid-labile pHPMA modification of four-arm oligoaminoamide pDNA polyplexes balances shielding and gene transfer activity in vitro and in vivo.

    PubMed

    Beckert, Linda; Kostka, Libor; Kessel, Eva; Krhac Levacic, Ana; Kostkova, Hana; Etrych, Tomas; Lächelt, Ulrich; Wagner, Ernst

    2016-08-01

    We report novel pH-reversibly surface-shielded polyplexes with enhanced gene transfer activity upon systemic administration. A four-arm-structured sequence-defined cationic oligomer KK[HK[(H-Sph-K)3HC]2]2 was designed and synthesized on solid-phase, containing additional lysine residues not only for improved pDNA polyplex stability, but also providing attachment points for subsequent polyplex functionalization with amine-reactive shielding polymers. Herein, the surface of polyplexes was shielded with hydrophilic polymers, monovalent PEG or monovalent and multivalent pHPMA, optionally attached to the polyplex via the acid-labile linker AzMMMan. Overall, surface modification with PEG or pHPMA resulted in a decrease in the zeta potential of polyplexes, consistent with the degree of surface shielding. At pH 6.0, only polyplexes modified via the acid-labile linkage showed an increase in zeta potential, consistent with a "deshielding" in acidic environment, expected as beneficial for endosomal escape. Shielding was more efficient for multivalent pHPMA (20kDa, 30kDa) as compared to monovalent pHPMA (10kDa, 20kDa, 30kDa) or PEG (5kDa). In vitro transfection studies revealed higher gene expression by the polyplexes with the acid-labile shield as compared to their irreversibly shielded counterparts. Intravenous administration of AzMMMan-pHPMA modified polyplexes in an in vivo tumor mouse model mediated enhanced gene expression in the subcutaneous tumor and reduced undesirable expression in the liver.

  3. 32P-post-labelling of 7-(3-chloro-2-hydroxypropyl)guanine in white blood cells of workers occupationally exposed to epichlorohydrin.

    PubMed

    Plna, K; Osterman-Golkar, S; Nogradi, E; Segerbäck, D

    2000-02-01

    Epichlorohydrin (ECH) is a simple 3-carbon epoxide of industrial importance. It has been shown to be genotoxic in several systems and carcinogenic in experimental animals. The aim of the present investigation was to study DNA adducts of ECH as a biomarker of occupational exposure to this chemical. 7-(3-Chloro-2-hydroxypropyl)guanine (7-CHP-guanine) was analysed in DNA from white blood cells using an anion exchange-based adduct enrichment protocol of the (32)P-post-labelling/HPLC-based assay. Blood samples were collected from seven workers handling ECH (exposed), nine workers not handling ECH but normally present in the premises where this chemical is used (potentially exposed) and 13 office and factory workers from locations in the plant where ECH is not handled (controls). 7-CHP-guanine was detected in five of the seven workers exposed to ECH (1.6-7.1 mol/10(9) mol nucleotides) and in two of the nine workers potentially exposed to ECH (0.8-1.5 mol/10(9) mol nucleotides). This adduct was not detected in any of the 13 controls. The difference in adduct levels between exposed workers and controls was statistically significant (Mann-Whitney test, P < 0.001), as was the difference between exposed workers and potentially exposed workers (P = 0.017). The recovery of 7-CHP-guanine in the (32)P-post-labelling assay was on average 48 +/- 7%, which is considerably higher than previously reported for other 7-alkylguanines. The method used had a limit of detection of approximately 0.4 mol adduct/10(9) mol nucleotides using 20 microg DNA. This study shows for the first time ECH-induced DNA adducts in humans and suggests that 7-CHP-guanine may be used as a biomarker of occupational exposure to ECH.

  4. Structure-property relationship for in vitro siRNA delivery performance of cationic 2-hydroxypropyl-β-cyclodextrin: PEG-PPG-PEG polyrotaxane vectors.

    PubMed

    Badwaik, Vivek D; Aicart, Emilio; Mondjinou, Yawo A; Johnson, Merrell A; Bowman, Valorie D; Thompson, David H

    2016-04-01

    Nanoparticle-mediated siRNA delivery is a promising therapeutic approach, however, the processes required for transport of these materials across the numerous extracellular and intracellular barriers are poorly understood. Efficient delivery of siRNA-containing nanoparticles would ultimately benefit from an improved understanding of how parameters associated with these barriers relate to the physicochemical properties of the nanoparticle vectors. We report the synthesis of three Pluronic(®)-based, cholesterol end-capped cationic polyrotaxanes (PR(+)) threaded with 2-hydroxypropyl-β-cyclodextrin (HPβCD) for siRNA delivery. The biological data showed that PR(+):siRNA complexes were well tolerated (∼90% cell viability) and produced efficient silencing (>80%) in HeLa-GFP and NIH 3T3-GFP cell lines. We further used a multi-parametric approach to identify relationships between the PR(+) structure, PR(+):siRNA complex physical properties, and biological activity. Small angle X-ray scattering and cryoelectron microscopy studies reveal periodicity and lamellar architectures for PR(+):siRNA complexes, whereas the biological assays, ζ potential measurements, and imaging studies suggest that silencing efficiency is influenced by the effective charge ratio (ρeff), polypropylene oxide (PO) block length, and central PO block coverage (i.e., rigidity) of the PR(+) core. We infer from our findings that more compact PR(+):siRNA nanostructures arising from lower molecular weight, rigid rod-like PR(+) polymer cores produce improved silencing efficiency relative to higher molecular weight, more flexible PR(+) vectors of similar effective charge. This study demonstrates that PR(+):siRNA complex formulations can be produced having higher performance than Lipofectamine(®) 2000, while maintaining good cell viability and siRNA sequence protection in cell culture.

  5. The encapsulation of β-lapachone in 2-hydroxypropyl-β-cyclodextrin inclusion complex into liposomes: a physicochemical evaluation and molecular modeling approach.

    PubMed

    Cavalcanti, Isabella M F; Mendonça, Elisângela A M; Lira, Mariane C B; Honrato, Sara B; Camara, Celso A; Amorim, Rosa V S; Mendes Filho, Josué; Rabello, Marcelo M; Hernandes, Marcelo Z; Ayala, Alejandro P; Santos-Magalhães, Nereide S

    2011-10-09

    The aim of this study was to encapsulate lapachone (β-lap) or inclusion complex (β-lap:HPβ-CD) in liposomes and to evaluate their physicochemical characteristics. In addition, the investigation of the main aspects of the interaction between β-lap and 2-hydroxypropyl-β-cyclodextrin (HPβ-CD), using both experimental and molecular modeling approaches was discussed. Furthermore, the in vitro drug release kinetics was evaluated. First, a phase solubility study of β-lap in HPβ-CD was performed and the β-lap:HPβ-CD was prepared by the freeze-drying technique. A 302-fold increase of solubility was achieved for β-lap in HPβ-CD solution with a constant of association K(1:1) of 961 M(-1) and a complexation efficiency of β-lap of 0.1538. (1)H NMR, TG, DSC, IR, Raman and SEM indicated a change in the molecular environment of β-lap in the inclusion complex. Molecular modeling confirms these results suggesting that β-lap was included in the cavity of HPβ-CD, with an intermolecular interaction energy of -23.67 kJ mol(-1). β-lap:HPβ-CD and β-lap-loaded liposomes presented encapsulation efficiencies of 93% and 97%, respectively. The kinetic rate constants of 183.95±1.82 μg/h and 216.25±2.34 μg/h were calculated for β-lap and β-lap:HPβ-CD-loaded liposomes, respectively. In conclusion, molecular modeling elucidates the formation of the inclusion complex, stabilized through hydrogen bonds, and the encapsulation of β-lap and β-lap:HPβ-CD into liposomes could provide an alternative means leading eventually to its use in cancer research.

  6. Co-operative effects of thoracic X-ray irradiation and N-nitrosobis(2-hydroxypropyl) amine administration on lung tumorigenesis in neonatal, juvenile and adult Wistar rats.

    PubMed

    Iwata, Ken-ichi; Yamada, Yutaka; Nakata, Akifumi; Oghiso, Yoichi; Tani, Shusuke; Doi, Kazutaka; Morioka, Takamitsu; Blyth, Benjamin J; Nishimura, Mayumi; Kakinuma, Shizuko; Shimada, Yoshiya

    2013-03-15

    Assessment of risks associated with childhood exposure to ionizing radiation when combined with chemical carcinogens is of great importance. We studied the age-dependence of the effect of combined exposure to ionizing radiation (IR) and a chemical carcinogen on lung carcinogenesis. Female 1-, 5-, and 22-week-old Wistar rats were locally irradiated on the thorax with X-rays (3.18 Gy) and/or were injected intraperitoneally with N-nitrosobis(2-hydroxypropyl)amine (BHP) (1g/kg body weight) 1 week after X-ray exposure or at 23 weeks of age. Rats were terminated at 90 weeks of age. We found that: (i) the incidence of lung tumors (adenoma and adenocarcinoma) increased slightly as a function of age at X-ray exposure, although this was not statistically significant, while the incidence induced by BHP decreased with increasing age at administration; (ii) combined exposure to X-rays at 5 or 22 weeks with BHP 1 week later enhanced the tumor incidence, and the effect at early-life stage (5 weeks irradiation) was more effective than that at late-life stage (22 weeks irradiation); (iii) combined exposure preferentially enhanced malignant transformation; (iv) although a longer interval between the X-ray and BHP treatments reduced the combined effect, risks of early-life irradiation at 1 or 5 weeks of age lasted into adulthood; (v) adenomas and adenocarcinomas induced by X-ray and/or BHP originated from surfactant apoprotein A-positive alveolar type II cells; and (vi), extracellular signal-regulated kinase pathway activation was observed in half the adenocarcinomas, regardless of the exposure schedule. In conclusion, combined exposure may enhance lung tumorigenesis more synergistically at early-life stage (5 weeks of age) than later-life stage.

  7. Systemic administration of 2-hydroxypropyl-β-cyclodextrin to symptomatic Npc1-deficient mice slows cholesterol sequestration in the major organs and improves liver function.

    PubMed

    Lopez, Adam M; Terpack, Sandi J; Posey, Kenneth S; Liu, Benny; Ramirez, Charina M; Turley, Stephen D

    2014-10-01

    In Niemann-Pick type C (NPC) disease, loss-of-function mutations in either NPC1 or NPC2 result in progressive accumulation of unesterified cholesterol (UC) and glycosphingolipids in all organs, leading to neurodegeneration, pulmonary dysfunction and sometimes liver failure. There is no cure for this disorder. Studies using primarily NPC mouse models have shown that systemic administration of 2-hydroxypropyl-β-cyclodextrin (2HPβCD), starting in early neonatal life, diminishes UC accumulation in most organs, slows disease progression and extends lifespan. The key question now is whether delaying the start of 2HPβCD treatment until early adulthood, when the amount of entrapped UC throughout the body is markedly elevated, has any of the benefits found when treatment begins at 7 days of age. In the present study, Npc1(-/-) and Npc1(+/+) mice were given saline or 2HPβCD subcutaneously at 49, 56, 63 and 70 days of age, with measurements of organ weights, liver function tests and tissue cholesterol levels performed at 77 days. In Npc1(-/-) mice, treatment with 2HPβCD from 49 days reduced whole-liver cholesterol content at 77 days from 33.0 ± 1.0 to 9.1 ± 0.5 mg/organ. Comparable improvements were seen in other organs, such as the spleen, and in the animal as a whole. There was a transient increase in biliary cholesterol concentration in Npc1(-/-) mice after 2HPβCD. Plasma alanine aminotransferase and aspartate aminotransferase activities in 77-day-old 2HPβCD-treated Npc1(-/-) mice were reduced compared with saline-treated controls. The lifespan of Npc1(-/-) mice given 2HPβCD marginally exceeded that of the saline-treated controls (99 ± 1.1 vs 94 ± 1.4 days, respectively; P < 0.05). Thus, 2HPβCD is effective in mobilizing entrapped cholesterol in late-stage NPC disease leading to improved liver function.

  8. 78 FR 55644 - Styrene, Copolymers with Acrylic Acid and/or Methacrylic Acid; Tolerance Exemption

    Federal Register 2010, 2011, 2012, 2013, 2014

    2013-09-11

    ... methacrylate, hydroxypropyl acrylate, hydroxyethyl methacrylate, and/or hydroxyethyl acrylate; and its sodium... methacrylate, hydroxypropyl acrylate, hydroxyethyl methacrylate, and/or hydroxyethyl acrylate; and its sodium... methacrylate, hydroxypropyl acrylate, hydroxyethyl methacrylate, and/or hydroxyethyl acrylate, and its...

  9. Thermomechanical behavior of amorphous tactic methacrylate polymers

    NASA Technical Reports Server (NTRS)

    Kiran, E.; Gillham, J. K.; Gipstein, E.

    1974-01-01

    Dynamic mechanical spectra of amorphous stereoregular poly(methyl methacrylate)s and poly(t-butyl methacrylate)s with assigned microtacticities are presented and discussed. An intermolecular argument is invoked to account for the higher glass transition temperature of syndiotactic vis a vis isotactic PMMA, in spite of the higher density of the latter at 30 C. An argument is presented to show that the ratio of glassy-region relaxation temperature to glass transition temperature is not only a measure of the degree of coupling of the beta and glass transition processes, but also of the degree to which intermolecular factors influence these processes. The greater extent of the low-temperature irreversibilities observed in the thermomechanical spectra of poly(t-butyl methacrylate)s is attributed to the brittle character induced by the bulky side groups which presumably weaken cohesive forces.

  10. 40 CFR 721.10153 - Modified methyl methacrylate, 2-hydroxyethyl methacrylate polymer (generic).

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ...-hydroxyethyl methacrylate polymer (generic). 721.10153 Section 721.10153 Protection of Environment...-hydroxyethyl methacrylate polymer (generic). (a) Chemical substance and significant new uses subject to... methacrylate polymer (PMN P-08-6) is subject to reporting under this section for the significant new...

  11. 40 CFR 721.10153 - Modified methyl methacrylate, 2-hydroxyethyl methacrylate polymer (generic).

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ...-hydroxyethyl methacrylate polymer (generic). 721.10153 Section 721.10153 Protection of Environment...-hydroxyethyl methacrylate polymer (generic). (a) Chemical substance and significant new uses subject to... methacrylate polymer (PMN P-08-6) is subject to reporting under this section for the significant new...

  12. 40 CFR 721.9492 - Polymers of styrene, cyclohexyl methacrylate and substituted methacrylate.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... 40 Protection of Environment 31 2014-07-01 2014-07-01 false Polymers of styrene, cyclohexyl... Significant New Uses for Specific Chemical Substances § 721.9492 Polymers of styrene, cyclohexyl methacrylate... generically as polymers of styrene, cyclohexyl methacrylate and substituted methacrylate (PMNs...

  13. 40 CFR 721.10153 - Modified methyl methacrylate, 2-hydroxyethyl methacrylate polymer (generic).

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ...-hydroxyethyl methacrylate polymer (generic). 721.10153 Section 721.10153 Protection of Environment...-hydroxyethyl methacrylate polymer (generic). (a) Chemical substance and significant new uses subject to... methacrylate polymer (PMN P-08-6) is subject to reporting under this section for the significant new...

  14. 40 CFR 721.10153 - Modified methyl methacrylate, 2-hydroxyethyl methacrylate polymer (generic).

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ...-hydroxyethyl methacrylate polymer (generic). 721.10153 Section 721.10153 Protection of Environment...-hydroxyethyl methacrylate polymer (generic). (a) Chemical substance and significant new uses subject to... methacrylate polymer (PMN P-08-6) is subject to reporting under this section for the significant new...

  15. 40 CFR 721.10153 - Modified methyl methacrylate, 2-hydroxyethyl methacrylate polymer (generic).

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ...-hydroxyethyl methacrylate polymer (generic). 721.10153 Section 721.10153 Protection of Environment...-hydroxyethyl methacrylate polymer (generic). (a) Chemical substance and significant new uses subject to... methacrylate polymer (PMN P-08-6) is subject to reporting under this section for the significant new...

  16. Synergistic effect of EMF-BEMER-type pulsed weak electromagnetic field and HPMA-bound doxorubicin on mouse EL4 T-cell lymphoma.

    PubMed

    Říhová, Blanka; Etrych, Tomáš; Šírová, Milada; Tomala, Jakub; Ulbrich, Karel; Kovář, Marek

    2011-12-01

    We have investigated the effects of low-frequency pulsed electromagnetic field (LF-EMF) produced by BEMER device on experimental mouse T-cell lymphoma EL4 growing on conventional and/or athymic (nude) mice. Exposure to EMF-BEMER slowed down the growth of tumor mass and prolonged the survival of experimental animals. The effect was more pronounced in immuno-compromised nude mice compared to conventional ones. Acceleration of tumor growth was never observed. No measurable levels of Hsp 70 or increased levels of specific anti-EL4 antibodies were detected in the serum taken from experimental mice before and at different intervals during the experiment, i.e. before solid tumor appeared, at the time of its aggressive growth, and at the terminal stage of the disease. A significant synergizing antitumor effect was seen when EL4 tumor-bearing mice were simultaneously exposed to EMF-BEMER and treated with suboptimal dose of synthetic HPMA copolymer-based doxorubicin, DOX(HYD)-HPMA. Such a combination may be especially useful for heavily treated patients suffering from advanced tumor and requiring additional aggressive chemotherapy which, however, at that time could represent almost life-threatening way of medication.

  17. UV-Curable Polyurethane-Methacrylate Co-Networks and Interpenetrating Networks

    DTIC Science & Technology

    1989-05-30

    were: methyl methacrylate (MMA), ethyl methacrylate (EMA), hydroxyethyl methacrylate ( HEMA ), butyl methacrylate (BMA), lauryl methacrylate (LMA), and...ACCESSION NO. 11. TITLE (include Security Classification) UV’V-Curable Polyurethane- Methacrylate Co-Networks and Interpenetrating Networks 12. PERSONAL...by block number 4 Castor oil was reacted in varying ratios with 6-isocyanatoethyl methacrylate to form a liquid urethane- methacrylate prepolymer. This

  18. Exposure to volatile methacrylates in dental personnel.

    PubMed

    Hagberg, Stig; Ljungkvist, Göran; Andreasson, Harriet; Karlsson, Stig; Barregård, Lars

    2005-06-01

    Dental personnel are exposed to acrylates due to the acrylic resin-based composites and bonding agents used in fillings. It is well known that these compounds can cause contact allergy in dental personnel. However, in the 1990s, reports emerged on asthma also caused by methacrylates. The main volatile acrylates in dentistry are 2-hydroxyethyl methacrylate and methyl methacrylate. The aim of this study was to quantify the exposure to these acrylates in Swedish dental personnel. We studied the exposure to 2-hydroxyethyl methacrylate and methyl methacrylate in five randomly selected public dental clinics and at the Faculty of Odontology at Göteborg University. In total, 21 whole-day and 46 task-specific short-term (1-18 min) measurements were performed. The median 8-hour time-weighted averages were 2.5 microg/m3 (dentists) and 2.9 microg/m3 (dental nurses) for 2-hydroxyethyl methacrylate, and 0.8 microg/m3 (dentists) and 0.3 microg/m3 (dental nurses) for methyl methacrylate. The maximum short-term exposure levels were 79 microg/m3 for 2-hydroxyethyl methacrylate and 15 microg/m3 for methyl methacrylate, similar in dentists and dental nurses. The observed levels are much lower than in complete denture fabrication. We found only one previous study in dentistry and it showed similar results (though it reported short-term measurements only). Irritant effects would not be expected in healthy people at these levels. Nevertheless, occupational respiratory diseases due to methacrylates may occur in dental personnel, and improvements in the handling of these chemicals in dentistry are warranted. This includes better vials for the bonding agents and avoiding evaporation from discarded materials.

  19. 21 CFR 172.775 - Methacrylic acid-divinylbenzene copolymer.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ... 21 Food and Drugs 3 2014-04-01 2014-04-01 false Methacrylic acid-divinylbenzene copolymer. 172.775... Additives § 172.775 Methacrylic acid-divinylbenzene copolymer. Methacrylic acid-divinylbenzene copolymer may... produced by the polymerization of methacrylic acid and divinylbenzene. The divinylbenzene functions as...

  20. Methacrylated glycol chitosan as a photopolymerizable biomaterial.

    PubMed

    Amsden, Brian G; Sukarto, Abby; Knight, Darryl K; Shapka, Stephen N

    2007-12-01

    Glycol chitosan is a derivative of chitosan that is soluble at neutral pH and possesses potentially useful biological properties. With the goal of obtaining biocompatible hydrogels for use as tissue engineering scaffolds or drug delivery depots, glycol chitosan was converted to a photopolymerizable prepolymer through graft methacrylation using glycidyl methacrylate in aqueous media at pH 9. N-Methacrylation was verified by both (1)H NMR and (13)C NMR. The degree of N-methacrylation, measured via (1)H NMR, was easily varied from 1.5% to approximately 25% by varying the molar ratio of glycidyl methacrylate to glycol chitosan and the reaction time. Using a chondrocyte cell line, the N-methacrylated glycol chitosan was found to be noncytotoxic up to a concentration of 1 mg/mL. The prepolymer was cross-linked in solution using UV light and Irgacure 2959 photoinitiator under various conditions to yield gels of low sol content ( approximately 5%), high equilibrium water content (85-95%), and thicknesses of up to 6 mm. Cross-polarization magic-angle spinning (13)C solid state NMR verified the complete conversion of the double bonds in the gel. Chondrocytes seeded directly onto the gel surface, populated the entirety of the gel and remained viable for up to one week. The hydrogels degraded slowly in vitro in the presence of lysozyme at a rate that increased as the cross-link density of the gels decreased.

  1. 40 CFR 721.9492 - Polymers of styrene, cyclohexyl methacrylate and substituted methacrylate.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... 40 Protection of Environment 31 2011-07-01 2011-07-01 false Polymers of styrene, cyclohexyl... Significant New Uses for Specific Chemical Substances § 721.9492 Polymers of styrene, cyclohexyl methacrylate...) The chemical substances identified generically as polymers of styrene, cyclohexyl methacrylate...

  2. 40 CFR 721.9492 - Polymers of styrene, cyclohexyl methacrylate and substituted methacrylate.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... 40 Protection of Environment 32 2013-07-01 2013-07-01 false Polymers of styrene, cyclohexyl... Significant New Uses for Specific Chemical Substances § 721.9492 Polymers of styrene, cyclohexyl methacrylate...) The chemical substances identified generically as polymers of styrene, cyclohexyl methacrylate...

  3. 40 CFR 721.9492 - Polymers of styrene, cyclohexyl methacrylate and substituted methacrylate.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 40 Protection of Environment 30 2010-07-01 2010-07-01 false Polymers of styrene, cyclohexyl... Significant New Uses for Specific Chemical Substances § 721.9492 Polymers of styrene, cyclohexyl methacrylate...) The chemical substances identified generically as polymers of styrene, cyclohexyl methacrylate...

  4. 40 CFR 721.9492 - Polymers of styrene, cyclohexyl methacrylate and substituted methacrylate.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... 40 Protection of Environment 32 2012-07-01 2012-07-01 false Polymers of styrene, cyclohexyl... Significant New Uses for Specific Chemical Substances § 721.9492 Polymers of styrene, cyclohexyl methacrylate...) The chemical substances identified generically as polymers of styrene, cyclohexyl methacrylate...

  5. Effects of sulfamethoxazole-trimethoprim associated to resveratrol on its free form and complexed with 2-hydroxypropyl-β-cyclodextrin on cytokines levels of mice infected by Toxoplasma gondii.

    PubMed

    Bottari, Nathieli B; Baldissera, Matheus D; Tonin, Alexandre A; Rech, Virginia C; Nishihira, Vivian S K; Thomé, Gustavo R; Camillo, Giovana; Vogel, Fernanda F; Duarte, Marta M M F; Schetinger, Maria Rosa C; Morsch, Vera M; Tochetto, Camila; Fighera, Rafael; Da Silva, Aleksandro S

    2015-10-01

    The aim of this study was to investigate the effects of resveratrol on its free form and complexed with 2-hydroxypropyl-β-cyclodextrin (HPβCD) when associated with sulfamethoxazole-trimethoprim (ST) on cytokines levels of mice (n = 60) experimentally infected by Toxoplasma gondii. Groups A and E were used as controls (untreated): negative and positive, respectively. The onset of treatment started 20 days post-infection (PI), and it lasted for 10 consecutive days. ST was administered orally in doses of 0.5 mg kg(-1) for groups B and F, while 100 mg kg(-1) was the dose for resveratrol in its free form (groups C - G), inclusion complex (groups D and H), and on free and inclusion complex together (groups I - J). On day 31 PI, blood samples were collected in order to evaluate the cytokine profile. The mice that received drug combination (I and J) showed a significant (P < 0.05) reduction in the number of cysts in the brain compared to other infected groups (E - H). The results showed that mice from the Group E had increased (P < 0.001) levels of pro-inflammatory cytokines, while IL-10 levels were reduced when compared to the Group A. Additionally, there were increased levels of IL-4 and IFN-γ in animals of groups C and D, respectively (P < 0.05). Animals of the Group B showed reduced levels of IL-1, IL-4, IL-6, TNF-α, and IFN-γ (P < 0.05). Mice infected and treated (groups F - J) showed increased levels of pro-inflammatory cytokines along with a reduction of IL-10. Treatment with the combination of drugs (the Group J) led to a protective effect, i.e. reduction in pro-inflammatory cytokines. Therefore, resveratrol associated with ST was able to modulate seric cytokine profile and moderate the tissue inflammatory process caused by T. gondii infection, as well as to reduce parasite multiplication.

  6. Quantification of N-(3-chloro-2-hydroxypropyl)valine in human haemoglobin as a biomarker of epichlorohydrin exposure by gas chromatography-tandem mass spectrometry with stable-isotope dilution.

    PubMed

    Bader, Michael; Rosenberger, Wolfgang; Gutzki, Frank-Mathias; Tsikas, Dimitrios

    2009-05-01

    Epichlorohydrin (ECH) is an important industrial intermediate for the production of polymers and surface coatings. Animal experiments support the classification of ECH as a carcinogen, and a significant contribution to the cancer risk of ECH exposed humans has to be considered. Upon uptake, epichlorohydrin reacts with nucleophilic moieties of N- and S-containing macromolecules to form stable adducts, e.g. with haemoglobin. In this article, we describe a GC-tandem MS method for the quantitative analysis of the primary ECH adduct to the N-terminal amino acid of human haemoglobin, i.e. of N-(3-chloro-2-hydroxypropyl)valine (CHPV), using a globin labelled with d(5)-ECH as the internal standard. Incubation of erythrocyte lysate from human blood with ECH or d(5)-ECH yielded two reaction products, with CHPV being the major component. The GC-tandem MS method is based on a modified Edman degradation procedure with subsequent O-acetylation. The limits of detection and quantification of this method are 10 and 25 pmol/g globin, respectively. Intra- and inter-assay imprecision of the method was about 12 and 15%, respectively, and the mean recovery was 105 and 96% at the levels of 25 and 100 pmol of CHPV per g globin, respectively. The present study reports for the first time on the analysis of CHPV as a haemoglobin adduct of ECH using GC-tandem MS and a stable-isotope labelled internal standard. By this method we quantified haemoglobin adducts of ECH in the blood of subjects potentially exposed to ECH after a freight train accident. Our study points to CHPV in human haemoglobin as a possible biomarker for epichlorohydrin exposure.

  7. 21 CFR 882.5300 - Methyl methacrylate for cranioplasty.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... methacrylate for cranioplasty. (a) Identification. Methyl methacrylate for cranioplasty (skull repair) is a self-curing acrylic that a surgeon uses to repair a skull defect in a patient. At the time of...

  8. 21 CFR 882.5300 - Methyl methacrylate for cranioplasty.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... methacrylate for cranioplasty. (a) Identification. Methyl methacrylate for cranioplasty (skull repair) is a self-curing acrylic that a surgeon uses to repair a skull defect in a patient. At the time of...

  9. 21 CFR 882.5300 - Methyl methacrylate for cranioplasty.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ... methacrylate for cranioplasty. (a) Identification. Methyl methacrylate for cranioplasty (skull repair) is a self-curing acrylic that a surgeon uses to repair a skull defect in a patient. At the time of...

  10. 21 CFR 882.5300 - Methyl methacrylate for cranioplasty.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ... methacrylate for cranioplasty. (a) Identification. Methyl methacrylate for cranioplasty (skull repair) is a self-curing acrylic that a surgeon uses to repair a skull defect in a patient. At the time of...

  11. 21 CFR 882.5300 - Methyl methacrylate for cranioplasty.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ... methacrylate for cranioplasty. (a) Identification. Methyl methacrylate for cranioplasty (skull repair) is a self-curing acrylic that a surgeon uses to repair a skull defect in a patient. At the time of...

  12. Incorporating Diblock Copolymer Nanoparticles into Calcite Crystals: Do Anionic Carboxylate Groups Alone Ensure Efficient Occlusion?

    PubMed Central

    2016-01-01

    New spherical diblock copolymer nanoparticles were synthesized via RAFT aqueous dispersion polymerization of 2-hydroxypropyl methacrylate (HPMA) at 70 °C and 20% w/w solids using either poly(carboxybetaine methacrylate) or poly(proline methacrylate) as the steric stabilizer block. Both of these stabilizers contain carboxylic acid groups, but poly(proline methacrylate) is anionic above pH 9.2, whereas poly(carboxybetaine methacrylate) has zwitterionic character at this pH. When calcite crystals are grown at an initial pH of 9.5 in the presence of these two types of nanoparticles, it is found that the anionic poly(proline methacrylate)-stabilized particles are occluded uniformly throughout the crystals (up to 6.8% by mass, 14.0% by volume). In contrast, the zwitterionic poly(carboxybetaine methacrylate)-stabilized particles show no signs of occlusion into calcite crystals grown under identical conditions. The presence of carboxylic acid groups alone therefore does not guarantee efficient occlusion: overall anionic character is an additional prerequisite. PMID:27042383

  13. Gene silencing activity of siRNA polyplexes based on biodegradable polymers.

    PubMed

    Varkouhi, Amir K; Lammers, Twan; Schiffelers, Raymond M; van Steenbergen, Mies J; Hennink, Wim E; Storm, Gert

    2011-04-01

    Cationic polymers are used as non-viral vectors for nucleic acid delivery. In this study, two biodegradable cationic polymers were evaluated for the purpose of siRNA delivery: pHPMA-MPPM (poly((2-hydroxypropyl) methacrylamide 1-methyl-2-piperidine methanol)) and TMC (O-methyl-free N,N,N-trimethylated chitosan). The silencing activity and the cellular cytotoxicity of polyplexes based on these biodegradable polymers were compared with those based on non-biodegradable pDMAEMA (poly(2-dimethylamino)ethyl methacrylate) and PEI (polyethylenimine) and with the regularly used lipidic transfection agent Lipofectamine. To promote endosomal escape, either the endosomolytic peptide diINF-7 was added to the formulations or photochemical internalization (PCI) was applied. Incubation of H1299 human lung cancer cells expressing firefly luciferase with polyplexes based on pHPMA-MPPM and TMC showed 30-40% silencing efficiency. This silencing activity was equal to or better than that obtained with the standard transfectants. Under all experimental conditions tested, the cytotoxicity of the biodegradable polymers was low. The application of PCI, as well as the addition of the diINF-7 peptide to the formulations increased their silencing activity up to 70-80%. This demonstrates that pHPMA-MPPM- and TMC-based polyplexes benefit substantially from endosomal escape enhancement. Importantly, the polyplexes retained their silencing activity in the presence of serum, and they showed low cytotoxicity. These biodegradable vectors are therefore attractive systems for further in vivo evaluations.

  14. Targetable Polymer-Antiangiogenic Drug Conjugates for Systemic Breast Cancer Therapy

    DTIC Science & Technology

    2006-09-01

    hydroxypropyl )methacrylamide (HPMA) copolymer-TNP-470 conjugates with and without the targeting moiety (RGD4C) in the side chains. 2) To evaluate the...GG-RGD4C) 90 10 0 0.6 0.24 - 38.1 1.4 P4 HPMA-GFLGG-Fu 95 0 5 - - 0.24 83.5 1.7 Legends: HPMA= N-(2- hydroxypropyl ) methacrylamide, G=Glycine, F

  15. pH-sensitive methacrylic copolymers and the production thereof

    SciTech Connect

    Mallapragada, Surya K.; Anderson, Brian C.; Bloom, Paul D.; Sheares Ashby, Valerie V.

    2007-01-09

    The present invention provides novel multi-functional methacrylic copolymers that exhibit cationic pH-sensitive behavior as well as good water solubility under acidic conditions. The copolymers are constructed from tertiary amine methacrylates and poly(ethylene glycol) containing methacrylates. The copolymers are useful as gene vectors, pharmaceutical carriers, and in protein separation applications.

  16. pH-sensitive methacrylic copolymers and the production thereof

    DOEpatents

    Mallapragada, Surya K.; Anderson, Brian C.; Bloom, Paul D.; Sheares Ashby, Valerie V.

    2006-02-14

    The present invention provides novel multi-functional methacrylic copolymers that exhibit cationic pH-sensitive behavior as well as good water solubility under acidic conditions. The copolymers are constructed from tertiary amine methacrylates and poly(ethylene glycol) containing methacrylates. The copolymers are useful as gene vectors, pharmaceutical carriers, and in protein separation applications.

  17. 21 CFR 172.775 - Methacrylic acid-divinylbenzene copolymer.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... 21 Food and Drugs 3 2010-04-01 2009-04-01 true Methacrylic acid-divinylbenzene copolymer. 172.775... HUMAN CONSUMPTION Other Specific Usage Additives § 172.775 Methacrylic acid-divinylbenzene copolymer. Methacrylic acid-divinylbenzene copolymer may be safely used in food in accordance with the...

  18. 21 CFR 172.775 - Methacrylic acid-divinylbenzene copolymer.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ... 21 Food and Drugs 3 2012-04-01 2012-04-01 false Methacrylic acid-divinylbenzene copolymer. 172.775... HUMAN CONSUMPTION Other Specific Usage Additives § 172.775 Methacrylic acid-divinylbenzene copolymer. Methacrylic acid-divinylbenzene copolymer may be safely used in food in accordance with the...

  19. 21 CFR 172.775 - Methacrylic acid-divinylbenzene copolymer.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... 21 Food and Drugs 3 2011-04-01 2011-04-01 false Methacrylic acid-divinylbenzene copolymer. 172.775... HUMAN CONSUMPTION Other Specific Usage Additives § 172.775 Methacrylic acid-divinylbenzene copolymer. Methacrylic acid-divinylbenzene copolymer may be safely used in food in accordance with the...

  20. Solute solvent interaction in methyl methacrylate and 2-hydroxyethyl methacrylate monomers solutions

    NASA Astrophysics Data System (ADS)

    Al-ghamdi, Attieh A.; Bahattab, M. A.; Farhoud, M.; Al-Dossary, Mishal; Al-Enizi, Abdullah; Al-Deyab, S. S.

    2006-11-01

    Solute-solvent interactions are studied using induced birefringence measurements in monomers solutions of methyl methacrylate (MMA) and 2-hydroxyethyl methacrylate (HEMA), dissolved in ethanol, acetone, ethyl acetate, tetrahydrofuran and dimethyl sulfoxide, over a broad range of concentrations. The data are combined with refractive index and density to calculate the electric, optical and molar Kerr constants. All related microscopic parameters concerning the molecular structure such as nonlinear Kerr constants, anisotropic factors, and optical anisotropy have been calculated.

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

    PubMed

    Viljanen, Eeva K; Skrifvars, Mikael; Vallittu, Pekka K

    2005-01-01

    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.

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

    PubMed

    Chen, T; Kusy, R P

    1997-08-01

    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.

  3. A pre-formed methyl methacrylate cranioplasty.

    PubMed

    Cooper, P R; Schechter, B; Jacobs, G B; Rubin, R C; Wille, R L

    1977-09-01

    The use of a pre-formed methyl methacrylate cranioplasty prosthesis reinforced with stainless steel wire is described. The prosthesis is non-reactive, virtually unbreakable, and undentable. Pre-forming of the prosthesis in the dental laboratory using a mold of the patient's bony defect as a model saves considerable operating time, and when employed for a large cranial defect the three dimensional cosmetic effect is superior to intra-operatively fashioned prostheses.

  4. Reactivity of methacrylates in insertion polymerization.

    PubMed

    Rünzi, Thomas; Guironnet, Damien; Göttker-Schnetmann, Inigo; Mecking, Stefan

    2010-11-24

    Polymerization of ethylene by complexes [{(P^O)PdMe(L)}] (P^O = κ(2)-(P,O)-2-(2-MeOC(6)H(4))(2)PC(6)H(4)SO(3))) affords homopolyethylene free of any methyl methacrylate (MMA)-derived units, even in the presence of substantial concentrations of MMA. In stoichiometric studies, reactive {(P^O)Pd(Me)L} fragments generated by halide abstraction from [({(P^O)Pd(Me)Cl}μ-Na)(2)] insert MMA in a 1,2- as well as 2,1-mode. The 1,2-insertion product forms a stable five-membered chelate by coordination of the carbonyl group. Thermodynamic parameters for MMA insertion are ΔH(++) = 69.0(3.1) kJ mol(-1) and ΔS(++) = -103(10) J mol(-1) K(-1) (total average for 1,2- and 2,1-insertion), in comparison to ΔH(++) = 48.5(3.0) kJ mol(-1) and ΔS(++) = -138(7) J mol(-1) K(-1) for methyl acrylate (MA) insertion. These data agree with an observed at least 10(2)-fold preference for MA incorporation vs MMA incorporation (not detected) under polymerization conditions. Copolymerization of ethylene with a bifunctional acrylate-methacrylate monomer yields linear polyethylenes with intact methacrylate substituents. Post-polymerization modification of the latter was exemplified by free-radical thiol addition and by cross-metathesis.

  5. Dimensional accuracy of thermoformed polymethyl methacrylate.

    PubMed

    Jagger, R G

    1996-12-01

    Thermoforming of polymethyl methacrylate sheet is used to produce a number of different types of dental appliances. The purpose of this study was to determine the dimensional accuracy of thermoformed polymethyl methacrylate specimens. Five blanks of the acrylic resin were thermoformed on stone casts prepared from a silicone mold of a brass master die. The distances between index marks were measured both on the cast and on the thermoformed blanks with an optical comparator. Measurements on the blanks were made again 24 hours after processing and then 1 week, 1 month, and 3 months after immersion in water. Linear shrinkage of less than 1% (range 0.37% to 0.52%) was observed 24 hours after removal of the blanks from the cast. Immersion of the thermoformed specimens in water resulted in an increase in measured dimensions, but after 3 months' immersion these increases were still less than those of the cast (range 0.07% to 0.18%). It was concluded that it is possible to thermoform Perspex polymethyl methacrylate accurately.

  6. Immobilization of enzymes on 2-hydroxyethyl methacrylate and glycidyl methacrylate copolymer brushes.

    PubMed

    Ren, Tanchen; Mao, Zhengwei; Moya, Sergio Enrique; Gao, Changyou

    2014-08-01

    The immobilization of enzymes is of paramount importance to maintain their activity and stability. In this study, surface-initiated atom-transfer radical polymerization was applied to prepare poly(2-hydroxyethyl methacrylate)-block-poly(2-hydroxyethyl methacrylate-co-glycidyl methacrylate) brushes on glass slides. The polymerization kinetics was followed by using a quartz crystal microbalance with dissipation monitoring and ellipsometry in terms of mass and thickness growth, respectively. The surface chemical compositions of the obtained polymer brushes were characterized by X-ray photoelectron spectroscopy. Their mass, thickness, and enzyme-immobilization ability could be easily tuned by the initiator reaction time, monomer ratio, and polymerization time. The antibacterial activity and stability of the immobilized lysozymes were studied by fluorescent staining and bacteria lysis assay, which revealed that the lysozymes on the copolymer brushes had good stability during storage at 4 °C for up to 30 days.

  7. Allergic contact dermatitis from acrylic nails in a flamenco guitarist.

    PubMed

    Alcántara-Nicolás, F A; Pastor-Nieto, M A; Sánchez-Herreros, C; Pérez-Mesonero, R; Melgar-Molero, V; Ballano, A; De-Eusebio, E

    2016-12-01

    Acrylates are molecules that are well known for their strong sensitizing properties. Historically, many beauticians and individuals using store-bought artificial nail products have developed allergic contact dermatitis from acrylates. More recently, the use of acrylic nails among flamenco guitarists to strengthen their nails has become very popular. A 40-year-old non-atopic male patient working as a flamenco guitarist developed dystrophy, onycholysis and paronychia involving the first four nails of his right hand. The lesions were confined to the fingers where acrylic materials were used in order to strengthen his nails to play the guitar. He noticed improvement whenever he stopped using these materials and intense itching and worsening when he began reusing them. Patch tests were performed and positive results obtained with 2-hydroxyethyl methacrylate (2-HEMA), 2-hydroxyethyl acrylate (2-HEA), ethyleneglycol-dimethacrylate (EGDMA) and 2-hydroxypropyl methacrylate (2-HPMA). The patient was diagnosed with occupational allergic contact dermatitis likely caused by acrylic nails. Artificial nails can contain many kinds of acrylic monomers but most cases of contact dermatitis are induced by 2-HEMA, 2-HPMA and EGDMA. This is the first reported case of occupational allergic contact dermatitis from acrylates in artificial nails in a professional flamenco guitar player. Since the practice of self-applying acrylic nail products is becoming very popular within flamenco musicians, we believe that dermatology and occupational medicine specialists should be made aware of the potentially increasing risk of sensitization from acrylates in this setting.

  8. Multifunctional poly(alkyl methacrylate) films for dental care.

    PubMed

    Nielsen, Birthe V; Nevell, Thomas G; Barbu, Eugen; Smith, James R; Rees, Gareth D; Tsibouklis, John

    2011-02-01

    Towards the evaluation of non-permanent dental coatings for their capacity to impart dental-care benefits, thin films of a homologous series of comb-like poly(alkyl methacrylate)s (ethyl to octadecyl) have been deposited, from aqueous latex formulations, onto dentally relevant substrates. AFM studies have shown that the thickness (40-300 nm) and surface roughness (8-12 nm) of coherent polymer films are influenced by the degree of polymerization and by the length of the pendant chain. Of the polymers under consideration, poly(butyl methacrylate) formed a close-packed film that conferred to dental substrates a high degree of inhibition to acid-mediated erosion (about 27%), as evaluated by released-phosphate determinations. The potential utility of the coatings to act as anti-sensitivity barriers has been evaluated by determining the hydraulic conductance of coated bovine-dentine substrates; single treatments of dentine discs with poly(butyl methacrylate) or with poly(ethyl methacrylate) effected mean respective reductions in fluid flow of about 23% with respect to water-treated controls; repeated applications of the poly(butyl methacrylate) latex led to mean reductions in fluid flow of about 80%. Chromometric measurements have shown that pellicle-coated hydroxyapatite discs treated with poly(butyl methacrylate), poly(hexyl methacrylate) or poly(lauryl methacrylate) exhibit significant resistance to staining by food chromogens.

  9. On permeability of methyl methacrylate, 2-hydroxyethyl methacrylate and triethyleneglycol dimethacrylate through protective gloves in dentistry.

    PubMed

    Andreasson, Harriet; Boman, Anders; Johnsson, Stina; Karlsson, Stig; Barregård, Lars

    2003-12-01

    Continuous glove use is more common in dentistry than in most other occupations, and the glove should offer protection against blood-borne infections, skin irritants and contact allergens. Methacrylate monomers are potent contact allergens, and it is known that these substances may penetrate the glove materials commonly used. The aim of this study was to assess the permeability of various types of gloves to methyl methacrylate (MMA), 2-hydroxyethyl methacrylate (HEMA) and triethyleneglycol dimethacrylate (TEGDMA) with special reference to combinations with ethanol or acetone. The permeation rate and time lag breakthrough (lag-BT) for MMA (neat, or diluted to 30% in ethanol or acetone), HEMA (30% in water, ethanol, or acetone) and TEGDMA (30% in ethanol or acetone) were investigated for different protective gloves. Nine different types of gloves were tested for one or several of these methacrylates. The lag-BT for neat MMA was

  10. Zwitterionic Poly(amino acid methacrylate) Brushes

    PubMed Central

    2014-01-01

    A new cysteine-based methacrylic monomer (CysMA) was conveniently synthesized via selective thia-Michael addition of a commercially available methacrylate-acrylate precursor in aqueous solution without recourse to protecting group chemistry. Poly(cysteine methacrylate) (PCysMA) brushes were grown from the surface of silicon wafers by atom-transfer radical polymerization. Brush thicknesses of ca. 27 nm were achieved within 270 min at 20 °C. Each CysMA residue comprises a primary amine and a carboxylic acid. Surface zeta potential and atomic force microscopy (AFM) studies of the pH-responsive PCysMA brushes confirm that they are highly extended either below pH 2 or above pH 9.5, since they possess either cationic or anionic character, respectively. At intermediate pH, PCysMA brushes are zwitterionic. At physiological pH, they exhibit excellent resistance to biofouling and negligible cytotoxicity. PCysMA brushes undergo photodegradation: AFM topographical imaging indicates significant mass loss from the brush layer, while XPS studies confirm that exposure to UV radiation produces surface aldehyde sites that can be subsequently derivatized with amines. UV exposure using a photomask yielded sharp, well-defined micropatterned PCysMA brushes functionalized with aldehyde groups that enable conjugation to green fluorescent protein (GFP). Nanopatterned PCysMA brushes were obtained using interference lithography, and confocal microscopy again confirmed the selective conjugation of GFP. Finally, PCysMA undergoes complex base-catalyzed degradation in alkaline solution, leading to the elimination of several small molecules. However, good long-term chemical stability was observed when PCysMA brushes were immersed in aqueous solution at physiological pH. PMID:24884533

  11. Injectible bodily prosthetics employing methacrylic copolymer gels

    DOEpatents

    Mallapragada, Surya K.; Anderson, Brian C.

    2007-02-27

    The present invention provides novel block copolymers as structural supplements for injectible bodily prosthetics employed in medical or cosmetic procedures. The invention also includes the use of such block copolymers as nucleus pulposus replacement materials for the treatment of degenerative disc disorders and spinal injuries. The copolymers are constructed by polymerization of a tertiary amine methacrylate with either a (poly(ethylene oxide)-b-poly(propylene oxide)-b-poly(ethylene oxide) polymer, such as the commercially available Pluronic.RTM. polymers, or a poly(ethylene glycol) methyl ether polymer.

  12. Methacrylic resin having a high solar radiant energy absorbing property and process for producing the same

    SciTech Connect

    Abe, K.; Kamada, K.; Nakai, Y.

    1981-10-20

    A methacrylic resin having a high solar radiant energy absorbing property wherein an organic compound (A) containing cupric ion and a compound (B) having at least one p-o-h bond in a molecule are contained into the methacrylic resin selected from poly(Methyl methacrylate) or methacrylic polymers containing at least 50% by weight of a methyl methacrylate unit. A process for producing said methacrylic resin is also disclosed.

  13. DEGRADATION OF POLY(METHYL METHACRYLATE) IN SOLUTION

    EPA Science Inventory

    The rate of degradation of poly(methyl methacrylate) (PMMA) to methyl methacrylate (MMA) was investigated in the liquid phase with toluene as the solvent. The degradation experiments were carried out in a tubular flow reactor at 1000 psig (6.8 MPa) and at four different temperat...

  14. Isostructural dinuclear phenoxo-/acetato-bridged manganese(II), cobalt(II), and zinc(II) complexes with labile sites: kinetics of transesterification of 2-hydroxypropyl-p-nitrophenylphosphate.

    PubMed

    Arora, Himanshu; Barman, Suman K; Lloret, Francesc; Mukherjee, Rabindranath

    2012-05-21

    Using the dinucleating phenol-based ligand 2,6-bis[3-(pyridin-2-yl)pyrazol-1-ylmethyl]-4-methylphenol] (HL(2)), in its deprotonated form, the six new dinuclear complexes [M(II)(2)(L(2))(μ-O(2)CMe)(2)(MeCN)(2)][PF(6)] (M = Mn (2a), Co (3a), Zn (4a)) and [M(II)(2)(L(2))(μ-O(2)CMe)(2)(MeCN)(2)][BPh(4)] (M = Mn (2b), Co (3b), Zn (4b)) have been synthesized. Crystallographic analyses on 2b·2MeCN, 3b·2MeCN, and 4b·2MeCN reveal that these complexes have closely similar μ-phenoxo bis(μ-carboxylato) structures. The physicochemical properties (absorption and ESI-MS spectral data, 2a,b, 3a,b, and 4a,b; (1)H NMR, 4a,b) of the cations of 2a-4a are identical with those of 2b-4b. Each metal ion is terminally coordinated by a pyrazole nitrogen and a pyridyl nitrogen from a 3-(pyridin-2-yl)pyrazole unit and a solvent molecule (MeCN). Thus, each metal center assumes distorted-octahedral M(II)N(3)O(3) coordination. Temperature-dependent magnetic studies on Mn(II) and Co(II) dimers reveal the presence of intramolecular antiferromagnetic (J = -8.5 cm(-1)) for 2b and ferromagnetic exchange coupling (J = +2.51 cm(-1)) for 3b, on the basis of the Hamiltonian H = -JS(1)·S(2). The exchange mechanism is discussed on the basis of magneto-structural parameters (M···M distance). Spectroscopic properties of the complexes have also been investigated. The pH titration and kinetics of phosphatase (transesterification) activity on 2-hydroxypropyl-p-nirophenylphosphate (HPNP) were studied in MeOH/H(2)O (33%, v/v) with 2a-4a, due to solubility reasons. This comparative kinetic study revealed the effect of the metal ion on the rate of hydrolysis of HPNP, which has been compared with what we recently reported for [Ni(II)(2)(L(2))(μ-O(2)CMe)(2)(MeOH)(H(2)O)][ClO(4)] (1a). The efficacy in the order of conversion of substrate to product (p-nitrophenolate ion) follows the order 4a > 3a > 2a > 1a, under identical experimental conditions. Notably, this trend follows the decrease of pK(a) values of

  15. Uptake of isoprene, methacrylic acid and methyl methacrylate into aqueous solutions of sulfuric acid and hydrogen peroxide.

    PubMed

    Liu, Ze; Ge, Maofa; Wang, Weigang

    2012-01-01

    Multiphase acid-catalyzed oxidation by hydrogen peroxide has been suggested to be a potential route to secondary organic aerosol formation from isoprene and its gas-phase oxidation products, but the lack of kinetics data significantly limited the evaluation of this process in the atmosphere. Here we report the first measurement of the uptake of isoprene, methacrylic acid and methyl methacrylate into aqueous solutions of sulfuric acid and hydrogen peroxide. Isoprene cannot readily partition into the solution because of its high volatility and low solubility, which hinders its further liquid-phase oxidation. Both methacrylic acid and methyl methacrylate can enter the solutions and be oxidized by hydrogen peroxide, and steady-state uptake was observed with the acidity of solution above 30 wt.% and 70 wt.%, respectively. The steady-state uptake coefficient of methacrylic acid is much larger than that of methyl methacrylate for a solution with same acidity. These observations can be explained by the different reactivity of these two compounds caused by the different electron-withdrawing conjugation between carboxyl and ester groups. The atmospheric lifetimes were estimated based on the calculated steady-state uptake coefficients. These results demonstrate that the multiphase acid-catalyzed oxidation of methacrylic acid plays a role in secondary organic aerosol formation, but for isoprene and methyl methacrylate, this process is not important in the troposphere.

  16. Optimization of Brush-like Cationic Copolymers for Non-viral Gene Delivery

    PubMed Central

    Wei, Hua; Pahang, JoshuelA; Pun, Suzie H.

    2012-01-01

    Polyethylenimine (PEI) is one of the most broadly used polycations for gene delivery due to its high transfection efficiency and commercial availability but materials are cytotoxic and often polydisperse. The goal of current work is to develop an alternative family of polycations based on controlled living radical polymerization (CLRP) and to optimize the polymer structure for efficient gene delivery. In this study, well-defined poly(glycidyl methacrylate)(P(GMA)) homopolymers were synthesized using reversible addition fragmentation chain transfer (RAFT) polymerization followed by decoration using three different types of oligoamines, i.e., tetraethylenepentamine (TEPA), pentaethylenehexamine (PEHA), and tris(2-aminoethyl)amine (TREN), respectively, to generate various P(GMA-oligoamine) homopolycations. The effect of P(GMA) backbone length and structure of oligoamine on gene transfer efficiency was then determined. The optimal polymer, P(GMA-TEPA)50, provided comparable transfection efficiency but lower cytotoxicity than PEI. P(GMA-TEPA)50 was then used as the cationic block in di-block copolymers containing hydrophilic N-(2-hydroxypropyl) methacrylamide (HPMA) and oligo(ethylene glycol) monomethyl ether methacrylate (OEGMA). Polyplexes of block copolymers were stable against aggregation in physiological salt condition and in Opti-MEM due to the shielding effect of P(HPMA) and P(OEGMA). However, the presence of the HPMA/OEGMA block significantly decreased the transfection efficacy of P(GMA-TEPA)50homopolycation. To compensate for reduced cell uptake caused by the hydrophilic shell of polyplex, the integrin-binding peptide, RGD, was conjugated to the hydrophilic chain end of P(OEGMA)15-b-P(GMA-TEPA)50 copolymer by Michael-type addition reaction. At low polymer to DNA ratios, the RGD-functionalized polymer showed increased gene delivery efficiency to HeLa cells compared to analogous polymers lacking RGD. PMID:23240866

  17. A Robust Cross-Linking Strategy for Block Copolymer Worms Prepared via Polymerization-Induced Self-Assembly

    PubMed Central

    2016-01-01

    A poly(glycerol monomethacrylate) (PGMA) chain transfer agent is chain-extended by reversible addition–fragmentation chain transfer (RAFT) statistical copolymerization of 2-hydroxypropyl methacrylate (HPMA) with glycidyl methacrylate (GlyMA) in concentrated aqueous solution via polymerization-induced self-assembly (PISA). A series of five free-standing worm gels is prepared by fixing the overall degree of polymerization of the core-forming block at 144 while varying its GlyMA content from 0 to 20 mol %. 1H NMR kinetics indicated that GlyMA is consumed much faster than HPMA, producing a GlyMA-rich sequence close to the PGMA stabilizer block. Temperature-dependent oscillatory rheological studies indicate that increasing the GlyMA content leads to progressively less thermoresponsive worm gels, with no degelation on cooling being observed for worms containing 20 mol % GlyMA. The epoxy groups in the GlyMA residues can be ring-opened using 3-aminopropyltriethoxysilane (APTES) in order to prepare core cross-linked worms via hydrolysis-condensation with the siloxane groups and/or hydroxyl groups on the HPMA residues. Perhaps surprisingly, 1H NMR analysis indicates that the epoxy–amine reaction and the intermolecular cross-linking occur on similar time scales. Cross-linking leads to stiffer worm gels that do not undergo degelation upon cooling. Dynamic light scattering studies and TEM analyses conducted on linear worms exposed to either methanol (a good solvent for both blocks) or anionic surfactant result in immediate worm dissociation. In contrast, cross-linked worms remain intact under such conditions, provided that the worm cores comprise at least 10 mol % GlyMA. PMID:27134311

  18. Improvement of holographic thermal stability in phenanthrenequinone-doped poly(methyl methacrylate-co-methacrylic acid) photopolymer

    NASA Astrophysics Data System (ADS)

    Yu, Dan; Liu, Hongpeng; Wang, Heng; Wang, Jian; Jiang, Yongyuan; Sun, Xiudong

    2011-08-01

    Experimental studies of holographic thermal stability in phenanthrenequinone (PQ)-doped poly(methyl methacrylate-co-methacrylic acid) [P(MMA-co-MAA)] photopolymers are presented. A possibility to improve the thermal stability of holograms is demonstrated by doping methacrylic acid (MAA) into the poly(methyl methacrylate) (PMMA) polymer matrix. MAA as a copolymerization monomer can form a more stable polymer matrix with methyl methacrylate (MMA) monomer and increase average molecular weight of photoproducts, which finally depress the diffusion of photoproduct. The optimized MAA concentration copolymerized into P(MMA-co-MAA) polymer matrix can bring nearly a month's lifetime of gratings, which is obviously an improvement over the usual PQ-PMMA material under thermal treatment.

  19. Studies on novel radiopaque methyl methacrylate: glycidyl methacrylate based polymer for biomedical applications.

    PubMed

    Dawlee, S; Jayakrishnan, A; Jayabalan, M

    2009-12-01

    A new class of radiopaque copolymer using methyl methacrylate (MMA) and glycidyl methacrylate (GMA) monomers was synthesized and characterized. The copolymer was made radiopaque by the epoxide ring opening of GMA using the catalyst o-phenylenediamine and the subsequent covalent attachment of elemental iodine. The copolymer was characterized by Fourier transform infrared (FTIR) spectra, energy dispersive X-ray analysis using environmental scanning electron microscope (EDAX), thermogravimetric analysis (TGA), and differential scanning calorimetry (DSC). X-ray visibility of the copolymer was checked by X-radiography. Blood compatibility and cytotoxicity of the newly synthesized copolymer were also evaluated. The iodinated copolymer was thermally stable, blood compatible, non-cytotoxic, and highly radiopaque. The presence of bulky iodine group created a new copolymer with modified properties for potential use in biomedical applications.

  20. Solid state dye lasers based on 2-hydroxyethyl methacrylate and methyl methacrylate co-polymers

    NASA Astrophysics Data System (ADS)

    Giffin, Shirin M.; McKinnie, Iain T.; Wadsworth, William J.; Woolhouse, Anthony D.; Smith, Gerald J.; Haskell, Tim G.

    1999-03-01

    The laser performance of a range of solid state dye lasers based on rhodamine 590-doped co-polymers of 2-hydroxyethyl methacrylate (HEMA) and methyl methacrylate (MMA) has been investigated. The optimisation of preparation conditions, including polymerisation initiator and solvent for dye delivery is discussed in detail. Laser efficiency is compared for different polymeric hosts and dye concentrations with a range of output couplers, cavity lengths and repetition rates. Passive and dynamic loss have been determined for each host medium. Laser efficiencies of optimised polymers are among the highest reported for rhodamine 590-doped solid state dye lasers under these operating conditions. Highest slope efficiency of 35% and lowest threshold fluence of 0.06 J cm -2 were obtained with dimethyl sulphoxide (DMSO) additive in MPMMA at 10 Hz repetition rate.

  1. Genotoxicity and cytotoxicity of 2-hydroxyethyl methacrylate.

    PubMed

    Pawlowska, Elzbieta; Poplawski, Tomasz; Ksiazek, Dominika; Szczepanska, Joanna; Blasiak, Janusz

    2010-02-01

    Resin-based methacrylate materials are widely used in restorative dentistry. They are viscous substances that are converted into solid material via polymerization. This process, however, may be incomplete, leading to the release of monomers into the oral cavity and the pulp, which can be reached through the dentin micro-channels. This opens the opportunity for the monomers to reach the bloodstream. Monomers can reach concentrations in the millimolar range, high enough to cause cellular damage, so it is justified to study their potential toxic effects. In the present work we investigated the cytotoxicity and genotoxicity of 2-hydroxyethyl methacrylate (HEMA) in human peripheral blood lymphocytes and A549 lung-tumour cells. HEMA at concentrations up to 10mM neither affected the viability of the cells nor interacted with isolated plasmid DNA during a 1h exposure. However, HEMA induced concentration-dependent DNA damage in lymphocytes, as assessed by alkaline and pH 12.1 versions of the comet assay. HEMA did not cause double-strand breaks, as assessed by the neutral version of the comet assay and pulsed-field gel electrophoresis. The use of DNA repair enzymes, spin traps and vitamin C produced results suggesting that HEMA induced oxidative modifications to DNA bases. DNA damage caused by HEMA at 10mM was removed within 120min. HEMA induced apoptosis in a concentration-dependent manner and caused cell-cycle delay at the G0/G1-checkpoint. Methylglycol chitosan displayed a protective effect against the DNA-damaging action of HEMA. The results obtained in this study suggest that HEMA induces adverse biological effects, mainly via reactive oxygen species, which can lead to DNA damage, apoptosis and cell-cycle delay. Chitosan and its derivatives can be considered as additional components of dental restoration to decrease the harmful potency of HEMA.

  2. Biocompatible Bacterial Cellulose-Poly(2-hydroxyethyl methacrylate) Nanocomposite Films

    PubMed Central

    Figueiredo, Andrea G. P. R.; Figueiredo, Ana R. P.; Alonso-Varona, Ana; Fernandes, Susana C. M.; Palomares, Teodoro; Rubio-Azpeitia, Eva; Barros-Timmons, Ana; Silvestre, Armando J. D.; Pascoal Neto, Carlos; Freire, Carmen S. R.

    2013-01-01

    A series of bacterial cellulose-poly(2-hydroxyethyl methacrylate) nanocomposite films was prepared by in situ radical polymerization of 2-hydroxyethyl methacrylate (HEMA), using variable amounts of poly(ethylene glycol) diacrylate (PEGDA) as cross-linker. Thin films were obtained, and their physical, chemical, thermal, and mechanical properties were evaluated. The films showed improved translucency compared to BC and enhanced thermal stability and mechanical performance when compared to poly(2-hydroxyethyl methacrylate) (PHEMA). Finally, BC/PHEMA nanocomposites proved to be nontoxic to human adipose-derived mesenchymal stem cells (ADSCs) and thus are pointed as potential dry dressings for biomedical applications. PMID:24093101

  3. Biocompatible bacterial cellulose-poly(2-hydroxyethyl methacrylate) nanocomposite films.

    PubMed

    Figueiredo, Andrea G P R; Figueiredo, Ana R P; Alonso-Varona, Ana; Fernandes, Susana C M; Palomares, Teodoro; Rubio-Azpeitia, Eva; Barros-Timmons, Ana; Silvestre, Armando J D; Pascoal Neto, Carlos; Freire, Carmen S R

    2013-01-01

    A series of bacterial cellulose-poly(2-hydroxyethyl methacrylate) nanocomposite films was prepared by in situ radical polymerization of 2-hydroxyethyl methacrylate (HEMA), using variable amounts of poly(ethylene glycol) diacrylate (PEGDA) as cross-linker. Thin films were obtained, and their physical, chemical, thermal, and mechanical properties were evaluated. The films showed improved translucency compared to BC and enhanced thermal stability and mechanical performance when compared to poly(2-hydroxyethyl methacrylate) (PHEMA). Finally, BC/PHEMA nanocomposites proved to be nontoxic to human adipose-derived mesenchymal stem cells (ADSCs) and thus are pointed as potential dry dressings for biomedical applications.

  4. Quaternary ammonium poly(diethylaminoethyl methacrylate) possessing antimicrobial activity.

    PubMed

    Farah, Shady; Aviv, Oren; Laout, Natalia; Ratner, Stanislav; Beyth, Nurit; Domb, Abraham J

    2015-04-01

    Quaternary ammonium (QA) methacrylate monomers and polymers were synthesized from a N-alkylation of N,N-diethylaminoethyl methacrylate (DEAEM) monomer. Linear copolymers, and for the first time reported crosslinked nanoparticles (NPs), based QA-PDEAEM were prepared by radical polymerization of the quaternized QA-DEAEM monomers with either methyl methacrylate (MMA) or a divinyl monomer. QA-PDEAEM NPs of 50-70 nm were embedded in polyethylene vinyl acetate coating. QA-polymers with N-C8 and N-C18 alkyl chains and copolymers with methyl methacrylate were prepared at different molar ratios and examined for their antimicrobial effectiveness. These coatings exhibited strong antibacterial activity against four representative Gram-positive and Gram-negative bacteria.

  5. Methacrylate-based monolithic layers for planar chromatography of polymers.

    PubMed

    Maksimova, E F; Vlakh, E G; Tennikova, T B

    2011-04-29

    A series of macroporous monolithic methacrylate-based materials was synthesized by in situ free radical UV-initiated copolymerization of functional monomers, such as glycidyl methacrylate (GMA), butyl methacrylate (BuMA), 2-aminoethyl methacrylate (AEMA), 2-hydroxyethyl methacrylate (HEMA) and 2-cyanoethyl methacrylate (CEMA), with crosslinking agent, namely, ethylene glycol dimethacrylate (EDMA). The materials obtained were applied as the stationary phases in simple and robust technique - planar chromatography (PLC). The method of separation layer fabrication representing macroporous polymer monolith bound to the specially prepared glass surface was developed and optimized. The GMA-EDMA and BuMA-EDMA matrixes were successfully applied for the separation of low molecular weight compounds (the mixture of several dies), as well as poly(vinylpyrrolidone) and polystyrene homopolymers of different molecular weights using reversed-phase mechanism. The materials based on copolymers AEMA-HEMA-EDMA and CEMA-HEMA-EDMA were used for normal-phase PLC separation of 2,4-dinitrophenyl amino acids and polystyrene standards.

  6. Thermally Switchable Thin Films of an ABC Triblock Copolymer of Poly(n-butyl methacrylate)-poly(methyl methacrylate)-poly(2-fluoroethyl methacrylate)

    SciTech Connect

    Zhang, Shanju; Liu, Zhan; Bucknall, David G.; He, Lihong; Hong, Kunlun; Mays, Jimmy; Allen, Mark

    2011-01-01

    The thermo-responsive behavior of polymer films consisting of novel linear triblock copolymers of poly(n-butyl methacrylate)-poly(methyl methacrylate)-poly(2-fluoroethyl methacrylate) (PnBuMA-PMMA-P2FEMA) are reported using differential scanning calorimetry (DSC), atomic forcing microscopy (AFM), X-ray photoelectron spectroscopy (XPS) and contacting angle (CA) measurements. The surface morphology, wettability and chemical structure of thin films of these triblock copolymers on silicon wafers as a function of temperature have been investigated. It has been shown that the wettability of the films is thermally switchable. Detailed structural analysis shows that thermo-responsive surface composition changes are produced. The underlying mechanism of the thermoresponsive behavior is discussed.

  7. Thermally switchable thin films of an ABC triblock copolymer of poly( n -butyl methacrylate)-poly(methyl methacrylate)-poly(2-fluoroethyl methacrylate)

    NASA Astrophysics Data System (ADS)

    Zhang, Shanju; Liu, Zhan; Bucknall, David G.; He, Lihong; Hong, Kunlun; Mays, Jimmy W.; Allen, Mark G.

    2011-09-01

    The thermo-responsive behavior of polymer films consisting of novel linear triblock copolymers of poly( n-butyl methacrylate)-poly(methyl methacrylate)-poly(2-fluoroethyl methacrylate) (PnBuMA-PMMA-P2FEMA) are reported using differential scanning calorimetry (DSC), atomic forcing microscopy (AFM), X-ray photoelectron spectroscopy (XPS) and contacting angle (CA) measurements. The surface morphology, wettability and chemical structure of thin films of these triblock copolymers on silicon wafers as a function of temperature have been investigated. It has been shown that the wettability of the films is thermally switchable. Detailed structural analysis shows that thermo-responsive surface composition changes are produced. The underlying mechanism of the thermoresponsive behavior is discussed.

  8. Chlorhexidine-releasing methacrylate dental composite materials.

    PubMed

    Leung, Danny; Spratt, David A; Pratten, Jonathan; Gulabivala, Kishor; Mordan, Nicola J; Young, Anne M

    2005-12-01

    Light curable antibacterial, dental composite restoration materials, consisting of 80 wt% of a strontium fluoroaluminosilicate glass dispersed in methacrylate monomers have been produced. The monomers contained 40-100 wt% of a 10 wt% chlorhexidine diacetate (CHXA) in hydroxyethylmethacrylate (HEMA) solution and 60-0 wt% of a 50/50 mix of urethane dimethacrylate (UDMA) and triethyleneglycol dimethacrylate (TEGDMA). On raising HEMA content, light cure polymerisation rates decreased. Conversely, water sorption induced swelling and rates of diffusion controlled CHXA release from the set materials increased. Experimental composites with 50 and 90 wt% of the CHXA in HEMA solution in the monomer were shown, within a constant depth film fermentor (CDFF), to have slower rates of biofilm growth on their surfaces between 1 and 7 days than the commercial dental composite Z250 or fluoride-releasing dental cements, Fuji II LC and Fuji IX. When an excavated bovine dentine cylinder re-filled with Z250 was placed for 10 weeks in the CDFF, both bacteria and polymers from the artificial saliva penetrated between the material and dentine. With the 50 wt% experimental HEMA/CHXA formulation, this bacterial microleakage was substantially reduced. Polymer leakage, however, still occurred. Both polymer and bacterial microleakage were prevented with a 90 wt% HEMA/CHXA restoration in the bovine dentine due to swelling compensation for polymerisation shrinkage in combination with antibacterial release.

  9. Furfuryl methacrylate plasma polymers for biomedical applications.

    PubMed

    Shirazi, Hanieh Safizadeh; Rogers, Nicholas; Michelmore, Andrew; Whittle, Jason D

    2016-09-08

    Furfuryl methacrylate (FMA) is a promising precursor for producing polymers for biomedical and cell therapy applications. Herein, FMA plasma polymer coatings were prepared with different powers, deposition times, and flow rates. The plasma polymer coatings were characterized using atomic force microscopy (AFM), scanning electron microscopy (SEM), x-ray photoelectron spectroscopy (XPS), and time-of-flight secondary ion mass spectrometry (ToF-SIMS). The results from AFM and SEM show the early growth of the coatings and the existence of particle aggregates on the surfaces. XPS results indicated no measureable chemical differences between the deposited films produced under different power and flow rate conditions. ToF-SIMS analysis demonstrated differing amounts of C5H5O (81 m/z) and C10H9O2 (161 m/z) species in the coatings which are related to the furan ring structure. Through judicious choice of plasma polymerization parameters, the quantity of the particle aggregates was reduced, and the fabricated plasma polymer coatings were chemically uniform and smooth. Primary human fibroblasts were cultured on FMA plasma polymer surfaces to determine the effect of surface chemical composition and the presence of particle aggregates on cell culture. Particle aggregates were shown to inhibit fibroblast attachment and proliferation.

  10. Sequence dependent conformations of glycidyl methacrylate/butyl methacrylate copolymers in the gas phase

    NASA Astrophysics Data System (ADS)

    Baker, Erin Shammel; Gidden, Jennifer; Simonsick, William J.; Grady, Michael C.; Bowers, Michael T.

    2004-11-01

    Sequence dependent conformations of a series of glycidyl methacrylate/butyl methacrylate (GMA/BMA) copolymers cationized by sodium were analyzed in the gas phase using ion mobility methods. GMA and BMA have the same nominal mass but vary in exact mass by 0.036 Da (CH4 versus O). Matrix assisted laser desorption/ionization (MALDI) was used to form Na+(GMA/BMA) copolymer ions and their collision cross-sections were measured in helium using ion mobility methods. The copolymer sequences from Na+(GMA/BMA)3 to Na+(GMA/BMA)5 (i.e. for the trimer to the pentamer) were studied. Analysis by molecular mechanics/dynamics indicates that each copolymer (regardless of sequence) forms a ring around the sodium ions due to Na+/oxygen electrostatic interactions. However, the structures vary in size, since the epoxy oxygen atoms in the glycidyl groups are attracted to the sodium ions while the carbon-composed butyl groups are not. This allows copolymers with more GMA segments to fold tighter (more spherically) around the sodium ion and have smaller cross-sections than copolymers with a larger amount of BMA segments in the sequence. Due to this cross-sectional difference, the GMA/BMA sequence compositions of the trimer and tetramer could be quantified.

  11. Osteoblast cell death on methacrylate polymers involves apoptosis.

    PubMed

    Gough, J E; Downes, S

    2001-12-15

    The success of an implant depends on the implant-tissue interface. There are many causes of implant failure, one of which is tissue necrosis. The aim of this in vitro study was to determine whether cell death of primary human osteoblasts (implant site specific cells) occurred by apoptosis (a form of programmed cell death) on two methacrylate polymers. Cells were cultured on poly(ethyl methacrylate)/tetrahydrofurfuryl methacrylate and poly(methyl methacrylate in the form of 13-mm discs, in conditioned medium containing leachable monomer and in the presence of various concentrations of monomer itself in the culture medium. It was found that monomer and leached monomer caused apoptosis of human osteoblast cells in this system. Tetrahydrofurfuryl methacrylate monomer was found to be more toxic than currently used monomer methylmethacrylate. Preincubation of polymers in serum containing medium was found to increase the biocompatibility of the polymers. High levels of apoptosis occurred on polymer used directly after polymerization. Apoptosis levels were decreased after polymer was incubated at 60 degrees C overnight or for 3 days. Apoptosis therefore may occur in cells at the implant site in vivo.

  12. Complex microparticulate systems based on glycidyl methacrylate and xanthan.

    PubMed

    Lungan, Maria-Andreea; Popa, Marcel; Desbrieres, Jacques; Racovita, Stefania; Vasiliu, Silvia

    2014-04-15

    Porous microparticles based on glycidyl methacrylate, dimethacrylic monomers [ethylene glycol dimethacrylate, diethylene glycol dimethacrylate, triethylene glycol dimethacrylate] and xanthan gum were synthesized by aqueous suspension polymerization method in the presence of toluene as diluent using two types of initiators: benzoyl peroxide and ammonium persulfate. The G microparticles based on glycidyl methacrylate and dimethacrylic monomers and X microparticles based on glycidyl methacrylate, xanthan and dimethacrylic monomers were characterized by various techniques including FT-IR spectroscopy, TG analysis, SEM analysis and DVS method. The specific surface areas were determined by DVS method, while the copolymer porosities and pore volume were obtained from the apparent and skeletal densities. The results have indicated that xanthan was included in the crosslinked matrix by means of covalent bonds. X microparticles have a porous structure with higher specific surface area (129-44 m(2)/g) and higher sorption capacities compared with G microparticles (69-31 m(2)/g).

  13. Health and Environmental Effects Profile for ethyl methacrylate

    SciTech Connect

    Not Available

    1986-06-01

    The Health and Environmental Effects Profile for ethyl methacrylate was prepared to support listings of hazardous constituents of a wide range of waste streams under Section 3001 of the Resource Conservation and Recovery Act (RCRA) and to provide health-related limits for emergency actions under Section 101 of the Comprehensive Environmental Response, Compensation and Liability Act (CERCLA). Both published literature and information obtained from Agency program office files were evaluated as they pertained to potential human health, aquatic life and environmental effects. Quantitative estimates are presented provided sufficient data are available. Ethyl methacrylate has been determined to be a systemic toxicant. An acceptable daily intake (ADI) for ethyl methacrylate is 0.086 mg/kg/day for oral exposure.

  14. Protonation of diethylaminoethyl methacrylate by acids in various solvents

    SciTech Connect

    Zhuravleva, I.L.; Bune, E.V.; Bogachev, Yu.S.; Sheinker, A.P.; Teleshov, E.N.

    1988-04-10

    It was established by /sup 1/H and /sup 13/C NMR that diethylaminoethyl methacrylate exists in the unprotonated form in solvents which are not acids. In the presence of an equimolar amount of hydrochloric or trifluoroacetic acids the amino ester is fully protonated, irrespective of the solvent. The diethylaminoethyl methacrylate-acetic acid system exists in the form of a molecular complex with a hydrogen bond and in the protonated form; the proportions of the protonated form were estimated in various solvents. The change in the reactivity of diethylaminoethyl methacrylate and its salts in polymerization was explained by a change in the electronic state of CH/sub 2/ = group of the monomer as a result of its protonation and of the formation of a hydrogen bond between the C = O group of the monomer and the solvent.

  15. Poly(methyl methacrylate)-cellulose nitrate copolymers. I. Preparation

    SciTech Connect

    Badran, B.M.; Sherif, S.; Abu-Sedira, A.A.

    1981-03-01

    Poly(methyl methacrylate)-cellulose nitrate copolymers were prepared in the form of rods and sheets by bulk polymerization using benzoyl peroxide as initiator. Suspension polymerization did not succeed in preparing poly(methyl methacrylate)-cellulose nitrate copolymers, especially when cellulose nitrate of 11.4% nitrogen content was used. The parameters such as cellulose nitrate concentration, nitrogen content of cellulose nitrate, the amount of initiator and the reaction time, and the temperature are discussed. The prepared copolymers were irradiated for specified periods of up to 11.83 Mrad. It was found that poly(methyl methacrylate)-cellulose nitrate copolymers did not dissolve in any conventional solvent, but they swelled. Swelling decreases with increasing cellulose nitrate concentrations, nitrogen content of cellulose nitrate, and irradiation dose, indicating the crosslinked structure of the prepared copolymers.

  16. 40 CFR 721.10523 - Perfluoroalkylethyl methacrylate copolymer with hydroxymethyl acrylamide, vinyl chloride and long...

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... copolymer with hydroxymethyl acrylamide, vinyl chloride and long chain fatty alkyl acrylate (generic). 721... Substances § 721.10523 Perfluoroalkylethyl methacrylate copolymer with hydroxymethyl acrylamide, vinyl... methacrylate copolymer with hydroxymethyl acrylamide, vinyl chloride and long chain fatty alkyl acrylate (PMN...

  17. 40 CFR 721.10523 - Perfluoroalkylethyl methacrylate copolymer with hydroxymethyl acrylamide, vinyl chloride and long...

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... copolymer with hydroxymethyl acrylamide, vinyl chloride and long chain fatty alkyl acrylate (generic). 721... Substances § 721.10523 Perfluoroalkylethyl methacrylate copolymer with hydroxymethyl acrylamide, vinyl... methacrylate copolymer with hydroxymethyl acrylamide, vinyl chloride and long chain fatty alkyl acrylate (PMN...

  18. Review of Polymerization and Properties of Aminoalkyl Acrylates and Aminoalkyl Methacrylates

    DTIC Science & Technology

    1988-07-01

    to Russian investigators Korshunov, Bodnaryuk, and Kut’in, in 1975.2 The patent concerned the synthesis of methacrylate monomers containing an amino...group through transesterification. These researchers used alkyl methacrylates , mainly methyl methacrylate (MMA), as precursors for the synthesis. For...Ratios (rl, r2) of Aminoalkyl Methacrylates and Other Vinyl Monomers Monomer1 Moromer2 rl r2 DMAEMA MMA 0.717 0.676 DMAEMA BMA 0.705 0.66 BDIMA MMA 0.612

  19. Final report of the safety assessment of methacrylate ester monomers used in nail enhancement products.

    PubMed

    2005-01-01

    Methacrylate ester monomers are used in as artificial nail builders in nail enhancement products. They undergo rapid polymerization to form a hard material on the nail that is then shaped. While Ethyl Methacrylate is the primary monomer used in nail enhancement products, other methacrylate esters are also used. This safety assessment addresses 22 other methacrylate esters reported by industry to be present in small percentages as artificial nail builders in cosmetic products. They function to speed up polymerization and/or form cross-links. Only Tetrahydrofurfuryl Methacrylate was reported to the FDA to be in current use. The polymerization rates of these methacrylate esters are within the same range as Ethyl Methacrylate. While data are not available on all of these methacrylate esters, the available data demonstrated little acute oral, dermal, or i.p. toxicity. In a 28-day inhalation study on rats, Butyl Methacrylate caused upper airway irritation; the NOAEL was 1801 mg/m3. In a 28-day oral toxicity study on rats, t-Butyl Methacrylate had a NOAEL of 20 mg/kg/day. Beagle dogs dosed with 0.2 to 2.0 g/kg/day of C12 to C18 methacrylate monomers for 13 weeks exhibited effects only in the highest dose group: weight loss, emesis, diarrhea, mucoid feces, or salivation were observed. Butyl Methacrylate (0.1 M) and Isobutyl Methacrylate (0.1 M) are mildly irritating to the rabbit eye. HEMA is corrosive when instilled in the rabbit eye, while PEG-4 Dimethacrylate and Trimethylolpropane Trimethacrylate are minimally irritating to the eye. Dermal irritation caused by methacrylates is documented in guinea pigs and rabbits. In guinea pigs, HEMA, Isopropylidenediphenyl Bisglycidyl Methacrylate, Lauryl Methacrylate, and Trimethylolpropane Trimethacrylate are strong sensitizers; Butyl Methacrylate, Cyclohexyl Methacrylate, Hexyl Methacrylate, and Urethane Methacrylate are moderate sensitizers; Hydroxypropyl Methacrylate is a weak sensitizer; and PEG-4 Dimethacrylate and

  20. The lower alkyl methacrylates: Genotoxic profile of non-carcinogenic compounds.

    PubMed

    Albertini, Richard J

    2017-03-01

    All of the lower alkyl methacrylates are high production chemicals with potential for human exposure. The genotoxicity of seven mono-functional alkyl esters of methacrylic acid, i.e. methyl methacrylate, ethyl methacrylate, hydroxyethyl methacrylate, n-, i- and t-butyl methacrylate and 2 ethyl hexyl methacrylate, as well as methacrylic acid itself, the acyl component common to all, is reviewed and compared with the lack of carcinogenicity of methyl methacrylate, the representative member of the series so evaluated. Also reviewed are the similarity of structure, chemical and biological reactivity, metabolism and common metabolic products of this group of compounds which allows a category approach for assessing genotoxicity. As a class, the lower alkyl methacrylates are universally negative for gene mutations in prokaryotes but do exhibit high dose clastogenicity in mammalian cells in vitro. There is no convincing evidence that these compounds induce genotoxic effects in vivo in either sub-mammalian or mammalian species. This dichotomy of effects can be explained by the potential genotoxic intermediates generated in vitro. This genotoxic profile of the lower alkyl methacrylates is consistent with the lack of carcinogenicity of methyl methacrylate.

  1. 21 CFR 73.3127 - Vinyl alcohol/methyl methacrylate-dye reaction products.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ... 21 Food and Drugs 1 2013-04-01 2013-04-01 false Vinyl alcohol/methyl methacrylate-dye reaction... Vinyl alcohol/methyl methacrylate-dye reaction products. (a) Identity. The color additives are formed by reacting the dyes, either alone or in combination, with a vinyl alcohol/methyl methacrylate copolymer,...

  2. 21 CFR 73.3127 - Vinyl alcohol/methyl methacrylate-dye reaction products.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ... 21 Food and Drugs 1 2012-04-01 2012-04-01 false Vinyl alcohol/methyl methacrylate-dye reaction... Vinyl alcohol/methyl methacrylate-dye reaction products. (a) Identity. The color additives are formed by reacting the dyes, either alone or in combination, with a vinyl alcohol/methyl methacrylate copolymer,...

  3. 21 CFR 73.3127 - Vinyl alcohol/methyl methacrylate-dye reaction products.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ... 21 Food and Drugs 1 2014-04-01 2014-04-01 false Vinyl alcohol/methyl methacrylate-dye reaction... Vinyl alcohol/methyl methacrylate-dye reaction products. (a) Identity. The color additives are formed by reacting the dyes, either alone or in combination, with a vinyl alcohol/methyl methacrylate copolymer,...

  4. 21 CFR 73.3127 - Vinyl alcohol/methyl methacrylate-dye reaction products.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... 21 Food and Drugs 1 2011-04-01 2011-04-01 false Vinyl alcohol/methyl methacrylate-dye reaction... Vinyl alcohol/methyl methacrylate-dye reaction products. (a) Identity. The color additives are formed by... methacrylate-dye reaction product listed under this section into commerce shall submit to the Food and...

  5. 21 CFR 73.3127 - Vinyl alcohol/methyl methacrylate-dye reaction products.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... 21 Food and Drugs 1 2010-04-01 2010-04-01 false Vinyl alcohol/methyl methacrylate-dye reaction... Vinyl alcohol/methyl methacrylate-dye reaction products. (a) Identity. The color additives are formed by... methacrylate-dye reaction product listed under this section into commerce shall submit to the Food and...

  6. 21 CFR 177.2000 - Vinylidene chloride/methyl acrylate/methyl methacrylate polymers.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ... methacrylate polymers. 177.2000 Section 177.2000 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) INDIRECT FOOD ADDITIVES: POLYMERS Substances for Use as Basic.../methyl methacrylate polymers. The vinylidene chloride/methyl acrylate/methyl methacrylate polymers...

  7. Mössbauer studies of solid state decomposition of methyl methacrylate-ethyl methacrylate copolymers containing ferric chloride

    NASA Astrophysics Data System (ADS)

    Kapur, G. S.; Brar, A. S.

    1990-07-01

    Methyl methacrylate (MMA)-ethyl methacrylate (EMA) copolymers of different monomer concentrations containing anhydrous ferric chloride were prepared by bulk polymerization at 70°C. TGA studies showed that inclusion of iron salt increases the thermal stability of copolymers by 50°C. Mössbauer spectra of copolymers heated at different temperatures showed the presence of Fe3+ species only, in different environments. The mechanism of thermal stabilization of copolymer has been proposed on the basis of IR, TGA and Mössbauer spectroscopy studies.

  8. Solid-state dye lasers based on copolymers of 2-hydroxyethyl methacrylate and methyl methacrylate doped with rhodamine 6G

    NASA Astrophysics Data System (ADS)

    Costela, A.; Florido, F.; Garcia-Moreno, I.; Duchowicz, R.; Amat-Guerri, F.; Figuera, J. M.; Sastre, R.

    1995-04-01

    Rhodamine 6G has been dissolved in copolymers of 2-HydroxyEthyl MethAcrylate (HEMA) and Methyl MethAcrylate (MMA) and the resulting solid-state solutions have been pumped at 337 nm and 532 nm. Lasing efficiencies similar to those found in ethanol solution have been obtained with a 1:1 vol/vol HEMA: MMA copolymer matrix, and lifetimes of ca. 10 000 (337 nm pumping) and ca. 75 000 (532 nm pumping) pulses at repetition rates up to 15 Hz and 10 Hz, respectively, have been demonstrated.

  9. Crosslinked superhydrophobic films fabricated by simply casting poly(methyl methacrylate-butyl acrylate-hydroxyethyl methacrylate)-b-poly(perfluorohexylethyl methacrylate) solution

    NASA Astrophysics Data System (ADS)

    Wen, Xiufang; Ye, Chao; Cai, Zhiqi; Xu, Shouping; Pi, Pihui; Cheng, Jiang; Zhang, Lijuan; Qian, Yu

    2015-06-01

    This study focuses on the preparation of superhydrophobic films by crosslinkable polymer material-Poly(methyl methacrylate-butyl acrylate-hydroxyethyl methacrylate)-b-Poly(perfluorohexylethyl methacrylate) (P (MMA-BA-HEMA)-b-PFMA) with a simple one-step casting process. Nanoscale micelle particles with core-shell structure was obtained by dissolving the polymer and curing agent in the mixture of acetone and 1H, 1H, 5H octafluoropentyl-1,1,2,2 tetrafluoroethyl ether (FHT). Superhydrophobic films were fabricated by casting the micelle solution on the glass slides. By controlling the polymer concentration and acetone/FHT volume ratio, superhydrophobic polymer film with water contact angle of 153.2 ± 2.1° and sliding angle of 4° was obtained. By introducing a curing agent into the micelle solution, mechanical properties of the films can be improved. The adhension grade and hardness of the crosslinked superhydrophobic films reached 2 grade and 3H, respectively. The hydrophobicity is attributed to the synergistic effect of micro-submicro-nano-meter scale roughness by nanoscale micelle particles and low surface energy of fluoropolymer. This procedure makes it possible for widespread applications of superhydrophobic film due to its simplicity and practicability.

  10. 21 CFR 177.1830 - Styrene-methyl methacrylate copolymers.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ... methacrylate copolymers identified in this section may be safely used as components of plastic articles... weight percent of polymer units derived from styrene. (b) The finished plastic food-contact article, when... not to exceed an absorbance of 0.15. (3) Ultraviolet-absorbing distilled water and 8 and 50...

  11. Synthesis of acrylates and methacrylates from coal-derived syngas

    SciTech Connect

    Spivey, J.J.; Gogate, M.R.; Jang, B.W.L.

    1995-12-31

    Acrylates and methacrylates are among the most widely used chemical intermediates in the world. One of the key chemicals of this type is methyl methacrylate. Of the 4 billion pounds produced each year, roughly 85% is made using the acetone-cyanohydrin process, which requires handling of large quantities of hydrogen cyanide and produces ammonium sulfate wastes that pose an environmental disposal challenge. The U.S. Department of Energy and Eastman Chemical Company are sharing the cost of research to develop an alternative process for the synthesis of methyl methacrylate from syngas. Research Triangle Institute is focusing on the synthesis and testing of active catalysts for the condensation reactions, and Bechtel is analyzing the costs to determine the competitiveness of several process alternatives. Results thus far show that the catalysts for the condensation of formaldehyde and the propionate are key to selectively producing the desired product, methacrylic acid, with a high yield. These condensation catalysts have both acid and base functions and the strength and distribution of these acid-base sites controls the product selectivity and yield.

  12. Synthesis and Characterization of Carboxymethylcellulose-Methacrylate Hydrogel Cell Scaffolds

    PubMed Central

    Reeves, Robert; Ribeiro, Andreia; Lombardo, Leonard; Boyer, Richard; Leach, Jennie B.

    2012-01-01

    Many carbohydrates pose advantages for tissue engineering applications due to their hydrophilicity, degradability, and availability of chemical groups for modification. For example, carboxymethylcellulose (CMC) is a water-soluble cellulose derivative that is degradable by cellulase. Though this enzyme is not synthesized by mammalian cells, cellulase and the fragments derived from CMC degradation are biocompatible. With this in mind, we created biocompatible, selectively degradable CMC-based hydrogels that are stable in routine culture, but degrade when exposed to exogenous cellulase. Solutions of CMC-methacrylate and polyethylene glycol dimethacrylate (PEG-DM) were co-crosslinked to form stable hydrogels; we found that greater CMC-methacrylate content resulted in increased gel swelling, protein diffusion and rates of degradation by cellulase, as well as decreased gel shear modulus. CMC-methacrylate/PEG-DM gels modified with the adhesive peptide RGD supported fibroblast adhesion and viability. We conclude that hydrogels based on CMC-methacrylate are suitable for bioengineering applications where selective degradability may be favorable, such as cell scaffolds or controlled release devices. PMID:22708058

  13. Occupational asthma due to methyl methacrylate and cyanoacrylates.

    PubMed Central

    Lozewicz, S; Davison, A G; Hopkirk, A; Burge, P S; Boldy, D A; Riordan, J F; McGivern, D V; Platts, B W; Davies, D; Newman Taylor, A J

    1985-01-01

    Five patients had asthma provoked by cyanoacrylates and one by methyl methacrylate, possibly because of the development of a specific hypersensitivity response. Acrylates have wide domestic as well as industrial uses, and inhalation of vapour emitted during their use can cause asthma. PMID:4071461

  14. Reactive compatibilization of PBT/ABS blends by methyl methacrylate, glycidyl methacrylate, ethyl acrylate terpolymers

    NASA Astrophysics Data System (ADS)

    Hale, Wesley Raymond

    The impact resistance of poly(butylene terephthalate), PBT, has been improved by blending with acrylonitrile-butadiene-styrene terpolymers, ABS, as a minor dispersed phase; however, extensive coarsening of the dispersed phase in the blends occurs under certain heat fabrication conditions. The incorporation of certain reactive polymers (compatibilizers) that are miscible with the styrene/acrylonitrile (SAN) matrix of ABS should result in more stable morphologies. Terpolymers of methyl methacrylate, glycidyl methacrylate (GMA), ethyl acrylate, MGE, are effective as reactive compatibilizers for blends of PBT with SAN and ABS materials. The epoxide groups of MGE react with the carboxyl endgroups of PBT to form a MGE-g-PBT graft copolymer at the PBT/SAN interface to provide improved SAN or ABS dispersion, morphological stability, and a broadening of the melt processing window. Additionally, compatibilization produces large improvements in the low temperature fracture toughness of PBT/ABS blends; however, the toughness depends on the order of mixing blend components due to crosslinking reactions involving the epoxide groups of MGE catalyzed by residual acids present in some emulsion-made ABS materials. The PBT, ABS, and MGE type, content, and composition have been examined to evaluate their effects on the mechanical and morphological properties of PBT/ABS blends. Additionally, the effects of different processing conditions have been examined. High PBT melt viscosity is desirable for improving ABS dispersion and low temperature toughness of the blends. Generally, ABS materials with a high rubber content and low melt viscosity are desirable for toughening PBT. Moderate amounts of GMA in the blend were found to significantly improve blend properties. Melt blending can be performed using a variety of equipment; however, a co-rotating intermeshing twin screw extruder is the most effective for producing blends with excellent properties. The fracture properties of PBT

  15. Release of Water Soluble Drugs from Dynamically Swelling POLY(2-HYDROXYETHYL Methacrylate - CO - Methacrylic Acid) Hydrogels.

    NASA Astrophysics Data System (ADS)

    Kou, Jim Hwai-Cher

    In this study, ionizable copolymers of HEMA and methacrylic acid (MA) are investigated for their potential use in developing pH dependent oral delivery systems. Because of the MA units, these gels swell extensively at high pH. Since solute diffusion in the hydrophilic polymers depends highly on the water content of the matrix, it is anticipated that the release rate will be modulated by this pH induced swelling. From a practical point of view, the advantage of the present system is that one can minimize drug loss in the stomach and achieve a programmed release in intestine. This approach is expected to improve delivery of acid labile drugs or drugs that cause severe gastrointestinal side effects. This work mainly focuses on the basic understanding of the mechanism involved in drug release from the poly(HEMA -co- MA) gels, especially under dynamic swelling conditions. Equilibrium swelling is first characterized since water content is the major determinant of transport properties in these gels. Phenylpropanolamine (PPA) is chosen as the model drug for the release study and its diffusion characteristics in the gel matrix determined. The data obtained show that the PPA diffusivity follows the free volume theory of Yasuda, which explains the accelerating effect of swelling on drug release. A mathematical model based on a diffusion mechanism has been developed to describe PPA release from the swelling gels. Based on this model, several significant conclusions can be drawn. First, the release rate can be modulated by the aspect ratio of the cylindrical geometry, and this has a practical implication in dosage form design. Second, the release rate can be lowered quite considerably if the dimensional increase due to swelling is significant. Consequently, it is the balance between the drug diffusivity increase and the gel dimensional growth that determines the release rate from the swelling matrix. Third, quasi-steady release kinetics, which are characteristic of swelling

  16. Poly(methacrylic acid-co-methyl methacrylate) beads promote vascularization and wound repair in diabetic mice.

    PubMed

    Martin, Daniel C; Semple, John L; Sefton, Michael V

    2010-05-01

    Topical application of beads made from poly(methacrylic acid-co-methyl methacrylate) (45 mol % methacrylic acid, MAA) increased the number of blood vessels and improved 1.5 x 1.5 cm full thickness wound closure in a diabetic mouse (db/db) model. Three groups were compared: MAA beads, control poly(methyl methacrylate) beads (PMMA), and no bead blanks. MAA bead treatment significantly increased percent wound closure at all timepoints (7, 14, and 21 days) with MAA bead-treated wounds almost closed at day 21 (91 +/- 5.4% MAA vs. 79 +/- 3.2% PMMA or 76 +/- 4.8% no beads; p < 0.05). This was consistent with the expected significant increase in vascularity in the MAA group at days 7 and 14. For example at day 14, MAA bead-treated wounds had a vascular density of 22.7 +/- 2.6 vessels/hpf compared with 17.0 +/- 2.0 vessels/hpf in the PMMA bead group (p < 0.05). Epithelial gap and migration measurements suggested that the increased vascularity leads to enhanced epithelial cell migration as a principal means of wound closure. Although studies are underway to elucidate the mechanism of this angiogenic response, the results presented here support the notion that such materials, perhaps in other forms, may be useful in wound care or in other situations where vascularity is to be enhanced without the use of exogenous growth factors.

  17. Poly(sulfobetaine methacrylate)s as electrode modifiers for inverted organic electronics.

    PubMed

    Lee, Hyunbok; Puodziukynaite, Egle; Zhang, Yue; Stephenson, John C; Richter, Lee J; Fischer, Daniel A; DeLongchamp, Dean M; Emrick, Todd; Briseno, Alejandro L

    2015-01-14

    We demonstrate the use of poly(sulfobetaine methacrylate) (PSBMA), and its pyrene-containing copolymer, as solution-processable work function reducers for inverted organic electronic devices. A notable feature of PSBMA is its orthogonal solubility relative to solvents typically employed in the processing of organic semiconductors. A strong permanent dipole moment on the sulfobetaine moiety was calculated by density functional theory. PSBMA interlayers reduced the work function of metals, graphene, and poly(3,4-ethylenedioxythiophene):poly(styrenesulfonate) (PEDOT:PSS) by over 1 eV, and an ultrathin interlayer of PSBMA reduced the electron injection barrier between indium tin oxide (ITO) and C70 by 0.67 eV. As a result, the performance of organic photovoltaic devices with PSBMA interlayers is significantly improved, and enhanced electron injection is demonstrated in electron-only devices with ITO, PEDOT:PSS, and graphene electrodes. This work makes available a new class of dipole-rich, counterion-free, pH insensitive polymer interlayers with demonstrated effectiveness in inverted devices.

  18. Tri- and tetra-substituted cyclen based lanthanide(III) ion complexes as ribonuclease mimics: a study into the effect of log Ka, hydration and hydrophobicity on phosphodiester hydrolysis of the RNA-model 2-hydroxypropyl-4-nitrophenyl phosphate (HPNP).

    PubMed

    Fanning, Ann-Marie; Plush, Sally E; Gunnlaugsson, Thorfinnur

    2015-05-28

    A series of tetra-substituted 'pseudo' dipeptide ligands of cyclen (1,4,7,10,-tetraazacyclododecane) and a tri-substituted 3'-pyridine ligand of cyclen, and the corresponding lanthanide(III) complexes were synthesised and characterised as metallo-ribonuclease mimics. All complexes were shown to promote hydrolysis of the phosphodiester bond of 2-hydroxypropyl-4-nitrophenyl phosphate (HPNP, τ1/2 = 5.87 × 10(3) h), a well known RNA mimic. The La(III) and Eu(III) tri-substituted 3'-pyridine lanthanide(III) complexes being the most efficient in promoting such hydrolysis at pH 7.4 and at 37 °C; with τ1/2 = 1.67 h for La(III) and 1.74 h for Eu(III). The series was developed to provide the opportunity to investigate the consequences of altering the lanthanide(III) ion, coordination ability and hydrophobicity of a metallo-cavity on the rate of hydrolysis using the model phosphodiester, HPNP, at 37 °C. To further provide information on the role that the log Ka of the metal bound water plays in phosphodiester hydrolysis the protonation constants and the metal ion stability constants of both a tri and tetra-substituted 3'pyridine complex were determined. Our results highlighted several key features for the design of lanthanide(III) ribonucelase mimics; the presence of two metal bound water molecules are vital for pH dependent rate constants for Eu(III) complexes, optimal pH activity approximating physiological pH (∼7.4) may be achieved if the log Ka values for both MLOH and ML(OH)2 species occur in this region, small changes to hydrophobicity within the metallo cavity influence the rate of hydrolysis greatly and an amide adjacent to the metal ion capable of forming hydrogen bonds with the substrate is required for achieving fast hydrolysis.

  19. Solid coatings deposited from liquid methyl methacrylate via Plasma Polymerization

    NASA Astrophysics Data System (ADS)

    Wurlitzer, Lisa; Maus-Friedrichs, Wolfgang; Dahle, Sebastian

    2016-09-01

    The polymerization of methyl methacrylate via plasma discharges is well known today. Usually, plasma-enhanced chemical vapor deposition (PECVD) is used to deposit polymer coatings. Solid coatings are formed out of the liquid phase from methyl methacrylate via dielectric barrier discharge. The formation of the coating proceeds in the gas and the liquid phase. To learn more about the reactions in the two phases, the coatings from MMA monomer will be compared to those from MMA resin. Finally, attenuated total reflection infrared spectroscopy, confocal laser scanning microscopy and X-ray photoelectron spectroscopy are employed to characterize the solid coatings. In conclusion, the plasma enhanced chemical solution deposition is compared to the classical thermal polymerization of MMA.

  20. Azulene methacrylate polymers: synthesis, electronic properties, and solar cell fabrication.

    PubMed

    Puodziukynaite, Egle; Wang, Hsin-Wei; Lawrence, Jimmy; Wise, Adam J; Russell, Thomas P; Barnes, Michael D; Emrick, Todd

    2014-08-06

    We report the synthesis of novel azulene-substituted methacrylate polymers by free radical polymerization, in which the azulene moieties represent hydrophobic dipoles strung pendant to the polymer backbone and impart unique electronic properties to the polymers. Tunable optoelectronic properties were realized by adjusting the azulene density, ranging from homopolymers (having one azulene group per repeat unit) to copolymers in which the azulene density was diluted with other pendant groups. Treating these polymers with organic acids revealed optical and excitonic behavior that depended critically on the azulene density along the polymer chain. Copolymers of azulene with zwitterionic methacrylates proved useful as cathode modification layers in bulk-heterojunction solar cells, where the relative azulene content affected the device metrics and the power conversion efficiency reached 7.9%.

  1. Physical properties of agave cellulose graft polymethyl methacrylate

    SciTech Connect

    Rosli, Noor Afizah; Ahmad, Ishak; Abdullah, Ibrahim; Anuar, Farah Hannan

    2013-11-27

    The grafting polymerization of methyl methacrylate and Agave cellulose was prepared and their structural analysis and morphology were investigated. The grafting reaction was carried out in an aqueous medium using ceric ammonium nitrate as an initiator. The structural analysis of the graft copolymers was carried out by Fourier transform infrared and X-ray diffraction. The graft copolymers were also characterized by field emission scanning electron microscopy (FESEM). An additional peak at 1732 cm{sup −1} which was attributed to the C=O of ester stretching vibration of poly(methyl methacrylate), appeared in the spectrum of grafted Agave cellulose. A slight decrease of crystallinity index upon grafting was found from 0.74 to 0.68 for cellulose and grafted Agave cellulose, respectively. Another evidence of grafting showed in the FESEM observation, where the surface of the grafted cellulose was found to be roughed than the raw one.

  2. [Chest granuloma secondary to methyl methacrylate. Case report].

    PubMed

    Martínez-Bistrain, Ricardo; Robles García, Verónica; Cornejo-Morales, Ivonne

    2010-01-01

    We present the case of a patient with a history of a massive left hemithorax crushing injury in 1985; the exact management of the lesion is unknown. Twenty years later he had a thoracic fistula with a culture that was reported as positive for Enteroccocus faecalis and Staphyloccocus epidermidis. The patient was referred by the chest surgery service with the diagnosis of rib osteomyelitis once complementary imaging tests were performed (plain X-rays, CAT scan and MRI). The patient underwent surgery at our service; a granulomatous reaction secondary to a foreign body (methyl methacrylate and Ethibon) was reported. Chest reconstruction for massive lesions is possible with methyl methacrylate. Imaging studies involve the well-known difficulty to identify this material, given that it may produce signals and densities that are difficult to interpret by specialized physicians.

  3. Penile enlargement with methacrylate injection: is it safe?

    PubMed

    Torricelli, Fabio Cesar Miranda; Andrade, Enrico Martins de; Marchini, Giovanni Scala; Lopes, Roberto Iglesias; Claro, Joaquim Francisco Almeida; Cury, Jose; Srougi, Miguel

    2013-01-01

    CONTEXT Penis size is a great concern for men in many cultures. Despite the great variety of methods for penile augmentation, none has gained unanimous acceptance among experts in the field. However, in this era of minimally invasive procedure, injection therapy for penile augmentation has become more popular. Here we report a case of methacrylate injection in the penis that evolved with penile deformity and sexual dysfunction. This work also reviews the investigation and management of this pathological condition. CASE REPORT A 36-year-old male sought medical care with a complaint of penile deformity and sexual dysfunction after methacrylate injection. The treatment administered was surgical removal. Satisfactory cosmetic and functional results were reached after two months. CONCLUSIONS There is a need for better structured scientific research to evaluate the outcomes and complication rates from all penile augmentation procedures.

  4. SYNTHESIS OF METHYL METHACRYLATE FROM COAL-DERIVED SYNGAS

    SciTech Connect

    Makarand R. Gogate; James J. Spivey; Joseph R. Zoeller; Richard D. Colberg; Gerald N. Choi; Samuel S. Tam

    1999-04-21

    Research Triangle Institute (RTI), Eastman Chemical Company, and Bechtel collectively are developing a novel three-step process for the synthesis of methyl methacrylate (MMA) from coal-derived syngas that consists of the steps of synthesis of a propionate, its condensation with formaldehyde to form methacrylic acid (MAA), and esterification of MAA with methanol to produce MMA. The research team has completed the research on the three-step methanol-based route to MMA. Under an extension to the original contract, we are currently evaluating a new DME-based process for MMA. The key research need for DME route is to develop catalysts for DME partial oxidation reactions and DME condensation reactions. Over the last quarter (January-March/99), in-situ formaldehyde generation and condensation with methyl propionate were tested over various catalysts and reaction conditions. The patent application is in preparation and the results are retained for future reports.

  5. Positron annihilation investigations on poly(methyl methacrylate)

    NASA Astrophysics Data System (ADS)

    Mohamed, Hamdy F. M.; Abd-Elsadek, Gomaa G.

    2000-06-01

    Positron lifetime and Doppler broadened annihilation radiation were measured for seven different samples of poly(methyl methacrylate) at room temperature in vacuum. The polymerisation of methyl methacrylate was carried out as a bulk polymerisation in the presence of benzoyl peroxide as an initiator. The effect of the amount of the initiator on the viscosity-average molecular weight was studied. It was found that the viscosity-average molecular weight decreased with increasing amount of the initiator. The average lifetime and intensity of ortho-positronium ( o-Ps) increased with increasing viscosity-average molecular weight up to 6.85 × 10 4 and remained constant after that. The S-parameter showed a similar behaviour as that of the o-Ps intensity.

  6. Preparation and characterization of methacrylate hydrogels for zeta potential control

    NASA Technical Reports Server (NTRS)

    Gregonis, D. E.; Ma, S. M.; Vanwagenen, R.; Andrade, J. D.

    1976-01-01

    A technique based on the measurement of streaming potentials has been developed to evaluate the effects of hydrophilic coatings on electroosmotic flow. The apparatus and procedure are described as well as some results concerning the electrokinetic potential of glass capillaries as a function of ionic strength, pH, and temperature. The effect that turbulence and entrance flow conditions have on accurate streaming potential measurements is discussed. Various silane adhesion promoters exhibited only a slight decrease in streaming potential. A coating utilizing a glycidoxy silane base upon which methylcellulose is applied affords a six-fold decrease over uncoated tubes. Hydrophilic methacrylate gels show similar streaming potential behavior, independent of the water content of the gel. By introduction of positive or negative groups into the hydrophilic methacrylate gels, a range of streaming potential values are obtained having absolute positive or negative signs.

  7. Physical properties of agave cellulose graft polymethyl methacrylate

    NASA Astrophysics Data System (ADS)

    Rosli, Noor Afizah; Ahmad, Ishak; Abdullah, Ibrahim; Anuar, Farah Hannan

    2013-11-01

    The grafting polymerization of methyl methacrylate and Agave cellulose was prepared and their structural analysis and morphology were investigated. The grafting reaction was carried out in an aqueous medium using ceric ammonium nitrate as an initiator. The structural analysis of the graft copolymers was carried out by Fourier transform infrared and X-ray diffraction. The graft copolymers were also characterized by field emission scanning electron microscopy (FESEM). An additional peak at 1732 cm-1 which was attributed to the C=O of ester stretching vibration of poly(methyl methacrylate), appeared in the spectrum of grafted Agave cellulose. A slight decrease of crystallinity index upon grafting was found from 0.74 to 0.68 for cellulose and grafted Agave cellulose, respectively. Another evidence of grafting showed in the FESEM observation, where the surface of the grafted cellulose was found to be roughed than the raw one.

  8. SYNTHESIS OF METHACRYLATES FROM COAL-DERIVED SYNGAS

    SciTech Connect

    Jang, B.W.L.; Spivey, J.J.; Gogate, M.R.; Zoeller, J.R.; Colberg, R.D.; Choi, G.N.

    1999-12-01

    Research Triangle Institute (RTI), Eastman Chemical Company, and Bechtel have developed a novel process for synthesis of methyl methacrylate (MMA) from coal-derived syngas, under a contract from the US Department of Energy/Fossil Energy Technology Center (DOE/FETC). This project has resulted in five US patents (four already published and one pending publication). It has served as the basis for the technical and economic assessment of the production of this high-volume intermediate from coal-derived synthesis gas. The three-step process consists of the synthesis of a propionate from ethylene carbonylation using coal-derived CO, condensation of the propionate with formaldehyde to form methacrylic acid (MAA); and esterification of MAA with methanol to yield MMA. The first two steps, propionate synthesis and condensation catalysis, are the key technical challenges and the focus of the research presented here.

  9. Pediatric poisonings from household products: hydrofluoric acid and methacrylic acid.

    PubMed

    Perry, H E

    2001-04-01

    Household products continue to be a cause of poisoning morbibidity and mortality. Young children frequently are exposed to cleaning products and cosmetics in the course of exploring their environment. Most of these exposures are insignificant, but some result in death or permanent disability. This review discusses two products that have been responsible for serious injury and death in children: hydrofluoric acid and methacrylic acid. It also discusses federal initiatives designed to protect children from these and other household hazards.

  10. Gelatin methacrylate microspheres for controlled growth factor release.

    PubMed

    Nguyen, Anh H; McKinney, Jay; Miller, Tobias; Bongiorno, Tom; McDevitt, Todd C

    2015-02-01

    Gelatin has been commonly used as a delivery vehicle for various biomolecules for tissue engineering and regenerative medicine applications due to its simple fabrication methods, inherent electrostatic binding properties, and proteolytic degradability. Compared to traditional chemical cross-linking methods, such as the use of glutaraldehyde (GA), methacrylate modification of gelatin offers an alternative method to better control the extent of hydrogel cross-linking. Here we examined the physical properties and growth factor delivery of gelatin methacrylate (GMA) microparticles (MPs) formulated with a wide range of different cross-linking densities (15-90%). Less methacrylated MPs had decreased elastic moduli and larger mesh sizes compared to GA MPs, with increasing methacrylation correlating to greater moduli and smaller mesh sizes. As expected, an inverse correlation between microparticle cross-linking density and degradation was observed, with the lowest cross-linked GMA MPs degrading at the fastest rate, comparable to GA MPs. Interestingly, GMA MPs at lower cross-linking densities could be loaded with up to a 10-fold higher relative amount of growth factor than conventional GA cross-linked MPs, despite the GA MPs having an order of magnitude greater gelatin content. Moreover, a reduced GMA cross-linking density resulted in more complete release of bone morphogenic protein 4 and basic fibroblast growth factor and accelerated release rate with collagenase treatment. These studies demonstrate that GMA MPs provide a more flexible platform for growth factor delivery by enhancing the relative binding capacity and permitting proteolytic degradation tunability, thereby offering a more potent controlled release system for growth factor delivery.

  11. Gelatin Methacrylate Microspheres for Growth Factor Controlled Release

    PubMed Central

    Nguyen, Anh H.; McKinney, Jay; Miller, Tobias; Bongiorno, Tom; McDevitt, Todd C.

    2014-01-01

    Gelatin has been commonly used as a delivery vehicle for various biomolecules for tissue engineering and regenerative medicine applications due to its simple fabrication methods, inherent electrostatic binding properties, and proteolytic degradability. Compared to traditional chemical cross-linking methods, such as the use of glutaraldehyde (GA), methacrylate modification of gelatin offers an alternative method to better control the extent of hydrogel cross-linking. Here we examined the physical properties and growth factor delivery of gelatin methacrylate (GMA) microparticles formulated with a wide range of different cross-linking densities (15–90%). Less methacrylated MPs had decreased elastic moduli and larger mesh sizes compared to GA MPs, with increasing methacrylation correlating to greater moduli and smaller mesh sizes. As expected, an inverse correlation between microparticle cross-linking density and degradation was observed, with the lowest cross-linked GMA MPs degrading at the fastest rate, comparable to GA MPs. Interestingly, GMA MPs at lower cross-linking densities could be loaded with up to a 10-fold higher relative amount of growth factor over conventional GA cross-linked MPs, despite an order of magnitude greater gelatin content of GA MPs. Moreover, a reduced GMA cross-linking density resulted in more complete release of bone morphogenic protein 4 (BMP4) and basic fibroblast growth factor (bFGF) and accelerated release rate with collagenase treatment. These studies demonstrate that GMA MPs provide a more flexible platform for growth factor delivery by enhancing the relative binding capacity and permitting proteolytic degradation tunability, thereby offering a more potent controlled release system for growth factor delivery. PMID:25463489

  12. Enhanced surface segregation of poly(methyl methacrylate) end-capped with 2-perfluorooctylethyl methacrylate by introduction of a second block.

    PubMed

    Ni, Huagang; Gao, Jie; Li, Xuehua; Hu, Yanyan; Yan, Donghuan; Ye, XiuYun; Wang, Xinping

    2012-01-01

    New fluorinated copolymers of poly(methyl methacrylate)-b-poly(butyl methacrylate) or poly(n-octadecyl methacrylate) end-capped with 2-perfluorooctylethyl methacrylate (PMMA(x)-b-PBMA(y)-ec-PFMA(z) or PMMA(x)-b-PODMA(y)-ec-PFMA(z)) were synthesized by living atom transfer radical polymerization. Thin films made of PMMA(230)-b-PODMA(y)-ec-PFMA(1) were characterized by differential scanning calorimetry, angle-resolved X-ray photoelectron spectroscopy and X-ray diffraction. These films were found to exhibit robust surface segregation of the end groups. Furthermore, the fluorine enrichment factor at the film surface was found to increase linearly with increasing degree of polymerization of poly(n-octadecyl methacrylate) and its increasing fusion enthalpy in the second block, which enhances the segregation of the fluorinated moieties.

  13. Multifunctional methacrylate-based coatings for glass and metal surfaces

    NASA Astrophysics Data System (ADS)

    Pospiech, Doris; Jehnichen, Dieter; Starke, Sandra; Müller, Felix; Bünker, Tobias; Wollenberg, Anne; Häußler, Liane; Simon, Frank; Grundke, Karina; Oertel, Ulrich; Opitz, Michael; Kruspe, Rainer

    2017-03-01

    In order to prevent freshwater biofouling glass and metal surfaces were coated with novel transparent methacrylate-based copolymers. The multifunctionality of the copolymers, such as adhesion to the substrate, surface polarity, mechanical long-term stability in water, and ability to form metal complexes was inserted by the choice of suitable comonomers. The monomer 2-acetoacetoxy ethyl methacrylate (AAMA) was used as complexing unit to produce copper(II) complexes in the coating's upper surface layer. The semifluorinated monomer 1H,1H,2H,2H-perfluorodecyl methacrylate was employed to adjust the surface polarity and wettability. Comprehensive surface characterization techniques, such as X-ray photoelectron spectroscopy (XPS) and contact angle measurements showed that surface compositions and properties can be easily adjusted by varying the concentrations of the comonomers. The formation of copper(II) complexes along the copolymer chains and their stability against washing out with plenty of water was proven by XPS. Copolymers containing semifluorinated comonomers significantly inhibited the growth of Achnanthidium species. Copolymers with copper-loaded AAMA-sequences were able to reduce both the growth of Achnanthidium spec. and Staphylococcus aureus.

  14. Methacrylate based gel polymer electrolyte for lithium-ion batteries

    NASA Astrophysics Data System (ADS)

    Isken, P.; Winter, M.; Passerini, S.; Lex-Balducci, A.

    2013-03-01

    A methacrylate based gel polymer electrolyte (GPE) was prepared and electrochemically investigated. The polymer was synthesized as a statistical co-polymer of oligo(ethylene glycol) methyl ether methacrylate (OEGMA) and benzyl methacrylate (BnMA) by free radical polymerization. The ethylene glycol side chain of OEGMA should be able to interact with the liquid electrolyte, thus keeping it inside the GPE, whereas BnMA was used to enhance the mechanical stability of the GPE. Such a polymer was able to retain liquid electrolyte up to 400% of its own weight, while the mechanical stability of the GPE was still high enough to be used as separator in lithium-ion batteries. The GPE displayed a conductivity of 1.8 mS cm-1 at 25 °C and an electrochemical stability window comparable to that of a standard liquid electrolyte. When used in lithium-ion batteries, such a GPE allowed a performance comparable to that obtained using conventional liquid electrolytes. Therefore the reported electrolyte was identified as a promising candidate as electrolyte for lithium-ion batteries.

  15. Evaluation of alternate routes for the synthesis of methyl methacrylate

    SciTech Connect

    Spivey, J.J.; Gogate, M.R.; Zoeller, J.R.; Colberg, R.D.; Choi, G.N.

    1998-12-31

    The use of coal-derived syngas to produce high value chemicals is an important means of upgrading this resource. One example of a chemical that can be produced from coal-derived syngas is methyl methacrylate (MMA). Poly-methyl methacrylate is widely used in coatings and in various industrial molded products. The most widely practiced commercial technology for the synthesis of MMA is the acetone cyanohydrin (ACH) process. This process requires handling of large quantities of toxic hydrogen cyanide and generates one mole of ammonium bisulfate waste per mole of MMA. This bisulfate must either be regenerated or discarded, either of which substantially increases the cost. The ACH technology is thus environmentally and economically untenable for any new MMA plant expansions that would be needed to meet increasing demand. The RTI-Eastman-Bechtel research team is developing an alternative, environmentally benign route to MMA consisting of three steps; (step 1) synthesis of a propionate from ethylene, carbon monoxide, and steam, (step 2) condensation of this propionate with formaldehyde, and (step 3) esterification of resulting methacrylic acid with methanol to form MMA. This paper describes the preliminary economics of the overall process compared to other emerging processes, and focuses on step 2, including long term testing of catalysts for the condensation of propionic acid with formaldehyde to form MAA.

  16. Efficient Synthesis of Poly(hydroxyethyl Methacrylate)-b-Poly(dimethylaminoethyl Methacrylate) Block Copolymer by Atom Transfer Radical Polymerization.

    NASA Astrophysics Data System (ADS)

    Tang, Wei; Loo, Yueh-Lin

    2009-03-01

    Polymers containing hydroxyethyl methacrylate (HEMA) and dimethylaminoethyl methacrylate (DMAEMA) have found wide applications in areas such as bioseparation, tissue engineering and controlled drug delivery. The controlled synthesis of block copolymers of PDMAEMA-b-PHEMA from PDMAEMA macroinitiator by atom transfer radical polymerization (ATRP), however, has not been successful due to the loss of chain end functionality during polymerization. We report an ATRP system that affords efficient chain extension from PDMAEMA to HEMA using Cu(0)/1,1,4,7,10,10-hexamethyltriethylenetetramine as the catalyst, 2-chloropropionitrile as the initiator in methanol at room temperature. A clear peak shift in the gel permeation chromatography trace towards shorter elution times indicates chain growth on HEMA addition. The chain end functionalities of PDMAEMA are thus retained and can be used to efficiently initiate chain extension reaction of HEMA. This new synthetic route opens new possibilities for the synthesis of pH- and temperature-responsive systems containing DMAEMA.

  17. Synthesis and characterization of injectable, water-soluble copolymers of tertiary amine methacrylates and poly(ethylene glycol) containing methacrylates.

    PubMed

    Anderson, Brian C; Mallapragada, Surya K

    2002-11-01

    Several homopolymers and copolymers of 2-(diethylamino)ethyl methacrylate (DEAEM) and poly(ethylene glycol) methyl ether methacrylate (PEGMEM) were synthesized using anionic polymerization initiated by potassium t-butoxide. The polymers were characterized by average molecular weight, polydispersity and monomeric unit composition. A very narrow molecular weight distribution was achieved with a well-controlled composition. The glass transition temperatures and compositions of the copolymers followed a Gordon-Taylor relationship. The water solubility and biocompatibility of the copolymers was compared to their parent homopolymers to determine if the addition of a poly(ethylene glycol) group was sufficient to solubilize the polymers in aqueous buffer solutions and to increase the biocompatibility of the polymers. These water-soluble, injectable cationic copolymers have potential applications in gene delivery as well as other biomaterial applications.

  18. Preparation of hydroxyapatite/poly(methyl methacrylate) and calcium silicate/poly(methyl methacrylate) interpenetrating hybrid composites.

    PubMed

    Monvisade, Pathavuth; Siriphannon, Punnama; Jermsungnern, Rapee; Rattanabodee, Sirirat

    2007-10-01

    Hydroxyapatite/poly(methyl methacrylate) (HAp/PMMA) and calcium silicate/poly(methyl methacrylate) (CS/PMMA) composites were prepared by interpenetrating bulk polymerization of methyl methacrylate (MMA) monomer in porous structures of HAp and CS. The porous HAp and CS templates were prepared by mixing their calcined powders with poly(vinyl alcohol) (PVA) solution, shaping by uniaxial pressing and then firing at 1,100 degrees C for HAp and 900 degrees C for CS. The templates were soaked in the solution mixture of MMA monomer and 0.1 mol% of benzoyl peroxide (BPO) for 24 h. The pre-composites were then bulk polymerized at 85 degrees C for 24 h under nitrogen atmosphere. The microstructures of the composites showed the interpenetrating of PMMA into the porous HAp and CS structures. Thermogravimetric analysis indicated that the PMMA content in the HAp/PMMA and CS/PMMA composites were 13 and 26 wt%, respectively. Weight average molecular weights (M(w)) of PMMA were about 491,000 for HAp/PMMA composites and about 348,000 for CS/PMMA composites. Compressive strengths of these composites were about 90-131 MPa in which they were significantly higher than their starting porous templates.

  19. Affinity chromatography of proteins on non-porous copolymerized particles of styrene, methyl methacrylate and glycidyl methacrylate.

    PubMed

    Chen, C H; Lee, W C

    2001-06-29

    Non-porous particles having an average diameter of 2.1 microm were prepared by co-polymerization of styrene, methyl methacrylate and glycidyl methacrylate, which was abbreviated as P(S-MMA-GMA). The particles were mechanically stable due to the presence of benzene rings in the backbone of polymer chains, and could withstand high pressures when a column packed with these particles was operated in the HPLC mode. The polymer particles were advantaged by immobilization of ligands via the epoxy groups on the particle surface that were introduced by one of the monomers, glycidyl methacrylate. As a model system, Cibacron Blue 3G-A was covalently immobilized onto the non-porous copolymer beads. The dye-immobilized P(S-MMA-GMA) particles were slurry packed into a 1.0 cm x 0.46 cm I.D. column. This affinity column was effective for the separation of turkey egg white lysozyme from a protein mixture. The bound lysozyme could be eluted to yield a sharp peak by using a phosphate buffer containing 1 M NaCl. For a sample containing up to 8 microg of lysozyme, the retained portion of proteins could be completely eluted without any slit peak. Due to the use of a shorter column, the analysis time was shorter in comparison with other affinity systems reported in the literature. The retention time could be reduced significantly by increasing the flow-rate, while the capacity factor remained at the same level.

  20. Molecular Dynamics Simulations of Hugoniot Relations for Poly[methyl methacrylate

    DTIC Science & Technology

    2011-11-01

    Molecular Dynamics Simulations of Hugoniot Relations for Poly[ methyl methacrylate ] by Tanya L. Chantawansri, Edward F. C. Byrd, Betsy M. Rice...Ground, MD 21005-5066 ARL-TR-5819 November 2011 Molecular Dynamics Simulations of Hugoniot Relations for Poly[ methyl methacrylate ...4. TITLE AND SUBTITLE Molecular Dynamics Simulations of Hugoniot Relations for Poly[ methyl methacrylate ] 5a. CONTRACT NUMBER 5b. GRANT NUMBER

  1. Preparation and evaluation of poly(alkyl methacrylate-co-methacrylic acid-co-ethylene dimethacrylate) monolithic columns for separating polar small molecules by capillary liquid chromatography.

    PubMed

    Lin, Shu-Ling; Wu, Yu-Ru; Lin, Tzuen-Yeuan; Fuh, Ming-Ren

    2015-04-29

    In this study, methacrylic acid (MAA) was incorporated with alkyl methacrylates to increase the hydrophilicity of the synthesized ethylene dimethacrylate-based (EDMA-based) monoliths for separating polar small molecules by capillary LC analysis. Different alkyl methacrylate-MAA ratios were investigated to prepare a series of 30% alkyl methacrylate-MAA-EDMA monoliths in fused-silica capillaries (250-μm i.d.). The porosity, permeability, and column efficiency of the synthesized MAA-incorporated monolithic columns were characterized. A mixture of phenol derivatives is employed to evaluate the applicability of using the prepared monolithic columns for separating small molecules. Fast separation of six phenol derivatives was achieved in 5 min with gradient elution using the selected poly(lauryl methacrylate-co-MAA-co-EDMA) monolithic column. In addition, the effect of acetonitrile content in mobile phase on retention factor and plate height as well as the plate height-flow velocity curves were also investigated to further examine the performance of the selected poly(lauryl methacrylate-co-MAA-co-EDMA) monolithic column. Moreover, the applicability of prepared polymer-based monolithic column for potential food safety applications was also demonstrated by analyzing five aflatoxins and three phenicol antibiotics using the selected poly(lauryl methacrylate-co-MAA-co-EDMA) monolithic column.

  2. Hardness of irradiated poly(methyl methacrylate) at elevated temperatures

    SciTech Connect

    Lu, K.-P.; Lee, Sanboh; Cheng, Cheu Pyeng

    2001-08-15

    The decrease in hardness induced by gamma irradiation in poly(methyl methacrylate) (PMMA) has been investigated. The hardness is assumed to decrease linearly with the concentration of radiation-induced defects. Annealing at high temperatures induces defect annihilation as tracked by an increase in hardness. The annihilation follows first-order kinetics during isothermal annealing. The dependence of hardness on the reciprocal of the time constant satisfies the Arrhenius equation, and the corresponding activation energy of the kinetic process decreases with increasing dose. The hardness of postannealed PMMA decreases linearly with increasing dose. {copyright} 2001 American Institute of Physics.

  3. Characterization and degradation of functionalized chitosan with glycidyl methacrylate.

    PubMed

    Flores-Ramírez, Nelly; Elizalde-Peña, Eduardo A; Vásquez-García, Salomón R; González-Hernández, Jesús; Martinez-Ruvalcaba, Agustín; Sanchez, Isaac C; Luna-Bárcenas, Gabriel; Gupta, Ram B

    2005-01-01

    The synthesis, characterization and degradation of a hybrid chitosan (CTS)/glycidyl methacrylate (GMA) material are reported. These versatile materials (natural-synthetic materials) are potential candidates for dental restoratives. All materials were characterized by infrared spectroscopy (FT-IR), X-ray diffraction and thermal (DSC) analysis. Particular attention was paid to the thermal stability and chemical resistance of the hybrid CTS materials. From dynamical rheological tests, it was concluded that CTS-GMA solutions behave as physical hydrogels. These pH-sensitive gels are an example of stimuli-responsive polymers, also known as 'smart polymers'.

  4. Methyl methacrylate permeability of dental and industrial gloves.

    PubMed

    Thomas, Sebastian; Padmanabhan, T V

    2009-01-01

    Our study was undertaken to measure the amount and time it took for methyl methacrylate monomer (MMA) to permeate latex, vinyl and industrial neoprene gloves and to compare the results to obtain a rating of the permeability of each of the gloves studied to MMA. The monomer, permeated under static conditions, was measured using a spectrophotometer. Latex and vinyl clinical gloves became permeable to MMA in a very short amount of time. Neoprene industrial gloves remained impervious for 25 minutes. Dentists and dental technicians should be aware of the toxic effects of MMA and understand that clinical gloves do not afford protection from MMA.

  5. Preparation of novel poly(hydroxyethyl methacrylate-co-glycidyl methacrylate)-grafted core-shell magnetic chitosan microspheres and immobilization of lactase.

    PubMed

    Zhao, Wei; Yang, Rui-Jin; Qian, Ting-Ting; Hua, Xiao; Zhang, Wen-Bin; Katiyo, Wendy

    2013-06-06

    Poly(hydroxyethyl methacrylate-co-glycidyl methacrylate)-grafted magnetic chitosan microspheres (HG-MCM) were prepared using reversed-phase suspension polymerization method. The HG-MCM presented a core-shell structure and regular spherical shape with poly(hydroxyethyl methacrylate-co-glycidyl methacrylate) grafted onto the chitosan layer coating the Fe3O4 cores. The average diameter of the magnetic microspheres was 10.67 μm, within a narrow size distribution of 6.6-17.4 μm. The saturation magnetization and retentivity of the magnetic microspheres were 7.0033 emu/g and 0.6273 emu/g, respectively. The application of HG-MCM in immobilization of lactase showed that the immobilized enzyme presented higher storage, pH and thermal stability compared to the free enzyme. This indicates that HG-MCM have potential applications in bio-macromolecule immobilization.

  6. Synthesis of branched poly(methyl methacrylate)s via controlled/living polymerisations exploiting ethylene glycol dimethacrylate as branching agent.

    PubMed

    Isaure, Francoise; Cormack, Peter A G; Graham, Susan; Sherrington, David C; Armes, Steven P; Bütun, Vural

    2004-05-07

    With appropriate choice of reaction composition and conditions, copolymerisation of methyl methacrylate and ethylene glycol dimethacrylate using Cu-based ATRP or GTP methodologies yields soluble branched polymers in facile one-pot reactions.

  7. Cell toxicity of methacrylate monomers-the role of glutathione adduct formation.

    PubMed

    Ansteinsson, V; Kopperud, H B; Morisbak, E; Samuelsen, J T

    2013-12-01

    Polymer-based dental restorative materials are designed to polymerize in situ. However, the conversion of methacrylate monomer to polymer is never complete, and leakage of the monomer occurs. It has been shown that these monomers are toxic in vitro; hence concerns regarding exposure of patients and dental personnel have been raised. Different monomer methacrylates are thought to cause toxicity through similar mechanisms, and the sequestration of cellular glutathione (GSH) may be a key event. In this study we examined the commonly used monomer methacrylates, 2-hydroxyethylmethacrylate (HEMA), triethylenglycol-dimethacrylate (TEGDMA), bisphenol-A-glycidyl-dimethacrylate (BisGMA), glycerol-dimethacrylate (GDMA) and methyl-methacrylate (MMA). The study aimed to establish monomers' ability to complex with GSH, and relate this to cellular toxicity endpoints. Except for BisGMA, all the monomer methacrylates decreased the GSH levels both in cells and in a cell-free system. The spontaneous formation of methacrylate-GSH adducts were observed for all methacrylate monomers except BisGMA. However, we were not able to correlate GSH depletion and toxic response measured as SDH activity and changes in cell growth pattern. Together, the current study indicates mechanisms other than GSH-binding to be involved in the toxicity of methacrylate monomers.

  8. 40 CFR 721.6920 - Butyl acrylate, polymer with substituted methyl styrene, methyl methacrylate, and substituted...

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... 40 Protection of Environment 32 2013-07-01 2013-07-01 false Butyl acrylate, polymer with... acrylate, polymer with substituted methyl styrene, methyl methacrylate, and substituted silane. (a... butyl acrylate, polymer with substituted methyl styrene, methyl methacrylate, and substituted...

  9. 40 CFR 721.6920 - Butyl acrylate, polymer with substituted methyl styrene, methyl methacrylate, and substituted...

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... 40 Protection of Environment 31 2011-07-01 2011-07-01 false Butyl acrylate, polymer with... acrylate, polymer with substituted methyl styrene, methyl methacrylate, and substituted silane. (a... butyl acrylate, polymer with substituted methyl styrene, methyl methacrylate, and substituted...

  10. 40 CFR 721.6920 - Butyl acrylate, polymer with substituted methyl styrene, methyl methacrylate, and substituted...

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 40 Protection of Environment 30 2010-07-01 2010-07-01 false Butyl acrylate, polymer with... acrylate, polymer with substituted methyl styrene, methyl methacrylate, and substituted silane. (a... butyl acrylate, polymer with substituted methyl styrene, methyl methacrylate, and substituted...

  11. 40 CFR 721.6920 - Butyl acrylate, polymer with substituted methyl styrene, methyl methacrylate, and substituted...

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... 40 Protection of Environment 31 2014-07-01 2014-07-01 false Butyl acrylate, polymer with... acrylate, polymer with substituted methyl styrene, methyl methacrylate, and substituted silane. (a... butyl acrylate, polymer with substituted methyl styrene, methyl methacrylate, and substituted...

  12. 21 CFR 177.2000 - Vinylidene chloride/methyl acrylate/methyl methacrylate polymers.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ... methacrylate polymers. 177.2000 Section 177.2000 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF...: POLYMERS Substances for Use as Basic Components of Single and Repeated Use Food Contact Surfaces § 177.2000 Vinylidene chloride/methyl acrylate/methyl methacrylate polymers. The vinylidene chloride/methyl...

  13. 21 CFR 177.2000 - Vinylidene chloride/methyl acrylate/methyl methacrylate polymers.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... methacrylate polymers. 177.2000 Section 177.2000 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF...: POLYMERS Substances for Use as Basic Components of Single and Repeated Use Food Contact Surfaces § 177.2000 Vinylidene chloride/methyl acrylate/methyl methacrylate polymers. The vinylidene chloride/methyl...

  14. 21 CFR 177.2000 - Vinylidene chloride/methyl acrylate/methyl methacrylate polymers.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ... methacrylate polymers. 177.2000 Section 177.2000 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF...: POLYMERS Substances for Use as Basic Components of Single and Repeated Use Food Contact Surfaces § 177.2000 Vinylidene chloride/methyl acrylate/methyl methacrylate polymers. The vinylidene chloride/methyl...

  15. 21 CFR 177.2000 - Vinylidene chloride/methyl acrylate/methyl methacrylate polymers.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... methacrylate polymers. 177.2000 Section 177.2000 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF...: POLYMERS Substances for Use as Basic Components of Single and Repeated Use Food Contact Surfaces § 177.2000 Vinylidene chloride/methyl acrylate/methyl methacrylate polymers. The vinylidene chloride/methyl...

  16. 40 CFR 721.6920 - Butyl acrylate, polymer with substituted methyl styrene, methyl methacrylate, and substituted...

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... 40 Protection of Environment 32 2012-07-01 2012-07-01 false Butyl acrylate, polymer with... acrylate, polymer with substituted methyl styrene, methyl methacrylate, and substituted silane. (a... butyl acrylate, polymer with substituted methyl styrene, methyl methacrylate, and substituted...

  17. Allergic contact gingivostomatitis from a temporary crown made of methacrylates and epoxy diacrylates.

    PubMed

    Kanerva, L; Alanko, K; Estlander, T

    1999-12-01

    Occupational allergic contact dermatitis caused by (meth)acrylates is common in dental personnel, whereas dental acrylic fillings and crowns have rarely been reported to cause problems in dental patients. Here we report on a 48-year-old woman who developed gingivitis, stomatitis, and perioral dermatitis after a temporary crown made of restorative, two-component material had been inserted. The manufacturer stated that the temporary crown base paste and catalyst contained three (meth)acrylates, namely, a proacrylate, which is a modification of 2,2-bis[4-(2-hydroxy-3-methacryloxypropoxy)phenyl]propane (BIS-GMA); a tricyclate, which is a saturated, aliphatic, tricyclic methacrylate; and urethane methacrylate. The manufacturer refused to give more exact information on the (meth)acrylates. Patch testing revealed that the patient was highly allergic to BIS-GMA, other epoxy diacrylates, and (meth)acrylates, as well as to the base paste and catalyst of the temporary crown. Accordingly, it was concluded that the allergic reaction was caused by BIS-GMA, or a cross-reacting (meth)acrylate, or other (meth)acrylates in the temporary crown.

  18. Antibacterial Adhesion of Polymethyl Methacrylate Modified by Borneol Acrylate.

    PubMed

    Sun, Xueli; Qian, Zhiyong; Luo, Lingqiong; Yuan, Qipeng; Guo, Ximin; Tao, Lei; Wei, Yen; Wang, Xing

    2016-10-07

    Polymethyl methacrylate (PMMA) is a widely used biomaterial. But there is still a challenge facing its unwanted bacterial adhesion, because the subsequent biofilm formation usually leads to failure of related implants. Herein, we present a borneol-modified PMMA based on a facile and effective stereochemical strategy, generating antibacterial copolymer named as P(MMA-co-BA). It was synthesized by free radical polymerization and studied with different ratio between methyl methacrylate (MMA) and borneol acrylate (BA) monomers. NMR, GPC and EA etc. were used to confirm their chemical features. Their films were challenged with Escherichia coli (Gram-negative) and Bacillus subtilis (Gram-positive), showing a BA content-dependent antibacterial performance. The minimum effective dose should be 10%. Then in vivo subcutaneous implantations in mice demonstrated their biocompatibilities through routine histotomy and HE staining. Therefore, P(MMA-co-BA)s not only exhibited their unique antibacterial character, but also suggested a potential for the safe usage of borneol-modified PMMA frame and devices for further implantation.

  19. Modified acrylic bone cement with high amounts of ethoxytriethyleneglycol methacrylate.

    PubMed

    Pascual, B; Gurruchaga, M; Ginebra, M P; Gil, F J; Planell, J A; Vázquez, B; San Román, J; Goñi, I

    1999-03-01

    One cause of arthroplasty failure is the brittle mechanical behavior of bone cements. However, the improvement of cement formulations must also be accompanied by the maintenance of a wide variety of characteristics. New bone cements were obtained by the substitution of high percentages, up to 60% (v/v), of methyl methacrylate (MMA) by a higher molecular weight and more hydrophilic monomer, ethoxytriethyleneglycol methacrylate (TEG). The essential advantages of these materials were the decrease of maximum temperature together with a decrease in the residual monomer content with respect to conventional cement formulations. The water absorption process obeyed diffusion laws and the equilibrium water content increased by the introduction of higher percentages of the hydrophilic component. This characteristic had an appreciable effect on the viscoelastic behavior analyzed by DMTA. These modified bone cements had reduced polymerization shrinkage and similar levels of porosity. Tensile test revealed that the introduction of TEGMA gave rise to an important modification of the mechanical behavior, with a noticeable increase in the fracture strain. This fact was also confirmed by means of the analysis of the fracture surfaces by SEM.

  20. Synthesis of Methyl Methacrylate from Coal-Derived Syngas

    SciTech Connect

    Gerald N. Choi; James J. Spivey; Jospeh R. Zoeller; Makarand R. Gogate; Richard D. Colberg; Samuel S. Tam

    1998-04-17

    Research Triangle Institute (RTI), Eastman Chemical Company, and Bechtel collectively are developing a novel three-step process for the synthesis of methyl methacrylate (MMA) from coal-derived syngas that consists of the steps of synthesis of a propionate, its condensation with formaldehyde to form methacrylic acid (MAA), and esterification of MAA with methanol to produce MMA. RTI has completed the research on the three-step methanol-based route to MMA. Under an extension to the original contract, RTI is currently evaluating a new DME-based process for MMA. The key research need for DME route is to develop catalysts for DME partial oxidation reactions and DME condensation reactions. Over the last month, RTI has finalized the design of a fixed-bed microreactor system for DME partial oxidation reactions. RTI incorporated some design changes to the feed blending system, so as to be able to blend varying proportions of DME and oxygen. RTI has also examined the flammability limits of DME-air mixtures. Since the lower flammability limit of DME in air is 3.6 volume percent, RTI will use a nominal feed composition of 1.6 percent in air, which is less than half the lower explosion limit for DME-air mixtures. This nominal feed composition is thus considered operationally safe, for DME partial oxidation reactions. RTI is also currently developing an analytical system for DME partial oxidation reaction system.

  1. CEC separation of heterocyclic amines using methacrylate monolithic columns.

    PubMed

    Barceló-Barrachina, Elena; Moyano, Encarnación; Puignou, Lluís; Galceran, Maria Teresa

    2007-06-01

    Two methacrylate-based monolithic columns, one with a negatively charged group (sulfonic group) and another with a new monomer N,N-dimethylamino ethyl acrylate (DMAEA), were prepared and tested for the separation of basic compounds by CEC. This new monolithic stationary phase was prepared by the in situ polymerization of DMAEA with butyl methacrylate and ethylene dimethacrylate, using a ternary porogenic solvent consisting of water, 1-propanol and 1,4-butanediol. The performance of this column was evaluated by means of the analysis of a family of heterocyclic amines. Separation conditions such as pH, amount of organic modifier, ionic strength and elution mode (normal or counterdirectional flow) were studied. At the optimal running electrolyte composition, and using the counterdirectional mode, symmetrical electrochromatographic peaks were obtained, with the number of theoretical plates up to 30,000 and a good resolution between closely related peaks. The 2-acrylamido-2-methyl-1-propane-sulfonic acid column was used for CEC-MS, taking advantage of the compatibility of its elution mode (normal flow) with the MS coupling.

  2. Degradation of poly(methyl methacrylate) in solution

    SciTech Connect

    Madras, G.; Smith, J.M.; McCoy, B.J.

    1996-06-01

    The rate of degradation of poly(methyl methacrylate) (PMMA) to methyl methacrylate (MMA) was investigated in the liquid phase with toluene as the solvent. The degradation experiments were carried out in a tubular flow reactor at 1,000 psig (6.8 MPa) and at four different temperatures (200, 225, 275, and 300 C). The polymer concentration was varied by 1 to 4 g/L. A discrete model for the first-order rate of polymer degradation was derived and compared to the continuous kinetics approach. Both models lead to the same expression for monomer concentration increasing linearly with time. Rate constants were evaluated using the moments of the molecular weight distributions of the reacted and unreacted polymer. The rate was first order in polymer concentration, and the activation energy was 8.4 kcal/mol (34 kJ/mol). This activation energy suggests that the rate controlling step for the thermal degradation of PMMA is the depropagation process.

  3. The biological properties of a novel ethyl methacrylate resin.

    PubMed

    Suzuki, T; Jinno, S; Hattori, N; Okeya, H; Ishikawa, A; Deguchi, M; Ohno, Y; Kawai, T; Noguchi, T

    2006-01-01

    A novel ethyl methacrylate (EMA) resin was developed to overcome the tissue, organ and systemic damage associated with the residual monomer of conventional methyl methacrylate (MMA) resin bone cement. EMA resin is a chemical/ photopolymerizable material and is easy to handle during clinical procedures. The biocompatibility of EMA was evaluated in accordance with ISO10993-6. No inflammatory response was observed 1 and 9 weeks after implantation in the dorsal subcutaneous tissue of ddY mice. EMA resin also demonstrated better biocompatibility when compared with conventional bone cements. Poly-L-lactic acid (PLLA) was used as a carrier for bone morphogenetic protein (BMP) and added to the EMA slurry. The EMA-PLLA composite membrane was sticky and BMP readily adhered to its surface. The EMA-PLLA-BMP composite membrane induced new bone formation, the new bone growing in the shape of the EMA in the thigh muscle pouch of ddY mice. This novel EMA resin has many potential clinical applications.

  4. Superhydrophobic terpolymer nanofibers containing perfluoroethyl alkyl methacrylate by electrospinning

    NASA Astrophysics Data System (ADS)

    Cengiz, Ugur; Avci, Merih Z.; Erbil, H. Yildirim; Sarac, A. Sezai

    2012-05-01

    A new statistical terpolymer containing perfluoroethyl alkyl methacrylate (Zonyl-TM), methyl methacrylate and butyl acrylate, poly(Zonyl-TM-ran-MMA-ran-BA) was synthesized in supercritical carbon dioxide at 200 bar and 80 °C using AIBN as an initiator by heterogeneous free radical copolymerization. Nanofibers of this terpolymer were produced by electrospinning from its DMF solution. The structural and thermal properties of terpolymers and electrospun poly(Zonyl-TM-MMA-BA) nanofibers were analyzed using Fourier transform infrared spectroscopy, nuclear magnetic resonance spectroscopy and differential scanning calorimetry. Nanofiber morphology was investigated by scanning electron microscopy. Electrospun nanofiber layer was found to be superhydrophobic with a water contact angle of 172 ± 1° and highly oleophobic with hexadecane, glycerol and ethylene glycol contact angles of 70 ± 1°, 167 ± 1° and 163 ± 1° respectively. The change of the contact angle results on the electrospun fiber layer and flat terpolymer surfaces by varying feed monomer composition were compared and discussed in the text.

  5. Novel syngas-based process for methyl methacrylate

    SciTech Connect

    Gogate, M.R.; Spivey, J.J.; Zoeller, J.R.; Choi, G.N.; Tam, S.S.; Tischer, R.E.; Srivastava, R.D.

    1996-12-31

    Research Triangle Institute (RTI), Eastman Chemical Company, and Bechtel are developing a novel process for synthesis of methyl methacrylate (MMA) from coal-derived syngas, under a contract from the U.S. Department of Energy, Pittsburgh Energy Technology Center. This three-step process consists of synthesis of a propionate, its condensation with formaldehyde, and esterification of resulting methacrylic acid (MAA) with methanol to produce MMA. Eastman has focused on the research on propionate synthesis step. The resultant Mo catalysts work efficiently at much less severe conditions (170{degrees}C and 30 atm) than the conventional Ni catalysts (270{degrees}C and 180 atm). Bechtel has performed an extensive cost analysis, which shows that Eastman`s propionate synthesis process is competitive with other technologies to produce the anhydride. In the second step, RTI and Eastman have developed active and stable V-SI-P and Ta metal oxide catalysts for condensation reactions of propionates with formaldehyde. RTI has demonstrated a novel correlation among the catalyst acid-base properties, condensation reaction yield, and long-term catalyst activity. Current research focuses on enhancing the condensation reaction yields, acid-base properties, in situ condensation in a high- temperature, high-pressure (HTHP) slurry reactor, and alternate formaldehyde feedstocks. Based on Eastman and RTI laboratory reactor operating data, a cost estimate is also being developed for the integrated process.

  6. The acute aquatic toxicity of a series of acrylate and methacrylate esters

    SciTech Connect

    Staples, C.A.; McLaughlin, J.E.; Hamilton, J.D.

    1994-12-31

    Acute aquatic toxicity data for several acrylate and methacrylate esters were reviewed. Acrylates included acrylic acid, ethyl-, and butyl-acrylate. Methacrylates included methacrylic acid, methyl-, and butyl-methacrylate. Tests were 48 hr or 96 hr standard flow through (invertebrates and fish) assays (measured exposure concentrations). These data are currently used in a risk assessment of acrylate/methacrylate environmental safety. Algal growth (Selanastrum capricomutum) 96 hr EC{sub 50}s were 0.17 mg/L (NOEC < 0.13 mg/L) for acrylic acid, 11.0 mg/L (NOEC < 6.5 mg/L) for ethyl acrylate, and 5.2 mg/L (NOEC < 3.8 mg/L) for butyl acrylate. Invertebrate (Daphnia magna) 48 hr LC{sub 50}s were 95.0 mg/L (NOEC 23.0 mg/L) for acrylic acid, 7.9 mg/L (NOEC 3.4 mg/L) for ethyl acrylate, and 8.2 mg/L (NOEC 2.4 mg/L) for butyl acrylate. Rainbow trout (Oncorhynchus mykiss) 96 hr LC{sub 50}s were 27.0 mg/L (NOEC 6.3 mg/L) for acrylic acid, 4.6 mg/L (NOEC 0.78 mg/L) for ethyl acrylate, and 5.2 mg/L (NOEC 3.8 mg/L) for butyl acrylate. Algae 96 hr EC{sub 50}s were 0.59 mg/L (NOEC 0.38 mg/L) for methacrylic acid, 170.0 mg/L (NOEC 100.0 mg/L) for methyl methacrylate, and 130.0 mg/L for butyl methacrylate. Daphnia magna 48 hr LC{sub 50}s were > 130.0 mg/L (NOEC 130.0 mg/L) for methacrylic acid, 69.0 mg/L (NOEC 48.0 mg/L) for methyl methacrylate, and 32.0 mg/L (NOEC 23.0 mg/L) for butyl methacrylate. Trout 96 hr LC{sub 50}s were 85.0 mg/L (NOEC 12.0 mg/L) for methacrylic acid and > 79.0 mg/L (NOEC 40.0 mg/L) for methyl methacrylate. The fathead minnow (Pimephales promelas) 96 hr LC{sub 50} was 11.0 mg/L for butyl methacrylate.

  7. Structural characterization of a poly(methacrylic acid)-poly(methyl methacrylate) copolymer by nuclear magnetic resonance and mass spectrometry.

    PubMed

    Giordanengo, Rémi; Viel, Stéphane; Hidalgo, Manuel; Allard-Breton, Béatrice; Thévand, André; Charles, Laurence

    2009-11-03

    Mass spectrometry (MS) and nuclear magnetic resonance (NMR) have been combined to achieve the complete microstructural characterization of a poly(methacrylic acid)-poly(methyl methacrylate) (PMAA-PMMA) copolymer synthesized by nitroxide-mediated polymerization. Various PMAA-PMMA species could be identified which mainly differ in terms of terminaisons. 1H and 13C NMR experiments revealed the structure of the end-groups as well as the proportion of each co-monomer in the copolymers. These end-group masses were further confirmed from m/z values of doubly charged copolymer anions detected in the single stage mass spectrum. In contrast, copolymer composition derived from MS data was not consistent with NMR results, obviously due to strong mass bias well known to occur during electrospray ionization of these polymeric species. Tandem mass spectrometry could reveal the random nature of the copolymer based on typical dissociation reactions, i.e., water elimination occurred from any two contiguous MAA units while MAA-MMA pairs gave rise to the loss of a methanol molecule. Polymer backbone cleavages were also observed to occur and gave low abundance fragment ions which allowed the structure of the initiating end-group to be confirmed.

  8. Analytical strategy for the molecular weight determination of random copolymers of poly(methyl methacrylate) and poly(methacrylic acid).

    PubMed

    Giordanengo, Rémi; Viel, Stéphane; Hidalgo, Manuel; Allard-Breton, Béatrice; Thévand, André; Charles, Laurence

    2010-06-01

    Molecular weight characterization of random amphiphilic copolymers currently represents an analytical challenge. In particular, molecules composed of methacrylic acid (MAA) and methyl methacrylate (MMA) as the repeat units raise issues in commonly used techniques. The present study shows that when random copolymers cannot be properly ionized by MALDI, and hence detected and measured in MS, one possible analytical strategy is to transform them into homopolymers, which are more amenable to this ionization technique. Then, by combining the molecular weight of the so-obtained homopolymers, as measured by MS, with the relative molar proportion of the MMA and MMA units, as given by (1)H NMR spectrum, one can straightforwardly estimate the molecular weight of the initial copolymer. A methylation reaction was performed to transform MAA-MMA copolymer samples into PMMA homopolymers, using trimethylsilyldiazomethane as a derivatization agent. Weight average molecular weight (M(w)) parameters of the MAA-MMA copolymers could then be derived from M(w) values obtained for the methylated MAA-MMA molecules by MALDI, which were also validated by pulsed gradient spin echo (PGSE) NMR. An alkene function in one of the studied copolymer end-groups was also shown to react with the methylation agent, giving rise to MMA-like polymeric by-products characterized by tandem mass spectrometry and which could be avoided by adjusting the amount of the trimethylsilyldiazomethane in the reaction medium.

  9. Poly(2-hydroxyethyl methacrylate-co-dodecyl methacrylate-co-acrylic acid): synthesis, physico-chemical characterisation and nafcillin carrier.

    PubMed

    Zecheru, Teodora; Rotariu, Traian; Rusen, Edina; Mărculescu, Bogdan; Miculescu, Florin; Alexandrescu, Laura; Antoniac, Iulian; Stancu, Izabela-Cristina

    2010-10-01

    In the present study polymeric microbeads of poly(2-hydroxyethyl methacrylate-co-dodecyl methacrylate-co-acrylic acid) or p(HEMA-co-dDMA-co-AA) were synthesised and characterized through FT-IR and scanning electron microscopy (SEM); their swelling behavior against saline solution was explored and their in vitro cytotoxicity was evaluated. Further, in order to elucidate kinetic aspects regarding the ternary system p(HEMA-co-dDMA-co-AA), a mathematical model of the reactivity ratios of the comonomers in the terpolymer has been conceived and analyzed. An intensified tendency of AA units accumulation in the copolymer has been noticed, in spite of HEMA units, while dDMA conserves in the copolymer the fraction from the feed. Three compositions have been selected for nafcillin-loading and their in vitro release capacity was evaluated. The compositions of 80:10:10 and 75:10:15 M ratios appear suitable for further in vivo testing, in order to be used as drug delivery systems in the treatment of different osseous diseases.

  10. Feedback-regulated paclitaxel delivery based on poly(N,N-dimethylaminoethyl methacrylate-co-2-hydroxyethyl methacrylate) nanoparticles.

    PubMed

    You, Jin-Oh; Auguste, Debra T

    2008-04-01

    pH-Sensitive poly(N,N-dimethylaminoethyl methacrylate (DMAEMA)/2-hydroxyethyl methacrylate (HEMA)) nanoparticles were prepared for the triggered release of paclitaxel within a tumor microenvironment. Tumors exhibit a lower extracellular pH than normal tissues. We show that paclitaxel release from DMAEMA/HEMA particles can be actively triggered by small, physiological changes in pH (within 0.2-0.6 pH units). Monodispersed nanoparticles were synthesized by forming an O/W emulsion followed by photopolymerization. Particles were characterized by transmission electron microscopy, dynamic light scattering, electrophoresis, and cytotoxicity. High release rates and swelling ratios are achieved at low pH, low crosslinking density, and high content of DMAEMA. Paclitaxel release is limited to 9% of the payload at pH 7.4 after a 2-h incubation at 37 degrees C. After adjusting to pH 6.8, 25% of the payload is released within 2h. Cell viability studies indicate that pH-sensitive DMAEMA/HEMA nanoparticles are not cytotoxic and may be used as an efficient, feedback-regulated drug delivery carrier.

  11. Radiation-grafted polymers for biomaterial applications. I. 2-hydroxyethyl methacrylate: ethyl methacrylate grafting onto low density polyethylene films

    SciTech Connect

    Cohn, D.; Hoffman, A.S.; Ratner, B.D.

    1984-08-01

    Studies were conducted on the radiation grafting of 2-hydroxyethyl methacrylate (HEMA) and ethyl methacrylate (EMA) by the mutual irradation technique onto low density polyethylene. Four different solution concentrations were used, and radiation doses ranged from 0.03 to 0.50 Mrad. Four copolymer compositions having different HEMA:EMA ratios were also studied using two total monomer concentrations. The kinetics of the grafting process demonstrated by the two monomers were basically different. While EMA showed a typical diffusion-controlled kinetic pattern, HEMA exhibited a more complex behavior, the main features of which were an induction period, a slight autoacceleration and a significant drop in graft level after a maximum is reached. The difference in behavior was interpreted in terms of partitioning of monomers into the polyethlene substrate. The surface topography of the grafted films was studied by means of scanning electron microscopy. A mechanism based on osmotic cell formation was suggested for the HEMA graft system. The copolymer systems investigated showed that the graft reaction is faster in the initial stages for higher percentages of EMA in the monomer mixtures; as grafting proceeds the trend is reversed. 24 references, 16 figures, 2 tables.

  12. Metal complexes of tetrapodal ligands: synthesis, spectroscopic and thermal studies, and X-ray crystal structure studies of Na(I), Ca(II), Sr(II), and Ba(II) complexes of tetrapodal ligands N,N,N',N'-tetrakis(2-hydroxypropyl)ethylenediamine and N,N,N',N'-tetrakis(2-hydroxyethyl)ethylenediamine.

    PubMed

    Hundal, Geeta; Hundal, Maninder Singh; Obrai, Sangeeta; Poonia, N S; Kumar, Subodh

    2002-04-22

    Twelve complexes 1-12 of general category [M(ligand)(anion)(x)(water)(y)], where ligand = N,N,N',N'-tetrakis(2-hydroxypropyl/ethyl)ethylenediamine (HPEN/HEEN), anion = anions of picric acid (PIC), 3,5-dinitrobenzoic acid (DNB), 2,4-dinitrophenol (DNP), and o-nitrobenzoic acid (ONB), M = Ca(2+), Sr(2+), Ba(2+), or Na(+), x = 1 and 2, and y = 0-4, were synthesized. All of these complexes were characterized by elemental analysis, IR, (1)H and (13)C NMR, and thermal studies. X-ray crystal studies of these complexes 1-12, [Ca(HPEN)(H(2)O)(2)](PIC)(2).H(2)O (1), [Ca(HEEN)(PIC)](PIC) (2), Ba(HPEN)(PIC)(2) (3), [Na(HPEN)(PIC)](2) (4), Ca(HPEN)(H(2)O)(2)](DNB)(2).H(2)O (5),Ca(HEEN)(H(2)O)](DNB)(2).H(2)O (6), [Sr(HPEN)(H(2)O)(3)](DNB)(2) (7), [Ba(HPEN)(H(2)O)(2)](DNB)(2).H(2)O](2) (8), [[Ba(HEEN)(H(2)O)(2)](ONB)(2)](2) (9), [[Sr(HPEN)(H(2)O)(2)](DNP)(2)](2) (10), [[Ba(HPEN)(H(2)O)(2)](DNP)(2)](2) (11), and [Ca(HEEN)(DNP)](DNP) (H(2)O) (12), have been carried out at room temperature. Factors which influence the stability and the type of complex formed have been recognized as H-bonding interactions, presence/absence of solvent, nature of the anion, and nature of the cation. Both the ligands coordinate the metal ion through all the six available donor atoms. The complexes 1 and 5-11 have water molecules in the coordination sphere, and their crystal structures show that water is playing a dual character. It coordinates to the metal ion on one hand and strongly hydrogen bonds to the anion on the other. These strong hydrogen bonds stabilize the anion and decrease the cation-anion interactions by many times to an extent that the anions are completely excluded out of the coordination sphere and produce totally charge-separated complexes. In the absence of water molecules as in 2 and 3 the number of hydrogen bonds is reduced considerably. In both the complexes the anions case interact more strongly with the metal ion to give rise to a partially charge-separated 2 or tightly ion

  13. Inhibitory effect of green tea extract on the process of pancreatic carcinogenesis induced by N-nitrosobis-(2-oxypropyl)amine (BOP) and on tumor promotion after transplantation of N-nitrosobis-(2-hydroxypropyl)amine (BHP)-induced pancreatic cancer in Syrian hamsters.

    PubMed

    Hiura, A; Tsutsumi, M; Satake, K

    1997-10-01

    Epidemiologic studies have shown a lower risk of gastrointestinal cancer in green tea drinkers. In the present study, the inhibitory effect of green tea extract (GTE) on the process of pancreatic carcinogenesis induced by N-nitrosobis-(2-oxypropyl)amine (BOP) and on tumor promotion after transplantation of N-nitrosobis-(2-hydroxypropyl)amine (BHP)-induced pancreatic cancer were investigated in hamsters. In the first experiment, shortly after the initiation of pancreatic carcinogenesis by BOP, the animals in the GTE group were given GTE (0.5 mg/L) in their drinking water and the control group was given tap water. All animals were sacrificed 24 weeks later. There were no significant differences in body weight, water intake, or food consumption between the two groups during the experiments. GTE consumption was approximately 1.25 mg/day/100 g body weight during this experiment. Seven of the 13 hamsters (54%) in the control group were found to have pancreatic tumors, versus six of the 18 hamsters (33%) in the GTE group. The average number of tumors in the control group was 1.0/hamster, compared with 0.5/hamster in the GTE group. The overall incidence of macroscopic pancreatic tumors in the GTE group was about half that in the control group. The incidence of pancreatic cancer was 54% (12/13) in the control group and 44% (8/18) in the GTE group. The number of pancreatic cancers, including invasive carcinoma and carcinoma in situ, in the GTE group was 0.88/hamster, significantly lower than in the control group (1.68/hamster) (p < 0.05). The incidence of atypical ductal hyperplasia, which is thought to be an early pancreatic cancer, was also significantly lower in the GTE group than in the control group (1.50/hamster vs. 4.65/hamster) (p < 0.05). In the second experiment, 1-mm3 pieces of BHP-induced pancreatic cancer were transplanted into the back of hamsters. The control group (N = 16) was maintained on the basal diet and tap water throughout the experiment, and the GTE

  14. SYNTHESIS OF METHYL METHACRYLATE FROM COAL-DERIVED SYNGAS

    SciTech Connect

    BEN W.-L. JANG; GERALD N. CHOI; JAMES J. SPIVEY; JOSPEH R. ZOELLER; RICHARD D. COLBERG.

    1999-01-20

    Research Triangle Institute (RTI), Eastman Chemical Company, and Bechtel collectively are developing a novel three-step process for the synthesis of methyl methacrylate (MMA) from coal-derived syngas that consists of the steps of synthesis of a propionate, its condensation with formaldehyde to form methacrylic acid (MAA), and esterification of MAA with methanol to produce MMA. The research team has completed the research on the three-step methanol-based route to MMA. Under an extension to the original contract, we are currently evaluating a new DME-based process for MMA. The key research need for DME route is to develop catalysts for DME partial oxidation reactions and DME condensation reactions. Over the last quarter(Oct.-Dec./98), we have investigated the condensation between methyl propionate and formaldehyde (MP/HCHO=4.5/1) at various reaction temperatures(280-360EC) over 5%, 10%, and 20% Nb O /SiO catalysts. The conversion of HCHO increases with reaction 2 5 2 temperature and niobium loading. MMA+MAA selectivity goes through a maximum with the temperature over both 10% and 20% Nb O /SiO . The selectivities to MMA+MAA are 67.2%, 2 5 2 72.3%and 58.1% at 320EC over 5%, 10%, 20% Nb O /SiO , respectively. However, the 2 5 2 conversion of formaldehyde decreases rapidly with time on stream. The results suggest that silica supported niobium catalysts are active and selective for condensation of MP with HCHO, but deactivation needs to be minimized for the consideration of commercial application. We have preliminarily investigated the partial oxidation of dimethyl ether(DME) over 5% Nb O /SiO catalyst. Reactant gas mixture of 0.1% DME, 0.1% O and balance nitrogen is 2 5 2 2 studied with temperature ranging from 200C to 500C. The conversion of DME first increases with temperature reaching an maximum at 400C then decreases. The selectivity to HCHO also increases with reaction temperature first. But the selectivity to HCHO decreases at temperature above 350C accompanied by

  15. SYNTHESIS OF METHYL METHACRYLATE FROM COAL-DERIVED SYNGAS

    SciTech Connect

    BEN W.-L. JANG; GERALD N. CHOI; JAMES J. SPIVEY; JOSPEH R. ZOELLER; RICHARD D. COLBERG

    1999-01-20

    Research Triangle Institute (RTI), Eastman Chemical Company, and Bechtel collectively are developing a novel three-step process for the synthesis of methyl methacrylate (MMA) from coal-derived syngas that consists of the steps of synthesis of a propionate, its condensation with formaldehyde to form methacrylic acid (MAA), and esterification of MAA with methanol to produce MMA. The research team has completed the research on the three-step methanol-based route to MMA. Under an extension to the original contract, we are currently evaluating a new DME-based process for MMA. The key research need for DME route is to develop catalysts for DME partial oxidation reactions and DME condensation reactions. Over the last quarter(Oct.-Dec./98), we have investigated the condensation between methyl propionate and formaldehyde (MP/HCHO=4.5/1) at various reaction temperatures(280-360EC) over 5%, 10%, and 20% Nb O /SiO catalysts. The conversion of HCHO increases with reaction 2 5 2 temperature and niobium loading. MMA+MAA selectivity goes through a maximum with the temperature over both 10% and 20% Nb O /SiO . The selectivities to MMA+MAA are 67.2%, 2 5 2 72.3%and 58.1% at 320EC over 5%, 10%, 20% Nb O /SiO , respectively. However, the 2 5 2 conversion of formaldehyde decreases rapidly with time on stream. The results suggest that silica supported niobium catalysts are active and selective for condensation of MP with HCHO, but deactivation needs to be minimized for the consideration of commercial application. We have preliminarily investigated the partial oxidation of dimethyl ether(DME) over 5% Nb O /SiO catalyst. Reactant gas mixture of 0.1% DME, 0.1% O and balance nitrogen is 2 5 2 2 studied with temperature ranging from 200°C to 500°C. The conversion of DME first increases with temperature reaching an maximum at 400°C then decreases. The selectivity to HCHO also increases with reaction temperature first. But the selectivity to HCHO decreases at temperature above 350

  16. Synthesis and aqueous solution properties of novel sugar methacrylate-based homopolymers and block copolymers.

    PubMed

    Narain, Ravin; Armes, Steven P

    2003-01-01

    We report the facile preparation of a range of novel, well-defined cyclic sugar methacrylate-based polymers without recourse to protecting group chemistry. 2-Gluconamidoethyl methacrylate (GAMA) and 2-lactobionamidoethyl methacrylate (LAMA) were prepared directly by reacting 2-aminoethyl methacrylate with D-gluconolactone and lactobionolactone, respectively. Homopolymerization of GAMA and LAMA by atom transfer radical polymerization (ATRP) gave reasonably low polydispersities as judged by aqueous gel permeation chromatography. A wide range of sugar-based block copolymers were prepared using near-monodisperse macroinitiators based on poly(ethylene oxide) [PEO], poly(propylene oxide) [PPO], or poly(e-caprolactone) [PCL] and/or by sequential monomer addition of other methacrylic monomers such as 2-(diethylamino)ethyl methacrylate [DEA], 2-(diisopropylaminoethyl methacrylate [DPA], or glycerol monomethacrylate [GMA]. The reversible micellar self-assembly of selected sugar-based block copolymers [PEO23-GAMA50-DEA100, PEO23-LAMA30-DEA50, PPO33-GAMA50, and PPO33-LAMA50] was studied in aqueous solution as a function of pH and temperature using dynamic light scattering, transmission electron microscopy, surface tensiometry, and 1H NMR spectroscopy.

  17. Poly(divinylbenzene-alkyl methacrylate) monolithic stationary phases in capillary electrochromatography.

    PubMed

    Huang, Hsi-Ya; Cheng, Yi-Jie; Liu, Wan-Ling; Hsu, Yi-Fen; Lee, Szetsen

    2010-09-10

    In this study, a series of poly(divinylbenzene-alkyl methacrylate) monolithic stationary phases, which were prepared by single step in situ polymerization of divinylbenzene and various alkyl methacrylates (butyl-, octyl-, or lauryl-methacrylate), were developed as separation columns of benzophenone compounds for capillary electrochromatography (CEC). In addition to the presence of plenty of benzene moieties, the stationary phases contained long and flexible alkyl groups on the surface. With an increase in the molecular length of alkyl methacrylate, the polymeric monolith, which had higher hydrophobicity, effectively reduced the peak tailing of benzophenones, but a weaker retention was observed. The unusual phenomenon was likely due to the pi-pi interaction between the aromatic compound and the polymeric material. The usage of longer alkyl methacrylate as reaction monomer limited the retention of aromatic compounds on the stationary phase surface, thus the pi-pi interaction between them was possibly reduced. Consequently, the retention time of aromatic compounds was markedly decreased with an increase in carbon length of alkyl methacrylate that was carried on the polymeric monolith. Compared to previous reports on polystyrene-based columns in which the peak-tailing problem was reduced by decreasing the benzene moieties on the stationary phase, this study demonstrated that the undesirable retention (peak-tailing) could also be improved by the inclusion of long alkyl methacrylate to the polystyrene-based columns.

  18. Synthesis and fluorescence properties of divalent europium-poly(methacrylate containing crown ether structure) complexes

    SciTech Connect

    Higashiyama, N.; Nakamura, H.; Mishima, T.; Shiokawa, J.; Adachi, G. )

    1991-02-01

    This paper reports on divalent europium complexes with poly(methacrylate containing crown ether structure)s, poly(crown ether)s, prepared and their fluorescence properties studied. The polymers used were poly(15-crown-5-methyl methacrylate) (PMA15C5), copoly(15- crown-5-methyl methacrylate-X) (copoly(MA15C5-X)); (X = MMA, EMA, BMA, 2-methoxyethyl methacrylate (MAGI) 3,6,9,12,15- pentaoxahexadecyl methacrylate (MAG5)), poly(18-crown-6- methyl methacrylate) (PMA18C6), and copoly(18-crown-6-methyl methacrylate-MMA) (copoly(MA18C6-MMA)), which were obtained by bulk polymerization. The fluorescence properties of Eu{sup 2+} polymers activated by complexing Eu{sup 2+} ions with crown ether groups were measured in powder form. The Eu{sup 2+}-poly (crown ether)s irradiated by UV light generally gave blue bright emission in the region of 420-465 nm. It was Eu{sup 2+}-copoly(Ma15C5-X); (X = MMA, EMA, and MAG1) that showed the largest emission intensity among the Eu{sup 2+} polymers, and its emission intensity was ca. 20% of that for CaWO{sub 4}:Pb (NBS1026) whose quantum efficiency is about 76%. The intensities of emission for the Eu{sup 2+} polymers containing 15-crown-5 were much larger than that for the ones containing 18-crown-6.

  19. Dye attached poly(hydroxyethyl methacrylate) cryogel for albumin depletion from human serum.

    PubMed

    Andac, Muge; Galaev, Igor; Denizli, Adil

    2012-05-01

    Cibacron Blue F3GA was immobilized on poly(hydroxyethyl methacrylate) cryogel and it was used for selective and efficient depletion of albumin from human serum. The poly(hydroxyethyl methacrylate) was selected as the basic component because of its inertness, mechanical strength, chemical and biological stability, and biocompatibility. Cibacron Blue F3GA was covalently attached to the poly(hydroxyethyl methacrylate) cryogel to produce poly(hydroxyethyl methacrylate)-Cibacron Blue F3GA cryogel affinity column. The poly(hydroxyethyl methacrylate)-Cibacron Blue F3GA cryogel was characterized with respect to gelation yield, swelling degree, total volume of macropores, Fourier Transform Infrared spectroscopy, and scanning electron microscopy. It was found that the maximum amount of adsorption (343 mg/g of dry cryogel) obtained from experimental results is very close to the calculated Langmuir adsorption capacity (345 mg/g of dry cryogel). The maximum adsorption capacity for poly(hydroxyethyl methacrylate)-Cibacron Blue F3GA cryogel column was obtained as 950 mg/g of dry cryogel for nondiluted serum. The adsorption capacity decreased with increasing dilution ratios while the depletion ratio of albumin remained as 77% in serum sample. Finally, the poly(hydroxyethyl methacrylate)-Cibacron Blue F3GA cryogel was optimized for using in the fast protein liquid chromatography system for rapid removal of the high abundant proteins from the human serum.

  20. Study of scintillation in natural and synthetic quartz and methacrylate

    NASA Astrophysics Data System (ADS)

    Amaré, J.; Borjabad, S.; Cebrián, S.; Cuesta, C.; Fortuño, D.; García, E.; Ginestra, C.; Gómez, H.; Herrera, D. C.; Martínez, M.; Oliván, M. A.; Ortigoza, Y.; Ortiz de Solórzano, A.; Pobes, C.; Puimedón, J.; Sarsa, M. L.; Villar, J. A.; Villar, P.

    2014-06-01

    Samples from different materials typically used as optical windows or light guides in scintillation detectors were studied in a very low background environment, at the Canfranc Underground Laboratory, searching for scintillation. A positive result can be confirmed for natural quartz: two distinct scintillation components have been identified, not being excited by an external gamma source. Although similar effect has not been observed neither for synthetic quartz nor for methacrylate, a fast light emission excited by intense gamma flux is evidenced for all the samples in our measurements. These results could affect the use of these materials in low energy applications of scintillation detectors requiring low radioactive background conditions, as they entail a source of background.

  1. A review of methods used to reinforce polymethyl methacrylate resin.

    PubMed

    Vallittu, P K

    1995-09-01

    Various methods to reinforce acrylic denture base material have been used to repair fractures in complete dentures. Metal wires and plates have been tested as reinforcement of polymethyl methacrylate (PMMA) resin. The contributions of the studies conducted on this biphase composite system are discussed in this review article. The literature has reported that even thin metal wires incorporated into the PMMA matrix increased the transverse strength of the PMMA construction. Metal mesh inserted into PMMA resin had negligible effects on the transverse strength of the restoration. macroscopic retention of the metal strengtheners to the PMMA had only a minor effect on the strength in contrast to microscopic retention, which showed a more marked effect. Chemical bonding between the PMMA and metal reinforcer enhanced the strength of the prosthesis with some exceptions.

  2. Methyl Methacrylate Polymerization in Nanoporous Matrix: Reactivity and Molecular Weight

    NASA Astrophysics Data System (ADS)

    Zhao, Haoyu; Simon, Sindee

    2011-03-01

    The influence of nanoconfinement on the free radical polymerization of methyl methacrylate is investigated. Nanoporous controlled pore glass (CPG) is used as a nanoconfining matrix for the polymerization. The reaction is followed by measuring heat flow as a function of reaction time during isothermal polymerization using differential scanning calorimetry (DSC). Preliminary results indicate several interesting effects for polymerization in 110 nm diameter pores: the induction time increases under nanoconfinement, the effective reaction rate constant increases, the effective activation energy is unchanged, and the gel effect or autoaccleration occurs at earlier times after induction. The latter result concerning the gel effect is presumably due to the decrease in diffusivity under nanoconfinement which results in a decrease in the termination rate of free radicals. The cause of the longer induction times and accelerated reaction rates just after induction are under investigation. The influence of nanoconfinement on molecular weight will also be examined.

  3. Interaction between N-vinylpyrrolidone and methyl methacrylate

    NASA Astrophysics Data System (ADS)

    Zaitseva, V. V.; Shtonda, A. V.; Tyurina, T. G.; Bagdasarova, A. R.; Zaitsev, S. Yu.

    2014-04-01

    It is established that the interaction of the isomers of N-vinylpyrrolidone (NVP) and methyl methacrylate (MMA) leads to the formation of molecular π-H- and H-complexes with energies within the limits of 10.2-13.6 (AM1) or 18.2-24.0 (B3LYP/6-311++G( d)) kJ/mol. The structures of complex-bound molecules are examined with respect to changes in the charges on terminal -C1=C2- groups, the distance between them and atoms in an H-bond, and the presence of combined overlapping molecular orbitals (MOs). The presence of an averaged complex that includes presumably all possible structures and allows us to perform the copolymerization of specified monomers in the absence of an initiator is confirmed by means of UV and NMR spectroscopy.

  4. Porous conductive polyblends of polyaniline in poly(methyl methacrylate)

    NASA Astrophysics Data System (ADS)

    Price, Aaron D.; Naguib, Hani E.

    2008-03-01

    The conductive polymer polyaniline is typically blended with conventional industrial thermoplastics in order to obtain an electrically conductive polymer blend with adequate mechanical properties. Processing these polyblends into foams yields a porous conductive material that exhibits immense application potential such as dynamic separation media and low-density electrostatic discharge protection. In the current study, the morphology of a thermally-processable blend consisting of an electrically conductive polyaniline-dodecylbenzene sulfonic acid complex and poly(methyl methacrylate) is explored using a two-phase batch foaming setup. The effect of blend composition and processing parameters on the resulting cellular morphology is investigated. Finally, the impact of the underlying microstructure on the frequency dependent electrical conductivity is elucidated.

  5. Radiation synthesis of nanosilver nanohydrogels of poly(methacrylic acid)

    NASA Astrophysics Data System (ADS)

    Gupta, Bhuvanesh; Gautam, Deepti; Anjum, Sadiya; Saxena, Shalini; Kapil, Arti

    2013-11-01

    Nanosilver nanohydrogels (nSnH) of poly(methacrylic acid) were synthesized and stabilized using gamma irradiation. The main objective of this study was to develop silver nanoparticles and to evaluate the antimicrobial activity. Radiation helps in the polymerization, crosslinking and reduction of silver nitrate as well. Highly stable and uniformly distributed silver nanoparticles have been obtained within hydrogel network by water in oil nanoemulsion polymerization and were evaluated by dynamic light scattering (DLS) and transmission electron microscopy (TEM) respectively. TEM showed almost spherical and uniform distribution of silver nanoparticles through the hydrogel network. The mean size of silver nanoparticles ranging is 10-50 nm. The nanohydrogels showed good swelling in water. Antibacterial studies of nSnH suggest that it can be a good candidate as coating material in biomedical applications.

  6. Chest wall reconstruction with methacrylate prosthesis in Poland syndrome.

    PubMed

    Arango Tomás, Elisabet; Baamonde Laborda, Carlos; Algar Algar, Javier; Salvatierra Velázquez, Angel

    2013-10-01

    Poland syndrome is a rare congenital malformation. This syndrome was described in 1841 by Alfred Poland at Guy's Hospital in London. It is characterized by hypoplasia of the breast and nipple, subcutaneous tissue shortages, lack of the costosternal portion of the pectoralis major muscle and associated alterations of the fingers on the same side. Corrective treatment of the chest and soft tissue abnormalities in Poland syndrome varies according to different authors. We report the case of a 17-year-old adolescent who underwent chest wall reconstruction with a methyl methacrylate prosthesis. This surgical procedure is recommended for large anterior chest wall defects, and it prevents paradoxical movement. Moreover it provides for individual remodeling of the defect depending on the shape of the patient's chest.

  7. Synthesis of Methyl Methacrylate From Coal-Derived Syngas

    SciTech Connect

    Ben W.-L. Jang; Gerald N. Choi; James J. Spivey; Jospeh R. Zoeller; Richard D. Colberg; Samuel S. Tam

    1998-07-27

    Research Triangle Institute (RTI), Eastman Chemical Company, and Bechtel collectively are developing a novel three-step process for the synthesis of methyl methacrylate (MMA) from coal-derived syngas that consists of the steps of synthesis of a propionate, its condensation with formaldehyde to form methacrylic acid (MAA), and esterification of MAA with methanol to produce MMA. RTI has completed the research on the three-step methanol-based route to MMA. Under an extension to the original contract, RTI is currently evaluating a new DME-based process for MMA. The key research need for DME route is to develop catalysts for DME partial oxidation reactions and DME condensation reactions. Over the last quarter(April-June, 1998), RTI has modified the reactor system including a new preheater and new temperature settings for the preheater. Continuous condensation of formaldehyde with propionic acid were carried out over 10% Nb O /SiO at 300°C without 2 5 2 interruption. Five activity and four regeneration cycles have been completed without plugging or material balance problems. The results show that 10% Nb O /SiO deactivates slowly with time 2 5 2 but can be regenerated, at least four times, to 100% of its original activity with 2% O in nitrogen 2 at 400°C. The cycles continue with consistent 90-95% of carbon balance. The reaction is scheduled to complete with 6 activity cycles and 5 regenerations. Used catalysts will be analyzed with TGA and XPS to determine bulk and surface coke content and coke properties. RTI will start the investigation of effects of propionic acid/formaldehyde ratio on reaction activity and product selectivity over 20% Nb O /SiO catalysts.

  8. Reactivity of Monovinyl (Meth)Acrylates Containing Cyclic Carbonates.

    PubMed

    Berchtold, Kathryn A; Nie, Jun; Stansbury, Jeffrey W; Bowman, Christopher N

    2008-12-09

    The tremendous diversity of materials properties available with polymers is due in large part to the ability to design structures from the monomeric state. The ease of use of comonomer mixtures only expands this versatility. While final polymer properties are obviously important in the selection or development of a material for a given purpose, for a number of applications, such as optical fiber coatings, photolithography and microelectronics, the additional requirement of a very rapid polymerization process may be equally critical. A class of unusually reactive mono-(meth)acrylate monomers bearing secondary functionality that includes carbonates, carbamates and oxazolidones, has been demonstrated but not fully explained. Here, the influence of an integral cyclic carbonate functional group on (meth)acrylate photopolymerization kinetics is examined in detail with respect to monomers with a wide variety of alternative secondary functionality structure as well as in comparison to conventional mono- and di-(meth)acrylates. The kinetic results from full cure studies of several cyclic carbonate-containing monomers clearly highlight specific structural variations that effectively promote monomer reactivity. Copolymerizations with tetrahydrofurfuryl methacrylate reflect similar dramatic kinetic effects associated with the novel monomers while partial cure homopolymerization studies reveal exceptional dark cure behavior linked to observations of uncommonly low ratios of termination to propagation rates throughout the conversion profile. Temperature effects on reaction kinetics, including both reaction rate and the individual kinetic parameters, as well as the temperature dependence of hydrogen bonding interactions specifically involving the secondary functional groups are probed as a means to understand better the fundamentally interesting and practically important behavior of these monomers.

  9. Vascular responsiveness to dimethylaminoethyl methacrylate and its degradation products.

    PubMed

    Abebe, Worku; Maddux, William F; Schuster, George S; Lewis, Jill B

    2003-07-01

    The increasing use of acrylate-based resins in dentistry has raised questions about the biocompatibility of these substances with oral tissues. The focus of the present investigation was to assess the responsiveness of blood vessels to the resin polymerization accelerating agent dimethylaminoethyl methacrylate (DMAEMA) and its degradation products dimethylethanolamine (DME) and methacrylic acid (MAA), using the rat aortic ring preparation as a tissue model. DMAEMA induced concentration-dependent relaxation of norepinephrine (NE)-contracted aortic rings with and without endothelium. N-nitro-L-arginine methyl ester (L-NAME) selectively inhibited the endothelium-dependent relaxation induced by DMAEMA, suggesting the release of nitric oxide from the endothelium by DMAEMA. Both indomethacin and glybenclamide attenuated the vasorelaxation elicited by DMAEMA in the presence as well as in the absence of endothelium, providing evidence for the role of vasorelaxant prostanoid(s) and K(ATP) channel activation in the responses observed. On the other hand, while MAA was without any apparent effect on the rat aorta, DMAEMA at high and DME at relatively low concentrations caused contraction of the tissues with and without endothelium in the absence of NE. The DME-induced contraction was inhibited by indomethacin, suggesting the involvement of contractile arachidonic acid metabolite(s) in the action of DME. This observation was supported by the findings of increased thromboxane A(2) (TXA(2)) production in aortic rings incubated with DME. Taken together, the data suggest that both DMAEMA and its degradation product, DME, are vasoactive, inducing vasorelaxation and contraction by various mechanisms that may involve the release of nitric oxide from the endothelium, the activation of smooth muscle K(ATP) channels, and the generation of vasorelaxant prostanoid(s) and TXA(2). These effects may play a role in tissue homeostasis and certain adverse conditions associated with the use of

  10. Synthesis of acrylates and Methacrylates from Coal-Derived Syngas

    SciTech Connect

    1997-05-12

    Research Triangle Institute (RTI), Eastman Chemical Company, and Bechtel collectively are developing a novel process for the synthesis of methyl methacrylate (MMA) from coal-derived syngas, under a contract from the U.S. Department of Energy, Federal Energy Technology Center. This three-step process consists of synthesis of a propionate, its condensation with formaldehyde, and esterification of resulting methacrylic acid (MAA) with methanol to produce MMA. Eastman has focused on the propionate synthesis step. The resultant Mo catalysts work efficiently at much less severe conditions (170{degrees}C and 30 atm) than the conventional Ni catalysts (270{degrees} C and 180 atm). Bechtel has performed an extensive cost analysis which shows that Eastman`s propionate synthesis step is competitive with other technologies to produce the anhydride. Eastman and Bechtel have also compared the RTI- Eastman-Bechtel three-step methanol route to five other process routes to MMA. The results show that the product MMA can be produced at 520/lb, for a 250 Mlb/year MMA plant, and this product cost is competitive to all other process routes to MMA, except propyne carbonylation. In the second step, RTI and Eastman have developed active and stable V-SI-P tertiary metal oxide catalysts, Nb/Si0{sub 2}, and Ta/Si0{sub 2} catalysts for condensation of propionic anhydride or propionic acid with formaldehyde. RTI has demonstrated a novel correlation among the catalyst acid-base properties, condensation reaction yield, and long-term catalyst performance. Eastman and Bechtel have used the RTI experimental results of a 20 percent Nb/Si0{sub 2} catalyst, in terms of reactant conversions, MAA selectivities, and MAA yield, for their economic analysis. Recent research focuses on enhancing the condensation reaction yields, a better understanding of the acid-base property correlation and enhancing the catalyst lifetime.

  11. Manufacture of poly(2-hydroxyethyl methacrylate-co-methyl methacrylate) hydrogel tubes for use as nerve guidance channels.

    PubMed

    Dalton, Paul D; Flynn, Lauren; Shoichet, Molly S

    2002-09-01

    Hydrogel tubes of poly(2-hydroxyethyl methacrylate-co-methyl methacrylate) (p(HEMA-co-MMA)) made by liquid-liquid centrifugal casting are being investigated as potential nerve guidance channels in the central nervous system. An important criterion for the nerve guidance channel is that its mechanical properties are similar to those of the spinal cord, where it will be implanted. The formulated p(HEMA-co-MMA) tubes are soft and flexible, consisting of a gel-like outer layer, and an interconnected macroporous, inner layer. The relative thickness of the gel phase to macroporous phase is controlled by the formulation chemistry, and specifically by the ratio of co-monomers, HEMA and MMA. By varying the surface chemistry of the mold within which the tubes are synthesized, tubes were prepared with either a "cracked" or a smooth outer morphology. Tubes with the cracked outer morphology had periodic channels that traversed the wall of the tube, which resulted in a lower modulus than smooth outer morphology tubes, yet likely greater diffusive permeability. For tubes (and not rods) to be formed, phase separation must precede gelation as is detailed in a formulation phase diagram for HEMA, MMA and water. The tensile elastic modulus of p(HEMA-co-MMA) tubes reflected the formulation chemistry, with greater moduli (up to 400 kPa) recorded for tubes having 10 wt% MMA. The p(HEMA-co-MMA) tubes therefore had similar mechanical properties to those of the spinal cord, which has a reported elastic modulus range between 200 and 600 kPa.

  12. Monitoring of acid-base status of workers at a methyl methacrylate and polymethyl methacrylate production plant in Bulgaria.

    PubMed

    Prakova, Gospodinka R

    2003-01-01

    This study was carried out on 104 workers at three work operations and a control (nonproduction) area, within a methyl methacrylate (MMA)/polymethyl methacrylate (PMMA) production facility in Bulgaria. Airborne monitoring was conducted over a 10-year period for MMA and the reactant chemicals methanol and acetone cyanhydrine at the MMA operation, and MMA was monitored at the PMMA operation. Acid-base status of the workers was evaluated using traditional criteria (pH, pCO(2), pO(2), and HCO(3) in plasma). Data from retrospective monitoring of air levels of the chemicals were compared with the acid-base status of workers at the plant. In some cases air concentrations exceeded the threshold limit value, with the highest percentage of overexposure occurring with airborne MMA in the PMMA production operation. Acid-base disruption indicated by reductions in plasma pH and HCO(3) was found for all groups except the control population. The highest percentage reduction was associated with PMMA production workers. Additionally, respiratory acidosis, indicated by increased pCO(2), was noted in the MMA production and maintenance groups, implying that the response to MMA exposure may involve both the metabolic and respiratory acidosis component. This study was unique in that the combined exposure to MMA and the precursor chemical (methanol) were shown to produce the same effects in workers. It is suggested that when combined exposure occurs, disruption of acid-base status may occur. Enforcement of PPM requirements for coveralls and gloves should prevent skin contamination. Additionally, improvement of equipment in MMA and PMMA production areas is recommended: (1) automation of some manual operations; (2) use of respiratory protection during equipment cleaning; and (3) installation of local ventilation when applicable.

  13. Dual-Responsive pH and Temperature Sensitive Nanoparticles Based on Methacrylic Acid and Di(ethylene glycol) Methyl Ether Methacrylate for the Triggered Release of Drugs.

    PubMed

    Khine, Yee Yee; Jiang, Yanyan; Dag, Aydan; Lu, Hongxu; Stenzel, Martina H

    2015-08-01

    A series of thermo-and pH-responsive poly(methyl methacrylate)-block-poly[methacrylic acid-co-di(ethylene glycol) methyl ether methacrylate] PMMA-b-P[MAA-co-DEGMA] block copolymers were synthesized by RAFT polymerization and self-assembled into micelles. The molar ratio of MAA was altered from 0-12% in order to modulate the lower critical solution temperature (LCST) of PDEGMA. The release of the drug albendazole from the micelle was strongly dependent on the temperature and the LCST value of the polymer. Systems below the LCST released the drug slowly while increasing the temperature above the LCST or decreasing the pH value to 5 resulted in the burst-like release of the drug. ABZ delivered in this pH-responsive drug carrier had a higher toxicity than the free drug or the drug delivered in a non-responsive drug carrier.

  14. Radical Polymerization of Vinyl Acetate and Methyl Methacrylate Using Organochromium Initiators Complexed with Macrocyclic Polyamines

    DTIC Science & Technology

    1994-06-30

    METHYL METHACRYLATE USING ORGANOCHROMIUM REA NTS COMPLEXED WITH MACROCYCLIC A• by Daniela Mardare, Scott Gaynor, Krzysztof Matyjaszewski DTIC Published... Daniela Mardare, Scott Gaynor, Krzysztof Matyjaszewski 7. PERFORMING ORGANIZATION NAME(S) AND ADORESS(ES) a. PERFORMING ORGANIZATION Carnegie Mellon

  15. Amphiphilic copolymers of sucrose methacrylate and acrylic monomers: bio-based materials from renewable resource.

    PubMed

    de Oliveira, Heitor F N; Felisberti, Maria Isabel

    2013-04-15

    Regioselective sucrose 1'-O-methacrylate obtained by transesterification catalyzed by Proteinase-N was copolymerized with hydrophilic N-isopropylacrylamide and hydrophobic methyl methacrylate in different molar ratios by free radical polymerization. The copolymers were characterized by (13)C nuclear magnetic resonance spectroscopy, gel permeation chromatography, differential scanning calorimetry and thermogravimetry. Solubility and phase behavior of aqueous solutions were also investigated. The glass transition of the copolymers presents a positive deviation from the values of the homopolymers due to the high density of inter and intramolecular hydrogen bonding. Their solubility is strongly dependent on the composition. Copolymers poor in methyl methacrylate are water soluble, while copolymers richer in methyl methacrylate behaves as hydrogel. These hydrogels are not chemically crosslinked and their form can be design prior swelling by the conventional processing methods, such as solvent casting and extrusion for instance. Copolymers of N-isopropylacrylamide are water soluble and their aqueous solutions present a lower critical solution temperature behavior forming thermoreversible hydrogels.

  16. Biomimetic potential of some methacrylate-based copolymers: a comparative study.

    PubMed

    Zecheru, Teodora; Filmon, Robert; Rusen, Edina; Mărculescu, Bogdan; Zerroukhi, Amar; Cincu, Corneliu; Chappard, Daniel

    2009-11-01

    Preparation of new biocompatible materials for bone recovery has consistently gained interest in the last few decades. Special attention was given to polymers that contain negatively charged groups, such as phosphate, carboxyl, and sulfonic groups toward calcification. This present paper work demonstrates that other functional groups present also potential application in bone pathology. New copolymers of 2-hydroxyethyl methacrylate with diallyldimethylammonium chloride (DADMAC), glycidyl methacrylate (GlyMA), methacrylic acid (MAA), 2-methacryloyloxymethyl acetoacetate (MOEAA), 2-methacryloyloxyethyltriethylammonium chloride (MOETAC), and tetrahydrofurfuryl methacrylate (THFMA) were obtained. The copolymers were characterized by FTIR, swelling potential, and they were submitted to in vitro tests for calcification and cytotoxicity evaluation. GlyMA and MOETAC-containing copolymers show promising results for further in vivo mineralization tests, as a potential alternative to the classical bone grafts, in bone tissue engineering.

  17. Estimation of monomer content in polymethyl methacrylate contact lens materials by Raman spectroscopy.

    PubMed

    Kantarci, Z; Aksoy, S; Hasirci, N

    1997-07-01

    Polymethyl methacrylate is the most commonly used contact lens material due to its excellent optical properties. However the presence of residual monomer in the structure alters its transparency as well as its biocompatibility, thus, there is a need to detect any remaining methyl methacrylate. Raman spectroscopy is a rapid, sensitive, and non destructive method as compared to other spectroscopic, chromatographic or polarographic methods. In this study, the spectra of some lens materials (prepared from methyl methacrylate, 2-hydroxy ethyl methacrylate, Hexamethyl disiloxane and polypropylene glycol with or without the addition of crosslinker ethylene glycol dimethylacrylate) were obtained by Raman spectroscopy. It was observed that an amount of crosslinker present in the structure proves effective for the unpolymerized monomer content. None of the samples, except those containing nexamethyl disiloxane, demonstrated any monomer residue.

  18. 40 CFR 721.10517 - Alkyl methacrylates, polymer with substituted carbomonocycle, hydroxymethyl acrylamide and...

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... substituted carbomonocycle, hydroxymethyl acrylamide and fluorinatedalkyl acrylate (generic). 721.10517... Substances § 721.10517 Alkyl methacrylates, polymer with substituted carbomonocycle, hydroxymethyl acrylamide... substituted carbomonocycle, hydroxymethyl acrylamide and fluorinatedalkyl acrylate (PMN P-10-485) is...

  19. 40 CFR 721.10517 - Alkyl methacrylates, polymer with substituted carbomonocycle, hydroxymethyl acrylamide and...

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... substituted carbomonocycle, hydroxymethyl acrylamide and fluorinatedalkyl acrylate (generic). 721.10517... Substances § 721.10517 Alkyl methacrylates, polymer with substituted carbomonocycle, hydroxymethyl acrylamide... substituted carbomonocycle, hydroxymethyl acrylamide and fluorinatedalkyl acrylate (PMN P-10-485) is...

  20. Preparation of Optically Transparent Films of Poly(methyl methacrylate) (PMMA) and Montmorillonite

    DTIC Science & Technology

    2001-11-01

    methacrylate] [PMMA] and Montmorillonite DISTRIBUTION: Approved for public release, distribution unlimited This paper is part of the following report...Society V6.4 Preparation of Optically Transparent Films of Poly(methyl methacrylate) (PMMA) and Montmorillonite Elena Vasiliul, Chyi-Shan Wang"’ 2...exchanged with 1.40 meq/g of dimethyl dehydrogenated tallow ammonium from a sodium montmorillonite , Cloisite Na+ (CNa). Since the cation-exchange

  1. Chiral ligand-exchange separation and determination of malic acid enantiomers in apple juice by open-tubular capillary electrochromatography.

    PubMed

    Aydoğan, Cemil; Karakoç, Veyis; Denizli, Adil

    2015-11-15

    This study describes the application of an open tubular capillary column for chiral ligand-exchange separation and determination of malic acid enantiomers in apple juice by open-tubular capillary electrochromatography (OT-CEC). The open tubular column was prepared by in-situ grafting polymerization of 3-chloro-2-hydroxypropyl methacrylate (HPMA-Cl) and followed by L-Histidine (L-His) modification. L-His was used as a chiral ligand-exchange selector and copper (II) as a central ion. The electrochromatographic characterization of the open tubular column was performed with the use of thiourea as an electroosmotic flow (EOF) marker. Factors affecting electrochromatographic enantioseparation of malic acid were also studied. The running buffer conditions for optimum enantioseparation of malic acid were found to be ACN/5.0mM CuSO4, 20.0mM (NH4)2SO4 (60/40%, v/v) adjusted to pH 3.0. The separation and determination of the enantiomers of malic acid in the apple juice solution diluted 10- to 40-folds were successfully achieved.

  2. Synthesis of Acrylates and Methacrylates from Coal-Derived Syngas.

    SciTech Connect

    Gogate, M.R.; Spivey, J.J.; Zoeller, J.R.; Colberg, R.D.; Choi, G.N.; Tam, S.S.

    1997-10-17

    Research Triangle Institute (RTI), Eastman Chemical Company, and Bechtel collectively are developing a novel process for the synthesis of methyl methacrylate (MMA) from coal-derived syngas, under a contract from the U.S. Department of Energy/Federal Energy Technology Center (DOE/FETC). This three-step process consists of synthesis of a propionate, its condensation with formaldehyde, and esterification of resulting methacrylic acid (MAA) with methanol to produce MMA. Over the last quarter, RTI carried out activity tests on a pure (99 percent) Nb{sub 2}O{sub 5} catalyst, received from Alfa Aesar, under the following experimental conditions: T=300 C; P=4 atm, 72:38:16:4:220 mmol/h, PA:H{sub 2}0:HCHO:CH{sub 3}0H:N{sub 2}; 5-g catalyst charge. For the pure material, the MAA yields (based on HCHO and PA) were at 8.8 and 1.5 percent, clearly inferior compared to those for a 10-percent Nb{sub 2}O{sub 5}/Si0{sub 2} catalyst (20.1 and 4.5 percent). The X-ray diffraction (XRD) patterns of pure Nb{sub 2}O{sub 5} and 20-percent Nb{sub 2}O{sub 5}/Si0{sub 2} that while pure Nb{sub 2}O{sub 5} is very highly crystalline, Si0{sub 2} support for an amorphous nature of the 20 percent Nb{sub 2}O{sub 5}/Si0{sub 2} catalyst the last quarter, RTI also began research on the use of dimethyl ether (DME), product of methanol dehydrocondensation, as an alternate feedstock in MMA synthesis. As a result, formaldehyde is generated either externally or in situ, from DME, in the process envisaged in the contract extension. The initial work on the DME extension of the contract focuses on a tradeoff analysis that will include a preliminary economic analysis of the DME and formaldehyde routes and catalyst synthesis and testing for DME partial oxidation and condensation reactions. Literature guides exist for DME partial oxidation catalysts; however, there are no precedent studies on catalyst development for DME-methyl propionate (MP) condensation reactions, thereby making DME-MP reaction studies a

  3. SYNTHESIS OF METHYL METHACRYLATE FROM COAL-DERIVED SYNGAS

    SciTech Connect

    Makarand R. Gogate; James J. Spivey; Joseph R. Zoeller; Richard D. Colberg; Gerald N. Choi

    1999-07-19

    Research Triangle Institute (RTI), Eastman Chemical Company, and Bechtel collectively are developing a novel three-step process for the synthesis of methyl methacrylate (MMA) from coal-derived syngas that consists of the steps of synthesis of a propionate, its condensation with formaldehyde to form methacrylic acid (MAA), and esterification of MAA with methanol to produce MMA. The research team has completed the research on the three-step methanol-based route to MMA. Under an extension to the original contract, we are currently evaluating a new DME-based process for MMA. The key research need for DME route is to develop catalysts for DME partial oxidation reactions and DME condensation reactions. During the April-June quarter(04-06/99) the first in-situ formaldehyde generation from DME and condensation with methyl propionate is demonstrated and the results are summarized. The supported niobium catalyst shows better condensation activity, but supported tungsten catalyst has higher formaldehyde selectivity. The project team has also completed a 200-hour long term test of PA-HCHO condensation over 30% Nb{sub 2}O{sub 5}/SiO{sub 2}. Three activity cycles and two regeneration cycles were carried out. 30% Nb{sub 2}O{sub 5}/SiO{sub 2} showed similar MAA yields as 10% Nb{sub 2}O{sub 5}/SiO{sub 2} at 300 C. However, the deactivation appears to be slower with 30% Nb{sub 2}O{sub 5}/SiO{sub 2} than 10% Nb{sub 2}O{sub 5}/SiO{sub 2}. An detailed economic analysis of PA-HCHO condensation process for a 250 million lb/yr MMA plant is currently studied by Bechtel. Using the Amoco data-based azeotropic distillation model as the basis, an ASPEN flow sheet model was constructed to simulate the formaldehyde and propionic acid condensation processing section based on RTI's design data. The RTI MAA effluent azeotropic distillation column was found to be much more difficult to converge. The presence of non-condensible gases along with the byproduct DEK (both of which were not presented in

  4. SYNTHESIS OF METHYL METHACRYLATE FROM COAL-DERIVED SYNGAS

    SciTech Connect

    BEN W.-L. JANG; GERALD N. CHOI; JAMES J. SPIVEY; JOSPEH R. ZOELLER; RICHARD D. COLBERG

    1998-10-20

    Research Triangle Institute (RTI), Eastman Chemical Company, and Bechtel collectively are developing a novel three-step process for the synthesis of methyl methacrylate (MMA) from coal-derived syngas that consists of the steps of synthesis of a propionate, its condensation with formaldehyde to form methacrylic acid (MAA), and esterification of MAA with methanol to produce MMA. RTI has completed the research on the three-step methanol-based route to MMA. Under an extension to the original contract, RTI is currently evaluating a new DME-based process for MMA. The key research need for DME route is to develop catalysts for DME partial oxidation reactions and DME condensation reactions. Over the last quarter (July-September, 1998), the project team has completed the continuous condensation of formaldehyde with propionic acid over 10% Nb{sub 2}O{sub 5}/SiO{sub 2} at 300 C. Six activity and five regeneration cycles have been completed. The results show that 10% Nb{sub 2}O{sub 5}/SiO{sub 2} deactivates slowly with time but can be regenerated to its original activity with 2% O{sub 2} in nitrogen over night at 400 C. We have investigated the effects of regeneration, propionic acid/formaldehyde ratio (PA/HCHO = 4.5/1 to 1.5/1) and reaction temperature(280-300 C) on reaction activity and product selectivity over 20% Nb{sub 2}O{sub 5}/SiO{sub 2} catalysts. The regeneration effect on 20% Nb{sub 2}O{sub 5}/SiO{sub 2} is similar to the effect on 10% Nb{sub 2}O{sub 5}/SiO{sub 2}. The regeneration can bring the deactivated catalyst to its original activity. However, the selectivity to MAA decreases with regeneration while the selectivity to DEK and CO{sub 2} increases. When PA/HCHO ratio is decreased from 4.5/1 to 2.25/1 then to 1.5/1 at 300 C the MAA yield decreases but the MAA selectivity first increases then decreases. Decreasing the reaction temperature from 300 C to 280 C decreases the MAA yield from 39.5% to 30.7% but increases the MAA selectivity from 73.7% to 82.2%. The

  5. Novel catalysts for the environmentally friendly synthesis of methyl methacrylate

    SciTech Connect

    Spivey, J.J.; Gogate, M.R.; Zoeller, J.R.; Colberg, R.D.

    1997-11-01

    The development of a process for the synthesis of methyl methacrylate (MMA) from coal-derived syngas can alleviate the environmental hazards associated with the current commercial MMA technology, the acetone cyanohydrin (ACH) process. A three-step syngas-based process consisted of synthesis of a propionic acid, its condensation with formaldehyde, and esterification of resulting methacrylic acid (MAA) to form MMA. The first two steps, propionic acid synthesis and condensation, are discussed here. The low-temperature, low-pressure process for single-step hydrocarbonylation of ethylene to propionic acid is carried out using a homogeneous iodine-promoted Mo(CO){sub 6} catalyst at pressures (30--70 atm) and temperatures (150--200 C) lower than those reported for other catalysts. Mechanistic investigations suggest that catalysis is initiated by a rate-limiting CO dissociation from Mo(CO){sub 6}. This dissociation appears to be followed by an inner electron-transfer process of an I atom from EtI to the coordinately unsaturated Mo(CO){sub 5}. This homogeneous catalyst for propionate synthesis represents the first case of an efficient carbonylation process based on Cr group metals. The condensation of formaldehyde with propionic acid is carried out by acid-base bifunctional catalysts. As a result of screening over 80 catalytic materials, group V metals supported on an amorphous silica are found to be most effective. A 20% Nb/SiO{sub 2} catalyst appears to be the most active and stable catalyst thus far. Preliminary relations among the reaction yield and catalyst properties indicate that a high surface area and a low overall surface acidity (<50 = mol of NH{sub 3}/g), with a high proportion of the acidity being weak (<350 C desorption of NH{sub 3}), are desirable. Long-term deactivation of V-Si-P, Nb-Si, and Ta-Si catalysts suggests that carbon deposition is the primary cause for activity decay, and the catalyst activity is partially restorable by oxidative regeneration.

  6. Cholesterol-modified superporous poly(2-hydroxyethyl methacrylate) scaffolds for tissue engineering.

    PubMed

    Kubinová, Sárka; Horák, Daniel; Syková, Eva

    2009-09-01

    Modifications of poly(2-hydroxyethyl methacrylate) (PHEMA) with cholesterol and laminin have been developed to design scaffolds that promote cell-surface interaction. Cholesterol-modified superporous PHEMA scaffolds have been prepared by the bulk radical copolymerization of 2-hydroxyethyl methacrylate (HEMA), cholesterol methacrylate (CHLMA) and the cross-linking agent ethylene dimethacrylate (EDMA) in the presence of ammonium oxalate crystals to introduce interconnected superpores in the matrix. With the aim of immobilizing laminin (LN), carboxyl groups were also introduced to the scaffold by the copolymerization of the above monomers with 2-[(methoxycarbonyl)methoxy]ethyl methacrylate (MCMEMA). Subsequently, the MCMEMA moiety in the resulting hydrogel was hydrolyzed to [2-(methacryloyloxy)ethoxy]acetic acid (MOEAA), and laminin was immobilized via carbodiimide and N-hydroxysulfosuccinimide chemistry. The attachment, viability and morphology of mesenchymal stem cells (MSCs) were evaluated on both nonporous and superporous laminin-modified as well as laminin-unmodified PHEMA and poly(2-hydroxyethyl methacrylate-co-cholesterol methacrylate) P(HEMA-CHLMA) hydrogels. Neat PHEMA and laminin-modified PHEMA (LN-PHEMA) scaffolds facilitated MSC attachment, but did not support cell spreading and proliferation; the viability of the attached cells decreased with time of cultivation. In contrast, MSCs spread and proliferated on P(HEMA-CHLMA) and LN-P(HEMA-CHLMA) hydrogels.

  7. Synthesis and properties of methacrylic-functionalized tween monomer networks.

    PubMed

    Muzzalupo, Rita; Tavano, Lorena; Rossi, Cesare Oliviero; Cassano, Roberta; Trombino, Sonia; Picci, Nevio

    2009-02-03

    Tween surfactants possess very interesting properties such as biodegradability, biocompatibility, and low toxicity. The synthesis of acrylate monomers by means of the chemical modification of polysorbate surfactants Tween 20, 40, and 60 with unsaturated groups is described. Monomers were obtained as a result of the reaction of methacrylic anhydride with different grades of Tween surfactants. Further polymerization was carried out in tetrahydrofuran, dimethylformamide, and a mixture of water-tetrahydrofuran. Physicochemistry properties of the polymer networks were investigated, and the obtained results reveal that they strongly depend on the type of solvent used during the polymerization, as well as on the concentration of the casting solution. In particular, our study demonstrated that, depending on the solvent boiling point, i.e., the facility to remove the solvent from the polymer matrix, it is possible to predict properties of the network morphology. Moreover, in vitro studies on controlled release were accomplished to demonstrate the possibility of utilizing these new materials as drug delivery systems. All resulting networks represent a novel class of cross-linked polymeric materials useful both in pharmaceutical and chemical applications.

  8. Methyl methacrylate and respiratory sensitization: A Critical review

    PubMed Central

    Borak, Jonathan; Fields, Cheryl; Andrews, Larry S; Pemberton, Mark A

    2011-01-01

    Methyl methacrylate (MMA) is a respiratory irritant and dermal sensitizer that has been associated with occupational asthma in a small number of case reports. Those reports have raised concern that it might be a respiratory sensitizer. To better understand that possibility, we reviewed the in silico, in chemico, in vitro, and in vivo toxicology literature, and also epidemiologic and occupational medicine reports related to the respiratory effects of MMA. Numerous in silico and in chemico studies indicate that MMA is unlikely to be a respiratory sensitizer. The few in vitro studies suggest that MMA has generally weak effects. In vivo studies have documented contact skin sensitization, nonspecific cytotoxicity, and weakly positive responses on local lymph node assay; guinea pig and mouse inhalation sensitization tests have not been performed. Cohort and cross-sectional worker studies reported irritation of eyes, nose, and upper respiratory tract associated with short-term peaks exposures, but little evidence for respiratory sensitization or asthma. Nineteen case reports described asthma, laryngitis, or hypersensitivity pneumonitis in MMA-exposed workers; however, exposures were either not well described or involved mixtures containing more reactive respiratory sensitizers and irritants.The weight of evidence, both experimental and observational, argues that MMA is not a respiratory sensitizer. PMID:21401327

  9. Methyl Methacrylate Polymerization in Nanoporous Matrix: Reactivity and Resulting Properties

    NASA Astrophysics Data System (ADS)

    Zhao, Haoyu; Begum, Fatema; Simon, Sindee

    2012-02-01

    Nanoconfinement is well known to affect the properties of polymers, including changes in the glass transition temperature (Tg). In this work, the focus is on the influence of nanoconfinement on free radical polymerization reaction kinetics and the properties of the polymer produced. Controlled pore glass (CPG) is used as a nanoconfining matrix for methyl methacrylate (MMA) polymerization with pore diameters of 13 nm, 50 nm, and 110 nm. The reaction is followed by measuring heat flow as a function of reaction time during isothermal polymerization at temperatures ranging from 60 C to 95 C using differential scanning calorimetry (DSC). After reaction, the properties of the polymer are measured, including Tg, molecular weight, and tacticity. Nanoconfiment is found to result in earlier onset of autoacceleration, presumablely due to a decrease in the rate of termination arising from decreases in chain diffusivity in the confined state. In addition, Tg and molecular weight of the resulting PMMA are found to increase. A model of the nanoconfined reaction is able to quantitatively capture these effects by accounting for changes in chain diffusivity, and in native pores, also accounting for changes in intrinsic reaction rates.

  10. Directed Endothelial Cell Morphogenesis in Micropatterned Gelatin Methacrylate Hydrogels

    PubMed Central

    Nikkhah, Mehdi; Eshak, Nouran; Zorlutuna, Pinar; Annabi, Nasim; Castello, Marco; Kim, Keekyoung; Dolatshahi-Pirouz, Alireza; Edalat, Faramarz; Bae, Hojae; Yang, Yunzhi; Khademhosseini, Ali

    2013-01-01

    Engineering of organized vasculature is a crucial step in the development of functional and clinically relevant tissue constructs. A number of previous techniques have been proposed to spatially regulate the distribution of angiogenic biomolecules and vascular cells within biomaterial matrices to promote vascularization. Most of these approaches have been limited to two-dimensional (2D) micropatterned features or have resulted in formation of random vasculature within three-dimensional (3D) microenvironments. In this study, we investigate 3D endothelial cord formation within micropatterned gelatin methacrylate (GelMA) hydrogels with varying geometrical features (50–150 µm height). We demonstrated the significance dependence of endothelial cells proliferation, alignment and cord formation on geometrical dimensions of the patterned features. The cells were able to align and organize within the micropatterned constructs and assemble to form cord structures with organized actin fibers and circular/elliptical cross-sections. The inner layer of the cord structure was filled with gel showing that the micropatterned hydrogel constructs guided the assembly of endothelial cells into cord structures. Notably, the endothelial cords were retained within the hydrogel microconstructs for all geometries after two weeks of culture; however, only the 100 µm-high constructs provided the optimal microenvironment for the formation of circular and stable cord structures. Our findings suggest that endothelial cord formation is a preceding step to tubulogenesis and the proposed system can be used to develop organized vasculature for engineered tissue constructs. PMID:23018132

  11. The toxicokinetics and distribution of 2-hydroxyethyl methacrylate in mice.

    PubMed

    Durner, J; Kreppel, H; Zaspel, J; Schweikl, H; Hickel, R; Reichl, Franz X

    2009-04-01

    The cytotoxicity of dental composites has been attributed to the release of residual monomers from polymerized resin-based composites due to the degradation processes or the incomplete polymerisation of materials. 2-Hydroxyethyl methacrylate (HEMA) is one of the major components released from dental resin-based composites. It was shown in vitro that HEMA was released into the adjacent biophase from such materials during the first days after placement. In this study uptake, distribution, and excretion of 14C-HEMA applied via gastric tube or subcutaneous administration at dose levels well above those encountered in dental care were examined in mice to test the hypothesis that HEMA can reach cytotoxic levels in mammalian tissues. 14C-HEMA was taken up rapidly from the stomach and intestines after gastric administration and was widely distributed in the body following administration by each route. Most 14C was excreted within one day as (14)CO(2). Two metabolic pathways of 14C-HEMA can be described. The peak HEMA levels in all tissues examined after 24h were lower than known toxic levels. Therefore the study did not support the hypothesis.

  12. Aggregation and transport of Brij surfactants in hydroxyethyl methacrylate hydrogels.

    PubMed

    Kapoor, Yash; Bengani, Lokendrakumar C; Tan, Grace; John, Vijay; Chauhan, Anuj

    2013-10-01

    Surfactant loaded polymeric hydrogels find applications in several technological areas including drug delivery. Drug transport can be attenuated in surfactant loaded gels through partitioning of the drug in the surfactant aggregates. The drug transport depends on the type of the aggregates and also on the surfactant transport because diffusion of the surfactant leads to dissolution of the aggregates. The drug and the surfactant transport can be characterized by the surfactant monomer diffusivity Ds. and the critical aggregation concentration C(*). Here we focus on the transport in hydroxyethyl methacrylate (HEMA) hydrogels loaded with three different types of Brij surfactants. We measure transport of a hydrophobic drug cyclosporine and the surfactant for surfactant loadings ranging from 0.1% to 8%, and utilize the data to predict the values of Ds. and C(*). We show that the predictions based on surfactant transport are significantly different from those based on modeling the drug transport. The differences are attributed to the assumption of just one type of aggregate in the gel irrespective of the total concentration. The transport data suggests existence of multiple types of aggregates and this hypothesis is validated for Brij 98 by imaging of the microstructure with free fracture SEM.

  13. 2-hydroxyethyl methacrylate as an inhibitor of matrix metalloproteinase-2.

    PubMed

    Carvalho, Rodrigo V; Ogliari, Fabrício A; de Souza, Ana P; Silva, Adriana F; Petzhold, Cesar L; Line, Sergio R P; Piva, Evandro; Etges, Adriana

    2009-02-01

    This study evaluated the effect of different concentrations of 2-hydroxyethyl methacrylate (HEMA) on the inhibition of matrix metalloproteinase-2 (MMP-2) in vitro. Mouse gingival explants were cultured overnight in Dulbecco's modified Eagle's minimal essential medium, following which the expression of secreted enzymes was analyzed by gelatin zymography and the effects of different amounts of HEMA on enzyme activity were investigated. The gelatinolytic proteinases present in the conditioned media were characterized as being matrix metalloproteinases (MMPs) by means of specific chemical inhibition. The MMPs present in the conditioned media were identified, using immunoprecipitation, as MMP-2. Three major bands were detected in the zymographic assays and were characterized, according to their respective molecular weights, into the following forms of MMP-2: zymogene (72 kDa), intermediate (66 kDa), and active (62 kDa). All forms of MMP-2 were inhibited by HEMA in a dose-dependent manner, implying that MMP-2 may be inhibited by HEMA in vivo.

  14. Carboxybetaine methacrylate oligomer modified nylon for circulating tumor cells capture.

    PubMed

    Dong, Chaoqun; Wang, Huiyu; Zhang, Zhuo; Zhang, Tao; Liu, Baorui

    2014-10-15

    Circulating tumor cells (CTC) capture is one of the most effective approaches in diagnosis and treatment of cancers in the field of personalized cancer medicine. In our study, zwitterionic carboxybetaine methacrylate (CBMA) oligomers were grafted onto nylon via atomic transfer random polymerization (ATRP) which would serve as a novel material for the development of convenient CTC capture interventional medical devices. The chemical, physical and biological properties of pristine and modified nylon surfaces were assessed by Fourier transform infrared spectra, atomic force microscope, water contact angle measurements, X-ray photoelectron spectroscopy, protein adsorption, platelet adhesion, and plasma recalcification time (PRT) determinations, etc. The results, including the significant decrease of proteins adsorption and platelets adhesion, as well as prolonged PRTs demonstrated the extraordinary biocompatibility and blood compatibility of the modified surface. Furthermore, we showed that upon immobilization of anti-epithelial cell adhesion molecular (anti-EpCAM) antibody onto the CBMA moiety, the modified nylon surface can selectively capture EpCAM positive tumor cells from blood with high efficiency, indicating the potential of the modified nylon in the manufacture of convenient interventional CTC capture medical devices.

  15. Wettability interpretation of oxygen plasma modified poly(methyl methacrylate).

    PubMed

    Chai, Jinan; Lu, Fuzhi; Li, Baoming; Kwok, Daniel Y

    2004-12-07

    Poly(methyl methacrylate) (PMMA) has been modified via a dc pulsed oxygen plasma for different treatment times. The modified surfaces were characterized by X-ray photoelectron spectroscopy (XPS), optical profilometer, zeta potential, and advancing contact angle measurements. The measured advancing contact angles of water decreased considerably as a function of discharge. Several oxygen-based functionalities (carbonyl, carboxyl, carbonate, etc.) were detected by XPS, while zeta potential measurements confirmed an increase in negative charge for the treated PMMA surface. Evaluating the correlation between the concentration of polar chemical species and zeta potential, we found that increase in surface hydrophilicity results from the coeffect due to incorporation of oxygen functional groups and creation of charge states. The electrical double layer (EDL) effect was also considered in contact angle interpretation by introducing an additional surface tension term into Young's equation. We also found that EDL contribution to the solid-liquid interfacial tension is negligible and can be safely ignored for the systems considered here.

  16. Water-soluble polymer–drug conjugates for combination chemotherapy against visceral leishmaniasis

    PubMed Central

    Nicoletti, Salvatore; Seifert, Karin; Gilbert, Ian H.

    2010-01-01

    There is a need for new safe, effective and short-course treatments for leishmaniasis; one strategy is to use combination chemotherapy. Polymer–drug conjugates have shown promise for the delivery of anti-leishmanial agents such as amphotericin B. In this paper, we report on the preparation and biological evaluation of polymer–drug conjugates of N-(2-hydroxypropyl)methacrylamide (HPMA), amphotericin B and alendronic acid. The combinatorial polymer–drug conjugates were effective anti-leishmanial agents in vitro and in vivo, but offered no advantage over the single poly(HPMA)–amphotericin B conjugates. PMID:20338769

  17. 2-hydroxylethyl methacrylate (HEMA), a tooth restoration component, exerts its genotoxic effects in human gingival fibroblasts trough methacrylic acid, an immediate product of its degradation.

    PubMed

    Szczepanska, Joanna; Poplawski, Tomasz; Synowiec, Ewelina; Pawlowska, Elzbieta; Chojnacki, Cezary J; Chojnacki, Jan; Blasiak, Janusz

    2012-02-01

    HEMA (2-hydroxyethyl methacrylate), a methacrylate commonly used in dentistry, was reported to induce genotoxic effects, but their mechanism is not fully understood. HEMA may be degraded by the oral cavity esterases or through mechanical stress following the chewing process. Methacrylic acid (MAA) is the primary product of HEMA degradation. In the present work we compared cytotoxic and genotoxic effects induced by HEMA and MAA in human gingival fibroblasts (HGFs). A 6-h exposure to HEMA or MAA induced a weak decrease in the viability of HGFs. Neither HEMA nor MAA induced strand breaks in the isolated plasmid DNA, but both compounds evoked DNA damage in HGFs, as evaluated by the alkaline comet assay. Oxidative modifications to the DNA bases were monitored by the DNA repair enzymes Endo III and Fpg. DNA damage induced by HEMA and MAA was not persistent and was removed during a 120 min repair incubation. Results from the neutral comet assay indicated that both compounds induced DNA double strand breaks (DSBs) and they were confirmed by the γ-H2AX assay. Both compounds induced apoptosis and perturbed the cell cycle. Therefore, methacrylic acid, a product of HEMA degradation, may be involved in its cytotoxic and genotoxic action.

  18. Surface modification of silk fibroin fibers with poly(methyl methacrylate) and poly(tributylsilyl methacrylate) via RAFT polymerization for marine antifouling applications.

    PubMed

    Buga, Mihaela-Ramona; Zaharia, Cătălin; Bălan, Mihai; Bressy, Christine; Ziarelli, Fabio; Margaillan, André

    2015-06-01

    In this study, silk fibroin surface containing hydroxyl and aminogroups was firstly modified using a polymerizable coupling agent 3-(trimethoxysilyl) propyl methacrylate (MPS), in order to induce vinyl groups onto the fiber surface. The reversible addition-fragmentation chain transfer (RAFT)-mediated polymerization of methyl methacrylate (MMA) and tributylsilyl methacrylate (TBSiMA) through the immobilized vinyl bond on the silk fibroin surface in the presence of 2-cyanoprop-2-yl dithiobenzoate (CPDB) as chain-transfer agent and 2,2'-azobis(isobutyronitrile) (AIBN) as initiator was conducted in toluene solution at 70°C for 24h. The structure and properties of the modified fiber were characterized by Fourier Transform Infrared Spectroscopy, (13)C, (29)Si Nuclear Magnetic Resonance (NMR) spectroscopy, thermogravimetric analysis (TGA), scanning electron microscopy (SEM) and energy dispersive spectroscopy (EDS), confirming the presence of the coupling molecule and the methacrylate groups onto the silk fibroin fiber surface. Molecular weight distributions were assessed by triple detection size exclusion chromatography (TD-SEC) in order to verify the livingness of the polymerization.

  19. Poly(glycidyl methacrylate-co-2-hydroxyethyl methacrylate) Brushes as Peptide/Protein Microarray Substrate for Improving Protein Binding and Functionality.

    PubMed

    Lei, Zhen; Gao, Jiaxue; Liu, Xia; Liu, Dianjun; Wang, Zhenxin

    2016-04-27

    We developed a three-dimensional (3D) polymer-brush substrate for protein and peptide microarray fabrication, and this substrate was facilely prepared by copolymerization of glycidyl methacrylate (GMA) and 2-hydroxyethyl methacrylate (HEMA) monomers via surface-initiated atom transfer radical polymerization (SI-ATRP) on a glass slide. The performance of obtained poly(glycidyl methacrylate-co-2-hydroxyethyl methacrylate) (P(GMA-HEMA)) brush substrate was assessed by binding of human IgG with rabbit antihuman IgG antibodies on a protein microarray and by the determination of matrix metalloproteinase (MMP) activities on a peptide microarray. The P(GMA-HEMA) brush substrate exhibited higher immobilization capacities for proteins and peptides than those of a two-dimensional (2D) planar epoxy slide. Furthermore, the sensitivity of the P(GMA-HEMA) brush-based microarray on rabbit antihuman IgG antibody detection was much higher than that of its 2D counterpart. The enzyme activities of MMPs were determined specifically with a low detection limit of 6.0 pg mL(-1) for MMP-2 and 5.7 pg mL(-1) for MMP-9. By taking advantage of the biocompatibility of PHEMA, the P(GMA-HEMA) brush-based peptide microarray was also employed to evaluate the secretion of MMP-2 and MMP-9 by cells cultured off the chip or directly on the chip, and satisfactory results were obtained.

  20. Synthesis and characterization of fluorinated methacrylates-based copolymers containing cross-linkable pendant groups for optical waveguides

    NASA Astrophysics Data System (ADS)

    Kim, Ho June; Kim, Kwangsok; Chin, In-Joo

    2006-02-01

    Methacrylate based copolymers containing thermal and UV cross-linkable groups were prepared, ad their optical properties were investigated. Copolymerization of octafluoropentyl methacrylate (OFPMA) with hydroxyethyl methacrylate (HEMA) was followed by reacting HEMA and methacrylic anhydride (MAAN), yielding a fluorinated copolymer with cross-linkable pendant group. The refractive indices of the copolymers before cross-linking ranged from 1.4329 to 1.4646, and those of the cross-linked copolymers varied from 1.4500 to 1.4822, depending on the fluorine content.

  1. Synthesis of three different galactose-based methacrylate monomers for the production of sugar-based polymers.

    PubMed

    Desport, Jessica S; Mantione, Daniele; Moreno, Mónica; Sardón, Haritz; Barandiaran, María J; Mecerreyes, David

    2016-09-02

    Glycopolymers, synthetic sugar-containing macromolecules, are attracting ever-increasing interest from the chemistry community. Glycidyl methacrylate (GMA) is an important building block for the synthesis of sugar based methacrylate monomers and polymers. Normally, glycidyl methacrylate shows some advantages such as reactivity against nucleophiles or milder synthetic conditions such as other reactive methacrylate monomers. However, condensation reactions of glycidyl methacrylate with for instance protected galactose monomer leads to a mixture of two products due to a strong competition between the two possible pathways: epoxide ring opening or transesterification. In this paper, we propose two alternative routes to synthesize regiospecific galactose-based methacrylate monomers using the epoxy-ring opening reaction. In the first alternative route, the protected galactose is first oxidized to the acid in order to make it more reactive against the epoxide of GMA. In the second route, the protected sugar was first treated with epichlorohydrin followed by the epoxy ring opening reaction with methacrylic acid, to create an identical analogue of the ring-opening product of GMA. These two monomers were polymerized using conventional radical polymerization and were compared to the previously known galactose-methacrylate one. The new polymers show similar thermal stability but lower glass transition temperature (Tg) with respect to the known galactose methacrylate polymer.

  2. Horseradish peroxidase mediated free radical polymerization of methyl methacrylate.

    PubMed

    Kalra, B; Gross, R A

    2000-01-01

    This paper reports the free radical polymerization of methyl methacrylate (MMA) catalyzed by horseradish peroxidase (HRP). A novel method was developed whereby MMA polymerization can be carried out at ambient temperatures in the presence of low concentrations of hydrogen peroxide and 2,4-pentanedione in a mixture of water and a water-miscible solvent. Polymers of MMA formed were highly stereoregular with predominantly syndiotactic sequences (syn-dyad fractions from 0.82 to 0.87). Analyses of the chloroform-soluble fraction of syndio-PMMA products by GPC showed that they have number-average molecular weights, Mn, that range from 7500 to 75,000. By using 25% v/v of the cosolvents dioxane, tetrahydrofuran, acetone, and dimethylformamide, 85, 45, 7 and 2% product yields, respectively, resulted after 24 h. Increasing the proportion of dioxane to water from 1:3 to 1:1 and 3:1 resulted in a decrease in polymer yield from 45 to 38 and 7%, respectively. Increase in the enzyme concentration from 70 to 80 and 90 mg/mL resulted in increased reaction kinetics. By adjustment of the molar ratio of 2,4-pentanedione to hydrogen peroxide between 1.30:1.0 and 1.45:1.0, the product yields and Mn values were increased. On the basis of the catalytic properties of HRP and studies herein, we believe that the keto-enoxy radicals from 2,4-pentanedione are the first radical species generated. Then, initiation may take place through this radical or by the radical transfer to another molecule.

  3. Dual-functional electrospun poly(2-hydroxyethyl methacrylate).

    PubMed

    Zhang, Bo; Lalani, Reza; Cheng, Fang; Liu, Qingsheng; Liu, Lingyun

    2011-12-01

    Poly(2-hydroxyethyl methacrylate) (pHEMA) has been widely used in many biomedical applications due to its well-known biocompatibility. For tissue engineering applications, porous scaffolds that mimic fibrous structures of natural extracellular matrix and possess high surface-area-to-volume ratios are highly desirable. So far, a systematic approach to control diameter and morphology of pHEMA fibers has not been reported and potential applications of pHEMA fibers have barely been explored. In this work, pHEMA was synthesized and processed into fibrous scaffolds using an electrospinning approach. Fiber diameters from 270 nm to 3.6 μm were achieved by controlling polymer solution concentration and electrospinning flow rate. Post-electrospinning thermal treatment significantly improves integrity of the electrospun membranes in water. The pHEMA microfibrous membranes exhibited water absorption up to 280% (w/w), whereas the pHEMA hydrogel only absorbed 70% water. Fibrinogen adsorption experiments demonstrate that the electrospun pHEMA fibers highly resist nonspecific protein adsorption. Hydroxyl groups on electrospun pHEMA fibers were further activated for protein immobilization. A bovine serum albumin (BSA) binding capacity as high as 120 mg BSA/g membrane was realized at an intermediate fiber diameter. The pHEMA fibrous scaffolds functionalized with collagen I significantly promoted fibroblast adhesion, spreading, and proliferation. We conclude that the electrospun pHEMA fibers are dual functional, that is, they resist nonspecific protein adsorption meanwhile abundant hydroxyl groups on fibers allow effective conjugation of biomolecules in a nonfouling background. High water absorption and dual functionality of the electrospun pHEMA fibers may lead to a number of potential applications such as wound dressings, tissue scaffolds, and affinity membranes.

  4. Assessment of methyl methacrylate genotoxicity by the micronucleus test.

    PubMed

    Araújo, Amarildo Mariano de; Alves, Guilherme Rodrigues; Avanço, Guilherme Trevisan; Parizi, José Luiz Santos; Nai, Gisele Alborghetti

    2013-01-01

    The aim of this study was to evaluate the genotoxic potential of methyl methacrylate (MMA) vapor by simulating standard occupational exposure of 8 hours per day and using the micronucleus test. We used 32 adult male Wistar rats divided into three groups: A - 16 rats exposed to MMA for 8 hours a day, B - Eight rats receiving single subcutaneous doses of cyclophosphamide on the first day of the experiment (positive control), C - Eight rats receiving only water and food ad libitum (negative control). Eight rats from group A and all of the rats from groups B and C were sacrificed 24 hours after beginning the experiment (acute exposure in group A). The remaining animals in group A were sacrificed 5 days after the experiment began (repeated exposure assessment in group A, simulating occupational exposure 40 hours/week). Femoral bone marrow was collected from each rat at the time of sacrifice for use in the micronucleus test. Two slides were completed per animal and were stained with Giemsa staining. Two thousand polychromatic erythrocytes were counted per animal. The Kruskal-Wallis test followed by a multiple comparisons test (Dunn test) was used for statistical analysis. The median number of micronuclei was 7.00 in the group exposed to MMA for 1 day, 2.00 in the group exposed to MMA for 5 days, 9.00 in the group exposed to cyclophosphamide (positive control) and 0.756 in the negative control group (p < 0.0001). MMA was genotoxic when measured after 1 day of exposure but was not evidently genotoxic after 5 days.

  5. Can quaternary ammonium methacrylates inhibit matrix MMPs and cathepsins?

    PubMed Central

    Tezvergil-Mutluay, Arzu; Agee, Kelli A.; Mazzoni, Annalisa; Carvalho, Ricardo M.; Carrilho, Marcela; Tersariol, Ivarne L.; Nascimento, Fabio D.; Imazato, Satoshi; Tjäderhane, Leo; Breschi, Lorenzo; Tay, Franklin R; Pashley, David H.

    2014-01-01

    Objective Dentin matrices release ICTP and CTX fragments during collagen degradation. ICTP fragments are known to be produced by MMPs. CTX fragments are thought to come from cathepsin K activity. The purpose of this study was to determine if quaternary methacrylates (QAMs) can inhibit matrix MMPs and cathepsins. Methods Dentin beams were demineralizated, and dried to constant weight. Beams were incubated with rh-cathepsin B, K, L or S for 24 h at pH 7.4 to identify which cathepsins release CTX at neutral pH. Beams were dipped in ATA, an antimicrobial QAM to determine if it can inhibit dentin matrix proteases. Other beams were dipped in another QAM (MDPB) to determine if it produced similar inhibition of dentin proteases. Results Only beams incubated with cathepsin K lost more dry mass than the controls and released CTX. Dentin beams dipped in ATA and incubated for 1 week at pH 7.4, showed a concentration-dependent reduction in weight-loss. There was no change in ICTP release from control values, meaning that ATA did not inhibit MMPs. Media concentrations of CTX fell significantly at 15 wt% ATA indicating that ATA inhibits capthesins. Beams dipped in increasing concentrations of MDPB lost progressively less mass, showing that MDPB is a protease-inhibitor. ICTP released from controls or beams exposed to low concentrations were the same, while 5 or 10% MDPB significantly lowered ICTP production. CTX levels were strongly inhibited by 2.5–10% MDPB, indicating that MDPB is a potent inhibitor of both MMPs and cathepsin K. Significance CTX seems to be released from dentin matrix only by cathepsin K. MMPs and cathepsin K and B may all contribute to matrix degradation. PMID:25467953

  6. Facile Fabrication of Gradient Surface Based on (meth)acrylate Copolymer Films

    NASA Astrophysics Data System (ADS)

    Zhang, Y.; Yang, H.; Wen, X.-F.; Cheng, J.; Xiong, J.

    2016-08-01

    This paper describes a simple and economic approach for fabrication of surface wettability gradient on poly(butyl acrylate - methyl methacrylate) [P (BA-MMA)] and poly(butyl acrylate - methyl methacrylate - 2-hydroxyethyl methacrylate) [P (BA-MMA-HEMA)] films. The (meth)acrylate copolymer [including P (BA-MMA) and P (BA-MMA-HEMA)] films are hydrolyzed in an aqueous solution of NaOH and the transformation of surface chemical composition is achieved by hydrolysis in NaOH solution. The gradient wetting properties are generated based on different functional groups on the P (BA-MMA) and P (BA-MMA-HEMA) films. The effects of both the surface chemical and surface topography on wetting of the (meth)acrylate copolymer film are discussed. Surface chemical composition along the materials length is determined by XPS, and surface topography properties of the obtained gradient surfaces are analyzed by FESEM and AFM. Water contact angle system (WCAs) results show that the P (BA-MMA-HEMA) films provide a larger slope of the gradient wetting than P (BA-MMA). Moreover, this work demonstrates that the gradient concentration of chemical composition on the poly(meth) acrylate films is owing to the hydrolysis processes of ester group, and the hydrolysis reactions that have negligible influence on the surface morphology of the poly(meth) acrylate films coated on the glass slide. The gradient wettability surfaces may find broad applications in the field of polymer coating due to the compatibility of (meth) acrylate polymer.

  7. Conversion of (Meth)acrylic acids to methane granular sludge: Initiation by specific anerobic microflora

    SciTech Connect

    Shtarkman, N.B.; Obraztova, A.Y.; Laurinavichyus, K.S.; Galushko, A.S.; Akimenko, V.K.

    1995-03-01

    The role of a specific anaerobic microflora in the initiation of degradation of (meth)acrylic acids to methane by granular sludge from a UASB reactor was investigated. Associations of anaerobic bacteria isolated from the anaerobic sludge, which was used for a long time for treatment of wastewater from (meth)acrylate production, were able to realize the initial stage of (meth)acrylic acid decomposition, i.e., a conversion of acrylic and methacrylic acids to propionic and isobutyric acids, respectively. When added to granules, these association played a role of an {open_quotes}initiator{close_quotes} of the degradation process, which was then continued by the granular sludge microflora utilizing propionate and isobutyrate. Some characteristics of the granules adapted to propionate or isobutyrate are presented. The rates of propionate and isobutyrate consumption by adapted granules is, respectively, 21 and 53 times higher than the values obtained for nonadapted granules. A combined use of {open_quotes}initiating{close_quotes} bacteria and adapted granules provided degradation of (meth)acrylic acids with a maximum methane yield. The possibility is discussed of employing the granules, which are adapted to short-chain fatty acids, and the {open_quotes}initiating{close_quotes} bacteria, which accomplish the initial steps of the organic material decomposition to lower fatty acids, for the conversion of various chemical compounds to methane. 10 refs., 3 figs., 2 tabs.

  8. Preparation and characterization of alkyl methacrylate-based monolithic columns for capillary gas chromatography applications.

    PubMed

    Yusuf, Kareem; Aqel, Ahmad; A L Othman, Zeid; Badjah-Hadj-Ahmed, Ahmed Yacine

    2013-08-02

    Gas chromatography (GC) is considered the least common application of both polymer and silica-based monolithic columns. This study describes the fabrication of alkyl methacrylate monolithic materials for use as stationary phases in capillary gas chromatography. Following the deactivation of the capillary surface with 3-(trimethoxysilyl)propyl methacrylate (TMSM), the monoliths were formed by the co-polymerization of either hexyl methacrylate (HMA) or lauryl methacrylate (LMA) with different percentage of ethylene glycol dimethacrylate (EDMA) in presence of an initiator (azobisisobutyronitrile, AIBN) and a mixture of porogens include 1-propanol, 1,4-butanediol and water. The monoliths were prepared in 500mm length capillaries possessing inner diameters of 250μm. The efficiencies of the monolithic columns for low molecular weight compounds significantly improved as the percentage of crosslinker was increased, because of the greater proportion of pores less than 50nm. The columns containing lower percentages of crosslinker were able to rapidly separate a series of 8 alkane members in 0.7min, but the separation was less efficient for the light alkanes. Columns prepared with the lauryl methacrylate monomer yielded a different morphology for the monolith-interconnected channels. The channels were more branched, which increased the separation time, and unlike the other columns, allowed for temperature programming.

  9. Flexural properties of ethyl or methyl methacrylate-UDMA blend polymers.

    PubMed

    Kanie, Takahito; Kadokawa, Akihiko; Arikawa, Hiroyuki; Fujii, Koichi; Ban, Seiji

    2010-10-01

    Light-curing polyethyl methacrylate (PEMA)-urethane dimethacrylate (UDMA) resins and polymethyl methacrylate (PMMA)-UDMA resins were prepared by two processes. For first step, PEMA or PMMA powders were fully dissolved in ethyl methacrylate (EMA) or methyl methacrylate (MMA) and then the PEMA-EMA/PMMA-MMA mixtures were mixed with UDMA. The flexural properties of cured PEMA-UDMA and PMMA-UDMA polymers were measured using two PEMA (Mw: 300,000-400,000 and 650,000-1,000,000) and three PMMA (Mw: 30,000-60,000, 350,000 and 650,000-1,000,000) powders with different molecular weight, four mixing ratios of PMMA-MMA, and three mixing ratios of PMMA-MMA mixture and UDMA oligomer. Polymers with PMMA(Mw: 350,000) MMA=25/50, and with PMMA(Mw: 350,000)-MMA/UDMA=1/2 and =1/1, showed no-fracture in a flexural test at 1 mm/min and flexural strength and flexural modulus showed no significant difference compared with those of commercially available heat- and self-curing acrylic resins (p>0.01). Within limitation of this investigation, methyl methacrylate-UDMA blend polymer of this composition is available for denture base resin.

  10. Effects of Surfactants on the Properties of Mortar Containing Styrene/Methacrylate Superplasticizer

    PubMed Central

    Negim, El-Sayed; Kozhamzharova, Latipa; Khatib, Jamal; Bekbayeva, Lyazzat; Williams, Craig

    2014-01-01

    The physical and mechanical properties of mortar containing synthetic cosurfactants as air entraining agent are investigated. The cosurfactants consist of a combination of 2% dodecyl benzene sodium sulfonate (DBSS) and either 1.5% polyvinyl alcohol (PVA) or 1.5% polyoxyethylene glycol monomethyl ether (POE). Also these cosurfactants were used to prepare copolymers latex: styrene/butyl methacrylate (St/BuMA), styrene/methyl methacrylate (St/MMA), and styrene/glycidyl methacrylate (St/GMA), in order to study their effects on the properties of mortar. The properties of mortar examined included flow table, W/C ratio, setting time, water absorption, compressive strength, and combined water. The results indicate that the latex causes improvement in mortar properties compared with cosurfactants. Also polymer latex containing DBSS/POE is more effective than that containing DBSS/PVA. PMID:24955426

  11. Toughening epoxy resin with poly(methyl methacrylate)-grafted natural rubber

    SciTech Connect

    Rezaifard, A.H.; Hodd, K.A.; Barton, J.M.

    1993-12-31

    A novel rubber, poly(methyl methacrylate)-g-natural rubber (Hevea-plus MG), has been studied as a toughening agent for bisphenol A diglycidyl ether (Shell 828 epoxy resin) cured with piperidine. Effective dispersions of the rubber, in concentrations of 2-10 parts per hundred parts resin, were achieved by adjusting the solubility parameter of the epoxy to approximate that of poly(methyl methacrylate) by adding bisphenol A. The fracture energy of the rubber-modified resin was determined by compact tension tests (in the temperature range -60 to +40{degrees}C) and by Charpy impact tests. The poly(methyl methacrylate)-g-natural rubber was found to be an effective toughening agent for the epoxy resin at both low and high rates of strain. Possible fracture mechanisms are discussed. 22 refs., 16 figs., 5 tabs.

  12. Night-time atmospheric degradation of a series of butyl methacrylates

    NASA Astrophysics Data System (ADS)

    Teruel, Mariano A.; López, Rocío S. Pérez; Barnes, Ian; Blanco, María B.

    2016-11-01

    Rate coefficients for the reactions of NO3 with n-butyl methacrylate (k1), iso-butyl methacrylate (k2) and tert-butyl methacrylate (k3) have been determined at 298 K and atmospheric pressure using the relative rate method. The following rate coefficients (×10-15 cm3 molecule-1 s-1) were obtained for the first time: k1 = (5.5 ± 2.6), k2 = (5.8 ± 2.8) and k3 = (5.6 ± 2.5). The NO3 reactions of these compounds could contribute to the removal of NOx and as NOy reservoirs. The potential importance for the tropospheric nitrogen budget of these reactions is discussed and atmospheric lifetimes for the butyl esters are calculated.

  13. Development and characterization of thermoplastic films from sorghum distillers dried grains grafted with various methacrylates.

    PubMed

    Reddy, Narendra; Shi, Zhen; Temme, Lisa; Xu, Helan; Xu, Lan; Hou, Xiuliang; Yang, Yiqi

    2014-03-19

    Distillers Dried Grains (DDG) obtained during production of ethanol from grain sorghum were grafted with methacrylates and compression molded into films with good dry and wet tensile properties. Since sorghum DDG contains up to 45% proteins that are indigestible by animals, it is necessary to find alternative applications to make sorghum ethanol economically competitive. In this research, sorghum DDG was grafted with methyl, ethyl, and butyl methacrylates, the grafted DDG was compression molded into films, and the properties of the grafted DDG and films were studied. At a grafting ratio of 40%, butyl methacrylate (BMA) grafted films had a strength of 4.8 MPa and elongation of 1.8% when dry and 3.1 MPa and 8.1% when wet, indicating that the films had good strength and wet stability. Films developed from grafted DDG show the potential to overcome the brittleness and poor water stability of biopolymer-based films and be useful for various applications.

  14. Effects of surfactants on the properties of mortar containing styrene/methacrylate superplasticizer.

    PubMed

    Negim, El-Sayed; Kozhamzharova, Latipa; Khatib, Jamal; Bekbayeva, Lyazzat; Williams, Craig

    2014-01-01

    The physical and mechanical properties of mortar containing synthetic cosurfactants as air entraining agent are investigated. The cosurfactants consist of a combination of 2% dodecyl benzene sodium sulfonate (DBSS) and either 1.5% polyvinyl alcohol (PVA) or 1.5% polyoxyethylene glycol monomethyl ether (POE). Also these cosurfactants were used to prepare copolymers latex: styrene/butyl methacrylate (St/BuMA), styrene/methyl methacrylate (St/MMA), and styrene/glycidyl methacrylate (St/GMA), in order to study their effects on the properties of mortar. The properties of mortar examined included flow table, W/C ratio, setting time, water absorption, compressive strength, and combined water. The results indicate that the latex causes improvement in mortar properties compared with cosurfactants. Also polymer latex containing DBSS/POE is more effective than that containing DBSS/PVA.

  15. Novel poly(methyl methacrylate)-based semi-interpenetrating polyelectrolyte gels for rechargeable lithium batteries

    NASA Astrophysics Data System (ADS)

    Kalapala, Saibabu; Easteal, Allan J.

    Novel semi-interpenetrating polymer gel electrolytes designed for use in rechargeable lithium polymer batteries are synthesised from methyl methacrylate and the lithium salt of 2-acrylamido-2-methylpropanesulfonic acid (LiAMPS). The gels are made by first synthesising linear chains of poly(LiAMPS) by free radical polymerisation of LiAMPS dissolved in dimethyl acetamide (DMA) or DMA/ethylene carbonate mixtures, then co-polymerisation of methyl methacrylate and a cross-linking monomer (tetraethyleneglycol diacrylate) to form the semi-interpenetrating network. The electrical conductivity of the gels is determined as a function of LiAMPS and methyl methacrylate (MMA) concentrations, cross-link density, and solvent composition. The conductivity ( σ) is found to be in the range 0.2 ≤ σ ≤ 0.8 mS cm -1 at ambient temperature (20 ± 1 °C).

  16. Basic study of a new denture base resin applying hydrophobic methacrylate monomer.

    PubMed

    Umemoto, K; Kurata, S

    1997-06-01

    To improve the water sorption of poly(methyl methacrylate), new hydrophobic monomers, such as norbonyl and phenyl methacrylate, were studied to determine the resin with lower water sorption with no decrease in mechanical property. Water sorption of the copolymers of the hydrophobic monomers and MMA decreased with the increase in the concentration of the monomers. Compressive and bending strength of the copolymers were higher than that of PMMA, and the elastic modulus in bending was the same as that of PMMA. In addition, the transverse-deflection values satisfied ADA specifications. Dynamic mechanical thermal analysis of the copolymers showed a similar tendency to that of PMMA in spite of the introduction of bulky groups, such as norbonyl and phenyl, in the polymer molecule. The polymerization shrinkage in volume was in the following order: norbonyl < phenyl < methyl methacrylate.

  17. Assessment of the skin sensitising potency of the lower alkyl methacrylate esters.

    PubMed

    Kimber, Ian; Pemberton, Mark A

    2014-10-01

    There is continued interest in, and imperatives for, the classification of contact allergens according to their relative skin sensitising potency. However, achieving that end can prove problematic, not least when there is an apparent lack of concordance between experimental assessments of potency and the prevalence allergic contact dermatitis as judged by clinical experience. For the purpose of exploring this issue, and illustrating the important considerations that are required to reach sound judgements about potency categorisation, the lower alkyl methacrylate esters (LAM) have been employed here as a case study. Although the sensitising potential of methyl methacrylate (MMA) has been reviewed previously, there is available new information that is relevant for assessment of skin sensitising potency. Moreover, for the purposes of this article, analyses have been extended to include also other LAM for which relevant data are available: ethyl methacrylate (EMA), n-butyl methacrylate (nBMA), isobutyl methacrylate (iBMA), and 2-ethylhexyl methacrylate (EHMA). In addressing the skin sensitising activity of these chemicals and in drawing conclusions regarding relative potency, a number of sources of information has been considered, including estimates of potency derived from local lymph node assay (LLNA) data, the results of guinea pig assays, and data derived from in silico methods and from recently developed in vitro approaches. Moreover, clinical experience of skin sensitisation of humans by LAM has also been evaluated. The conclusion drawn is that MMA and other LAM are contact allergens, but that none of these chemicals has any more than weak skin sensitising potency. We have also explored here the possible bases for this modest sensitising activity. Finally, the nature of exposure to LAM has been reviewed briefly and on the basis of that information, together with an understanding of skin sensitising potency, a risk assessment has been prepared.

  18. Lipase catalyzed HEMA initiated ring-opening polymerization: in situ formation of mixed polyester methacrylates by transesterification.

    PubMed

    Takwa, Mohamad; Xiao, Yan; Simpson, Neil; Malmström, Eva; Hult, Karl; Koning, Cor E; Heise, Andreas; Martinelle, Mats

    2008-02-01

    2-Hydroxyethyl methacrylate (HEMA) was used as initiator for the enzymatic ring-opening polymerization (ROP) of omega-pentadecalactone (PDL) and epsilon-caprolactone (CL). The lipase B from Candida antarctica was found to catalyze the cleavage of the ester bond in the HEMA end group of the formed polyesters, resulting in two major transesterification processes, methacrylate transfer and polyester transfer. This resulted in a number of different polyester methacrylate structures, such as polymers without, with one, and with two methacrylate end groups. Furthermore, the 1,2-ethanediol moiety (from HEMA) was found in the polyester products as an integral part of HEMA, as an end group (with one hydroxyl group) and incorporated within the polyester (polyester chains acylated on both hydroxyl groups). After 72 h, as a result of the methacrylate transfer, 79% (48%) of the initial amount of the methacrylate moiety (from HEMA) was situated (acylated) on the end hydroxyl group of the PPDL (PCL) polyester. In order to prepare materials for polymer networks, fully dimethacrylated polymers were synthesized in a one-pot procedure by combining HEMA-initiated ROP with end-capping using vinyl methacrylate. The novel PPDL dimethacrylate (>95% incorporated methacrylate end groups) is currently in use for polymer network formation. Our results show that initiators with cleavable ester groups are of limited use to obtain well-defined monomethacrylated macromonomers due to the enzyme-based transesterification processes. On the other hand, when combined with end-capping, well-defined dimethacrylated polymers (PPDL, PCL) were prepared.

  19. Production of microencapsulate glycidyl methacrylate with melamine formaldehyde resin shell materials

    NASA Astrophysics Data System (ADS)

    Bel, T.; Ulku, G.; Kizilcan, N.; Cimenoglu, H.; Yahya, N.; Baydogan, N.

    2016-11-01

    This study gives some information about the preparation of Glycidyl Methacrylate (GMA) microcapsules with Melamine Formaldehyde (MF) resin as a shell material (MF-GMA). Melamine formaldehyde resin containing hydroxyl groups was synthesized in the first step. Second step includes the addition of GMA monomer along with Sodium Dodecyl Benzenesulfonate (SDBS) and Polyvinyl Alcohol (PVA) aqueous solution for getting emulsible solution. The resultant MF-GMA microcapsules had good enclosing performance and thermal stability. The characteristic properties and the morphology of microencapsulated Glycidyl Methacrylate were examined by using FTIR analysis and their morphology was investigated by using optical microscope.

  20. [Gas chromatographic analysis of methyl methacrylate and methanol in its esterification mixture].

    PubMed

    Wu, C; Zeng, C

    1997-09-01

    A fast, simple and accurate gas chromatographic method is established for determining the content of methyl methacrylate (MMA) and methanol in the esterification mixture of methacrylic acid with methanol in the presence of sulfuric acid. In the measurement, polyethylene glycol-20M/sodium hydroxide was adopted as liquid phase, coated on the acid-washed 201 pink support. n-Heptane was used as the internal standard and the correction factors of MMA and methanol obtained were 1.65 and 4.10, respectively. It is significant for this method to be used to control MMA production by acetone cyanohydrin method and to improve the production technology.

  1. The Mark-Houwink-Sakurada Relation for Poly(Methyl Methacrylate)

    NASA Astrophysics Data System (ADS)

    Wagner, Herman L.

    1987-04-01

    In this third review of a series, the literature values for the viscosity-molecular weight relationship (Mark-Houwink-Sakurada) for poly(methyl methacrylate) have been critically evaluated. Although most of the studies have been concerned with conventionally produced poly(methyl methacrylate), some work has also been done with the isotactic polymer. The Mark-Houwink relations for the following solvents are discussed: benzene, toluene, acetone, chloroform, 2-butanone, and tetrahydrofuran, as well as for several other infrequently used solvents. The values of the coefficient K in the relation [η]=KM0.5 for several theta solvents are also reported.

  2. Photo-Physical Behavior and Fluorescence of Thermo Switchable Nanocomposite Based on Methyl Methacrylate -Spirobenzopyran.

    PubMed

    Rouhani, Shohre; Pishvaei, Malihe

    2017-03-01

    Nanocomposites with thermo and photo-switchable fluorescent properties were synthesized via mini-emulsion polymerization based on spiropyran and methyl methacrylate monomer. The photophysical behavior of fluorescence nanocomposites was investigated by fluorescence spectrophotometry in different temperature, UV-light and time of exposure. It was found that methyl methacrylate polymer is capable of acting as a protective layer and play a critical role in improving the photostability of colorants. The nanocomposites exhibited excellent fluorescent thermo-switching action with respect to the free spiro molecule. Graphical Abstract ᅟ.

  3. pH-sensitive methacrylic copolymer gels and the production thereof

    DOEpatents

    Mallapragada, Surya K.; Anderson, Brian C.

    2007-05-15

    The present invention provides novel gel forming methacrylic blocking copolymers that exhibit cationic pH-sensitive behavior as well as good water solubility. The copolymers are constructed by polymerization of a tertiary amine methacrylate with either a (poly(ethylene oxide)-b-poly(propylene oxide)-b-poly(ethylene oxide) polymer, such as the commercially available Pluronic.RTM. polymers, or a poly(ethylene glycol)methyl ether polymer. The polymers may be used for drug and gene delivery, protein separation, as structural supplements, and more.

  4. Disabling disturbance of olfaction in a dental technician following exposure to methyl methacrylate.

    PubMed

    Braun, D; Wagner, W; Zenner, H-P; Schmahl, F W

    2002-10-01

    It is often difficult to diagnose dysosmia due to occupational olfactotoxic substances. The authors present a case of disabling disturbance of olfaction in a dental technician. This is very likely to have been caused by exposure to methyl methacrylate. From 1988-1992, the dental technician had very extensive and sustained contact with a self-polymerizing acrylic resin based on methyl methacrylate. Her perception of smell was still normal in 1988, but it deteriorated up to 1992. The olfactory disorders have persisted and impede social life and occupational rehabilitation.

  5. Reactive Poly(Amic Acid)/ Poly(Glycidyl Methacrylate-r-Poly(ethylene Glycol) Methyl Ether Methacrylate) Blends as Gas Permeation Membranes

    NASA Astrophysics Data System (ADS)

    Beaulieu, Michael; Watkins, James

    2012-02-01

    Polymers containing polar moieties, such as ether groups show an affinity for acidic gases, such as CO2 due to dipole-quadrapole interactions. Polymer blends in which one of the components is poly(ethylene glycol) (PEG) have been studied extensively in literature as a CO2/light gas permeation membrane, but due to the crystallization and poor mechanical properties have been difficult to incorporate PEG above 60wt%. In this study, a series of random copolymers containing both glycidyl methacrylate and poly(ethylene glycol) methyl ether methacrylate in different ratios are blended with a poly(amic acid) prepolymer made from 4, 4'-oxydianiline and pyromellitic dianhydride to create gas permeation membranes. By using a reactive blend PEG loadings above 70% have been realized with sufficient mechanical properties, and since the side chain on the PEGMA is short these blends do not suffer from crystallization.

  6. Terminal-Selective Transesterification of Chlorine-Capped Poly(Methyl Methacrylate)s: A Modular Approach to Telechelic and Pinpoint-Functionalized Polymers.

    PubMed

    Ogura, Yusuke; Terashima, Takaya; Sawamoto, Mitsuo

    2016-04-20

    Terminal-selective transesterification of chlorine-capped poly(methyl methacrylate)s (PMMA-Cl) with alcohols was developed as a modular approach to create telechelic and pinpoint-functionalized polymers. Being sterically less hindered and electronically activated, both the α-end ethyl ester and ω-end methyl ester of PMMA-Cl were efficiently and selectively transesterified with diverse alcohols in the presence of a titanium alkoxide catalyst, while retaining the pendent esters intact, to almost quantitatively give various chlorine-capped telechelic PMMAs. In sharp contrast to conventional telechelic counterparts, the telechelic polymers obtained herein yet carry a chlorine atom at the ω-terminal to further work as a macroinitiator in living radical polymerization. The iterative process of living radical polymerization and terminal-selective transesterification successfully afforded unique pinpoint-functionalized polymers where a single functional monomer unit was introduced into the desired site of the polymer chains.

  7. Molecularly imprinted films of acrylonitrile/methyl methacrylate/acrylic acid terpolymers: influence of methyl methacrylate in the binding performance of L-ephedrine imprinted films.

    PubMed

    Brisbane, Carrie; McCluskey, Adam; Bowyer, Michael; Holdsworth, Clovia I

    2013-05-07

    Molecularly imprinted polymeric films (MIPFs) highly selective to 1R,2S(-)ephedrine (L-ephedrine, EPD) were produced by phase inversion post-polymerization imprinting on poly(acrylonitrile-co-methyl methacrylate-co-acrylic acid) (PAMA) terpolymers. The inclusion of methyl methacrylate (MMA) to the polymer formulation resulted in enhanced EPD selectivity which appears to be dictated by polymer composition to achieve the necessary balance between polymer rigidity and porosity. Substitution of MMA with methyl acrylate, ethyl acrylate and n-butyl acrylate resulted in a loss of EPD selectivity and EPD entrapment within the polymer matrix not observed in PAMA MIPFs. MMA, by virtue of its methyl group, is able to provide the scaffolding and rigidity necessary for stability and preservation of imprinted cavities within the PAMA MIPF leading to high EPD selectivity.

  8. Effects of monomers and homopolymer contents on the dry and wet tensile properties of starch films grafted with various methacrylates.

    PubMed

    Shi, Zhen; Reddy, Narendra; Shen, Li; Hou, Xiuliang; Yang, Yiqi

    2014-05-21

    Starch grafted with four different methacrylates was compression molded to form thermoplastic films with good strength and water stability. Starch is an inexpensive and biodegradable polymer but is nonthermoplastic and needs to be chemically modified to make starch suitable for various applications. In this research, starch was grafted with four methacrylates (methyl, ethyl, butyl, and hexyl), and the effect of the length of the alkyl ester group on grafting parameters, thermoplasticity, and properties of thermoplastic films developed have been studied. Influence of grafting conditions on % grafting efficiency, % homopolymers, and % monomer conversion were studied, and the grafted starch was characterized using thermogravimetric analysis (TGA), differential scanning calorimetry (DSC), and nuclear magnetic resonance ((1)H NMR). At similar grafting ratios, butyl methacrylate (BMA) provided better strength and elongation to the starch films than the other three methacrylates. Grafting of methacrylates appears to be an economical approach to develop thermoplastic products from starch.

  9. In situ synthesis of cobalt ferrite nanoparticle/polymer hybrid from a mixed Fe-Co methacrylate for magnetic hyperthermia

    NASA Astrophysics Data System (ADS)

    Hayashi, Koichiro; Maeda, Kazuki; Moriya, Makoto; Sakamoto, Wataru; Yogo, Toshinobu

    2012-09-01

    Hyperthermic CoFe2O4 nanoparticle (CFO NP)/polymer hybrids were synthesized by hydrolysis-condensation from a complex of Co and Fe possessing methacrylate ligands. Single-crystal analysis revealed that the complex consisted of two Co and four Fe metal atoms coordinated by methacrylate and 2-methoxyethoxy groups. The complex was copolymerized with 2-hydroxyethyl methacrylate (HEMA) and the resulting copolymer was then hydrolyzed to form a CFO NP/copolymer of poly(methacrylate) and poly(2-hydroxyethyl methacrylate) hybrid. Copolymerization with HEMA enhanced the stability of the hybrid in water. The size and magnetic properties of CFO in the hybrid were controlled by adjusting the hydrolysis conditions. Moreover, the hybrid generated heat under an alternating current magnetic field; its exothermal properties depended on the magnetic properties of the hybrid, the strength of the applied field, and the CFO NP content in the agar phantom matrix.

  10. Characterisation of poly(alkyl methacrylate)s by means of electrospray ionisation-tandem mass spectrometry (ESI-MS/MS)

    NASA Astrophysics Data System (ADS)

    Jackson, Anthony T.; Slade, Susan E.; Scrivens, James H.

    2004-11-01

    Electrospray ionisation-tandem mass spectrometry (ESI-MS/MS) has been employed for the characterisation of two poly(alkyl methacrylate) polymers, namely poly(methyl methacrylate) (PMMA) and poly(n-butyl methacrylate) (PBMA). Collision-induced dissociation (CID) experiments were performed in a quadrupole orthogonal time-of-flight (ToF) tandem mass spectrometer fitted with a nanospray source. Tandem mass spectra from singly, doubly and triply charged precursor ions (with alkali metals used for cationisation of the oligomers) are shown and the data are compared to those previously generated by means of matrix-assisted laser desorption/ionisation-collision-induced dissociation (MALDI-CID). These data indicate that cations with greater ionic radii may yield the most useful structural information as the mass-to-charge ratio of the precursor ion increases, whereas lithium or sodium ions are proposed to be ideal for obtaining spectra from lower molecular weight oligomers. Fragment ions at low mass-to-charge ratios dominate the spectra. Two series of peaks may be used to calculate the masses of the initiating and terminating end groups of the polymer. Ion peaks of greater mass-to-charge ratios form series that may be used to infer sequence information from the polymers.

  11. Effects of metal ions on entero-soluble poly(methacrylic acid-methyl methacrylate) coating: a combined analysis by ATR-FTIR spectroscopy and computational approaches.

    PubMed

    Cilurzo, Francesco; Gennari, Chiara G M; Selmin, Francesca; Vistoli, Giulio

    2010-04-05

    Poly(methacrylic acid-methyl methacrylate)s (HPMMs) are pH-dependent polymers which ionize and form salts (PMMs) in neutral conditions. Despite their wide use in tablet coating, the interactions of PMMs with electrolytes present in biorelevant media and luminal fluids have been scantly investigated. The data generated in the current work provide the basic information on the effect of bivalent cations, namely, Ca2+, Zn2+ and Mn2+, on the HPMMs' solubility and, consequently, on the performances (disintegration and drug dissolution) of acetaminophen gastroresistant tablets when exposed to fluid containing such salts. The interactions between polymers and metal ions were analyzed by ATR-FTIR spectroscopy and in silico combining molecular dynamics simulations to explore the conformational profiles of several oligomers with different M(w), taken as model of the polymers, with ab initio and semiempirical calculations in the gas phase. The computational results agree with the experimental data in terms of spatial disposition of the bications with respect to PMMs (Ca2+ and Mn2+ as bidentate form and Zn2+ as monodentate ligand) and interaction strength (Zn2+ > Mn(2+) > Ca2+). The tablet disintegration and dissolution rate of acetaminophen were strongly affected by the interactions of the dissolving copolymer with the metal ions which led to coating insolubilization. These preliminary results underline that the ingestion of metal ions at high concentrations could affect the drug liberation from gastroresistant dosage forms.

  12. Optical Properties of Nanocellulose Dispersions in Water, Dimethylformamide and Poly(Methyl Methacrylate)

    DTIC Science & Technology

    2013-10-01

    measurements for cellulose and PMMA thin- films . ..13  v List of Tables Table 1. Recorded optical data for nanocellulose in water...applications beyond thin films . In particular, the effects of nanocellulose fibers in higher concentrations, processed in different solvents, and...Optical Properties of Nanocellulose Dispersions in Water, Dimethylformamide and Poly(Methyl Methacrylate) by James F. Snyder, Joshua Steele

  13. Recent Origin of the Methacrylate Redox System in Geobacter sulfurreducens AM-1 through Horizontal Gene Transfer.

    PubMed

    Arkhipova, Oksana V; Meer, Margarita V; Mikoulinskaia, Galina V; Zakharova, Marina V; Galushko, Alexander S; Akimenko, Vasilii K; Kondrashov, Fyodor A

    2015-01-01

    The origin and evolution of novel biochemical functions remains one of the key questions in molecular evolution. We study recently emerged methacrylate reductase function that is thought to have emerged in the last century and reported in Geobacter sulfurreducens strain AM-1. We report the sequence and study the evolution of the operon coding for the flavin-containing methacrylate reductase (Mrd) and tetraheme cytochrome с (Mcc) in the genome of G. sulfurreducens AM-1. Different types of signal peptides in functionally interlinked proteins Mrd and Mcc suggest a possible complex mechanism of biogenesis for chromoproteids of the methacrylate redox system. The homologs of the Mrd and Mcc sequence found in δ-Proteobacteria and Deferribacteres are also organized into an operon and their phylogenetic distribution suggested that these two genes tend to be horizontally transferred together. Specifically, the mrd and mcc genes from G. sulfurreducens AM-1 are not monophyletic with any of the homologs found in other Geobacter genomes. The acquisition of methacrylate reductase function by G. sulfurreducens AM-1 appears linked to a horizontal gene transfer event. However, the new function of the products of mrd and mcc may have evolved either prior or subsequent to their acquisition by G. sulfurreducens AM-1.

  14. Controlled Degradation of Poly(Ethyl Cyanoacrylate-Co-Methyl Methacrylate)(PECA-Co-PMMA) Copolymers

    Technology Transfer Automated Retrieval System (TEKTRAN)

    This paper describes a method for modifying poly(ethyl cyanoacrylate) in order to control the degradation and the stability as well as the glass transition temperatures. Copolymers of poly(ethyl cyanoacrylate-co-methyl methacrylate) (PECA-co-PMMA) with various compositions were synthesized by free ...

  15. Chest Wall Reconstruction Using a Methyl Methacrylate Neo-Rib and Mesh.

    PubMed

    Suzuki, Kei; Park, Bernard J; Adusumilli, Prasad S; Rizk, Nabil P; Huang, James; Jones, David R; Bains, Manjit S

    2015-08-01

    Prosthetic reconstruction of the chest wall after oncologic resection is performed by means of various techniques using different materials. We describe a new technique of chest wall reconstruction that includes the use of Marlex mesh and the creation of a neo-rib from a Steinmann pin and methyl methacrylate.

  16. Enthalpy of mixing of methacrylic acid with organic solvents at 293 K

    NASA Astrophysics Data System (ADS)

    Sergeev, V. V.

    2016-03-01

    The enthalpies of mixing of binary systems of methacrylic acid with acetonitrile, benzene, hexane, 1,2-dichloroethane, and acetic acid are measured calorimetrically at 293 K and atmospheric pressure. The enthalpy of mixing of all the studied binary systems is positive over the range of concentrations.

  17. RAFT "grafting-through" approach to surface-anchored polymers: Electrodeposition of an electroactive methacrylate monomer.

    PubMed

    Grande, C D; Tria, M C; Felipe, M J; Zuluaga, F; Advincula, R

    2011-02-01

    The synthesis of homopolymer and diblock copolymers on surfaces was demonstrated using electrodeposition of a methacrylate-functionalized carbazole dendron and subsequent reversible addition-fragmentation chain transfer (RAFT) "grafting-through" polymerization. First, the anodically electroactive carbazole dendron with methacrylate moiety (G1CzMA) was electrodeposited over a conducting surface (i.e. gold or indium tin oxide (ITO)) using cyclic voltammetry (CV). The electrodeposition process formed a crosslinked layer of carbazole units bearing exposed methacrylate moieties. This film was then used as the surface for RAFT polymerization process of methyl methacrylate (MMA), styrene (S), and tert-butyl acrylate (TBA) in the presence of a free RAFT agent and a free radical initiator, resulting in grafted polymer chains. The molecular weights and the polydispersity indices (PDI) of the sacrificial polymers were determined by gel permeation chromatography (GPC). The stages of surface modification were investigated using X-ray photoelectron spectroscopy (XPS), ellipsometry, and atomic force microscopy (AFM) to confirm the surface composition, thickness, and film morphology, respectively. UV-Vis spectroscopy also confirmed the formation of an electro-optically active crosslinked carbazole film with a [Formula: see text] - [Formula: see text] absorption band from 450-650nm. Static water contact angle measurements confirmed the changes in surface energy of the ultrathin films with each modification step. The controlled polymer growth from the conducting polymer-modified surface suggests the viability of combining electrodeposition and grafting-through approach to form functional polymer ultrathin films.

  18. Use of methacrylate-modified chitosan to increase the durability of dentine bonding systems.

    PubMed

    Diolosà, Marina; Donati, Ivan; Turco, Gianluca; Cadenaro, Milena; Di Lenarda, Roberto; Breschi, Lorenzo; Paoletti, Sergio

    2014-12-08

    This study aimed at investigating the effect of a methacrylate-modified chitosan on the durability of adhesive interfaces to improve the clinical performance of dental restorations. Chitosan was modified with methacrylic acid (Chit-MA70) on 16% of the amino groups. Viscosity, rheology, and (1)H NMR spectroscopy were performed to characterize the modified polysaccharide. Chit-MA70 was blended into a primer of an "etch-and-rinse" experimental adhesive system and tested on human teeth. The presence of methacrylate moieties and of residual positive charges on the polysaccharide chain allowed Chit-MA70 to covalently bind to the restorative material and electrostatically interact with demineralized dentin. The Chit-MA70 containing an adhesive system showed values of the immediate bond strength (26.0 ± 8.7 MPa) comparable to the control adhesive system (25.5 ± 8.7 MPa). However, it was shown that upon performing thermo-mechanical cycling treatment of the dental restoration on human teeth, the adhesive with the methacrylate-modified chitosan, in variance with the control adhesive, did not show any decrease in the bond strength (28.4 ± 8.8 MPa). The modified chitosan is proposed as a component of the "etch-and-rinse" adhesive system to efficiently improve the durability of dental restorations.

  19. Versatility of Alkyne-Modified Poly(Glycidyl Methacrylate) Layers for Click Reactions

    SciTech Connect

    Soto-Cantu, Dr. Erick; Lokitz, Bradley S; Hinestrosa Salazar, Juan Pablo; Deodhar, Chaitra; Messman, Jamie M; Ankner, John Francis; Kilbey, II, S Michael

    2011-01-01

    Functional soft interfaces are of interest for a variety of technologies. We describe three methods for preparing substrates with alkyne groups, which show versatility for 'click' chemistry reactions. Two of the methods have the same root: formation of thin, covalently attached, reactive interfacial layers of poly(glycidyl methacrylate) (PGMA) via spin coating onto silicon wafers followed by reactive modification with either propargylamine or 5-hexynoic acid. The amine or the carboxylic acid moieties react with the epoxy groups of PGMA, creating interfacial polymer layers decorated with alkyne groups. The third method consists of using copolymers comprising glycidyl methacrylate and propargyl methacrylate (pGP). The pGP copolymers are spin coated and covalently attached on silicon wafers. For each method, we investigate the factors that control film thickness and content of alkyne groups using ellipsometry, and study the nanophase structure of the films using neutron reflectometry. Azide-terminated polymers of methacrylic acid and 2-vinyl-4,4-dimethylazlactone synthesized via reversible addition-fragmentation chain transfer polymerization were attached to the alkyne-modified substrates using 'click' chemistry, and grafting densities in the range of 0.007-0.95 chains nm{sup -2} were attained. The maximum density of alkyne groups attained by functionalization of PGMA with propargylamine or 5-hexynoic acid was approximately 2 alkynes nm{sup -3}. The alkyne content obtained by the three decorating approaches was sufficiently high that it was not the limiting factor for the click reaction of azide-capped polymers.

  20. Highly superporous cholesterol-modified poly(2-hydroxyethyl methacrylate) scaffolds for spinal cord injury repair.

    PubMed

    Kubinová, Sárka; Horák, Daniel; Hejčl, Aleš; Plichta, Zdeněk; Kotek, Jiří; Syková, Eva

    2011-12-15

    Modifications of poly(2-hydroxyethyl methacrylate) (PHEMA) with cholesterol and the introduction of large pores have been developed to create highly superporous hydrogels that promote cell-surface interactions and that can serve as a permissive scaffold for spinal cord injury (SCI) treatment. Highly superporous cholesterol-modified PHEMA scaffolds have been prepared by the bulk radical copolymerization of 2-hydroxyethyl methacrylate (HEMA), cholesterol methacrylate (CHLMA), and ethylene dimethacrylate (EDMA) cross-linking agent in the presence of ammonium oxalate crystals to establish interconnected pores in the scaffold. Moreover, 2-[(methoxycarbonyl)methoxy]ethyl methacrylate (MCMEMA) was incorporated in the polymerization recipe and hydrolyzed, thus introducing carboxyl groups in the hydrogel to control its swelling and softness. The hydrogels supported the in vitro adhesion and proliferation of rat mesenchymal stem cells. In an in vivo study of acute rat SCI, hydrogels were implanted to bridge a hemisection cavity. Histological evaluation was done 4 weeks after implantation and revealed the good incorporation of the implanted hydrogels into the surrounding tissue, the progressive infiltration of connective tissue and the ingrowth of neurofilaments, Schwann cells, and blood vessels into the hydrogel pores. The results show that highly superporous cholesterol-modified PHEMA hydrogels have bioadhesive properties and are able to bridge a spinal cord lesion.

  1. Characterization of methyl methacrylate grafting onto preirradiated biodegradable lignocellulose fiber by gamma-radiation.

    PubMed

    Khan, Ferdous

    2005-01-14

    Gamma-radiation-induced graft copolymerization of methyl methacrylate onto natural lignocellulose (jute) fiber was carried out by the preirradiation method in an aqueous medium by using octylphenoxy-polyethoxyethanol as an emulsifier. The different factors that influenced the graft copolymer reaction process were investigated. In the case of radiation-dose-dependent grafting, samples irradiated in the presence of air produced up to 73% graft weight compared to 53% obtained in the case of irradiation in a nitrogen environment. By assuming Arrhenius reaction kinetics, the activation energy (E(a)) of the grafting reaction process was evaluated for different reaction temperatures. Moreover, the graft copolymer reaction was controlled by incorporating a homopolymer-inhibiting agent and three different chain-transfer agents in the reaction medium. The mechanical and thermal properties of jute fiber 'as received' and jute-graft-poly(methyl methacrylate) were also investigated. The results showed that the percentage of grafting with jute fiber has a significant effect on the properties. The kinetic parameters were evaluated from TGA thermograms by using Broido's method in the temperature range 240-350 degrees C. Scanning electron micrographs show that the structural changes on the surface of jute fibers were induced by graft copolymerization of methyl methacrylate monomer. Fiber-fiber surface friction was measured in terms of the average maximum load and the kinetic friction. SEM of jute-graft-poly(methyl methacrylate).

  2. Copolymer of methacrylic acid with its diethylammonium salt: Effective waterproofing agent for oil wells

    SciTech Connect

    Kuznetsova, O.N.; Avvakumova, N.I.

    1992-08-10

    In the development of technology for the copolymerization of methacrylic acid with its diethylammonium salt (MAA-MAA{center_dot}DEA), the polymer-like reaction of polymethacrylic acid (PMAA) with diethylamine (DEA) and the polymerization of MAA in the presence of DEA have been studied. 13 refs., 3 figs., 4 tabs.

  3. 76 FR 77709 - Butyl acrylate-methacrylic acid-styrene polymer; Tolerance Exemption

    Federal Register 2010, 2011, 2012, 2013, 2014

    2011-12-14

    ... AGENCY 40 CFR Part 180 Butyl acrylate-methacrylic acid-styrene polymer; Tolerance Exemption AGENCY... from the requirement of a tolerance for residues of 2-Propenoic acid, 2-methyl-, polymer with butyl 2...-styrene polymer when used as an inert ingredient in a pesticide chemical formulation....

  4. 21 CFR 177.1030 - Acrylonitrile/butadiene/styrene/methyl methacrylate copolymer.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    .../styrene/methyl methacrylate copolymer consists of: (1) 73 to 79 parts by weight of a matrix polymer... composition range as the matrix polymer. (b) Adjuvants. The copolymer identified in paragraph (a) of this...: POLYMERS Substances for Use as Basic Components of Single and Repeated Use Food Contact Surfaces §...

  5. 21 CFR 177.1030 - Acrylonitrile/butadiene/styrene/methyl methacrylate copolymer.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    .../styrene/methyl methacrylate copolymer consists of: (1) 73 to 79 parts by weight of a matrix polymer... composition range as the matrix polymer. (b) Adjuvants. The copolymer identified in paragraph (a) of this... HUMAN SERVICES (CONTINUED) FOOD FOR HUMAN CONSUMPTION (CONTINUED) INDIRECT FOOD ADDITIVES:...

  6. 21 CFR 177.1030 - Acrylonitrile/butadiene/styrene/methyl methacrylate copolymer.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    .../styrene/methyl methacrylate copolymer consists of: (1) 73 to 79 parts by weight of a matrix polymer... composition range as the matrix polymer. (b) Adjuvants. The copolymer identified in paragraph (a) of this...: POLYMERS Substances for Use as Basic Components of Single and Repeated Use Food Contact Surfaces §...

  7. 21 CFR 177.1030 - Acrylonitrile/butadiene/styrene/methyl methacrylate copolymer.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    .../styrene/methyl methacrylate copolymer consists of: (1) 73 to 79 parts by weight of a matrix polymer... composition range as the matrix polymer. (b) Adjuvants. The copolymer identified in paragraph (a) of this...: POLYMERS Substances for Use as Basic Components of Single and Repeated Use Food Contact Surfaces §...

  8. Gamma radiation-induced grafting of glycidyl methacrylate (GMA) onto water hyacinth fibers

    NASA Astrophysics Data System (ADS)

    Madrid, Jordan F.; Nuesca, Guillermo M.; Abad, Lucille V.

    2013-04-01

    Water hyacinth fibers (Eichhornia crassipes) were functionalized using radiation-induced graft polymerization of glycidyl methacrylate by γ-rays from 60Co source. The simultaneous grafting technique was employed wherein the water hyacinth fibers were irradiated in nitrogen atmosphere in the presence of glycidyl methacrylate dissolved in water/methanol solvent. The effects of different grafting parameters to the grafting yield were evaluated. The optimal values of solvent, absorbed dose, dose rate, and concentration of monomer were found to be 1:3 (volume/volume) water-methanol solvent, 10 kGy, 8 kGy h-1 dose rate and 5% volume/volume glycidyl methacrylate, respectively. Using the optimum conditions, degree of grafting of approximately 58% was achieved. The grafted water hyacinth fibers were characterized using Attenuated Total Reflectance-Fourier Transformed Infrared Spectroscopy (ATR-FTIR), Thermogravimetric Analysis (TGA), Scanning Electron Microscopy (SEM) and Energy Dispersive X-ray Spectroscopy (EDX). The results of these tests confirmed the successful grafting of glycidyl methacrylate onto water hyacinth fibers.

  9. 40 CFR 721.10375 - Hydroxypropyl methacrylate, reaction products with propylene oxide and ethylene oxide, copolymer...

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... products with propylene oxide and ethylene oxide, copolymer with N-vinyl caprolactam (generic). 721.10375... Substances § 721.10375 Hydroxypropyl methacrylate, reaction products with propylene oxide and ethylene oxide... products with propylene oxide and ethylene oxide, copolymer with N-vinyl caprolactam (PMN P-10-200)...

  10. 40 CFR 721.10375 - Hydroxypropyl methacrylate, reaction products with propylene oxide and ethylene oxide, copolymer...

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... products with propylene oxide and ethylene oxide, copolymer with N-vinyl caprolactam (generic). 721.10375... Substances § 721.10375 Hydroxypropyl methacrylate, reaction products with propylene oxide and ethylene oxide... products with propylene oxide and ethylene oxide, copolymer with N-vinyl caprolactam (PMN P-10-200)...

  11. 40 CFR 721.10375 - Hydroxypropyl methacrylate, reaction products with propylene oxide and ethylene oxide, copolymer...

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... products with propylene oxide and ethylene oxide, copolymer with N-vinyl caprolactam (generic). 721.10375... Substances § 721.10375 Hydroxypropyl methacrylate, reaction products with propylene oxide and ethylene oxide... products with propylene oxide and ethylene oxide, copolymer with N-vinyl caprolactam (PMN P-10-200)...

  12. ABC Triblock Copolymer Worms: Synthesis, Characterization, and Evaluation as Pickering Emulsifiers for Millimeter-Sized Droplets

    PubMed Central

    2016-01-01

    Polymerization-induced self-assembly (PISA) is used to prepare linear poly(glycerol monomethacrylate)–poly(2-hydroxypropyl methacrylate)–poly(benzyl methacrylate) [PGMA–PHPMA–PBzMA] triblock copolymer nano-objects in the form of a concentrated aqueous dispersion via a three-step synthesis based on reversible addition–fragmentation chain transfer (RAFT) polymerization. First, GMA is polymerized via RAFT solution polymerization in ethanol, then HPMA is polymerized via RAFT aqueous solution polymerization, and finally BzMA is polymerized via “seeded” RAFT aqueous emulsion polymerization. For certain block compositions, highly anisotropic worm-like particles are obtained, which are characterized by small-angle X-ray scattering (SAXS) and transmission electron microscopy (TEM). The design rules for accessing higher order morphologies (i.e., worms or vesicles) are briefly explored. Surprisingly, vesicular morphologies cannot be accessed by targeting longer PBzMA blocks—instead, only spherical nanoparticles are formed. SAXS is used to rationalize these counterintuitive observations, which are best explained by considering subtle changes in the relative enthalpic incompatibilities between the three blocks during the growth of the PBzMA block. Finally, the PGMA–PHPMA–PBzMA worms are evaluated as Pickering emulsifiers for the stabilization of oil-in-water emulsions. Millimeter-sized oil droplets can be obtained using low-shear homogenization (hand-shaking) in the presence of 20 vol % n-dodecane. In contrast, control experiments performed using PGMA–PHPMA diblock copolymer worms indicate that these more delicate nanostructures do not survive even these mild conditions. PMID:27795581

  13. Examination of fabrication conditions of acrylate-based hydrogel formulations for doxorubicin release and efficacy test for hepatocellular carcinoma cell.

    PubMed

    Bayramoglu, Gulay; Gozen, Damla; Ersoy, Gozde; Ozalp, V Cengiz; Akcali, K Can; Arica, M Yakup

    2014-01-01

    The objective of the present study was to develop 2-hydroxypropyl methacrylate-co-polyethylene methacrylate [p(HPMA-co-PEG-MEMA)] hydrogels that are able to efficiently entrap doxorubicin for the application of loco-regional control of the cancer disease. Systemic chemotherapy provides low clinical benefit while localized chemotherapy might provide a therapeutic advantage. In this study, effects of hydrogel properties such as PEG chains length, cross-linking density, biocompatibility, drug loading efficiency, and drug release kinetics were evaluated in vitro for targeted and controlled drug delivery. In addition, the characterization of the hydrogel formulations was conducted with swelling experiments, permeability tests, Fourier transform infrared, SEM, and contact angle studies. In these drug-hydrogel systems, doxorubicin contains amine group that can be expected a strong Lewis acid-base interaction between drug and polar groups of PEG chains, thus the drug was released in a timely fashion with an electrostatic interaction mechanism. It was observed that doxorubicin release from the hydrogel formulations decreased when the density of cross-linking, and drug/polymer ratio were increased while an increase in the PEG chains length of the macro-monomer (i.e. PEG-MEMA) in the hydrogel system was associated with an increase in water content and doxorubicin release. The biocompatibility of the hydrogel formulations has been investigated using two measures: cytotoxicity test (using lactate dehydrogenase assay) and major serum proteins adsorption studies. Antitumor activity of the released doxorubicin was assessed using a human SNU398 human hepatocellular carcinoma cell line. It was observed that doxorubicin released from all of our hydrogel formulations which remained biologically active and had the capability to kill the tested cancer cells.

  14. Properties of methacrylate-thiol-ene formulations as dental restorative materials

    PubMed Central

    Cramer, Neil B.; Couch, Charles L.; Schreck, Kathleen M.; Boulden, Jordan E.; Wydra, Robert; Stansbury, Jeffrey W.; Bowman, Christopher N.

    2010-01-01

    Objectives The objective of this study was to evaluate ternary methacrylate-thiol-ene systems, with varying thiol-ene content and thiol:ene stoichiometry, as dental restorative resin materials. It was hypothesized that an off-stoichiometric thiol-ene component would enhance interactions between the methacrylate and thiol-ene processes to reduce shrinkage stress while maintaining equivalent mechanical properties. Methods Polymerization kinetics and functional group conversions were determined by Fourier transform infrared spectroscopy (FTIR). Cured resin mechanical properties were evaluated using a three-point flexural test, carried out with a hydraulic universal test system. Polymerization shrinkage stress was measured with a tensometer coupled with simultaneous real-time conversion monitoring. Results The incorporation of thiol-ene mixtures as reactive diluents into conventional dimethacrylate resins previously was shown to combine synergistically advantageous methacrylate mechanical properties with the improved polymerization kinetics and reduced shrinkage stress of thiol-ene systems. In these systems, due to thiol consumption resultant from both the thiol-ene reaction and chain transfer involving the methacrylate polymerization, the optimum thiol:ene stoichiometry deviates from the traditional 1:1 ratio. Increasing the thiol:ene stoichiometry up to 3:1 results in systems with equivalent flexural modulus, 6 – 20 % reduced flexural strength, and 5 – 33 % reduced shrinkage stress relative to 1:1 stoichiometric thiol:ene systems. Significance Due to their improved overall functional group conversion, and shrinkage stress reduction while maintaining equivalent flexural modulus, methacrylate-thiol-ene resins, particularly those with excess thiol, beyond the conventional 1:1 thiol:ene molar ratio, yield superior dental restorative materials compared with purely dimethacrylate resins. PMID:20553973

  15. Disulfide-Functionalized Diblock Copolymer Worm Gels.

    PubMed

    Warren, Nicholas J; Rosselgong, Julien; Madsen, Jeppe; Armes, Steven P

    2015-08-10

    Two strategies for introducing disulfide groups at the outer surface of RAFT-synthesized poly(glycerol monomethacrylate)-poly(2-hydroxypropyl methacrylate) (PGMA-PHPMA, or Gx-Hy for brevity) diblock copolymer worms are investigated. The first approach involved statistical copolymerization of GMA with a small amount of disulfide dimethacrylate (DSDMA, or D) comonomer to afford a G54-D0.50 macromolecular chain transfer agent (macro-CTA); this synthesis was conducted in relatively dilute solution in order to ensure mainly intramolecular cyclization and hence the formation of linear chains. Alternatively, a new disulfide-based bifunctional RAFT agent (DSDB) was used to prepare a G45-S-S-G45 (or (G45-S)2) macro-CTA. A binary mixture of a non-functionalized G55 macro-CTA was utilized with each of these two disulfide-based macro-CTAs in turn for the RAFT aqueous dispersion polymerization of 2-hydroxypropyl methacrylate (HPMA). By targeting a PHPMA DP of 130 and systematically varying the molar ratio of the two macro-CTAs, a series of disulfide-functionalized diblock copolymer worm gels were obtained. For both formulations, oscillatory rheology studies confirmed that higher disulfide contents led to stronger gels, presumably as a result of inter-worm covalent bond formation via disulfide/thiol exchange. Using the DSDB-based macro-CTA led to the strongest worm gels, and this formulation also proved to be more effective in suppressing the thermosensitive behavior that is observed for the nondisulfide-functionalized control worm gel. However, macroscopic precipitation occurred when the proportion of DSDB-based macro-CTA was increased to 50 mol %, whereas the DSDMA-based macro-CTA could be utilized at up to 80 mol %. Finally, the worm gel modulus could be reduced to that of a nondisulfide-containing worm gel by reductive cleavage of the inter-worm disulfide bonds using excess tris(2-carboxyethyl)phosphine (TCEP) to yield thiol groups. These new biomimetic worm gels are

  16. Biodegradation of poly(2-hydroxyethyl methacrylate) (PHEMA) and poly{(2-hydroxyethyl methacrylate)-co-[poly(ethylene glycol) methyl ether methacrylate]} hydrogels containing peptide-based cross-linking agents.

    PubMed

    Casadio, Ylenia S; Brown, David H; Chirila, Traian V; Kraatz, Heinz-Bernhard; Baker, Murray V

    2010-11-08

    PHEMA-peptide and P[HEMA-co-(MeO-PEGMA)]-peptide conjugate hydrogels [where PHEMA = poly(2-hydroxyethyl methacrylate; PEGMA = poly(ethylene glycol) methacrylate] were readily prepared via photoinitiated free-radical polymerization in water. The PHEMA-peptide hydrogels were opaque and had a heterogeneous morphology of interconnected polymer droplets, characteristic of polymers that separate from the aqueous phase during the polymerization experiment. The P[HEMA-co-(MeO-PEGMA)]-peptide conjugates were transparent gels with a homogeneous morphology when formed in water, but when formed in aqueous NaCl solutions the P[HEMA-co-(MeO-PEGMA)]-peptide conjugates were also opaque and exhibited the heterogeneous morphology of interconnected polymer droplets. When incubated in solutions containing activated papain, P[HEMA-co-(MeO-PEGMA)]-peptide conjugates underwent degradation that was characterized by macroscopic changes to sample shape and size, sample weight, and microscopic structure. PHEMA-peptide conjugates did not undergo any significant degradation when incubated with papain, although ninhydrin-staining experiments suggested that some peptide cross-linker groups were cleaved during the incubation. The difference in degradation behavior of PHEMA-peptide and P[HEMA-co-(MeO-PEGMA)]-peptide conjugates is attributed to differences in aqueous solubility of PHEMA and P[HEMA-co-(MeO-PEGMA)].

  17. Synthesis and characterization of anionic amphiphilic model conetworks of 2-butyl-1-octyl-methacrylate and methacrylic acid: effects of polymer composition and architecture.

    PubMed

    Kali, Gergely; Georgiou, Theoni K; Iván, Béla; Patrickios, Costas S; Loizou, Elena; Thomann, Yi; Tiller, Joerg C

    2007-10-09

    Seven amphiphilic conetworks of methacrylic acid (MAA) and a new hydrophobic monomer, 2-butyl-1-octyl-methacrylate (BOMA), were synthesized using group transfer polymerization. The MAA units were introduced via the polymerization of tetrahydropyranyl methacrylate (THPMA) followed by the removal of the protecting tetrahydropyranyl group by acid hydrolysis after network formation. Both THPMA and BOMA were in-house synthesized. Ethylene glycol dimethacrylate (EGDMA) was used as the cross-linker. Six of the conetworks were model conetworks, containing copolymer chains between cross-links of precise molecular weight and composition. The prepared conetwork series covered a wide range of compositions and architectures. In particular, the MAA content was varied from 67 to 94 mol %, and three different conetwork architectures were constructed: ABA triblock copolymer-based, statistical copolymer-based, and randomly cross-linked. The linear conetwork precursors were analyzed by gel permeation chromatography and 1H NMR spectroscopy in terms of their molecular weight and composition, both of which were found to be close to the theoretically calculated values. The degrees of swelling (DS) of all the amphiphilic conetworks were measured in water and in THF over the whole range of ionization of the MAA units. The DSs in water increased with the degree of ionization (DI) and the content of the hydrophilic MAA units in the conetwork, while the DSs in THF increased with the degree of polymerization of the chains between the cross-links and by reducing the DI of the MAA units. Finally, the nanophase behavior of the conetworks was probed using small-angle neutron scattering and atomic force microscopy.

  18. Highly sensitive poly[glycidyl methacrylate-co-poly(ethylene glycol) methacrylate] brush-based flow-through microarray immunoassay device.

    PubMed

    Liu, Yingshuai; Wang, Wei; Hu, Weihua; Lu, Zhisong; Zhou, Xiaoqun; Li, Chang Ming

    2011-08-01

    Flow-through immunoassay is an attractive method for fast, inexpensive and high-throughput protein analyses. However, its practical application is limited by low sensitivity. In this work, a highly sensitive flow-through microarray immunoassay device is developed, in which a poly[glycidyl methacrylate-co-poly(ethylene glycol) methacrylate] (P(GMA-co-PEGMA)) brush as a flexible matrix is uniformly coated on a glass slide through a purge-free surface-initiated atom transfer radical polymerization (SI-ATRP) to immobilize capture proteins for a larger loading capacity and higher bioactivity while allowing easy target access to the brush-attached probes for efficient antibody-antigen (Ab-Ag) bindings. The integrated device is then constructed by simply laminating the protein-arrayed slide onto a ready-for-bonding double-sided adhesive tape-attached poly(methyl methacrylate) (PMMA) microfluidic structure. As a demonstration, a parallel microarray panel is designed to perform flow-through immunoassays for good detection flexibility and simultaneous analysis of various samples. The limit of detection (LOD) of 1-10 pg/mL for detected target proteins is achieved, which is one to two orders better than those of reported flow-through immunoassays. The device also demonstrates significantly reduced total assay time over the static microarray immunoassay. The rapid and sensitive detection can be mainly ascribed to the P(GMA-co-PEGMA) brushed substrate, of which both the hydrophilicity from its PEG component and the binding capability from its GMA moiety result in higher protein loading capacity, lower nonspecific adsorption, and higher Ab-Ag binding efficiency. The integrated microfluidic device was further used to detect an important cancer biomarker carcinoembryonic antigen (CEA) in serum and achieved a LOD of 10 pg/mL, demonstrating its great potential for clinical applications.

  19. Synthesis of [.sup.13C] and [.sup.2H] substituted methacrylic acid, [.sup.13C] and [.sup.2H] substituted methyl methacrylate and/or related compounds

    DOEpatents

    Alvarez, Marc A.; Martinez, Rodolfo A.; Unkefer, Clifford J.

    2008-01-22

    The present invention is directed to labeled compounds of the formulae ##STR00001## wherein Q is selected from the group consisting of --S--, --S(.dbd.O)--, and --S(.dbd.O).sub.2--, Z is selected from the group consisting of 1-naphthyl, substituted 1-naphthyl, 2-naphthyl, substituted 2-naphthyl, and phenyl groups with the structure ##STR00002## wherein R.sub.1, R.sub.2, R.sub.3, R.sub.4 and R.sub.5 are each independently selected from the group consisting of hydrogen, a C.sub.1-C.sub.4 lower alkyl, a halogen, and an amino group selected from the group consisting of NH.sub.2, NHR and NRR' where R and R' are each independently selected from the group consisting of a C.sub.1-C.sub.4 lower alkyl, an aryl, and an alkoxy group, and X is selected from the group consisting of hydrogen, a C.sub.1-C.sub.4 lower alkyl group, and a fully-deuterated C.sub.1-C.sub.4 lower alkyl group. The present invention is also directed to a process of preparing labeled compounds, e.g., process of preparing [.sup.13C]methacrylic acid by reacting a (CH.sub.3CH.sub.2O--.sup.13C(O)--.sup.13CH.sub.2)-- aryl sulfone precursor with .sup.13CHI to form a (CH.sub.3CH.sub.2O--.sup.13C(O)--.sup.13C(.sup.13CH.sub.3).sub.2)-- aryl sulfone intermediate, and, reacting the (CH.sub.3CH.sub.2O--.sup.13C(O)--.sup.13C(.sup.13CH.sub.3).sub.2)-- aryl sulfone intermediate with sodium hydroxide, followed by acid to form [.sup.13C]methacrylic acid. The present invention is further directed to a process of preparing [.sup.2H.sub.8]methyl methacrylate by reacting a (HOOC--C(C.sup.2H.sub.3).sub.2-- aryl sulfinyl intermediate with CD.sub.3I to form a (.sup.2H.sub.3COOC--C(C.sup.2H.sub.3).sub.2)-- aryl sulfinyl intermediate, and heating the(.sup.2H.sub.3COOC--C(C.sup.2H.sub.3).sub.2)-- aryl sulfinyl intermediate at temperatures and for time sufficient to form [.sup.2H.sub.8]methyl methacrylate.

  20. Synthesis and characterization of functionalized methacrylates for coatings and biomedical applications

    NASA Astrophysics Data System (ADS)

    Shemper, Bianca Sadicoff

    The research presented in this dissertation involves the design of polymers for biomaterials and for coatings applications. The development of non-wettable, hard UV-curing, or reactive coatings is discussed. The biomaterials section involves the syntheses of linear and star-like polymers of the functionalized monomer poly(propylene glycol) monomethacrylate (PPGM) via atom transfer radical polymerization (ATRP) (Chapter II). Its copolymerization with a perfluoroalkyl ethyl methacrylate monomer (1H,1H,2H,2H-heptadecafluorodecyl methacrylate) and the syntheses of linear and star-like amphiphilic copolymers containing the fluorinated monomer and poly(ethyleneglycol) methyl ether methacrylate (MPEGMA) are discussed in Chapter III. The four-arm amphiphilic block copolymer obtained showed unique associative properties leading to micellization in selective solvents. Chapter IV includes research involving the design of films with low surface energy by incorporating fluorine into the polymer. The synthesis, characterization and polymerization of a perfluoroalkylether-substituted methacrylic acid (C8F7) are discussed, and the properties of coatings obtained after its photopolymerization on different substrates are evaluated to confirm formation of low-surface energy polymeric coatings. Subsequently, hard coatings based on methyl (alpha-hydroxymethyl)acrylate (MHMA) were prepared via photopolymerization using UV-light. Firstly, mechanistic investigations into the photopolymerization behavior of (alpha-hydroxymethyl)acrylates (RHMA's) are reported (Chapter V). RHMA derivatives were photopolymerized with various multifunctional acrylates and methacrylates and the effect of crosslinker type and degree of functionality on photopolymerization rates and conversions was investigated. Then, in Chapter VI the synthesis of a series of new crosslinkers is described and their photopolymerization kinetics was investigated in bulk. The effect of these novel crosslinkers on the

  1. ATOM TRANSFER RADICAL POLYMERIZATION OF N-BUTYL METHACRYLATE IN AQUEOUS DISPERSED SYSTEMS: A MINIEMULSION APPROACH. (R826735)

    EPA Science Inventory

    Ultrasonication was applied in combination with a hydrophobe for the copper-mediated atom transfer radical polymerization of n-butyl methacrylate in an aqueous dispersed system. A controlled polymerization was successfully achieved, as demonstrated by a linear correlation between...

  2. A rare case of pseudotumor formation associated with methyl methacrylate hypersensitivity in a patient following cemented total knee arthroplasty.

    PubMed

    Kenan, Shachar; Kahn, Leonard; Haramati, Noga; Kenan, Samuel

    2016-08-01

    Hypersensitivity to orthopedic implant materials has been well documented with potential catastrophic consequences if not addressed pre-operatively. The spectrum of reactions is wide, from mild non-specific pain with localized erythema to severe periprosthetic inflammatory destruction and pseudotumor formation. It is therefore essential to identify patients who have or are at risk for implant-associated hypersensitivity. Although metal sensitivity is commonly cited as the cause of these reactions, methyl methacrylate (MMA) has rarely been implicated. To the best of our knowledge, methyl methacrylate-associated pseudotumor formation has not yet been described. The following is a case report of a 68-year-old female who, after undergoing a routine cemented right total knee arthroplasty, developed a painless, enlarging mass during a 13-year period. This mass was found to be a pseudotumor in association with methyl methacrylate hypersensitivity. A review of pseudotumor pathogenesis, methyl methacrylate hypersensitivity, and preoperative preventative care is discussed.

  3. Process for producing a well-adhered durable optical coating on an optical plastic substrate. [abrasion resistant polymethyl methacrylate lenses

    NASA Technical Reports Server (NTRS)

    Kubacki, R. M. (Inventor)

    1978-01-01

    A low temperature plasma polymerization process is described for applying an optical plastic substrate, such as a polymethyl methacrylate lens, with a single layer abrasive resistant coating to improve the durability of the plastic.

  4. (1)H and (13)C NMR chemical shifts of methacrylate molecules associated with DMPC and/or DPPC liposomes.

    PubMed

    Fujisawa, Seiichiro; Ishihara, Mariko; Kadoma, Yoshinori

    2005-01-01

    In the light of recent developments, changes in (1)H and (13)C NMR chemical shifts of methacrylate molecule associated with DMPC (L-alpha dimyristoylphosphatidylcholine) or DPPC (L-alpha-dipalmitoylphosphatidylcholine) liposomes as a model for mimic native lipid bilayers were studied at 30, 37, and 52 degrees C. The chemical shifts of 3Ha, 3C, and 4C resonances in methacrylates (see Fig. 2) were greatly shifted higher field, suggesting the methacrylate molecule-lipid bilayer interaction. Comparison of the findings with methyl methacrylate (MMA), ethylene dimethacrylate (EDMA), and triethyleneglycol dimethacrylate (TEGDMA) revealed that the interaction of dimethacrylates (EDMA, TEGDMA) was greater than monomethacrylate, MMA. Their interaction with DMPC liposomes was also judged by a differential scanning calorimetry (DSC), indicating that the interaction was characterized by decreasing the enthalpy, entropy, and transition co-operativity. The evidence of the upfield NMR-shifts for methacrylate molecules was also judged by the descriptors such as the reactivity (HOMO-LUMO energy) and the electrostatic function (partial charges) between methacrylate molecules and DPPC, calculated by a PM 3 semiempirical MO method. The upfield NMR shifts were considerably well interpreted from the descriptors. NMR screening technique in methacrylates to phospholipid targets would be highly valuable in biomaterial developments. Figure 2 Changes in (1)H and (13)C NMR chemical shifts of methacrylate molecule associated with DMPC or DPPC liposomes. DMPC liposomes/MMA (1:1, molar ratio) and DMPC/TEGDMA (1:1) liposomes were measured at 30 degrees C. In DPPC liposome system, the rippled gel phase was measured at 30 degrees C, whereas the liquid crystalline phase for MMA and for both EDMA and TEGDMA were measured at 52 degrees C and 37 degrees C, respectively.

  5. Experimental and theoretical investigation of the complexation of methacrylic acid and diisopropyl urea

    NASA Astrophysics Data System (ADS)

    Pogány, Peter; Razali, Mayamin; Szekely, Gyorgy

    2017-01-01

    The present paper explores the complexation ability of methacrylic acid which is one of the most abundant functional monomer for the preparation of molecularly imprinted polymers. Host-guest interactions and the mechanism of complex formation between methacrylic acid and potentially genotoxic 1,3-diisopropylurea were investigated in the pre-polymerization solution featuring both experimental (NMR, IR) and in silico density functional theory (DFT) tools. The continuous variation method revealed the presence of higher-order complexes and the appearance of self-association which were both taken into account during the determination of the association constants. The quantum chemical calculations - performed at B3LYP 6-311 ++G(d,p) level with basis set superposition error (BSSE) corrections - are in agreement with the experimental observations, reaffirming the association constants and justifying the validity of computational investigation of such systems. Furthermore, natural bond orbital analysis was carried out to appraise the binding properties of the complexes.

  6. Double-bond-containing polyallene-based triblock copolymers via phenoxyallene and (meth)acrylate.

    PubMed

    Ding, Aishun; Lu, Guolin; Guo, Hao; Huang, Xiaoyu

    2017-03-02

    A series of ABA triblock copolymers, consisting of double-bond-containing poly(phenoxyallene) (PPOA), poly(methyl methacrylate) (PMMA), or poly(butyl acrylate) (PBA) segments, were synthesized by sequential free radical polymerization and atom transfer radical polymerization (ATRP). A new bifunctional initiator bearing azo and halogen-containing ATRP initiating groups was first prepared followed by initiating conventional free radical homopolymerization of phenoxyallene with cumulated double bond to give a PPOA-based macroinitiator with ATRP initiating groups at both ends. Next, PMMA-b-PPOA-b-PMMA and PBA-b-PPOA-b-PBA triblock copolymers were synthesized by ATRP of methyl methacrylate and n-butyl acrylate initiated by the PPOA-based macroinitiator through the site transformation strategy. These double-bond-containing triblock copolymers are stable under UV irradiation and free radical circumstances.

  7. Effect of epoxidation on 30% poly(methyl methacrylate)-grafted natural rubber polymer electrolytes

    NASA Astrophysics Data System (ADS)

    Nazir, Khuzaimah; Aziz, Ahmad Fairoz; Adam, Nurul Ilham; Yahya, Muhd Zu Azhan; Ali, Ab Malik Marwan

    2015-08-01

    Epoxidized 30% poly(methyl methacrylate)-grafted natural rubber (EMG 30) as a polymer host in solid polymer electrolytes (SPEs) has been investigated. EMG30 was synthesized via performicepoxidation method onto 30% poly(methyl methacrylate)-grafted natural rubber (MG30) and the formations of epoxy group were discussed. The EMG30 were characterized by proton nuclear magnetic resonance (1HNMR) to investigate their chemical structure and differential scanning calorimeter to determine their crystallinity. A new peak in 1HNMR spectra (2.71 ppm) confirmed the appearance of epoxy group. SPE based on EMG30 doped with 40 wt% LiCF3SO3 show the highest conductivity. The complexation between EMG30 and LiCF3SO3 were confirmed by attenuated total reflection Fourier transform infrared (ATR-FTIR).

  8. Double-bond-containing polyallene-based triblock copolymers via phenoxyallene and (meth)acrylate

    NASA Astrophysics Data System (ADS)

    Ding, Aishun; Lu, Guolin; Guo, Hao; Huang, Xiaoyu

    2017-03-01

    A series of ABA triblock copolymers, consisting of double-bond-containing poly(phenoxyallene) (PPOA), poly(methyl methacrylate) (PMMA), or poly(butyl acrylate) (PBA) segments, were synthesized by sequential free radical polymerization and atom transfer radical polymerization (ATRP). A new bifunctional initiator bearing azo and halogen-containing ATRP initiating groups was first prepared followed by initiating conventional free radical homopolymerization of phenoxyallene with cumulated double bond to give a PPOA-based macroinitiator with ATRP initiating groups at both ends. Next, PMMA-b-PPOA-b-PMMA and PBA-b-PPOA-b-PBA triblock copolymers were synthesized by ATRP of methyl methacrylate and n-butyl acrylate initiated by the PPOA-based macroinitiator through the site transformation strategy. These double-bond-containing triblock copolymers are stable under UV irradiation and free radical circumstances.

  9. Double-bond-containing polyallene-based triblock copolymers via phenoxyallene and (meth)acrylate

    PubMed Central

    Ding, Aishun; Lu, Guolin; Guo, Hao; Huang, Xiaoyu

    2017-01-01

    A series of ABA triblock copolymers, consisting of double-bond-containing poly(phenoxyallene) (PPOA), poly(methyl methacrylate) (PMMA), or poly(butyl acrylate) (PBA) segments, were synthesized by sequential free radical polymerization and atom transfer radical polymerization (ATRP). A new bifunctional initiator bearing azo and halogen-containing ATRP initiating groups was first prepared followed by initiating conventional free radical homopolymerization of phenoxyallene with cumulated double bond to give a PPOA-based macroinitiator with ATRP initiating groups at both ends. Next, PMMA-b-PPOA-b-PMMA and PBA-b-PPOA-b-PBA triblock copolymers were synthesized by ATRP of methyl methacrylate and n-butyl acrylate initiated by the PPOA-based macroinitiator through the site transformation strategy. These double-bond-containing triblock copolymers are stable under UV irradiation and free radical circumstances. PMID:28252049

  10. Effect of epoxidation on 30% poly(methyl methacrylate)-grafted natural rubber polymer electrolytes

    SciTech Connect

    Nazir, Khuzaimah; Aziz, Ahmad Fairoz; Adam, Nurul Ilham; Yahya, Muhd Zu Azhan; Ali, Ab Malik Marwan

    2015-08-28

    Epoxidized 30% poly(methyl methacrylate)-grafted natural rubber (EMG 30) as a polymer host in solid polymer electrolytes (SPEs) has been investigated. EMG30 was synthesized via performicepoxidation method onto 30% poly(methyl methacrylate)-grafted natural rubber (MG30) and the formations of epoxy group were discussed. The EMG30 were characterized by proton nuclear magnetic resonance ({sup 1}HNMR) to investigate their chemical structure and differential scanning calorimeter to determine their crystallinity. A new peak in {sup 1}HNMR spectra (2.71 ppm) confirmed the appearance of epoxy group. SPE based on EMG30 doped with 40 wt% LiCF{sub 3}SO{sub 3} show the highest conductivity. The complexation between EMG30 and LiCF{sub 3}SO{sub 3} were confirmed by attenuated total reflection Fourier transform infrared (ATR-FTIR)

  11. Quaternary ammonium silane-functionalized, methacrylate resin composition with antimicrobial activities and self-repair potential

    PubMed Central

    Gong, Shi-qiang; Niu, Li-na; Kemp, Lisa K.; Yiu, Cynthia K.Y.; Ryou, Heonjune; Qi, Yi-pin; Blizzard, John D.; Nikonov, Sergey; Brackett, Martha G.; Messer, Regina L.W.; Wu, Christine D.; Mao, Jing; Brister, L. Bryan; Rueggeberg, Frederick A.; Arola, Dwayne D.; Pashley, David H.; Tay, Franklin R.

    2012-01-01

    Design of antimicrobial polymers for enhancing healthcare issues and minimizing environmental problems is an important endeavor with both fundamental and practical implications. Quaternary ammonium silane-functionalized methacrylate (QAMS) represents an example of antimicrobial macromonomers synthesized by a sol-gel chemical route; these compounds possess flexible Si-O-Si bonds. In present work, a partially-hydrolyzed QAMS copolymerized with bis-GMA is introduced. This methacrylate resin was shown to possess desirable mechanical properties with both a high degree of conversion and minimal polymerization shrinkage. Kill-on-contact microbiocidal activities of this resin were demonstrated using single-species biofilms of Streptococcus mutans (ATCC 36558), Actinomyces naeslundii (ATCC 12104) and Candida albicans (ATCC 90028). Improved mechanical properties after hydration provided the proof-of-concept that QAMS-incorporated resin exhibits self-repair potential via water-induced condensation of organic modified silicate (ormosil) phases within the polymerized resin matrix. PMID:22659173

  12. Surface-initiated Polymerization of Azidopropyl Methacrylate and its Film Elaboration via Click Chemistry.

    PubMed

    Saha, Sampa; Bruening, Merlin L; Baker, Gregory L

    2012-11-27

    Azidopropyl methacrylate (AzPMA), a functional monomer with a pendent azido group, polymerizes from surfaces and provides polymer brushes amenable to subsequent elaboration via click chemistry. In DMF at 50 °C, click reactions between poly(AzPMA) brushes and an alkynylated dye proceed with >90% conversion in a few minutes. However, in aqueous solutions, reaction with an alkyne-containing poly(ethylene glycol) methyl ether (mPEG, Mn=5000) gives <10% conversion after a 12-h reaction at room temperature. Formation of copolymers with AzPMA and polyethylene glycol methyl ether methacrylate (mPEGMA) enables control over the hydrophilicity and functional group density in the copolymer to increase the yield of aqueous click reactions. The copolymers show reaction efficiencies as high as 60%. These studies suggest that for aqueous applications such as bioconjugation via click chemistry, control over brush hydrophilicity is vital.

  13. Ab initio study of acrylate polymerization reactions: methyl methacrylate and methyl acrylate propagation.

    PubMed

    Yu, Xinrui; Pfaendtner, Jim; Broadbelt, Linda J

    2008-07-24

    The kinetic parameters of the free radical propagation of methyl methacrylate and methyl acrylate have been calculated using quantum chemistry and transition state theory. Multiple density functional theory (DFT) methods were used to calculate the activation energy, and it was found that MPWB1K/6-31G(d,p) yields results that are in very good agreement with experimental data. To obtain values of the kinetic parameters that were in the best agreement with experimental data, low frequencies were treated using a one-dimensional internal rotor model. Chain length effects were also explored by examining addition reactions of monomeric, dimeric, and trimeric radicals to monomer for both methyl methacrylate and methyl acrylate. The results show that the values for the addition of the trimeric radical to monomer are closest to experimental data. The kinetic parameters that were calculated using a continuum description of the monomer as a solvent were not significantly different from the vacuum results.

  14. Preparation of poly(methyl methacrylate) grafted hydroxyapatite nanoparticles via reverse ATRP.

    PubMed

    Wang, Yan; Xiao, Yan; Huang, Xiujuan; Lang, Meidong

    2011-08-15

    Surface-initiated reverse atom transfer radical polymerization (reverse ATRP) technical was successfully employed to modify hydroxyapatite (HAP) nanoparticles with poly(methyl methacrylate) (PMMA). The peroxide initiator moiety for reverse ATRP was covalently attached to the HAP surface through the surface hydroxyl groups. Reverse ATRP of methyl methacrylate (MMA) from the initiator-functionalized HAP was carried out, and the end bromide groups of grafted PMMA initiated ATRP of MMA subsequently. Fourier transformation infrared (FTIR) spectroscopy, thermal gravimetric analysis (TGA) and transmission electron microscopy (TEM) were employed to confirm the grafting and to characterize the nanoparticle structure. The grafted PMMA gave HAP nanoparticles excellent dispersibility in MMA monomer. As the amount of grafted PMMA increased, the dispersibility of surface-grafted HAP and the compressive strength of HAP/PMMA composites were improved.

  15. Grafting of Chitosan and Chitosantrimethoxylsilylpropyl Methacrylate on Single Walled Carbon Nanotubes-Synthesis and Characterization.

    PubMed

    Carson, Laura; Kelly-Brown, Cordella; Stewart, Melisa; Oki, Aderemi; Regisford, Gloria; Stone, Julia; Traisawatwong, Pasakorn; Durand-Rougely, Clarissa; Luo, Zhiping

    2010-09-01

    Acid functionalized single walled carbon nanotubes (CNTs) were grafted to chitosan by first reacting the oxidized CNTs with thionyl chloride to form acyl-chlorinated CNTs. This product was subsequently dispersed in chitosan and covalently grafted to form CNT-chitosan. CNT-chitosan was further grafted onto 3-trimethoxysilylpropyl methacrylate by free radical polymerization conditions, to yield CNT-g-chitosan-g-3-trimethoxysilylpropyl methacrylate (TMSPM), hereafter referred to as CNT-chitosan-3-TMSPM. These composites were characterized by Fourier Transform Infrared Resonance Spectroscopy (FTIR), carbon-13 nuclear magnetic resonance ((13)C NMR), Thermogravimetric Analysis (TGA), scanning electron microscopy (SEM) and transmission electron microscopy (TEM). The composite showed improved thermal stability and could be of great potential use in bone tissue engineering.

  16. Combinatory approach of methacrylated alginate and acid monomers for concrete applications.

    PubMed

    Mignon, Arn; Devisscher, Dries; Graulus, Geert-Jan; Stubbe, Birgit; Martins, José; Dubruel, Peter; De Belie, Nele; Van Vlierberghe, Sandra

    2017-01-02

    Polysaccharides, and especially alginate, can be useful for self-healing of cracks in concrete. Instead of weak electrostatic bonds present within calcium alginate, covalent bonds, by methacrylation of the polysaccharides, will result in mechanically stronger superabsorbent polymers (SAPs). These methacrylated alginate chains as backbone are combined with two acrylic monomers in a varying molar fraction. These SAPs show a moisture uptake capacity up to 110% their own weight at a relative humidity of 95%, with a negligible hysteresis. The swelling capacity increased (up to 246 times its own weight) with a decreasing acrylic acid/2 acrylamido-2-methylpropane sulfonic acid ratio. The SAPs also showed a thermal stability up to 200°C. Interestingly, the SAP composed of alginate and acrylic acid exerted a very limited decrease in compressive strength (up to 7% with addition of 1wt% SAP) rendering this material interesting for the envisaged self-healing application.

  17. Preparation of poly(methyl methacrylate) grafted titanate nanotubes by in situ atom transfer radical polymerization

    NASA Astrophysics Data System (ADS)

    Gao, Yuan; Gao, Xueping; Zhou, Yongfeng; Yan, Deyue

    2008-12-01

    This paper reports the successful preparation of core-shell hybrid nanocomposites by a 'grafting from' approach based on in situ atom transfer radical polymerization (ATRP) of methyl methacrylate (MMA) from titanate nanotubes (TNTs). Transmission electron microscope (TEM) images of the products provide direct evidence for the formation of a core-shell structure, possessing a hard core of TNTs and a soft shell of poly-MMA (PMMA). Fourier-transform infrared spectroscopy (FT-IR), hydrogen nuclear magnetic resonance (1H NMR), scanning electron microscopy (SEM), and thermal gravimetric analysis (TGA) were used to determine the chemical structure, morphology, and the grafted PMMA quantities of the resulting products. The grafted PMMA content was well controlled and increased with increasing monomer/initiator ratio. Further copolymerization of hydroxyethyl methacrylate (HEMA) with PMMA-coated TNTs as initiators was realized, illustrating the 'living' characteristics of the ATRP method used in this paper.

  18. RGDS- and SIKVAVS-Modified Superporous Poly(2-hydroxyethyl methacrylate) Scaffolds for Tissue Engineering Applications.

    PubMed

    Macková, Hana; Plichta, Zdeněk; Proks, Vladimír; Kotelnikov, Ilya; Kučka, Jan; Hlídková, Helena; Horák, Daniel; Kubinová, Šárka; Jiráková, Klára

    2016-11-01

    Three-dimensional hydrogel supports for mesenchymal and neural stem cells (NSCs) are promising materials for tissue engineering applications such as spinal cord repair. This study involves the preparation and characterization of superporous scaffolds based on a copolymer of 2-hydroxyethyl and 2-aminoethyl methacrylate (HEMA and AEMA) crosslinked with ethylene dimethacrylate. Ammonium oxalate is chosen as a suitable porogen because it consists of needle-like crystals, allowing their parallel arrangement in the polymerization mold. The amino group of AEMA is used to immobilize RGDS and SIKVAVS peptide sequences with an N-γ-maleimidobutyryloxy succinimide ester linker. The amount of the peptide on the scaffold is determined using (125) I radiolabeled SIKVAVS. Both RGDS- and SIKVAVS-modified poly(2-hydroxyethyl methacrylate) scaffolds serve as supports for culturing human mesenchymal stem cells (MSCs) and human fetal NSCs. The RGDS sequence is found to be better for MSC and NSC proliferation and growth than SIKVAVS.

  19. Fabrication slab waveguide based polymethyl methacrylate (PMMA) with spin coating method

    NASA Astrophysics Data System (ADS)

    Andriawan, Alan; Pramono, Yono Hadi; Masoed, Asnawi

    2016-11-01

    Fabrication and characterization slab waveguide based polymethyl methacrylate (PMMA) has been carried out. Slab waveguide fabrication done by the spin coating method. Slab waveguide fabrication process carried out by the rotational speed of 1000, 2000, and 3000 rpm respectively played for 10 seconds. Then the slab waveguides heated using a hot plate. Heating process starting from room temperature then increased 5°C to 70°C with a 5 minute warm-up time interval. From the results of characterization fabricated slab waveguides to determine the film thickness is made. Then made observations on the waveguide by passing the light beam He-Ne laser on the thin layer through a single mode optical fiber. From the results of characterization is known that the fabrication of a slab waveguide with a layer thickness of 166 μm. From this research it is known that polymethyl methacrylate (PMMA) can be used as a waveguide with a spin coating method.

  20. The color stability of silorane- and methacrylate-based resin composites.

    PubMed

    Kang, Aromi; Son, Sung-Ae; Hur, Bock; Kwon, Young Hoon; Ro, Jung Hoon; Park, Jeong-Kil

    2012-01-01

    The purpose of this study were to evaluate the discoloration of a silorane-based resin and two methacrylated-based resin composites upon exposure to different staining solutions coffee, red wine, porcine liver esterase and distilled water for 7 days. The colors of all specimens before and after storage in the solutions were measured by a spectrophotometer based on CIE Lab system, and the color differences thereby calculated. Data were statistically analyzed by ANOVA and Scheffe's test. For coffee and red wine, the mean color change in silorane-based resin was significantly lower than that in methacylate-based resin composites (p<0.05). For porcine liver esterase and distilled water, there was no significant difference in the mean values of color change between silorane- and methacrylate-based resin composites (p>0.05). In conclusion, the silorane-based resin composites exhibited better color stability (less ΔE) after exposure to the colored staining solutions.

  1. Preparation and Characterization of Poly(methyl methacrylate)-functionalized Carboxyl Multi-walled Carbon Nanotubes

    NASA Astrophysics Data System (ADS)

    Meng, Qing-jie; Zhang, Xing-xiang; Bai, Shi-he; Wang, Xue-chen

    2007-12-01

    An in situ polymerization process was used to prepare poly (methyl methacrylate) (PMMA)-functionalized carboxyl multi-walled carbon nanotubes using carboxylate carbon nanotubes and methyl methacrylate as reactants and benzoyl peroxide as an initiator agent. The functionalized multi-walled carbon nanotubes were characterized using transmission electron microscope, scanning electron microscope, nuclear magnetic resonance, Fourier transform infrared spectroscopy, thermogravimetric analysis and Raman. The results indicate that the PMMA chains are covalently linked with the surface of carboxylate carbon nanotubes. The surface morphology is controlled by the content of carboxylate carbon nanotubes in the reactants. The PMMA functionalized multi-walled carbon nanotubes are soluble in deuterated chloroform. The storage modulus and tanδ magnitude increase as the content of CCNTs increases up to 0.3%.

  2. Poly(methyl methacrylate)-cellulose nitrate copolymers. II. Physical and mechanical properties

    SciTech Connect

    Badran, B.M.; Sherif, S.; El-Sheltawi, S.T.; Abu-Sedira, A.A.

    1981-03-01

    Poly(methyl methacrylate)-cellulose nitrate copolymers were prepared by bulk polymerization using benzoyl peroxide as initiator. Cellulose nitrates of two different nitrogen contents (11.4 and 12.2%) were used. The prepared copolymers were ..gamma..-irradiated for specified periods of up to 11.83 Mrad. Their physical and mechanical properties were measured before and after irradiation. The title copolymers showed lower modulus, tensile strength, and elongation at break than poly(methyl methacrylate) itself, but they showed better hardness and abrasian. Irradiation of up to 6.57 Mrad improved the modulus of the copolymers. Hardness and abrasion were improved by increasing cellulose nitrate content. The prepared copolymers that contained cellulose nitrate of 11.4% nitrogen showed secondary transition points. The increase of cellulose nitrate concentration shifted both first and second transition points to relatively higher values.

  3. Novel antifouling oligo(ethylene glycol) methacrylate particles via surfactant-free emulsion polymerization.

    PubMed

    Buyukserin, Fatih; Camli, Sevket Tolga; Yavuz, Mustafa Selman; Budak, Gurer Guven

    2011-03-01

    The use of particle formulations with antifouling surface properties attracts increasing interest in several biotechnological applications. Majority of these studies utilize a poly(ethylene glycol) coating to render the corresponding surface nonrecognizable to biological macromolecules. Herein, we report a simple way to prepare novel antifouling colloids composed of oligo(ethylene glycol) backbones via surfactant-free emulsion polymerization. Monodisperse cross-linked poly(ethylene glycol) ethyl ether methacrylate particles were characterized by dynamic light scattering and transmission electron microscopy. The effects of monomer, cross-linker and initiator on particle characteristics were investigated. More importantly, a prominent blockage of bovine serum albumin adsorption was obtained for the poly(ethylene glycol)-based sub-micron (~200 nm) particles when compared with similar-sized poly(methyl methacrylate) counterparts.

  4. Grafting of Chitosan and Chitosantrimethoxylsilylpropyl Methacrylate on Single Walled Carbon Nanotubes-Synthesis and Characterization

    PubMed Central

    Carson, Laura; Kelly-Brown, Cordella; Stewart, Melisa; Oki, Aderemi; Regisford, Gloria; Stone, Julia; Traisawatwong, Pasakorn; Durand-Rougely, Clarissa; Luo, Zhiping

    2011-01-01

    Acid functionalized single walled carbon nanotubes (CNTs) were grafted to chitosan by first reacting the oxidized CNTs with thionyl chloride to form acyl-chlorinated CNTs. This product was subsequently dispersed in chitosan and covalently grafted to form CNT-chitosan. CNT-chitosan was further grafted onto 3-trimethoxysilylpropyl methacrylate by free radical polymerization conditions, to yield CNT-g-chitosan-g-3-trimethoxysilylpropyl methacrylate (TMSPM), hereafter referred to as CNT-chitosan-3-TMSPM. These composites were characterized by Fourier Transform Infrared Resonance Spectroscopy (FTIR), carbon-13 nuclear magnetic resonance (13C NMR), Thermogravimetric Analysis (TGA), scanning electron microscopy (SEM) and transmission electron microscopy (TEM). The composite showed improved thermal stability and could be of great potential use in bone tissue engineering. PMID:21765959

  5. Atom transfer radical polymerization to fabricate monodisperse poly[glycidyl methacrylate-co-poly (ethylene glycol) methacrylate] microspheres and its application for protein affinity purification.

    PubMed

    Yu, Ling; Shi, Zhuan Zhuan; Li, Chang Ming

    2015-09-01

    Poly[glycidyl methacrylate-co-poly (ethylene glycol) methacrylate] microspheres for the first time were successfully synthesized by atom transfer radical polymerization (ATRP) method at room temperature. The co-polymerization approach was investigated to delicately control the microsphere morphology and size-distribution by reaction conditions including solvent percentage, monomer loading and rotation speed. The results show that the average size of the microspheres is ∼5.7 μm with coexistence of epoxy, hydroxyl and ether groups, which provide plentiful functional sites for protein anchoring. The mechanism of the microsphere formation is proposed. The microsphere successfully demonstrates its unique application for affinity purification of proteins, in which the functional epoxy group facilitates a simple and efficient protein covalent immobilization to purify immunoglobulin G on the microspheres, while the hydrophilic poly (ethylene glycol) motif can repulse nonspecific protein adsorption for good specificity. This microspheres can be used in broad protein biosensors due to their abundant functional groups and high surface to volume ratio.

  6. Poly(glycidyl methacrylate)-A soft template for the facile preparation of poly(glycidyl methacrylate) core-copper nanoparticle shell nanocomposite

    NASA Astrophysics Data System (ADS)

    Mohammed Safiullah, S.; Abdul Wasi, K.; Anver Basha, K.

    2015-12-01

    Poly(glycidyl methacrylate) core/copper nanoparticle shell nanocomposite (PGMA/Cu nanohybrid) was prepared by simple two step method (i) The synthesis of poly(glycidyl methacrylate) (PGMA) beads by free radical suspension polymerization followed by (ii) direct deposition of copper nanoparticles (CuNPs) on activated PGMA beads. The PGMA beads were used as a soft template to host the CuNPs without surface modification of it. In this method the CuNPs were formed by chemical reduction of copper salts using sodium borohydride in water medium and deposited directly on the activated PGMA. Two different concentrations of copper salts were employed to know the effect of concentration on the shape and size of nanoparticles. The results showed that, the different sizes and shapes of CuNPs were deposited on the PGMA matrix. The X-ray Diffraction study results showed that the CuNPs were embedded on the surface of the PGMA matrix. The scanning electron microscopic images revealed that the fabrication of CuNPs on the PGMA matrix possess different shapes and changes the morphology and nature of PGMA beads significantly. The fluorescent micrograph also confirmed that the CuNPs were doped on the PGMA surface. The thermal studies have demonstrated that the CuNPs deposition on the surface of PGMA beads had a significant effect.

  7. Relationship between water structure and properties of poly(methyl methacrylate-b-2-hydroxyethyl methacrylate) by solid-state NMR.

    PubMed

    Mochizuki, Akira; Miwa, Yuko; Miyoshi, Riko; Namiki, Takahiro

    2017-03-22

    We previously reported that the platelet compatibility of methyl methacrylate (MMA)-2-hydroxyethyl methacrylate (HEMA) diblock copolymers is related to the characteristic water structure in the copolymer, as the copolymer has an excess amount of nonfreezing water when compared with that estimated from the amounts of water in HEMA and MMA homopolymers. Thus, in this study, the relationship between water structure and polymer structure, including the heterogeneity and mobility of the copolymer, was investigated using differential scanning calorimetry (DSC) and nuclear magnetic resonance (NMR) spectroscopy. The prepared copolymers were classified into two groups: copolymers with a short, constant polyMMA segment length (Mn = ~2900) and copolymers with a constant polyHEMA segment length (Mn = ~9500), whereas the lengths of the counter segments varied. DSC analysis showed that when the polyMMA and polyHEMA segment lengths are similar, the amount of nonfreezing water increases, regardless of the total molecular weight of the copolymer. NMR analysis showed that heterogeneity of the copolymer is enhanced and the mobility of the copolymer decreases when the segment lengths are similar. These findings suggested that the excess amount of nonfreezing water is formed when the properties of water near the HEMA unit change from freezing to nonfreezing owing to interactions with the MMA unit. In addition, it is suggested that the heterogeneity of the copolymer structure or the mobility of the polymer are involved in the generation of excess nonfreezing water.

  8. Study of polymeric interactions of copolymers: 2-hydroxyethyl methacrylate (HEMA) and 2,3-dihydroxypropyl methacrylate (DHPMA) with copper hydroxylated nanoballs.

    PubMed

    McCann, Krystal; Knudsen, Bernard; Ananthoji, Ramakanth; Perry, John J; Hilker, Brent; Zaworotko, Michael J; Harmon, Julie P

    2010-09-01

    2-hydroxyethyl methacrylate (HEMA) and 2,3-dihydroxypropyl methacrylate (DHPMA) were used to synthesize novel nanocomposites containing 0.5% by weight of copper hydroxylated nanoballs. Glass transition temperatures of the copolymers and their respective nanocomposites were determined by using differential scanning calorimetry (DSC). Thermogravimetric analysis (TGA) was employed to measure the degradation temperatures of the samples and to determine if the degradation is a single step process or multiple step process. The dielectric permittivity (epsilon') and loss factor (epsilon") were measured via Dielectric Analysis (DEA) in the frequency range 0.1 Hz to 100 kHz and between the temperature -150 to 190 degrees C. gamma, beta, and alphabeta conductivity relaxations were revealed using the electric modulus formalism. The activation energies for the relaxations were calculated. Argand plots of M" versus M' were used to study the viscoelastic effects of both copolymer and the composites. Herein we show that it is possible to tune solubility and relaxation properties which are important to the design of new biomaterials.

  9. Methylation of acidic moieties in poly(methyl methacrylate-co-methacrylic acid) copolymers for end-group characterization by tandem mass spectrometry.

    PubMed

    Giordanengo, Rémi; Viel, Stéphane; Hidalgo, Manuel; Allard-Breton, Béatrice; Thévand, André; Charles, Laurence

    2010-07-30

    The complete structural characterization of a copolymer composed of methacrylic acid (MAA) and methyl methacrylate (MMA) units was achieved using tandem mass spectrometry. In a first step, collision-induced dissociation (CID) of sodiated MAA-MMA co-oligomers allowed us to determine the co-monomeric composition, the random nature of the copolymer and the sum of the end-group masses. However, dissociation reactions of MAA-based molecules mainly involve the acidic pendant groups, precluding individual characterization of the end groups. Therefore, methylation of all the acrylic acid moieties was performed to transform the MAA-MMA copolymer into a PMMA homopolymer, for which CID mainly proceeds via backbone cleavages. Using trimethylsilyldiazomethane as a derivatization agent, this methylation reaction was shown to be complete without affecting the end groups. Using fragmentation rules established for PMMA polymers together with accurate mass measurements of the product ions and knowledge of reagents used for the studied copolymer synthesis, a structure could be proposed for both end groups and it was found to be consistent with signals obtained in nuclear magnetic resonance spectra.

  10. Synthesis and applications of shell cross-linked thermoresponsive hybrid micelles based on poly(N-isopropylacrylamide-co-3-(trimethoxysilyl)propyl methacrylate)-b-poly(methyl methacrylate).

    PubMed

    Wei, Hua; Cheng, Cheng; Chang, Cong; Chen, Wen-Qin; Cheng, Si-Xue; Zhang, Xian-Zheng; Zhuo, Ren-Xi

    2008-05-06

    Shell cross-linked (SCL) thermoresponsive hybrid micelles consisting of a cross-linked thermoresponsive hybrid hydrophilic shell and a hydrophobic core domain were synthesized from poly(N-isopropylacrylamide-co-3- (trimethoxysilyl)propyl methacrylate)-b-polymethyl methacrylate (P(NIPAAm-co-MPMA)-b-PMMA) amphiphilic block copolymers. Transmission electron microscopy (TEM) images showed that the SCL micelles formed regularly globular nanoparticles. The SCL micelles showed reversible dispersion/aggregation in response to temperature cycles through an outer polymer shell lower critical solution temperature (LCST) for PNIPAAm at around 33 degrees C, observed by turbidity measurements and dynamic light scattering (DLS). The drug loading and in vitro drug release properties of the SCL micelles bearing a silica-reinforced PNIPAAm shell were further studied, which showed that the SCL micelles exhibited a much improved entrapment efficiency (EE) as well as a slower release rate which allowed the entrapped molecules to be slowly released over a much longer period of time as compared with pure PNIPAAm-b-PMMA micelles.

  11. Effect of mouse VEGF164 on the viability of hydroxyethyl methacrylate-methyl methacrylate-microencapsulated cells in vivo: bioluminescence imaging.

    PubMed

    Cheng, Dangxiao; Lo, Chuen; Sefton, Michael V

    2008-11-01

    Bioluminescent imaging was used to track the viability of luciferase transfected L929 cells in poly(hydroxyethyl methacrylate-co-methyl methacrylate) (HEMA-MMA) microcapsules. Bioluminescence, as determined by Xenogen imaging after addition of luciferin to microcapsules in vitro, increased with time, consistent with an increase in cell number. Capsules were suspended in Matrigel and injected subcutaneously. The bioluminesence in vivo increased over the first 3 weeks and then decreased, both with and without the delivery of mVEGF(164) (1.2 ng/24 h/200 microcapsules in vitro); VEGF delivery was from microencapsulated doubly transfected cells (both luciferase and mVEGF(164)). VEGF delivery was sufficient to generate a greater number of vascular structures, but this did not result in the expected increase in microencapsulated cell viability. Interestingly, the number of vessels at day 28 was less than at day 21, consistent with what would be an expected reduction in VEGF secretion when cell viability is lost. The results presented here do not support the hypothesis that transfection of microencapsulated cells with VEGF is sufficient to correct the oxygen transport limitation, at least with this type of tissue engineering construct. On the other hand, bioluminescent imaging proved to be a useful method of monitoring microencapsulated cell viability over many weeks in vivo.

  12. Surface segregation of fluorinated moieties on poly(methyl methacrylate-ran-2-perfluorooctylethyl methacrylate) films during film formation: Entropic or enthalpic influences.

    PubMed

    Ye, Xiuyun; Zuo, Biao; Deng, Mao; Hei, Yanlin; Ni, Huagang; Lu, Xiaolin; Wang, Xinping

    2010-09-01

    The effects of solvents, fluorinated monomer content and film-formation methods on the surface structures of random copolymers composed of methyl methacrylate (MMA) and 2-perfluorooctylethyl methacrylate (FMA) were investigated by contact angle goniometry, X-ray photoelectron spectroscopy, sum frequency generation (SFG) vibrational spectroscopy and surface tension measurement. It is found that, with cyclohexanone as the solvent, there is a critical FMA content of 9mol%, below which the copolymer films by spin coating have a more surface segregation extent of fluorinated moieties than those by solution casting; above which the copolymer films by solution casting have a more surface segregation extent of fluorinated moieties than those by spin coating. However, with toluene as solvent, the critical FMA content lowers down to 3mol%. We believe that the solvent nature and the content of fluorinated moieties in the random copolymer have the great effect because the combined effect of these two factors can determine the random copolymer chain conformations and their thermodynamic dominating factors in the solution and at the solution-air interface. A thermodynamic analysis combining the entropic and enthalpic effects is suggested to explain the observed phenomenon. This research is believed to obtain an enhanced understanding of the surface formation mechanism of the polymer films and thus demonstrate how to promote the segregation of fluorinated moieties at the polymer film surfaces.

  13. Protein-resistant polyurethane by sequential grafting of poly(2-hydroxyethyl methacrylate) and poly(oligo(ethylene glycol) methacrylate) via surface-initiated ATRP.

    PubMed

    Jin, Zhilin; Feng, Wei; Zhu, Shiping; Sheardown, Heather; Brash, John L

    2010-12-15

    Protein-resistant polyurethane (PU) surfaces were prepared by sequentially grafting poly(2-hydroxyethyl methacrylate) (poly(HEMA)) and poly(oligo(ethylene glycol) methacrylate) (poly(OEGMA)) via surface-initiated atom transfer radical polymerization (s-ATRP). The chain lengths of poly(HEMA) and poly(OEGMA) were regulated via the ratio of monomer to sacrificial initiator in solution. The surfaces were characterized by water contact angle and X-ray photoelectron spectroscopy (XPS). The protein resistant properties of the surfaces were assessed by single and binary adsorption experiments with fibrinogen (Fg), lysozyme (Lys), and lactalbumin (Lac). The adsorption of all three proteins on the sequentially grafted poly(HEMA)-poly(OEGMA) surfaces (PU/PH/PO) was greatly reduced compared with the unmodified PU. Adsorption decreased with increasing poly(OEGMA) chain length. On the PU/PH/PO surface with longest poly(OEGMA) chain length (∼100), the decrease in Lys adsorption was in the range of 95-98% and the decrease in Fg and Lac adsorption was >99% compared with the unmodified PU. Adsorption from binary protein solutions showed that the PU/PH/PO surfaces resisted these proteins more or less equally, that is, independent of protein size.

  14. Photophysical, photochemical and laser behavior of some diolefinic laser dyes in sol-gel and methyl methacrylate/2-hydroxyethyl methacrylate copolymer matrices

    NASA Astrophysics Data System (ADS)

    Sakr, Mahmoud A. S.; Abdel Gawad, El-Sayed A.; Abou Kana, Maram T. H.; Ebeid, El-Zeiny M.

    2015-08-01

    The photophysical properties such as singlet absorption, molar absorptivity, fluorescence spectra, dipole moment, fluorescence quantum yields, fluorescence lifetimes and laser activity of 1,4-bis (β-Pyridyl-2-Vinyl) Benzene (P2VB), 2,5-distyryl-pyrazine (DSP) and 1,4-bis(2-methylstyryl)benzene(MSB) diolefineic laser dyes have been measured in different restricted hosts. (P2VB), (DSP) and (MSB) are embedded in transparent sol-gel glass and a copolymer of methyl methacrylate (MMA) and 2-hydroxyethyl methacrylate (HEMA) media. The absorption and fluorescence properties of these laser dyes in sol-gel glass matrices are compared with their respective properties in copolymer host. The photostability of these laser dyes in sol-gel glass and (MMA/HEMA) copolymer samples are measured in terms of half-life method (using nitrogen laser 337.1 nm in pumping), as the number of pulses necessary to reduce the dye laser intensity to 50% of its original value. The gel laser materials show improved photostability upon pumping by nitrogen laser compared with those in organic polymeric host matrix.

  15. Preparation and characterization of pH-sensitive and antifouling poly(vinylidene fluoride) microfiltration membranes blended with poly(methyl methacrylate-2-hydroxyethyl methacrylate-acrylic acid).

    PubMed

    Ju, Junping; Wang, Chao; Wang, Tingmei; Wang, Qihua

    2014-11-15

    Functional terpolymer of poly(methyl methacrylate-2-hydroxyethyl methacrylate-acrylic acid) (P(MMA-HEMA-AA)) was synthesized via a radical polymerization method. The terpolymer could be directly blended with poly(vinylidene fluoride) (PVDF) to prepare the microfiltration (MF) membranes via phase separate process. The synthesized polymers were characterized by Fourier transform infrared (FTIR), the nuclear magnetic resonance proton spectra ((1)H NMR). The membrane had the typical asymmetric structure and the hydrophilic side chains tended to aggregate on the membrane surface. The surface enrichment of amphiphilic copolymer and morphology of MF membranes were characterized by Fourier transform infrared attenuated total reflection spectroscopy (FTIR-ATR) and scanning electron microscopy (SEM). The contact angle (CA) and water uptake were also tested to assess the hydrophilicity and wetting characteristics of the polymer surface. The water filtration properties were measured. It was found the modified membranes showed excellent pH-sensitivity and pH-reversibility behavior. Furthermore, the hydrophilicity of the blended membranes increased, and the membranes showed good protein antifouling property.

  16. Study of the water structure in poly(methyl methacrylate-block-2-hydroxyethyl methacrylate) and its relationship to platelet adhesion on the copolymer surface.

    PubMed

    Mochizuki, Akira; Namiki, Takahiro; Nishimori, Yusuke; Ogawa, Haruki

    2015-01-01

    The water structure and platelet compatibility of poly(methyl methacrylate (MMA)-block-2-hydroxyethyl methacrylate (HEMA)) were investigated. The molecular weight (Mn) of the polyHEMA segment was kept constant (average: 9600), while the Mn of the polyMMA segment was varied from 1340 to 7390. The equilibrium water content of the copolymers was found to be mainly governed by the HEMA content. The water structure in the copolymers was characterized in terms of the amounts of non-freezing and freezing water (abbreviated as Wnf and Wfz, respectively) using differential scanning calorimetry. It was found that the Wnf for the copolymers were higher than those estimated from the Wnf for the HEMA and MMA homopolymers and that the amount of excess non-freezing water depended on the polyMMA segment length. In addition, X-ray diffraction analysis revealed that some of the copolymers had cold-crystallizable water. These facts suggested that the polyMMA segments were involved in determining the water structures in the copolymers. Furthermore, the platelet compatibility of the copolymers was improved as compared to that of the HEMA homopolymer. It was therefore concluded that the platelet compatibility of the copolymer was related to the amount of excess non-freezing water.

  17. Poly(butyl methacrylate-g-methoxypoly(ethylene glycol)) and poly(methyl methacrylate-g-methoxypoly(ethylene glycol)) graft copolymers: preparation and aqueous solution properties.

    PubMed

    Horgan, Adrian; Saunders, Brian; Vincent, Brian; Heenan, Richard K

    2003-06-15

    A series of water-soluble, amphiphilic graft copolymers has been prepared by free-radical copolymerization of methoxypoly(ethylene glycol) macromonomers, with either methyl methacrylate or butyl methacrylate as the comonomers, in water/ethanol solvent mixtures. Lower molecular weight copolymers were obtained by increasing the concentration of the initiator, azobisisobutyronitrile (AIBN), used in the polymerization reaction. However, the route used also led to the formation of significant quantities of tetramethylsuccinodinitrile, a toxic byproduct resulting from the cage reaction of AIBN. Static fluorescence measurements using pyrene as a probe, along with 1H NMR experiments, showed that the graft copolymers form aggregates in water at very low concentrations (approximately 0.01 g l(-1)) with the pendant hydrophilic graft chains forming a stabilizing shell around the hydrophobic backbone. An increase in the hydrophile-lipophile balance of the graft copolymers was found to lead to smaller aggregates with lower aggregation numbers and highly swollen hydrophilic shells, as revealed by small angle neutron scattering (SANS).

  18. Nonviral Plasmid DNA Carriers Based on N,N'-Dimethylaminoethyl Methacrylate and Di(ethylene glycol) Methyl Ether Methacrylate Star Copolymers.

    PubMed

    Mendrek, Barbara; Sieroń, Łukasz; Żymełka-Miara, Iwona; Binkiewicz, Paulina; Libera, Marcin; Smet, Mario; Trzebicka, Barbara; Sieroń, Aleksander L; Kowalczuk, Agnieszka; Dworak, Andrzej

    2015-10-12

    Star polymers with random and block copolymer arms made of cationic N,N'-dimethylaminoethyl methacrylate (DMAEMA) and nonionic di(ethylene glycol) methyl ether methacrylate (DEGMA) were synthesized via atom transfer radical polymerization (ATRP) and used for the delivery of plasmid DNA in gene therapy. All stars were able to form polyplexes with plasmid DNA. The structure and size of the polyplexes were precisely determined using light scattering and cryo-TEM microscopy. The hydrodynamic radius of a complex of DNA with star was dependent on the architecture of the star arms, the DEGMA content and the number of amino groups in the star compared to the number of phosphate groups of the nucleic acid (N/P ratio). The smallest polyplexes (Rh90°∼50 nm) with positive zeta potentials (∼15 mV) were formed of stars with N/P=6. The introduction of DEGMA into the star structure caused a decrease of polyplex cytotoxicity in comparison to DMAEMA homopolymer stars. The overall transfection efficiency using HT-1080 cells showed that the studied systems are prospective gene delivery agents. The most promising results were obtained for stars with random copolymer arms of high DEGMA content.

  19. Polystyrene nanoparticles based on poly(butyl methacrylate-g-methoxypoly(ethylene glycol)) and poly(methyl methacrylate-g-methoxypoly(ethylene glycol)) graft copolymers.

    PubMed

    Horgan, Adrian; Vincent, Brian

    2003-06-15

    The solubilization of styrene by poly(butyl methacrylate-g-methoxypoly(ethylene glycol)) and poly(methyl methacrylate-g-methoxypoly(ethylene glycol)) graft copolymers has been examined. From turbidity measurements the solubility limit of the monomer in the micelles was obtained and the distribution coefficients were evaluated. Dynamic light scattering revealed that below the solubility limit, solubilization leads to a slight increase in micelle size, while above the solubility limit, there is a dramatic increase in particle size and turbidity as oil-in-water emulsions are formed through coalescence of monomer-swollen micelles. Polymerizations carried out below the solubility limit using the graft copolymer micelles as templates resembled microemulsion polymerizations in nature and led to very fine sterically stabilized polystyrene latex particles. Through careful control of the monomer concentration and the polymerization temperature it was possible to obtain spherical nanosize latex particles with similar size to those of the micelle precursors (10 nm) up to 11% monomer by weight. Polymerizations above the solubility limit, on the other hand, showed similarities with emulsion polymerizations and resulted in larger particles with higher polydispersity.

  20. Detection of leachables and cytotoxicity after exposure to methacrylate- and epoxy-based root canal sealers in vitro.

    PubMed

    Lodienė, Greta; Kopperud, Hilde M; Ørstavik, Dag; Bruzell, Ellen M

    2013-10-01

    Root canal sealing materials may have toxic potential in vitro depending on the cell line, cytotoxicity assay, material chemistry, and degree of polymer curing. The aims of the present study were to detect leaching components from epoxy- or methacrylate-based root canal sealers and to investigate the degree of cytotoxicity after exposure to extracts from these materials. Qualitative determination of substances released from the materials was performed by gas- and liquid chromatography/mass spectrometry. Submandibular salivary gland acinar cell death (apoptosis/necrosis) was determined using a fluorescence staining/microscopy technique. The major leachable monomer from the epoxy-based material was bisphenol-A diglycidyl ether (BADGE), whereas leachables from the methacrylate-based materials were mainly triethylene glycol dimethacrylate (TEGDMA), urethane dimethacrylate (UDMA), hydroxyethyl methacrylate (HEMA), and polyethyleneglycol dimethacrylate (PEGDMA). Exposure to diluted extracts of cured methacrylate-based materials caused a postexposure time-dependent increase in cell death. This effect was not demonstrated as a result of exposure to undiluted extract of cured epoxy-based material. Extracts of all fresh materials induced apoptosis significantly, but at lower dilutions of the epoxy- than the methacrylate-based materials. The degree of leaching, determined from the relative chromatogram peak heights of eluates from the methacrylate-based sealer materials, corresponded with the degree of cell death induced by extracts of these materials.

  1. 2-(2-methoxyethoxy)ethyl methacrylate hydrogels with gradient of cross-link density

    NASA Astrophysics Data System (ADS)

    Kadlubowski, Slawomir; Matusiak, Malgorzata; Adamus, Agnieszka; Olejniczak, Magdalena N.; Kozanecki, Marcin

    2016-01-01

    Electron beam irradiation of 2-(2-methoxyethoxy)ethyl methacrylate and ethylene glycol dimethacrylate mixtures leads to the formation of cross-linked structures that exhibit a gradient of cross-link density, as demonstrated by gel fraction, swelling and Differential Scanning Calorimetry analysis. The reason for observed phase separation is formation of the high molecular weight clusters and its precipitation before gelation dose. This effect can be controlled/influenced by absorbed dose and cross-linker concentration.

  2. Biodegradable inorganic-organic hybrids of methacrylate star polymers for bone regeneration.

    PubMed

    Chung, Justin J; Fujita, Yuki; Li, Siwei; Stevens, Molly M; Kasuga, Toshihiro; Georgiou, Theoni K; Jones, Julian R

    2017-03-08

    Hybrids that are molecular scale co-networks of organic and inorganic components are promising biomaterials, improving the brittleness of bioactive glass and the strength of polymers. Methacrylate polymers have high potential as the organic source for hybrids since they can be produced, through controlled polymerization, with sophisticated polymer architectures that can bond to silicate networks. Previous studies showed the mechanical properties of hybrids can be modified by polymer architecture and molar mass (MM). However, biodegradability is critical if hybrids are to be used as tissue engineering scaffolds, since the templates must be remodelled by host tissue. Degradation by-products have to either completely biodegrade or be excreted by the kidneys. Enzyme, or bio-degradation is preferred to hydrolysis by water uptake as it is expected to give a more controlled degradation rate. Here, branched and star shaped poly(methyl methacrylate-co-3-(trimethoxysilyl)propyl methacrylate) (poly(MMA-co-TMSPMA)) were synthesized with disulphide based dimethacrylate (DSDMA) as a biodegradable branching agent. Biodegradability was confirmed by exposing the copolymers to glutathione, a tripeptide which is known to cleave disulphide bonds. Cleaved parts of the star polymer from the hybrid system were detected after 2weeks of immersion in glutathione solution, and MM was under threshold of kidney filtration. The presence of the branching agent did not reduce the mechanical properties of the hybrids and bone progenitor cells attached on the hybrids in vitro. Incorporation of the DSDMA branching agent has opened more possibilities to design biodegradable methacrylate polymer based hybrids for regenerative medicine.

  3. Fabrication of Poly(methyl Methacrylate) microfluidic chips by redox-initiated polymerization

    SciTech Connect

    Chen, Jiang; Lin, Yuehe; Chen, Gang

    2007-08-16

    In this report, a method based on the redox-initiated polymerization of methyl methacrylate (MMA) has been developed for the rapid fabrication of PMMA microfluidic chips.The new fabrication approach obviates the need for special equipment and significantly simplifies the process of fabricating microdevices. The attractive performance of the novel PMMA microchips has been demonstrated in connection with contactless conductivity detection for the separation and detection of ionic species.

  4. Durability of Poly(Methyl Methacrylate) Lenses Used in Concentrating Photovoltaic Technology (Revised) (Presentation)

    SciTech Connect

    Miller, D. C.; Carloni, J. D.; Pankow, J. W.; Gjersing, E. L.; To, B.; Packard, C. E.; Kennedy, C. E.; Kurtz, S. R.

    2012-01-01

    Concentrating photovoltaic (CPV) technology recently gained interest based on its expected low levelized cost of electricity, high efficiency, and scalability. Many CPV systems employ Fresnel lenses composed of poly(methyl methacrylate) (PMMA) to obtain a high optical flux density on the cell. The optical and mechanical durability of these lenses, however, is not well established relative to the desired surface life of 30 years. Our research aims to quantify the expected lifetime of PMMA in key market locations (FL, AZ, and CO).

  5. Organophosphazenes.22 Copolymerization of (Alpha-Methylethenylphenyl) Penta-fluorocyclotriphosphazenes with Styrene and Methyl Methacrylate.

    DTIC Science & Technology

    1988-03-15

    pennultimate effects , 19. BSTRACT (Continue on reverse it necessary and identify by block number) i ., i. Both 3- and 4- (l-Methylethenylphenyl...parameters for theA, styrene system show that the major perturbation produced by the phosphazene is a polar6 electron withdrawing effect . The methyl...methacrylate system was found to exhibit significant penultimate effects in its reactivity behavior. The copolymers were characteri-zed using elemental

  6. Radiation-grafting of ethylene glycol dimethacrylate (EGDMA) and glycidyl methacrylate (GMA) onto silicone rubber

    NASA Astrophysics Data System (ADS)

    Flores-Rojas, G. G.; Bucio, E.

    2016-10-01

    Silicone rubber (SR) was modified with a graft of ethylene glycol dimethacrylate (EGDMA) and glycidyl methacrylate (GMA) using either gamma-radiation or azobisisobutyronitrile (AIBN). The graft efficiency was evaluated as a function of monomer concentration, absorbed dose, reaction temperature, and concentration of AIBN. The hydrophilicity of the grafted films was measured by contact angle and their equilibrium swelling time in ethanol. Additional characterization by infrared (FTIR-ATR) spectroscopy, thermogravimetric analysis (TGA) and differential scanning calorimetry (DSC) is also reported.

  7. Inhibition of the polymerization of methyl methacrylate and methyl acrylate by mixtures of chloranil with phenothiazine

    SciTech Connect

    Ivanov, A.A; Lysenko, G.M.; Zholina, I.N.

    1985-09-01

    This paper investigates the kinetic peculiarities of inhibited polymerization of methyl methacrylate and methyl acrylate in the presence of mixtures of chloranil with phenothiazine. It is shown that depending on the structure of the monomer and the concentrations of the electron donor and electron acceptor, the radicals of propagation may form complexes with chloranil or with phenothiazine at the first step of the inhibition reaction or may interact with the complex (phenothiazine to chloranil).

  8. Study on chemical, UV and gamma radiation-induced grafting of 2-hydroxyethyl methacrylate onto chitosan

    NASA Astrophysics Data System (ADS)

    Casimiro, M. H.; Botelho, M. L.; Leal, J. P.; Gil, M. H.

    2005-04-01

    In the present study, 2-hydroxyethyl methacrylate has been grafted onto chitosan by using either chemical initiation, or photo-induction or gamma radiation-induced polymerisation, all under heterogeneous conditions. The evidence of grafting was provided by Fourier transform infrared spectroscopy and thermal analysis. The results concerning the effect of initiator concentration, initial monomer concentration and dose rate influencing on the yield of grafting reactions are presented. These suggest that gamma irradiation is the method that leads to higher yields of grafting.

  9. Synthesis of poly (2-hydroxyethyl methacrylate) (PHEMA) based nanoparticles for biomedical and pharmaceutical applications.

    PubMed

    Saini, Rajesh; Bajpai, Jaya; Bajpai, Anil K

    2012-01-01

    The performance of polymeric nanomaterials relies greatly upon their properties which are intimately related to the methods of fabrication of the materials. Among various synthetic polymers, the polymers of 2-hydroxyetyhyl methacrylate (PHEMA) maintain a prime position in biomedical field due to their useful physicochemical properties and suitability for controlled drug delivery applications. Here we focus on three methods of preparation of PHEMA nanoparticles, by suspension polymerization, emulsion polymerization and dispersion polymerization without the use of any surfactants.

  10. Preliminary dose response study of a gel dosimeter using 2-Hydroxyethyl Methacrylate (HEMA).

    PubMed

    Trapp, J V; Leach, M O; Webb, S

    2005-09-01

    In this work we present a gel dosimeter based on 2-Hydroxyethyl Methacrylate (HEMA). The gel dosimeter is manufactured in normal atmospheric oxygen (normoxic) and undergoes a measurable change after irradiation. The gel is shown to provide a signal to noise ratio of up to at least 35 and have a linear change in transverse relaxation rate up to 70 Gy when measured with magnetic resonance imaging.

  11. Photoluminescence of Electrospun Poly-Methyl-Methacrylate:Alq3 Composite Fibres

    NASA Astrophysics Data System (ADS)

    Tong, Ke-Qin; Xu, Chun-Xian; Wang, Qiong; Gu, Bao-Xiang; Zheng, Ke; Ye, Li-Hua; Li, Xin-Song

    2008-12-01

    Tris(8-hydroxyquinoline) aluminium doped poly-methyl-methacrylate (PMMA:Alq3) composite nanofibres are fabricated by electrospinning. The morphology of fibres is characterized by scanning electron microscopy. The photoluminescence of a series of the nanofibres with various contents of Alqs to PMMA is investigated. UV-visible absorption and the PL spectra analysis are employed to analyse the interaction between the polymer and the luminescent molecule.

  12. Occupational exposure to methyl methacrylate monomer induces generalised neuropathy in a dental technician.

    PubMed

    Sadoh, D R; Sharief, M K; Howard, R S

    1999-04-24

    A 36-year-old dental technician for 14 years developed paraesthesia and numbness in her legs. Neurophysiological studies revealed absent sensory nerve action potentials (SNAPs) from her lower limbs and normal upper limb SNAPs on presentation. Motor nerve studies were normal. Repeat studies 2 months after leaving her job showed some improvement in the lower limb SNAPs. It is suggested that her symptoms were caused by occupational exposure to methyl methacrylate monomer.

  13. Mechanical Characterization of a Dynamic and Tunable Methacrylated Hyaluronic Acid Hydrogel

    PubMed Central

    Ondeck, Matthew G.; Engler, Adam J.

    2016-01-01

    Hyaluronic acid (HA) is a commonly used natural polymer for cell scaffolding. Modification by methacrylate allows it to be polymerized by free radicals via addition of an initiator, e.g., light-sensitive Irgacure, to form a methacrylated hyaluronic acid (MeHA) hydrogel. Light-activated crosslinking can be used to control the degree of polymerization, and sequential polymerization steps allow cells plated onto or in the hydrogel to initially feel a soft and then a stiff matrix. Here, the elastic modulus of MeHA hydrogels was systematically analyzed by atomic force microscopy (AFM) for a number of variables including duration of UV exposure, monomer concentration, and methacrylate functionalization. To determine how cells would respond to a specific two-step polymerization, NIH 3T3 fibroblasts were cultured on the stiffening MeHA hydrogels and found to reorganize their cytoskeleton and spread area upon hydrogel stiffening, consistent with cells originally cultured on substrates of the final elastic modulus. PMID:26746491

  14. Fabrication, Modeling and Characterization of Multi-Crosslinked Methacrylate Copolymeric Nanoparticles for Oral Drug Delivery

    PubMed Central

    Ngwuluka, Ndidi C.; Pillay, Viness; Choonara, Yahya E.; Modi, Girish; Naidoo, Dinesh; du Toit, Lisa C.; Kumar, Pradeep; Ndesendo, Valence M.K.; Khan, Riaz A.

    2011-01-01

    Nanotechnology remains the field to explore in the quest to enhance therapeutic efficacies of existing drugs. Fabrication of a methacrylate copolymer-lipid nanoparticulate (MCN) system was explored in this study for oral drug delivery of levodopa. The nanoparticles were fabricated employing multicrosslinking technology and characterized for particle size, zeta potential, morphology, structural modification, drug entrapment efficiency and in vitro drug release. Chemometric Computational (CC) modeling was conducted to deduce the mechanism of nanoparticle synthesis as well as to corroborate the experimental findings. The CC modeling deduced that the nanoparticles synthesis may have followed the mixed triangular formations or the mixed patterns. They were found to be hollow nanocapsules with a size ranging from 152 nm (methacrylate copolymer) to 321 nm (methacrylate copolymer blend) and a zeta potential range of 15.8–43.3 mV. The nanoparticles were directly compressible and it was found that the desired rate of drug release could be achieved by formulating the nanoparticles as a nanosuspension, and then directly compressing them into tablet matrices or incorporating the nanoparticles directly into polymer tablet matrices. However, sustained release of MCNs was achieved only when it was incorporated into a polymer matrix. The experimental results were well corroborated by the CC modeling. The developed technology may be potentially useful for the fabrication of multi-crosslinked polymer blend nanoparticles for oral drug delivery. PMID:22016653

  15. Radiation grafting of acrylic and methacrylic acid to cellulose fibers to impart high water sorbency

    SciTech Connect

    Zahran, A.H.; Williams, J.L.; Stannett, V.T.

    1980-04-01

    Acrylic and methacrylic acids have been directly grafted to rayon and cotton using the preirradiation technique with /sup 60/ Co gamma rays. The rate of grafting increased with increasing temperature and monomer concentration, as did the final degree of grafting. The amount and rate of grafting also increased with the total irradiation dose but tended to level off at higher doses, in agreement with the leveling off of the radical content reported previously. Methacrylic acid grafted more and faster than acrylic acid to both rayon and cotton. Methacrylic acid grafted more with rayon than cotton, but acrylic acid gave somewhat similar yields with both fibers. The water abosrbency of the grafted fibers depended strongly on their posttreatment. Decrystallizing with 70% zinc chloride or with hot sodium hydroxidy developed supersorbency. The two treatments in succession, respectively, gave the highest values. Metacrylic acid brought about less sorbency than the corrsponding acrylic acid grafts. Useful levels of grafting and supersorbency could be readily and practically achieved by the methods described.

  16. UV-cured methacrylic membranes as novel gel-polymer electrolyte for Li-ion batteries

    NASA Astrophysics Data System (ADS)

    Nair, J. R.; Gerbaldi, C.; Meligrana, G.; Bongiovanni, R.; Bodoardo, S.; Penazzi, N.; Reale, P.; Gentili, V.

    In this paper, we report the synthesis and characterisation of novel methacrylic based polymer electrolyte membranes for lithium batteries. The method adopted for preparing the solid polymer electrolyte was the UV-curing process, which is well known for being easy, low cost, fast and reliable. It consists of a free radical photo polymerisation of poly-functional monomers: Bisphenol A ethoxylate (15 EO/phenol) dimethacrylate (BEMA) was chosen, as it can readily form flexible 3D networks and has long poly-ethoxy chains which can enhance the movement of Li +-ions inside the polymer matrix. The preliminary results reported here refer to systems where LiPF 6 solutions swelled the preformed polymer membranes. The tests on the conductivity, stability and cyclability of the membranes put in evidence the importance of the polymerisation in presence of mono-methacrylates acting as reactive diluents. Good values of ionic conductivity have been found, especially at ambient temperature. Much better results can be expected by choosing an appropriate mono-methacrylate to modify the polymeric membrane properties and by modifying the methodology of Li +-ions incorporation inside the polymer matrix.

  17. Hypercalcemia secondary to granulomatous disease caused by the injection of methacrylate: a case series

    PubMed Central

    Negri, Armando Luis; Rosa Diez, Guillermo; Del Valle, Elisa; Piulats, Elsa; Greloni, Gustavo; Quevedo, Alejandra; Varela, Federico; Diehl, Maria; Bevione, Pablo

    2014-01-01

    Summary Association of dysregulated calcium homeostasis and granulomatous disease is well established. There exist reports in the literature of granulomatous reactions produced by silicones associated with hypercalcemia. In this case series we report four young women that underwent methacrylate injections in gluteus, thighs and calves that developed granulomas with posterior appearance of hypercalcemia. This complication presented as subacute around 6 months after the procedure. The four patients have as common elements the presence of moderate to severe renal insufficiency, suppressed PTH and elevated calcitriol levels for the degree of renal function. In the image studies, two patients presented in the nuclear magnetic resonance of the gluteus hypodense nodular images compatible with granulomas. Two patients had a positron emission tomography performed showing increased metabolic activity in the muscles of the gluteal region compatible with granulomas. Two patients had a partial surgical resection of the gluteal lesions with the finding of methacrylate associated to foreign body granulomas. In these patients hypercalcemia was treated with oral or local injections of corticoids, intravenous bisphosphonates or ketoconazole with good response. Although the prevalence of this complication with methacrylate injection is not common, hypercalcemia secondary to granulomas should be considered in the differential diagnosis of patients with hypercalcemia when there is a history of this procedure, and especially if they have a reduction in their renal function. PMID:25002879

  18. Determination of thermodynamic properties of poly (cyclohexyl methacrylate) by inverse gas chromatography.

    PubMed

    Kaya, Ismet; Pala, Cigdem Yigit

    2014-07-01

    In this work, some thermodynamic properties of poly (cyclohexyl methacrylate) were studied by inverse gas chromatography (IGC). For this purpose, the polymeric substance was coated on Chromosorb W and which was filled into a glass column. The retention times (t(r)) of the probes were determined from the interactions of poly (cyclohexyl methacrylate) with n-pentane, n-hexane, n-heptane, n-octane, n-decane, methanol, ethanol, 2-propanol, butanol, acetone, ethyl methyl ketone, benzene, toluene and o-xylene by IGC technique. Then, the specific volume (Vg(0)) was determined for each probe molecule. By using (1/T; lnVg(0)) graphics, the glass transition temperature of poly (cyclohexyl methacrylate) was found to be 373 K. The adsorption heat under the glass transition temperature (deltaH(a)), and partial molar heat of sorption above the glass transition (deltaH1(S)), partial molar free energy of sorption (deltaG1(S)) and partial molar entropy of sorption (deltaS1(S)) belonging to sorption for every probe were calculated. The partial molar heat of mixing at infinite dilution (deltaH1(infinity)), partial molar free energy of mixing at infinite dilution (deltaG1(infinity)), Flory-Huggins interaction parameter (chi12(infinity)) and weight fraction activity coefficient (a1/w1)(infinity) values of polymer-solute systems were calculated at different column temperatures. The solubility parameters (delta2) of the polymer were obtained by IGC technique.

  19. Blends of isoprene-styrene/methacrylate monomer systems as denture soft lining material.

    PubMed

    Nazhat, S N; Parker, S; Riggs, P D; Braden, M

    2001-08-01

    This work further develops the concept of using an elastomer gelled with methacrylate monomers to produce a methacrylate-based soft lining material without the use of a plasticizer. An isoprene-styrene (SIS) block copolymer was mixed with methyl methacrylate (MMA) and 1,6-hexandiol dimethacrylate (HDMA). The HDMA was used as a cross-linking agent. The elastomer/monomer ratios were maintained at 50/50 whereas the monomers ranged from 0 to 100%) HDMA. Mechanical properties and water absorption/desorption characteristics were used to assess the effect of varying the monomer compositions. The results indicated that phase separation took place, in particular at high HDMA content. This significantly increased the Young's modulus and decreased the elongation to break. Generally, the water uptake tended to decrease with increasing HDMA content, reflecting the effect of modulus. Second absorption cycles gave higher uptake values compared to the first. Formulations with a high amount of HDMA gave materials with modulus values too high for soft lining applications. This suggests that the optimum formulation requires a compromise between modulus and water uptake.

  20. Physicochemical, mechanical, and biological properties of bone cements prepared with functionalized methacrylates.

    PubMed

    Sabino, Marco A; Ajami, Diana; Salih, Vehid; Nazhat, Showan N; Vargas-Coronado, Rossana; Cauich-Rodríguez, Juan V; Ginebra, Ma Pau

    2004-10-01

    Bone cements prepared with methyl methacrylate (MMA) as a base monomer and either methacrylic acid (MAA) or diethyl amino ethyl methacrylate (DEAEMA) as comonomers were characterized in terms of curing behavior, mechanical properties, and their in vitro biocompatibility. The curing time and setting temperature were found to be composition dependent while the residual monomer was not greatly affected by the presence of either acidic or alkaline comonomers in the bone cements. For samples with MAA comonomer, a faster curing time and higher setting temperature were observed when compared to the cement with DEAEMA comonomer. In terms of mechanical properties, the highest compressive strength was exhibited by formulations containing MAA, while the highest impact strength was shown by the formulations prepared with DEAEMA. There were no differences observed between the two formulations for tensile, shear, and bending strength values. Similarly, fatigue crack propagation studies did not reveal differences with the addition of either DEAEMA or MAA.No differences were observed in the initial number of attached primary rat femur osteoblasts on the different bone cements and positive controls. However, after 48 h there was a reduced proliferation in the cells grown on bone cements containing MAA.

  1. Fabrication, modeling and characterization of multi-crosslinked methacrylate copolymeric nanoparticles for oral drug delivery.

    PubMed

    Ngwuluka, Ndidi C; Pillay, Viness; Choonara, Yahya E; Modi, Girish; Naidoo, Dinesh; du Toit, Lisa C; Kumar, Pradeep; Ndesendo, Valence M K; Khan, Riaz A

    2011-01-01

    Nanotechnology remains the field to explore in the quest to enhance therapeutic efficacies of existing drugs. Fabrication of a methacrylate copolymer-lipid nanoparticulate (MCN) system was explored in this study for oral drug delivery of levodopa. The nanoparticles were fabricated employing multicrosslinking technology and characterized for particle size, zeta potential, morphology, structural modification, drug entrapment efficiency and in vitro drug release. Chemometric Computational (CC) modeling was conducted to deduce the mechanism of nanoparticle synthesis as well as to corroborate the experimental findings. The CC modeling deduced that the nanoparticles synthesis may have followed the mixed triangular formations or the mixed patterns. They were found to be hollow nanocapsules with a size ranging from 152 nm (methacrylate copolymer) to 321 nm (methacrylate copolymer blend) and a zeta potential range of 15.8-43.3 mV. The nanoparticles were directly compressible and it was found that the desired rate of drug release could be achieved by formulating the nanoparticles as a nanosuspension, and then directly compressing them into tablet matrices or incorporating the nanoparticles directly into polymer tablet matrices. However, sustained release of MCNs was achieved only when it was incorporated into a polymer matrix. The experimental results were well corroborated by the CC modeling. The developed technology may be potentially useful for the fabrication of multi-crosslinked polymer blend nanoparticles for oral drug delivery.

  2. Autonomous healing materials based on epoxidized natural rubber and ethylene methacrylic acid ionomers

    NASA Astrophysics Data System (ADS)

    Arifur Rahman, Md; Penco, Maurizio; Peroni, Isabella; Ramorino, Giorgio; Janszen, Gerardus; Di Landro, Luca

    2012-03-01

    The development of autonomous healing material has an enormous scientific and technological interest. In this context, this research work deals with the investigation of autonomous healing behavior of epoxidized natural rubber (ENR) and its blends with ethylene methacrylic acid ionomers. The autonomous healing behavior of ENR and its blends containing two different ionomers [poly(ethylene-co-methacrylic acid sodium salt) (EMNa) and poly(ethylene-co-methacrylic acid zinc salt) (EMZn)] has been studied by ballistic puncture tests. Interestingly, EMNa/ENR blends exhibit complete healing just after the ballistic test but EMZn/ENR blends do not show full self-repairing. The healing efficiency has been evaluated by optical microscopy and a depressurized air-flow test. The healing mechanism has been investigated by characterizing thermal and mechanical properties of the blends. The chemical structure studied by FTIR and thermal analysis show that the ion content of ionomers and functionality of ENR has a significant influence on the self-healing behavior.

  3. The electrochemical detection of Ru(II) in a methyl methacrylate solution.

    PubMed

    De Wael, Karolien; Adriaens, Annemie; Temmerman, Eduard

    2006-02-15

    This article describes the voltammetric behaviour of RuCl(2)(PPh(3))(3) in a methyl methacrylate (MMA) solution. Acquiring this type of information is only possible when the ohmic resistance can be kept sufficiently low. Therefore, the conductivity study of pure methyl methacrylate and a tetrabutylammonium tetrafluoroborate (TBABF(4)) methyl methacrylate solution has been described as well. Impedance measurements show an increase in conductivity by adding TBABF(4), while a conductometric curve illustrates the presence of ion pairs, triple ions and quadrupoles depending on the TBABF(4) concentration. The conductivity of a 0.1molL(-1) TBABF(4)-MMA solution (formation of charged triple ions) was high enough to perform electrochemical experiments and a calibration curve could be obtained. The ability of obtaining relevant electrochemical data in low conducting media opens up new perspectives, especially for electroanalytical purposes used to monitor polymer reactions, more specific atom transfer radical polymerization (ATRP) reactions. This method employs a redox process with transition metal complexes in which a halogen ion is transferred reversibly between the transition metal and the polymer chain end. The dynamic equilibrium can be monitored by measuring the ruthenium concentration.

  4. Development of microporous drug-releasing films cast from artificial nanosized latexes of poly(styrene-co-methyl methacrylate) or poly(styrene-co-ethyl methacrylate).

    PubMed

    Otto, Daniel P; Vosloo, Hermanus C M; Liebenberg, Wilna; de Villiers, Melgardt M

    2008-08-01

    Two sets of copolymers comprising of styrene and either methyl or ethyl methacrylate as comonomer were conveniently synthesized by microemulsion copolymerization. The purified materials were characterized by GPC-MALLS and were shown to form artificial nanolatexes in THF. ATR-FTIR analysis revealed differences in copolymer composition and based on the copolymer properties, a selection of copolymers was chosen to cast drug-loaded, microporous films that exhibit microencapsulation of drug agglomerates. The contact angles of the copolymers suggested potential applications in medical devices to prevent the formation of bacterial biofilms that commonly result in infections. Additionally, the different copolymeric films showed two phases of drug release characterized by a rapid initial drug release followed by a zero-order phase. Depending on the application, one could select the copolymer films that best suited the application i.e. for short-term drug release applications such as urinary catheters or long-term applications such as artificial implants.

  5. Identification of covalent binding sites of ethyl 2-cyanoacrylate, methyl methacrylate and 2-hydroxyethyl methacrylate in human hemoglobin using LC/MS/MS techniques.

    PubMed

    Jeppsson, Marina C; Mörtstedt, Harriet; Ferrari, Giovanni; Jönsson, Bo A G; Lindh, Christian H

    2010-10-01

    Acrylates are used in vast quantities, for instance in paints, adhesive glues, molding. They are potent contact allergens and known to cause respiratory hypersensitivity and asthma. Here we study ethyl 2-cyanoacrylate (ECA), methyl methacrylate (MMA) and 2-hydroxyethyl methacrylate (HEMA). There are only limited possibilities to measure the exposure to acrylates, especially for biological monitoring. The aim of the present study was to investigate the chemical structures of adducts formed after reaction of hemoglobin (Hb) with ECA, MMA, and HEMA. This information may be used to identify adducted Hb peptides for biological monitoring of exposure to acrylates. Hb-conjugates with ECA, MMA, and HEMA were synthesized in vitro. The conjugates were digested by trypsin and pronase E. Adducted peptides were characterized and analyzed by liquid chromatography and nano electro spray/hybrid quadrupole time-of-flight mass spectrometry (MS) as well as tandem quadrupole MS. The search for the adducted peptides was facilitated by visualizing the MS data by different computer programs. The results showed that ECA binds covalently to cysteines at the 104 position in the α and the position 112 in the β-chains in Hb. MMA and HEMA bound to all the cysteines in both chains, Cys(104) in the α-chain and Cys(93) and 112 in the β-chain. The full-length spectra of in un-digested Hb confirmed this binding pattern. There was no reaction with N-acetyl-L-lysine at physiological pH. The adducted peptides were possible to measure using LC/MS/MS in selected reaction monitoring mode. These peptides may be used for biological monitoring of exposure to ECA, MMA and HEMA.

  6. Amphiphilic model conetworks based on cross-linked star copolymers of benzyl methacrylate and 2-(dimethylamino)ethyl methacrylate: synthesis, characterization, and DNA adsorption studies.

    PubMed

    Achilleos, Demetra S; Georgiou, Theoni K; Patrickios, Costas S

    2006-12-01

    Six amphiphilic model conetworks of a new structure, that of cross-linked "in-out" star copolymers, were synthesized by the group transfer polymerization (GTP) of the hydrophobic monomer benzyl methacrylate (BzMA) and the ionizable hydrophilic monomer 2-(dimethylamino)ethyl methacrylate (DMAEMA) in a one-pot preparation. The synthesis took place in tetrahydrofuran (THF) using tetrabutylammonium bibenzoate (TBABB) as the catalyst, 1-methoxy-1-(trimethylsiloxy)-2-methyl-propene (MTS) as the initiator, and ethylene glycol dimethacrylate (EGDMA) as the cross-linker. Three heteroarm star-, two star block-, one statistical copolymer star-, and one homopolymer star-based networks were prepared. The synthesis of these star-based networks involved four to six steps, including the preparation of the linear (co)polymers, the "arm-first" and the "in-out" star copolymers, and finally the network. The precursors and the extractables were characterized using gel permeation chromatography (GPC) and proton nuclear magnetic resonance (1H NMR) spectroscopy. The degrees of swelling (DSs) of all the networks were measured in THF, while the aqueous DSs were measured as a function of pH. The DSs at low pH were higher than those at neutral or high pH because of the protonation of the DMAEMA units and were found to be dependent on the structure of the network. The DSs in THF were higher than those in neutral water and were independent of the structure. Finally, DNA adsorption studies onto the networks indicated that the DNA binding was governed by electrostatics.

  7. Facile construction of macroporous hybrid monoliths via thiol-methacrylate Michael addition click reaction for capillary liquid chromatography.

    PubMed

    Lin, Hui; Ou, Junjie; Liu, Zhongshan; Wang, Hongwei; Dong, Jing; Zou, Hanfa

    2015-01-30

    A facile approach based on thiol-methacrylate Michael addition click reaction was developed for construction of porous hybrid monolithic materials. Three hybrid monoliths were prepared via thiol-methacrylate click polymerization by using methacrylate-polyhedral oligomeric silsesquioxane (POSS) (cage mixture, n=8, 10, 12, POSS-MA) and three multi-thiol crosslinkers, 1,6-hexanedithiol (HDT), trimethylolpropane tris(3-mercaptopropionate) (TPTM) and pentaerythritol tetrakis(3-mercaptopropionate) (PTM), respectively, in the presence of porogenic solvents (n-propanol and PEG 200) and a catalyst (dimethylphenylphosphine, DMPP). The obtained monoliths possessed high thermal and chemical stabilities. Besides, they all exhibited high column efficiencies and excellent separation abilities in capillary liquid chromatography (cLC). The highest column efficiency could reach ca. 195,000N/m for butylbenzene on the monolith prepared with POSS-MA and TPTM (monolith POSS-TPTM) in reversed-phase (RP) mode at 0.64mm/s. Good chromatographic performance were all achieved in the separations of polycyclic aromatic hydrocarbons (PAHs), phenols, anilines, EPA 610 as well as bovine serum albumin (BSA) digest. The high column efficiencies in the range of 51,400-117,000N/m (achieved on the monolith POSS-PTM in RP mode) convincingly demonstrated the high separation abilities of these thiol-methacrylate based hybrid monoliths. All the results demonstrated the feasibility of the phosphines catalyzed thiol-methacrylate Michael addition click reaction in fabrication of monolithic columns with high efficiency for cLC applications.

  8. Two birds, one stone: dual targeting of the cancer cell surface and subcellular mitochondria by the galectin-3-binding peptide G3-C12.

    PubMed

    Sun, Wei; Li, Lian; Yang, Qing-Qing; Zhang, Zhi-Rong; Huang, Yuan

    2017-01-09

    Active tumor-targeting approaches using specific ligands have drawn considerable attention over the years. However, a single ligand often fails to simultaneously target the cancer cell surface and subcellular organelles, which limits the maximum therapeutic efficacy of delivered drugs. We describe a polymeric delivery system modified with the G3-C12 peptide for sequential dual targeting. In this study, galectin-3-targeted G3-C12 peptide was conjugated onto the N-(2-hydroxypropyl) methacrylamide (HPMA) copolymer for the delivery of D(KLAKLAK)2 (KLA) peptide. G3-C12-HPMA-KLA exhibited increased receptor-mediated internalization into galectin-3-overexpressing PC-3 cells. Furthermore, G3-C12 peptide also directed HPMA-KLA conjugates to mitochondria. This occurred because the apoptosis signal triggered the accumulation of galectin-3 in mitochondria, and the G3-C12 peptide that specifically bound to galectin-3 was trafficked along with its receptor intracellularly. As a result, G3-C12-HPMA-KLA disrupted the mitochondrial membrane, increased the generation of reactive oxygen species (ROS) and induced cytochrome c release, which ultimately resulted in enhanced cytotoxicity. An in vivo study revealed that the G3-C12 peptide significantly enhanced the tumor accumulation of the KLA conjugate. In addition, G3-C12-HPMA-KLA exhibited the best therapeutic efficacy and greatly improved the animal survival rate. Our work demonstrates that G3-C12 is a promising ligand with dual-targeting functionality.

  9. Effect of curing environment on mechanical properties and polymerizing behaviour of methyl-methacrylate autopolymerizing resin.

    PubMed

    Ogawa, T; Hasegawa, A

    2005-03-01

    Methyl-methacrylate autopolymerizing resin is used for multiple applications. Therefore, the mechanical properties of autopolymerizing resin should be assessed comprehensively including strength, stiffness and hardness. Any methods that effectively improve these mechanical properties are desirable. The objective of this study is to examine the effects of the curing environment: air or water with/without pressure, and air or water temperature during polymerization, on the strength, stiffness and hardness of autopolymerizing resin. In addition, we examined the polymerizing behaviour associated with the mechanical properties. Autopolymerizing methyl-methacrylate resin (Unifast II) was polymerized under the following conditions: in air and water with/without pressure at 10, 23, 30, 40, 60 and 80 degrees C. The resin specimens were subjected to a transverse test (three-point flexural test) and micro-Brinell surface hardness test. Fractured surfaces of the specimens after the transverse test were examined using a scanning electron microscope (SEM). The transverse strength and transverse modulus increased with increasing curing temperature in both wet and dry conditions. Pressured wet conditions increased transverse strength and transverse modulus over non-pressured wet and dry conditions. The resin polymerized in dry conditions showed higher surface hardness than the one polymerized in wet conditions at matching temperature. The SEM images of fractured surfaces cured at lower temperature exhibited porosity within the polymer base and cracks between the base and poly-methyl-methacrylate (PMMA) particulates. Surfaces of the resin polymerized in wet conditions were characterized with PMMA particulates having rougher surfaces suggestive of water incorporation. Raising temperature and pressuring during polymerization increase strength and stiffness of autopolymerizing resin. However, wet condition reduces surface hardness of resin compared with dry condition. These altered

  10. Flexural Strength Comparison of Silorane- and Methacrylate-Based Composites with Pre-impregnated Glass Fiber

    PubMed Central

    Doozandeh, Maryam; Alavi, Ali Asghar; Karimizadeh, Zahra

    2016-01-01

    Statement of the Problem Sufficient adhesion between silorane/methacrylate-based composites and methacrylate impregnated glass fiber increases the benefits of fibers and enhances the mechanical and clinical performance of both composites. Purpose The aim of this study was to evaluate the compatibility of silorane and methacrylate-based composites with pre-impregnated glass fiber by using flexural strength (FS) test. Materials and Method A total of 60 bar specimens were prepared in a split mold (25×2×2 mm) in 6 groups (n=10). In groups 1 and 4 (control), silorane-based (Filtek P90) and nanohybrid (Filtek Z350) composites were placed into the mold and photopolymerized with a high-intensity curing unit. In groups 2 and 5, pre-impregnated glass fiber was first placed into the mold and after two minutes of curing, the mold was filled with respective composites. Prior to filling the mold in groups 3 and 6, an intermediate adhesive layer was applied to the glass fiber. The specimens were stored in distilled water for 24 hours and then their flexural strength was measured by 3 point bending test, using universal testing machine at the crosshead speed of 1 mm/min. Two-way ANOVA and post-hoc test were used for analyzing the data (p< 0.05). Results A significant difference was observed between the groups (p< 0.05). The highest FS was registered for combination of Z350 composite, impregnated glass fiber, and application of intermediate adhesive layer .The lowest FS was obtained in Filtek P90 alone. Cohesive failure in composite was the predominant failure in all groups, except group 5 in which adhesive failure between the composite and fiber was exclusively observed. Conclusion Significant improvement in FS was achieved for both composites with glass fiber. Additional application of intermediate adhesive layer before composite build up seems to increase FS. Nanohybrid composite showed higher FS than silorane-based composite. PMID:27284555

  11. Addition of silver nanoparticles reduces the wettability of methacrylate and silorane-based composites.

    PubMed

    Kasraei, Shahin; Azarsina, Mohadese

    2012-01-01

    Incorporation of silver nanoparticles into composite resins is recommended for their reported antibacterial properties, but this incorporation can affect the wettability of such materials. Therefore, this study evaluated the effect of nano-silver addition to silorane-based and methacrylate-based composites on their contact angle. Nano-silver particles were added to Z250 (methacrylate-based) and P90 (silorane-based) composites at 0.5% and 1% by weight. The control group had no additions. SEM-EDX analysis was performed to confirm the homogeneity of the nano-silver distribution. Seventy-two composite discs were prepared and standardized to the identical surface roughness values, and then distributed randomly into 6 groups containing 12 samples each (N = 12). Two random samples from each group were observed by atomic force microscopy. Distilled water contact angle measurements were performed for the wettability measurement. Two-way ANOVA, followed by the Tukey-HSD test, with a significance level of 5%, were used for data analysis. It was observed that wettability was significantly different between the composites (p = 0.0001), and that the addition of nano-silver caused a significant reduction in the contact angle (p = 0.0001). Wettability varied depending on the concentration of the nano silver (p = 0.008). Silorane-based composites have a higher contact angle than methacrylate-based composites. Within the limitations of this study, it can be concluded that the addition of 0.5% nano-silver particles to the composites caused a decrease in the contact angle of water.

  12. Utilization of Methacrylates and Polymer Matrices for the Synthesis of Ion Specific Resins

    SciTech Connect

    Czerwinski, Kenneth

    2013-10-29

    Disposal, storage, and/or transmutation of actinides such as americium (Am) will require the development of specific separation schemes. Existing efforts focus on solvent extraction systems for achieving suitable separation of actinide from lanthanides. However, previous work has shown the feasibility of ion-imprinting polymer-based resins for use in ion-exchange-type separations with metal ion recognition. Phenolic-based resins have been shown to function well for Am-Eu separations, but these resins exhibited slow kinetics and difficulties in the imprinting process. This project addresses the need for new and innovative methods for the selective separation of actinides through novel ion-imprinted resins. The project team will explore incorporation of metals into extended frameworks, including the possibility of 3D polymerized matrices that can serve as a solid-state template for specific resin preparation. For example, an anhydrous trivalent f-element chain can be formed directly from a metal carbonate, and methacrylic acid from water. From these simple coordination complexes, molecules of discrete size or shape can be formed via the utilization of coordinating ligands or by use of an anionic multi-ligand system incorporating methacrylate. Additionally, alkyl methyl methacrylates have been used successfully to create template nanospaces, which underscores their potential utility as 3D polymerized matrices. This evidence provides a unique route for the preparation of a specific metal ion template for the basis of ion-exchange separations. Such separations may prove to be excellent discriminators of metal ions, even between f-elements. Resins were prepared and evaluated for sorption behavior, column properties, and proton exchange capacity.

  13. Effect of Accelerated Artificial Aging on Translucency of Methacrylate and Silorane-Based Composite Resins

    PubMed Central

    Shirinzad, Mehdi; Rezaei-Soufi, Loghman; Mirtorabi, Maryam Sadat; Vahdatinia, Farshid

    2016-01-01

    Objectives: Composite restorations must have tooth-like optical properties namely color and translucency and maintain them for a long time. This study aimed to compare the effect of accelerated artificial aging (AAA) on the translucency of three methacrylate-based composites (Filtek Z250, Filtek Z250XT and Filtek Z350XT) and one silorane-based composite resin (Filtek P90). Materials and Methods: For this in vitro study, 56 composite discs were fabricated (n=14 for each group). Using scanning spectrophotometer, CIE L*a*b* parameters and translucency of each specimen were measured at 24 hours and after AAA for 384 hours. Data were analyzed using one-way ANOVA, Tukey's test and paired t-test at P=0.05 level of significance. Results: The mean (±standard deviation) translucency parameter for Filtek Z250, Filtek Z250XT, Filtek Z350XT and Filtek P90 was 5.67±0.64, 4.59±0.77, 7.87±0.82 and 4.21±0.71 before AAA and 4.25±0.615, 3.53±0.73, 5.94±0.57 and 4.12±0.54 after AAA, respectively. After aging, the translucency of methacrylate-based composites decreased significantly (P<0.05). However, the translucency of Filtek P90 did not change significantly (P>0.05). Conclusions: The AAA significantly decreased the translucency of methacrylate-based composites (Filtek Z250, Filtek Z250XT and Filtek Z350XT) but no change occurred in the translucency of Filtek P90 silorane-based composite. PMID:27928237

  14. Moleculary imprinted polymers with metalloporphyrin-based molecular recognition sites coassembled with methacrylic acid.

    PubMed

    Takeuchi, T; Mukawa, T; Matsui, J; Higashi, M; Shimizu, K D

    2001-08-15

    A diastereoselective molecularly imprinted polymer (MIP) for (-)-cinchonidine, PPM(CD), was prepared by the combined use of methacrylic acid and vinyl-substituted zinc(II) porphyrin as functional monomers. Compared to MIPs using only methacrylic acid or zinc porphyrin as a functional monomer, PM(CD) and PP(CD), respectively, PPM(CD) showed higher binding ability for (-)-cinchonidine in chromatographic tests using the MIP-packed columns. Scatchard analysis gave a higher association constant of PPM(CD) for (-)-cinchonidine (1.14 x 10(7) M(-1)) than those of PP(CD) (1.45 x 10(6) M(-1)) and PM(CD) (6.78 x 10(6) M(-1)). The affinity distribution of binding sites estimated by affinity spectrum analysis showed a higher percentage of high-affinity sites and a lower percentage of low-affinity sites in PPM(CD). The MIPs containing a zinc(II) porphyrin in the binding sites, PPM(CD) and PP(CD), showed fluorescence quenching according to the binding of (-)-cinchonidine, and the quenching was significant in the low-concentration range, suggesting that the high-affinity binding sites contain the porphyrin residue. The correlation of the relative fluorescence intensity against log of (-)-cinchonidine concentrations showed a linear relationship. These results revealed that the MIP having highly specific binding sites was assembled by the two functional monomers, vinyl-substituted zinc(II) porphyrin and methacrylic acid, and they cooperatively worked to yield the specific binding. In addition, the zinc(II) porphyrin-based MIPs appeared to act as fluorescence sensor selectively responded by binding events of the template molecule.

  15. Far infrared-assisted encapsulation of filter paper strips in poly(methyl methacrylate) for proteolysis.

    PubMed

    Chen, Qiwen; Bao, Huimin; Zhang, Luyan; Chen, Gang

    2016-02-01

    Filter paper strips were enclosed between two poly(methyl methacrylate) plates to fabricate paper-packed channel microchips under pressure in the presence of far infrared irradiation. After the enclosed paper strip was oxidized by periodate, trypsin was covalently immobilized in them to fabricate microfluidic proteolysis bioreactor. The feasibility and performance of the unique bioreactor were demonstrated by digesting BSA and lysozyme. The results were comparable to those of conventional in-solution proteolysis while the digestion time was significantly reduced to ∼18 s. The suitability of the microfluidic paper-based bioreactors to complex proteins was demonstrated by digesting human serum.

  16. Controlling of optical energy gap of Co-ferrite quantum dots in poly (methyl methacrylate) matrix

    NASA Astrophysics Data System (ADS)

    El-Sayed, H. M.; Agami, W. R.

    2015-07-01

    Different crystallite sizes of Co-ferrite nanoparticles were prepared and dispersed in the matrix of poly (methyl methacrylate) (PMMA) polymer. The effect of crystallite size on the structure and optical energy gap of Co-nanoferrite/PMMA composite has been studied. The optical energy gap of Co-ferrite was greatly affected by the crystallite size. This result was discussed in terms of the formation of electron-hole exciton using particle in a box model. The effective mass and the Bohr radius of the formed exciton have been calculated from the spectroscopic measurements.

  17. Generalized peripheral neuropathy in a dental technician exposed to methyl methacrylate monomer

    SciTech Connect

    Donaghy, M.; Rushworth, G.; Jacobs, J.M. )

    1991-07-01

    A 58-year-old dental prosthetic technician developed generalized sensorimotor peripheral neuropathy. Neurophysiologic studies showed a generalized sensorimotor neuropathy of axonal degeneration type. Examination of a sural nerve biopsy showed a moderately severe axonal neuropathy with loss of large myelinated fibers and unmyelinated axons. There was evidence of slow ongoing degeneration and considerable fiber regeneration. Electron microscopy showed increased numbers of filaments in a few fibers. These findings show resemblances to the nerve changes caused by another acrylic resin, acrylamide. They suggest that the neuropathy may have been caused by 30 years of occupational cutaneous and inhalational exposure to methyl methacrylate monomer since they excluded other recognized causes of neuropathy.

  18. Radiation synthesis of acrylamide/N,N-(dimethylamino) ethyl methacrylate grafted onto low density polyethylene films

    NASA Astrophysics Data System (ADS)

    Abdel Ghaffar, A. M.

    2011-02-01

    Radiation-induced graft copolymerization of acrylamide/N,N-(dimethylamino) ethyl methacrylate (AAm/DMAEMA) onto low density polyethylene films was carried out. The effect of grafting conditions such as solvent type and comonomer composition were studied. Characterization of the prepared films was investigated by Fourier transform infrared. Some selected properties such as thermal stability and swelling behavior were determined. It was found that grafting efficiency, swelling behavior and thermal stability increased with increasing DMAEMA content. Scanning electron microscopy was used for predicting the change in surface morphology via the grafted films. The improvement in properties of the prepared films make it possible to use them in some practical applications.

  19. Synthesis and swelling behavior of Protein-g-poly Methacrylic acid/kaolin superabsorbent hydrogel composites

    NASA Astrophysics Data System (ADS)

    Sadeghi, Mohammad

    2008-08-01

    A novel superabsorbent hydrogel composite based on Collagen have been prepared via graft copolymerization of Methacrylic acid (MAA) in the presence of kaolin powder using methylenebisacrylamide (MBA) as a crosslinking agent and ammonium persulfate (APS) as an initiator. The composite structure was confirmed using FTIR spectroscopy. A new absorption band at 1728 cm-1 in the composite spectrum confirmed kaolin-organic polymer linkage. The effect of kaolin amount and MBA concentration showed that with increasing of these parameters, the water absorbency of the superabsorbent composite was decreased. The swelling measurements of the hydrogels were conducted in aqueous salt solutions.

  20. Thermal response of polystyrene/poly methyl methacrylate (PS/PMMA) polymeric blends

    NASA Astrophysics Data System (ADS)

    Mathur, Vishal; Sharma, Kananbala

    2016-12-01

    The present paper reports the investigationsto evaluate thermal behavior of polystyrene/poly methyl methacrylate (PS/PMMA) polymeric blends, prepared at different compositions through solution casting method. The glass transition temperatures have been obtained using dynamic mechanical analyzer. Simultaneous measurements of temperature dependentthermal transport properties (thermal conductivity and thermal diffusivity) have been made using Hot Disk Thermal Constants Analyzer based on transient plane source. The study reveals that blending of PS with PMMA leads to different phase morphologies corresponding to different composition range which further affects the thermal performance of respective blends.

  1. Turning electrospun poly(methyl methacrylate) nanofibers into graphitic nanostructures by in situ electron beam irradiation

    SciTech Connect

    Duan, H. G.; Xie, E. Q.; Han, L.

    2008-02-15

    Using ultrathin electrospun poly(methyl methacrylate) (PMMA) nanofibers as precursor, graphitic nanofibers, nanobridges, nanocones, and fullerenelike onions could be prepared by electron beam irradiation in a controlled manner. With the help of the high resolution transmission electron microscopy, the real time processing of the carbonization and graphitization of the PMMA nanofibers could be investigated. This way to obtain graphitic nanostructures has promising applications in graphitic carbon nanostructure electronics and devices. Because PMMA is a widely used standard high resolution electron resist, this graphitization could be combined with electron beam lithography to obtain high resolution patterned graphitic circuits.

  2. Femtosecond laser fabrication of tubular waveguides in poly(methyl methacrylate).

    PubMed

    Zoubir, Arnaud; Lopez, Cedric; Richardson, Martin; Richardson, Kathleen

    2004-08-15

    Femtosecond laser direct writing is employed for the fabrication of buried tubular waveguides in bulk poly(methyl methacrylate). A novel technique using selective chemical etching is presented to resolve the two-dimensional refractive-index profile of the fabrication structures. End-to-end coupling in the waveguides reveals a near-field intensity distribution that results from the superimposition of several propagating modes with different azimuthal symmetries. Mode analysis of the tubular waveguides is performed using the finite-difference method, and the possible propagating mode profiles are compared with the experimental data.

  3. Structure/property relationships in methacrylate/dimethacrylate polymers for dental applications

    NASA Astrophysics Data System (ADS)

    Mehlem, Jeremy John

    Since its invention Bis-GMA or one of its analogs has been the main component of the polymer portion of composites for dental restorations. The need for dilution of Bis-GMA and its analogs to optimize its properties has long been recognized. Bis-GMA is a highly viscous monomer. This high viscosity leads to early vitrification, which limits conversion during cure. This viscosity also limits filler loading. Vitrification at low conversions leads to heterogeneous systems composed of low and high cross-link density phases. The low cross-link density phases behave as defects in the system; therefore, if the amount of low cross-link density phases in the system can be reduced and a more uniform network structure can be achieved, then the mechanical properties of the resin can be improved. Since the increase in viscosity during cure causes vitrification, it is logical that a system with a low initial viscosity will delay the onset of vitrification. Reactive diluents such as triethylene glycol dimethacrylate (TEGDMA) are effective at lower levels. However, large amounts negatively affect matrix properties by increasing polymerization shrinkage and water sorption. Shrinkage has been cited as one of the main deficiencies in dental composites. The goal of this project is to improve upon standard viscosity modifying comonomers such as triethylene glycol dimethacrylate. The comonomers that were explored were phenyloxyethyl methacrylate, cyclohexyl methacrylate, and tert-butylcylcohexyl methacrylate. Multicomponent systems based on analogs of ethylene glycol dimethacrylates with different length ethyl glycol chains were also examined. The substitution of monomethacrylates for TEGDMA as a comonomer resulted in enhanced or negligible affects on the mechanical properties of Bis-MEPP based polymer systems while reducing polymerization shrinkage. 129Xenon NMR and TappingMode(TM) AFM were used to characterize the heterogeneity of dimethacrylates systems during their cure cycle as well

  4. Photoinitiated polymerization of methyl methacrylate using Q-sized ZnO colloids

    SciTech Connect

    Hoffman, A.J.; Yee, H.; Mills, G.; Hoffmann, M.R.

    1992-06-25

    Q-sized ZnO particles are determined to be efficient photoinitiators of methyl methacrylate polymerization. The effects of semiconductor particle size, solvent, initiator concentration, monomer concentration, and light intensity on reaction rates are examined. The reaction path is initiated anionically, followed by free-radical propogation steps. Polymerization increases with increased photoinitiator and monomer concentration and particle size; it also has a dependence upon the square root of the light intensity. Illumination-induced holes are scavenged by the solvent. 29 refs., 8 figs., 2 tabs.

  5. Polyelectrolyte complexes based on (quaternized) poly[(2-dimethylamino)ethyl methacrylate]: behavior in contact with blood.

    PubMed

    Yancheva, Elena; Paneva, Dilyana; Danchev, Dobri; Mespouille, Laetitia; Dubois, Philippe; Manolova, Nevena; Rashkov, Iliya

    2007-07-09

    Polyelectrolyte complexes (PECs) between (quaternized) poly[2-(dimethylamino)ethyl methacrylate] (PDMAEMA) and (crosslinked) N-carboxyethylchitosan (CECh) or poly(2-acrylamido-2-methylpropane sodium sulfonate) (PAMPSNa) were prepared and characterized in terms of their stability, equilibrium water content, and surface morphology. The evaluation of the behavior of the studied PECs in contact with blood revealed that the (crosslinked) CECh/(quaternized) PDMAEMA complexes had lost the inherent PDMAEMA cytotoxicity but still preserved haemostatic activity. In contrast, the complex formation between (quaternized) PDMAEMA and PAMPSNa allowed the preparation of materials with improved blood compatibility.

  6. Amine functionalization of cellulose surface grafted with glycidyl methacrylate by γ-initiated RAFT polymerization

    NASA Astrophysics Data System (ADS)

    Barsbay, Murat; Güven, Olgun; Kodama, Yasko

    2016-07-01

    This study presents the functionalization of poly(glycidyl methacrylate) (PGMA) grafted cellulose filter paper by a model compound, ethylenediamine (EDA), through the epoxy groups of PGMA. Cellulose based copolymers were prepared via the radiation-induced and RAFT-mediated graft polymerization. The samples were characterized by ATR-FTIR spectroscopy, X-ray photoelectron spectroscopy (XPS), elemental analysis, contact angle measurements and scanning electron microscopy (SEM). An efficient modification density of around 1 mmol EDA/mg copolymer was attained within ca. 8 h, indicating that chemical composition of well-defined copolymers may further be tuned by appropriately selecting the reactive agents for use in many emerging fields.

  7. Elaboration of ammonio methacrylate copolymer based spongy cationic particles via double emulsion solvent evaporation process.

    PubMed

    Zafar, Nadiah; Bitar, Ahmad; Valour, Jean Pierre; Fessi, Hatem; Elaissari, Abdelhamid

    2016-04-01

    The aim of present work is to investigate systematic study of the preparation of biodegradable particles via double emulsion solvent evaporation technique. The used formation is based on cationic ammonium methacrylate copolymer Eudragit® RS 100, without the use of any stabilizer. The effect of process parameters like ultra turrax® stirring speed and stirring time, ultrasonication time, polymer amount, and volume of outer aqueous phases on the colloidal properties of particles was investigated. All prepared dispersions were characterized in terms of size, size distribution, and electrokinetic properties, and surface morphology was investigated.

  8. In-situ photopolymerization of monodisperse and discoid oxidized methacrylated alginate microgels in a microfluidic channel

    DOE PAGES

    Wang, Shuo; Jeon, Oju; Shankles, Peter G.; ...

    2016-02-03

    Here, we present a simple microfluidic technique to in-situ photopolymerize (by 365 nm ultraviolet) monodisperse oxidized methacrylated alginate (OMA) microgels using a photoinitiator (VA-086). By this technique, we generated monodisperse spherical OMA beads and discoid non-spherical beads with better shape consistency than ionic crosslinking methods do. We found that a high monomer concentration (8 w/v %), a high photoinitiator concentration (1.5 w/v %) and absence of oxygen are critical factors to cure OMA microgels. This photopolymerizing method is an alternative to current methods to form alginate microgels and is a simpler approach to generate non-spherical alginate microgels.

  9. Antibacterial properties of novel poly(methyl methacrylate) nanofiber containing silver nanoparticles.

    PubMed

    Kong, Hyeyoung; Jang, Jyongsik

    2008-03-04

    Poly(methyl methacrylate) (PMMA) nanofiber containing silver nanoparticles was synthesized by radical-mediated dispersion polymerization and applied to an antibacterial agent. UV-vis spectroscopic analysis indicated that the silver nanoparticles were continually released from the polymer nanofiber in aqueous solution. The antibacterial properties of silver/PMMA nanofiber against both Gram-negative (Escherichia coli) and Gram-positive (Staphylococcus aureus) bacteria were evaluated using minimum inhibitory concentration (MIC), the modified Kirby-Bauer method, and a kinetic test. The MIC test demonstrated that the silver/PMMA nanofiber had enhanced antimicrobial efficacy compared to that of silver sulfadiazine and silver nitrate at the same silver concentration.

  10. Properties of cellulase as template molecule on chitosan—methyl methacrylate membrane

    NASA Astrophysics Data System (ADS)

    Lian, Qi; Zheng, Xuefang; Wu, Haixia; Song, Shitao; Wang, Dongjun

    2015-12-01

    In this study, a novel molecular imprinting membrane made of chitosan and methyl methacrylate (MMA) was fabricated with cellulase as template molecule and the thermal response to cellulase was characterized. The film was characterized by infrared spectroscopy (IR), X-ray diffraction (XRD), scanning electron microscopy (SEM) and the permeation experiment. The results showed that the space structure of the film was as similar as the cellulase. Moreover, the membrane had advanced molecular imprinting capability to cellulase comparing to pepsin and pectinase at any temperature and the film had excellent ability to identify specific template molecule (cellulase) at the synthesis temperature compared to other temperatures.

  11. Non-fouling hydrogels of 2-hydroxyethyl methacrylate and zwitterionic carboxybetaine (meth)acrylamides.

    PubMed

    Kostina, Nina Yu; Rodriguez-Emmenegger, Cesar; Houska, Milan; Brynda, Eduard; Michálek, Jiří

    2012-12-10

    Five poly(betaine) brushes were prepared, and their resistance to blood plasma fouling was studied. Two carboxybetaines monomers were copolymerized with 2-hydroxyethyl methacrylate (HEMA) to prepare novel hydrogels. By increasing the content of the zwitterionic comonomer, a 4-fold increase in the water content could be achieved while retaining mechanical properties close to the widely used poly(HEMA) hydrogels. All hydrogels showed an unprecedentedly low fouling from blood plasma. Remarkably, by copolymerization with 10 mol % of carboxybetaine acrylamide, hydrogels fully resistant to blood plasma were prepared.

  12. Poly (methyl methacrylate) Formation and Patterning Initiated by Synchrotron X-ray Illumination

    SciTech Connect

    Xiao, J.; Je, J. H.; Wang, C. H.; Yang, T. Y.; Hwu, Y.

    2007-01-19

    A facile radiation method was developed to obtain micro-sized poly (methyl methacrylate) (PMMA) particles and create patterned coating on different substrates by a synchrotron x-ray induced dispersion polymerization. The polymerization of MMA monomer and well defined patterning was successfully realized. The produced PMMA particles and patterning were characterized by Fourier transformation infrared (FTIR), 1H-Nuclear Magnetic Resonance (NMR), and Scanning Electron Microscope (SEM). The observed patterning contrast essentially derived from a variation of size, density and morphology of particles and the type of substrate materials used.

  13. Fracture resistance of Kevlar-reinforced poly(methyl methacrylate) resin: a preliminary study.

    PubMed

    Berrong, J M; Weed, R M; Young, J M

    1990-01-01

    The reinforcing effect of Kevlar fibers incorporated in processed poly(methyl methacrylate) resin samples was studied using 0% (controls), 0.5%, 1%, and 2% by weight of the added fibers. The samples were subjected to impact testing to determine fracture resistance, and sample groups were statistically compared using an ANOVA. Each reinforced sample had significantly greater fracture resistance (P less than 0.05) than the control, and no difference was found either within or between control groups. The use of reinforcing Kevlar fibers appears to enhance the fracture resistance of acrylic resin denture base materials.

  14. Vibrational overtone enhancement of methyl methacrylate polymerization initiated by benzoyl peroxide decomposition

    NASA Astrophysics Data System (ADS)

    Grinevich, Oleg; Snavely, D. L.

    1997-03-01

    Vibrational overtone initiated polymerization has been demonstrated using intracavity photolysis of a benzoyl peroxide/methyl methacrylate mixture. Excitation of the 6 νCH overtone transition of the ground electronic state of benzoyl peroxide creates radicals which subsequently begin the polymerization process. Polymer yield was monitored by comparison of the 2 νCH overtone absorptions for the methyl, methylenic and olefinic CH stretches at 5946 and 6170 cm -1, respectively. Plots of polymer yield versus time demonstrate an autoacceleration of the polymerization rate commencing many hours after the photolysis period. The delay before autoacceleration depends on the duration of the photolysis.

  15. Emission from Polymethyl Methacrylate Irradiated by a Beam of Runaway Electrons of Subnanosecond Pulse Durations

    NASA Astrophysics Data System (ADS)

    Baksht, E. Kh.; Burachenko, A. G.; Beloplotov, D. V.; Tarasenko, V. F.

    2016-08-01

    Spectral and amplitude-temporal characteristics of emission from polymethyl methacrylate (fiberglass, PMMA) irradiated with a beam of runaway electrons of subnanosecond duration are investigated. It is found that at the beam current pulse duration within 200-600 ps at half maximum and the beam current density 10-200 A/cm2, the intensity maximum is registered at the wavelength ~490 nm and the emission pulse FWHM in the visible spectrum is ~1.5 ns at the half width. It is shown that the main contribution into the emission comes from luminescence.

  16. Carboxymethyl cellulose-g-poly(2-(dimethylamino) ethyl methacrylate) hydrogel as adsorbent for dye removal.

    PubMed

    Salama, Ahmed; Shukry, Nadia; El-Sakhawy, Mohamed

    2015-02-01

    A novel adsorbent was prepared via crosslinking graft copolymerization of 2-(dimethylamino) ethyl methacrylate (DMAEMA) onto carboxymethyl cellulose (CMC) backbone. Ethylene glycol dimethacrylate and potassium persulphate were used as crosslinker and initiator, respectively. CMC-g-PDMAEMA hydrogel was used to remove methyl orange (MO) from aqueous solutions. The adsorption kinetics and isotherms were found to follow Pseudo-second-order kinetic model and Langmuir model, respectively. The high maximum adsorption capacity (1825 mg/g) implied that CMC-g-PDMAEMA can be used as promising adsorbent for the synthetic dyes removal from wastewater.

  17. Thermo-reversible gelation of atactic poly(methyl methacrylate) in poly(ethylene glycol) oligomers.

    PubMed

    Gao, Yun; Yu, Chunhong; Chen, Minzhi; Wang, Xiaoliang; Zhou, Dongshan; Xue, Gi

    2013-04-01

    The temperature-concentration behavior of physical gel by atactic poly(methyl methacrylate) (aPMMA) in poly(ethylene glycol) oligomer (PEG400) was investigated. A liquid-liquid demixing interferes with a glass transition during cooling. The combination of demixing and T g leads to the formation of amorphous gels at low temperature. We suggest that the gelation of aPMMA/PEG400 is a glassy gel, in which short-range attractive depletion interaction in the polymer/oligomer system was the driving force at molecular level.

  18. Proton nuclear magnetic resonance spectroscopic detection and determination of ethylene glycol dimethacrylate as a contaminant of methyl methacrylate raw material.

    PubMed

    Hanna, G M; Lau-Cam, C A

    1995-01-01

    A simple, specific, and accurate proton nuclear magnetic resonance (1H NMR) spectroscopic method is presented for detection and assay of ethylene glycol dimethacrylate dimer as a contaminant of methyl methacrylate monomer. In addition to minimizing exposure of the analyst to the irritant and toxic methacrylic acid esters, the proposed method requires no sample preparation. Quantitations are based on integrals for signals of methylene protons of ethylene glycol dimethacrylate at 4.37 ppm and methyl protons of methyl methacrylate at 3.70 ppm. Analysis of 10 synthetic mixtures of the monomer with 1-11% of dimer yielded a dimer recovery of 100.5 +/- 2.05% (mean +/- standard deviation). Correspondence (correlation coefficient, r = 0.9999) between the amount of dimer added and the amount found was excellent. The proposed method measures as little as 1% of dimer.

  19. Iron-catalyzed AGET ATRP of methyl methacrylate using an alcohol as a reducing agent in a polar solvent.

    PubMed

    Xue, Zhigang; Zhou, Jun; He, Dan; Wu, Fan; Yang, Danfeng; Ye, Yun Sheng; Liao, Yonggui; Zhou, Xingping; Xie, Xiaolin

    2014-11-21

    The alcohols, methanol, ethanol, ethylene glycol (EG), and glycerol, were used as reducing agents for iron(III)-catalyzed activators generated by electron transfer atom transfer radical polymerizations (AGET ATRPs) of methyl methacrylate in polar solvents (N,N-dimethylformamide, N-methylpyrrolidone, or acetonitrile). The effects of the iron catalyst, initiator and alcohol on polymerization were investigated, and most of the systems showed the typical features of controlled radical polymerization. In studies of the ATRP behavior, polymerizations were well controlled with a linear increase in the molecular weight (Mn) versus conversion in agreement with the theoretical one, and low molecular weight distributions (Mw/Mn) were observed throughout the reactions. To gain a deeper understanding of the iron(III)/polar solvent-mediated ATRP, the polymerizations of various monomers (methyl acrylate, methyl methacrylate, n-butyl acrylate, and n-butyl methacrylate) were also investigated.

  20. Single step plasmid DNA purification using methacrylate monolith bearing combination of ion-exchange and hydrophobic groups.

    PubMed

    Smrekar, Vida; Smrekar, Franc; Strancar, Aleš; Podgornik, Aleš

    2013-02-08

    Purification of high quantities of human grade plasmid DNA is one of the most intensive production steps. Because of that several methods have been proposed, among them also chromatographic purification using methacrylate monoliths. Recently, a process comprising the combination of hydrophobic interaction (HIC) monolith and ion-exchange monolith was developed. In this work both chemistries were tried to be introduced on a single monolith. Methacrylate monoliths bearing octylamine groups, combination of butyl (C4) grafted methacrylate groups and diethylaminoethyl (DEAE) groups as well as grafted chains bearing both C4 and DEAE groups were prepared. All monoliths were investigated for their ionic and protein capacity and compared to conventional epoxy, C4, and DEAE methacrylate monoliths. Octylamine monolith and monolith bearing combination of C4 grafted methacrylate groups and DEAE groups were found to be the most promising candidates and were further tested for plasmid DNA (pDNA) dynamic binding capacity under ion-exchange (IEX) and HIC binding conditions and ability to separate open circular (OC) from supercoiled (SC) pDNA forms and RNA from pDNA. Since monolith bearing combination of grafted C4 methacrylate groups and DEAE groups was superior in all three tested features, exhibiting pDNA dynamic binding capacity of 4.7 mg/ml under IEX conditions and 2.1mg/ml under HIC conditions, it was used for the development of a single step purification method and tested with pure pDNA as well as with cell lysate. Developed method removed over 99% of RNA, host cell proteins (HCP) and genomic DNA (gDNA) demonstrating capacity to purify around 1.5mg of pDNA/ml of monolith from cell lysate.

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

    PubMed

    Trombelli, L; Lee, M B; Promsudthi, A; Guglielmoni, P G; Wikesjö, U M

    1999-06-01

    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.

  2. 75 FR 770 - Acrylic acid-benzyl methacrylate-1-propanesulfonic acid, 2-methyl-2-[(1-oxo-2-propenyl)amino...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2010-01-06

    ... AGENCY 40 CFR Part 180 Acrylic acid-benzyl methacrylate-1-propanesulfonic acid, 2- methyl-2... residues of acrylic acid-benzyl methacrylate-1- propanesulfonic acid, 2-methyl-2- -, monosodium salt... to establish a maximum permissible level for residues of acrylic acid-benzyl...

  3. Dynamic mechanical thermal analysis of dental polymers. I. Heat-cured poly(methyl methacrylate)-based materials.

    PubMed

    Clarke, R L

    1989-09-01

    The visco-elastic characteristics of homogeneous, heterogeneous and fibre-reinforced poly(methyl methacrylate) for use as denture base resins were measured by a dynamic mechanical thermal analyser in the frequency range 0.033-90 Hz. Dynamic Young's modulus of both polyethylene woven yarn and the polyaramid plain fabric-reinforced acrylics showed considerable improvement over the conventional denture base, whereas the carbon fibre-reinforced acrylic produced results lower than expected. From the loss tangent curves of the homogeneous and heterogeneous methacrylates their transition temperatures were recorded and the reciprocals of both the alpha and beta absorption temperatures were plotted against frequency to obtain their respective activation energies.

  4. The synthesis, properties, and applications of hydrophilic polymers and copolymers of hydroxyalkyl esters of acrylic and methacrylic acids

    NASA Astrophysics Data System (ADS)

    Asadov, Z. G.; Aliev, V. S.

    1992-05-01

    The scientific-technical and patent literature on the synthesis of hydroxyalkyl esters of acrylic and methacrylic acids by their catalytic reaction with epoxyalkanes, by the radical copolymerisation and polymerisation of presynthesised monomeric esters, and also by the chemical modification of polymerisation and copolymerisation products is surveyed. A wide variety of physicochemical properties of the polymers and copolymers based on the hydroxyalkyl esters of acrylic and methacrylic acids are described. The principal trends and prospects in the application of the high-molecular-weight products obtained in various branches of the national economy are indicated. The bibliography includes 158 references.

  5. Engineered Contractile Skeletal Muscle Tissue on a Microgrooved Methacrylated Gelatin Substrate

    PubMed Central

    Hosseini, Vahid; Ahadian, Samad; Ostrovidov, Serge; Camci-Unal, Gulden; Chen, Song; Kaji, Hirokazu; Ramalingam, Murugan

    2012-01-01

    To engineer tissue-like structures, cells must organize themselves into three-dimensional (3D) networks that mimic the native tissue microarchitecture. Microfabricated hydrogel substrates provide a potentially useful platform for directing cells into biomimetic tissue architecture in vitro. Here, we present microgrooved methacrylated gelatin hydrogels as a suitable platform to build muscle-like fibrous structures in a facile and highly reproducible fashion. Microgrooved hydrogel substrates with two different ridge sizes (50 and 100 μm) were fabricated to assess the effect of the distance between engineered myofibers on the orientation of the bridging C2C12 myoblasts and the formation of the resulting multinucleated myotubes. It was shown that although the ridge size did not significantly affect the C2C12 myoblast alignment, the wider-ridged micropatterned hydrogels generated more myotubes that were not aligned to the groove direction as compared to those on the smaller-ridge micropatterns. We also demonstrated that electrical stimulation improved the myoblast alignment and increased the diameter of the resulting myotubes. By using the microstructured methacrylated gelatin substrates, we built free-standing 3D muscle sheets, which contracted when electrically stimulated. Given their robust contractility and biomimetic microarchitecture, engineered tissues may find use in tissue engineering, biological studies, high-throughput drug screening, and biorobotics. PMID:22963391

  6. Poly(methyl methacrylate)-titania hybrid materials by sol-gel processing

    SciTech Connect

    Zhang, J.; Luo, S.; Gui, L.; Tang, Y.

    1996-12-31

    Sol-gel derived Poly(methyl methacrylate)-titania hybrid materials were synthesized by using acrylic acid or allyl acetylacetone (3-allyl-2,4-pentanedione) as coupling agents. Titanium butoxide modified with acrylic acid (or titanium isopropoxide modified with allyl acetylacetone) was hydrolyzed to produce a titania network, and then poly (methyl methacrylate) (PMMA) chains formed in situ through a radical polymerization were chemically bonded to the forming titania network to synthesize a hybrid material. Transparent hybrid materials with different contents of titania were achieved. With the increase of the titania content, the colors of the products changed form yellow to dark red. The synthesis process was investigated step by step by using FTIR spectroscopy, and the experimental results demonstrated that acrylate or acetylacetonato groups bound to titanium remain in the final hybrid materials. The thermal stability of the hybrid materials was considerably improved relative to pure PMMA. Field emission scanning electron microscopy (FE-SEM) analyses showed the hybrid materials are porous and pore diameters vary from 10nm to 100nm. The hybrid materials using allyl acetylacetone as the coupling agent exhibited thermochromic effects that both pure PMMA and titania do not have.

  7. Bond Strengths of Silorane- and Methacrylate-Based Composites to Various Underlying Materials

    PubMed Central

    Ozer, Sezin; Sen Tunc, Emine; Gonulol, Nihan

    2014-01-01

    Objective. To evaluate shear bond strength (SBS) values of a methacrylate (FZ 250) and a silorane-based (FS) resin composite to various underlying materials. Materials and Methods. A total of 80 samples were prepared with four different underlying materials; a flowable (FLC) and a bulk-fill flowable composite (BFC), and a conventional (CGIC) and resin modified glass-ionomer cement (RMGIC). These underlying materials were laminated plus to methacrylate or silorane-based resin composites (n = 10). To evaluate the specimens SBS values were evaluated with a universal testing machine (cross-head speed; 1.0 mm/min). Statistical comparisons were carried out using two-way ANOVA and Tukey's post hoc test with a significance level of P < 0.05. Results. SBS values for FZ250 were significantly higher than for FS for all of the underlying materials tested (P < 0.05). SBS values of FZ250 to BFC were significantly higher than to all other materials (P < 0.05), whereas SBS values of FS did not vary significantly according to underlying material (P > 0.05). Conclusion. The use of FS in conjunction with any of the tested materials showed lower SBS than the FZ 250. Also, new low elastic modulus liner BFC presented slightly good interfacial adhesion so, the usage of BFC as an underlying material may be preferable for FZ 250. PMID:24895608

  8. Low-cost fabrication of poly(methyl methacrylate) microchips using disposable gelatin gel templates.

    PubMed

    Chen, Zhi; Yu, Zhengyin; Chen, Gang

    2010-06-15

    A simple method based on disposable gelatin gel templates has been developed for the low-cost fabrication of poly(methyl methacrylate) (PMMA) microfluidic chips. Gelatin was dissolved in glycerol aqueous solution under heat to prepare a thermally reversible impression material. The molten gel was then sandwiched between a glass plate and a SU-8 template bearing negative relief of microstructure. After cooling, the negative SU-8 template could be easily separated from the solidified gelatin gel and a layer of gelatin template bearing positive relief of the microstructure was left on the glass plate. Subsequently, prepolymerized methyl methacrylate molding solution containing a UV-initiator was sandwiched between the gel template and a PMMA plate and was allowed to polymerize under UV light to fabricate PMMA channel plate at room temperature. Complete microchips could be obtained by bonding the channel plates with covers using plasticizer-assisted thermal bonding at 90 degrees C. Gelatin gel template can be mass-produced and will find application in the mass production of PMMA microchips at low cost. The prepared microfluidic microchips have been successfully employed in the capillary electrophoresis analysis of several ions in connection with contactless conductivity detection.

  9. Effects of star-shape poly(alkyl methacrylate) arm uniformity on lubricant properties

    DOE PAGES

    Robinson, Joshua W.; Qu, Jun; Erck, Robert; ...

    2016-03-29

    Star-shaped poly(alkyl methacrylate)s (PAMAs) were prepared and blended into an additive-free engine oil to assess the structure property relationship between macromolecular structure and lubricant performance. These additives were designed with a comparable number of repeating units per arm and the number of arms was varied between 3 and 6. Well-defined star-shaped PAMAs were synthesized by atom transfer radical polymerization (ATRP) via a core-first strategy from multi-functional headgroups. Observations of the polymer-oil blends suggest that stars with less than four arms are favorable as a viscosity index improver (VII), and molecular weight dominates viscosity-related effects over other structural features. Star-shaped PAMAs,more » as oil additives, effectively reduce the friction coefficient in both mixed and boundary lubrication regime. Several analogs outperformed commercial VIIs in both viscosity and friction performance. Furthermore, increased wear rates were observed for these star-shaped PAMAs in the boundary lubrication regime suggesting pressure-sensitive conformations may exist.« less

  10. Surface characterization and drug release from porous microparticles based on methacrylic monomers and xanthan.

    PubMed

    Lungan, Maria-Andreea; Popa, Marcel; Racovita, Stefania; Hitruc, Gabriela; Doroftei, Florica; Desbrieres, Jacques; Vasiliu, Silvia

    2015-07-10

    Porous crosslinked microparticles based on glycidyl methacrylate and xanthan were prepared by suspension polymerization and used for loading theophylline, a bronhodilatator drug, in order to obtain new drug delivery systems. The surface morphologies observed by means of SEM and AFM analysis demonstrated that microparticles show a spherical shape and are characterized by a porous structure. The presence of xanthan in the structure of microparticles leads to a decrease of surface roughness and pore diameters as well as to an increase of hydrophilicity degree compared to the micropaticles based only on glycidyl methacrylate. To analyze the in vitro release data various mathematical models were used, such as, first order, Higuchi model, Korsmeyer-Peppas model and Baker-Lonsdale model. Based on the highest values of the correlation coefficient, the analysis of the kinetic data indicate that drug release from G1 and X1 porous microparticles fits similarly well to the first order and Higuchi models and diffusion was the dominant mechanism of drug release.

  11. Syringyl Methacrylate, a Hardwood Lignin-Based Monomer for High-Tg Polymeric Materials

    PubMed Central

    2016-01-01

    As viable precursors to a diverse array of macromolecules, biomass-derived compounds must impart wide-ranging and precisely controllable properties to polymers. Herein, we report the synthesis and subsequent reversible addition–fragmentation chain-transfer polymerization of a new monomer, syringyl methacrylate (SM, 2,6-dimethoxyphenyl methacrylate), that can facilitate widespread property manipulations in macromolecules. Homopolymers and heteropolymers synthesized from SM and related monomers have broadly tunable and highly controllable glass transition temperatures ranging from 114 to 205 °C and zero-shear viscosities ranging from ∼0.2 kPa·s to ∼17,000 kPa·s at 220 °C, with consistent thermal stabilities. The tailorability of these properties is facilitated by the controlled polymerization kinetics of SM and the fact that one vs two o-methoxy groups negligibly affect monomer reactivity. Moreover, syringol, the precursor to SM, is an abundant component of depolymerized hardwood (e.g., oak) and graminaceous (e.g., switchgrass) lignins, making SM a potentially sustainable and low-cost candidate for tailoring macromolecular properties. PMID:27213117

  12. Effects of star-shape poly(alkyl methacrylate) arm uniformity on lubricant properties

    SciTech Connect

    Robinson, Joshua W.; Qu, Jun; Erck, Robert; Cosimbescu, Lelia; Zhou, Yan

    2016-03-29

    Star-shaped poly(alkyl methacrylate)s (PAMAs) were prepared and blended into an additive-free engine oil to assess the structure property relationship between macromolecular structure and lubricant performance. These additives were designed with a comparable number of repeating units per arm and the number of arms was varied between 3 and 6. Well-defined star-shaped PAMAs were synthesized by atom transfer radical polymerization (ATRP) via a core-first strategy from multi-functional headgroups. Observations of the polymer-oil blends suggest that stars with less than four arms are favorable as a viscosity index improver (VII), and molecular weight dominates viscosity-related effects over other structural features. Star-shaped PAMAs, as oil additives, effectively reduce the friction coefficient in both mixed and boundary lubrication regime. Several analogs outperformed commercial VIIs in both viscosity and friction performance. Furthermore, increased wear rates were observed for these star-shaped PAMAs in the boundary lubrication regime suggesting pressure-sensitive conformations may exist.

  13. Cold acetone fixation and methacrylate embedding. A suitable method for routine processing of bone marrow biopsies.

    PubMed

    Hantschick, M; Stosiek, P

    1998-01-01

    Here we report that acetone fixation at -18 degrees C with subsequent embedding in methyl-/butylmethacrylate is a reliable method for the routine processing of bone marrow biopsies. This method allows good conventional histological visualization of morphological details, which is comparable with other fixation procedures. The essential advantage of this method is that a wide range of monoclonal antibodies and polyclonal antisera can be used for immunohistochemical investigations for diagnostic and scientific purposes. The addition of 5% polyethylene glycol 400 to the acetone minimizes freeze-related artefacts. The immunohistochemical demonstration of a number of antigens is mostly affected by the medium used for slide preparation and to a lesser extent by the concentration of benzoylperoxide used for polymerization. Performing polymerization at 4 degrees C and using N, N-dimethyl-p-toluidine as accelerator allows the concentration of benzoylperoxide to be reduced to 0.2 g% (8.3 mmol). Under these conditions the methacrylate embedding procedure has only minimal effects on the quality of immuno- and enzyme histochemistry. Additionally, the simplified method for removing the polymerization inhibitor from the methacrylate components and the shortened impregnation step are further advantages of the embedding method described here.

  14. Radiation induced graft copolymerization of methyl methacrylate onto chrome-tanned pig skins

    NASA Astrophysics Data System (ADS)

    Pietrucha, K.; Pȩkala, W.; Kroh, J.

    Graft copolymerization of methyl methacrylate (MMA) onto chrome-tanned pig skins was carried out by the irradiation with 60Co ?-rays. The grafted polymethyl methacrylate (PMMA) chains were isolated by acid hydrolysis of the collagen backbone in order to characterize the graft copolymers. Proof of grafting was obtained through the detection of amino acid endgroups in the isolated grafts by reaction with ninhydrin. The grafting yield of MMA in aqueous emulsion was found to be higher than that for pure MMA and MMA in acetone. The degree of grafting increases with increasing monomer concentration in emulsion and reaches maximum at radiation dose ca 15 kGy. The yield of grafting is very high - ca 90% of monomer converts into copolymer and only 10% is converted into homopolymer. The present paper reports the physical properties of chrome-tanned pig skins after graft polymerization with MMA in emulsion. Modified leathers are more resistant against water absorption and abrasion in comparison with unmodified ones. They have more uniform structure over the whole surface, greater thickness and stiffness. The results reported seem to indicate that MMA may be used in the production of shoe upper and sole leathers. The mechanism of some of the processes occuring during radiation grafting of MMA in water emulsion on tanned leathers has been also suggested and discussed.

  15. Synthesis of Poly(Sorbitan Methacrylate) Hydrogel by Free-Radical Polymerization

    NASA Astrophysics Data System (ADS)

    Jeong, Gwi-Taek; Lee, Kyoung-Min; Yang, Hee-Seung; Park, Seok-Hwan; Park, Jae-Hee; Sunwoo, Changshin; Ryu, Hwa-Won; Kim, Doman; Lee, Woo-Tae; Kim, Hae-Sung; Cha, Wol-Seog; Park, Don-Hee

    Hydrogels are materials with the ability to swell in water through the retention of significant fractions of water within their structures. Owing to their relatively high degree of biocompatibility, hydrogels have been utilized in a host of biomedical applications. In an attempt to determine the optimum conditions for hydrogel synthesis by the free-radical polymerization of sorbitan methacrylate (SMA), the hydrogel used in this study was well polymerized under the following conditions: 50% (w/v) SMA as monomer, 1% (w/w) α, α'-azo-bis(isobutyro-nitrile) as thermal initiator, and 1% (w/w) ethylene glycol dimethacrylate as cross-liking agent. Under these conditions, the moisture content of the polymerized SMA hydrogel was higher than in the other conditions. Moreover, the moisture content of the poly(SMA) hydrogel was also found to be higher than that of the poly(methyl methacrylate [MMA]) hydrogel. When the Fourier transform-infrared spectrum of poly(SMA) hydrogel was compared with that of poly(MMA) hydrogel, we noted a band at 1735-1730/cm, which did not appear in the Fourier transform-infrared spectrum of poly(MMA). The surface of the poly(SMA) hydrogel was visualized through scanning electron microscopy, and was uniform and clear in appearance.

  16. Synthesis, characterization, and antibacterial activities of novel methacrylate polymers containing norfloxacin.

    PubMed

    Dizman, Bekir; Elasri, Mohamed O; Mathias, Lon J

    2005-01-01

    A novel methacrylate monomer containing a quinolone moiety was synthesized and homopolymerized in N,N-dimethylformamide (DMF) by using azobisisobutyronitrile (AIBN) as an initiator. The new monomer was copolymerized with poly(ethylene glycol) methyl ether methacrylate (MPEGMA) in DMF using the same initiator. The monomer, homopolymer, and copolymer were characterized by elemental analysis, thermogravimetric analysis (TGA), differential scanning calorimetry (DSC), size exclusion chromatography (SEC), FTIR, (13)C NMR, and (1)H NMR. The antibacterial activities of the monomer as well as polymers were investigated against Staphylococcus aureus and Escherichia coli, which are representative of Gram-positive and Gram-negative bacteria, respectively. All compounds showed excellent antibacterial activities against these two types of bacteria. The antibacterial activities were determined using the shaking flask method, where 25 mg/mL concentrations of each compound were tested against 10(5) CFU/mL bacteria solutions. The number of viable bacteria was calculated by using the spread plate method, where 100 microL of the incubated antibacterial agent in bacteria solutions were spread on agar plates and the number of viable bacteria was counted after 24 h of incubation period at 37 degrees C.

  17. Formation of poly(methyl methacrylate) thin films onto wool fiber surfaces by vapor deposition polymerization.

    PubMed

    Hassan, M Mahbubul; McLaughlin, J Robert

    2013-03-13

    Chemical vapor deposition (CVD) polymerization is a useful technique because of the possibility of forming very thin film of pure polymers on substrates with any geometric shape. In this work, thin films of poly(methyl methacrylate) or PMMA were formed on the surfaces of wool fabrics by a CVD polymerization process. Various polymerization initiators including dicumyl peroxide, tert-butyl peroxide, and potassium peroxydisulfate have been investigated to polymerize methyl methacrylate onto the surfaces of wool by the CVD polymerization. The wool fabrics were impregnated with initiators and were then exposed to MMA monomer vapor under vacuum at the boiling temperature of the monomer. Wool fabrics with vapor-deposited PMMA surfaces were characterized by elemental analysis, TGA, FTIR, disperse dye absorption, contact angles measurement, AFM, and SEM. PMMA-coated wool fabrics showed higher contact angle and absorbed more dyes than that of the control wool. It was evident from the results obtained by various characterization techniques that MMA was successfully polymerized and formed thin films on the surfaces of wool fabrics by all initiators investigated but the best results were achieved with tert-butyl peroxide.

  18. Computational evidence for self-initiation in spontaneous high-temperature polymerization of methyl methacrylate.

    PubMed

    Srinivasan, Sriraj; Lee, Myung Won; Grady, Michael C; Soroush, Masoud; Rappe, Andrew M

    2011-02-17

    This paper presents computational evidence for the occurrence of diradical mechanism of self-initiation in thermal polymerization of methyl methacrylate. Two self-initiation mechanisms of interest were explored with first-principles density functional theory calculations. Singlet and triplet potential energy surfaces were constructed. The formation of two Diels-Alder adducts, cis- and trans-dimethyl 1,2-dimethylcyclobutane-1,2-dicarboxylate and dimethyl 2-methyl-5-methylidene-hexanedioate, on the singlet surface was identified. Transition states were calculated using B3LYP/6-31G* and assessed using MP2/6-31G*. The calculated energy barriers and rate constants with different levels of theory were found to show good agreement to corresponding data obtained from laboratory experiments. The presence of a diradical intermediate on the triplet surface was identified. When MCSCF/6-31G* was used, the spin-orbit coupling constant for the singlet to triplet crossover was calculated to be 2.5 cm(-1). The mechanism of monoradical generation via a hydrogen abstraction by both triplet and singlet diradicals from a third monomer was identified to be the most likely mechanism of initiation in spontaneous polymerization of methyl methacrylate.

  19. Controllable surface morphology and properties via mist polymerization on a plasma-treated polymethyl methacrylate surface.

    PubMed

    Wan, S J; Wang, L; Xu, X J; Zhao, C H; Liu, X D

    2014-02-14

    Surface modification by grafting polymers on solid materials is an important strategy used to improve surface properties. This article reports that under appropriate conditions, very thin layers with desired morphologies may be constructed on a plasma-treated substrate by feeding a small quantity of a monomer with a mist stream carrying droplets produced from monomer solutions. We investigate the effects of process parameters that affect layer morphology, including exposure time to the mist stream, concentration of the monomer solution, and solvent selectivity. For a methyl methacrylate solution in ethanol, nanoparticles are uniformly grown with increasing monomer concentration or exposure time and finally form a porous layer at 3.65 mol L(-1) for 30 min. Decreasing solvent polarity not only affects surface morphology, but also increases hydrophobicity of the resulting surface. With 2,2,3,4,4,4-hexafluorobutyl methacrylate as the monomer, SEM and AFM micrographs indicated that mist polymerization results in numerous microspheres on the activated surface. These experimental results were interpreted by a mechanism in terms of an in situ polymerization accompanied by a phase transformation of the resulting polymer. Specifically, plasma treatment provides highly active cations and radicals to initiate very rapid polymerization, and the resulting polymers are consequently deposited from the liquid onto the surface under phase transition mechanisms.

  20. Transdermal regulation of vascular network bioengineering using a photopolymerizable methacrylated gelatin hydrogel

    PubMed Central

    Lin, Ruei-Zeng; Chen, Ying-Chieh; Moreno-Luna, Rafael; Khademhosseini, Ali; Melero-Martin, Juan M.

    2013-01-01

    The search for hydrogel materials compatible with vascular morphogenesis is an active area of investigation in tissue engineering. One candidate material is methacrylated gelatin (GelMA), a UV-photocrosslinkable hydrogel that is synthesized by adding methacrylate groups to the amine-containing side-groups of gelatin. GelMA hydrogels containing human endothelial colony-forming cells (ECFCs) and mesenchymal stem cells (MSCs) can be photopolymerized ex vivo and then surgically transplanted in vivo as a means to generate vascular networks. However, the full clinical potential of GelMA will be best captured by enabling minimally invasive implantation and in situ polymerization. In this study, we demonstrated the feasibility of bioengineering human vascular networks inside GelMA constructs that were first subcutaneously injected into immunodeficient mice while in liquid form, and then rapidly crosslinked via transdermal exposure to UV light. These bioengineered vascular networks developed within 7 days, formed functional anastomoses with the host vasculature, and were uniformly distributed throughout the constructs. Most notably, we demonstrated that the vascularization process can be directly modulated by adjusting the initial exposure time to UV light (15–45 s range), with constructs displaying progressively less vascular density and smaller average lumen size as the degree of GelMA crosslinking was increased. Our studies support the use of GelMA in its injectable form, followed by in situ transdermal photopolymerization, as a preferable means to deliver cells in applications that require the formation of vascular networks in vivo. PMID:23773819

  1. Effect of Montmorillonite Modification on Ultra Violet Radiation Cured Nanocomposite Filled with Glycidyl Methacrylate Modified Kenaf

    NASA Astrophysics Data System (ADS)

    Rozyanty, A. R.; Rozman, H. D.; Zhafer, S. F.; Musa, L.; Zuliahani, A.

    2016-06-01

    In this study nanocomposite cured by ultra violet radiation, were produced using modified montmorillonite (MMT) as reinforcing agent, chemically modified kenaf bast fiber as filler and unsaturated polyester as the matrix. Kenaf bast fiber was chemically modified with glycidyl methacrylate (GMA) whilst MMT were modified with cetyl trimethyl ammonium bromide (CTAB) and glycidyl methacrylate (GMA). Fixed 12 percent of GMA modified kenaf bast fiber with different percentage (i.e., 1, 3 and 5) of unmodified and modified MMT loading was used to produce the composite. The performed of GMA reaction with hydroxyl group of cellulose in kenaf bast fiber was evaluated using Fourier Transform infrared (FTIR) spectroscopy. GMA-MMT filled composite showed higher mechanical properties than MMT and CTAB-MMT filled composite. However, the increase of MMT, CTAB-MMT and GMA- MMT loading resulted in the reduction of mechanical properties. Scanning electron microscopy (SEM) analysis showed the evidence of compatibility enhancement between MMT and kenaf bast fiber with unsaturated polyester matrix.

  2. Radiopacity of Methacrylate and Silorane Composite Resins Using a Digital Radiographic System

    PubMed Central

    Firoozmand, Leily Macedo; Cordeiro, Mariana Gonçalves; Da Silva, Marcos André dos Santos

    2016-01-01

    The aim of this study was to evaluate the radiopacity of silorane and methacrylate resin composites, comparing them to the enamel, dentin, and aluminum penetrometer using a digital image. From six resin composites (Filtek™ P90, Filtek Z350, Filtek Z350 XT flow, Tetric Ceram, TPH Spectrum, and SureFil SDR flow) cylindrical disks (5 × 1 mm) were made and radiographed by a digital method, together with a 15-step aluminum step-wedge and a 1 mm slice of human tooth. The degree of radiopacity of each image was quantified using digital image processing. The mean values of the shades of gray of the tested materials were measured and the equivalent width of aluminum was calculated for each resin. The results of our work yielded the following radiopacity values, given here in descending order: Tetric Ceram > TPH > SDR > Z350 > Z350 flow > P90 > enamel > dentin. The radiopacity of the materials was different both for the enamel and for the dentin, except for resin P90, which was no different than enamel. In conclusion, silorane-based resin exhibited a radiopacity higher than dentin and closest to the enamel; a large portion of the methacrylate-based flow and conventional resins demonstrated greater radiopacity in comparison to dentin and enamel. PMID:27722199

  3. Photopolymerized multifunctional (meth)acrylates as model polymers for dental applications.

    PubMed

    Bland, M H; Peppas, N A

    1996-06-01

    Polymer networks that can serve as model systems for dental applications were prepared by photopolymerizations of 1,1,1-trimethylolpropane triacrylate, 1,1,1-trimethylolpropane trimethacrylate, 1,1,1-trimethylolethane trimethacrylate, ethylene glycol dimethacrylate, triethylene glycol dimethacrylate, Photomer 2028 and Photomer 3015. The UV polymerizations were initiated by 2,2-dimethoxy-2-phenyl-acetophenone. Volume shrinkage was followed over the course of polymerization using a dilatometric technique. Incident light intensities ranged from 1 mW cm-2 to 20 mW cm-2. The effects of monomer structure on % volume shrinkage, including pendant group size, molecular weight between reactive double bonds, and acrylate versus methacrylate monomers were investigated. In addition, the effect of incident light intensity on % volume shrinkage was studied. Typical volume shrinkage varied from 3.5% to 13.5%. The volume shrinkage decreased with increasing monomer rank and increased pendant group size; the shrinkage for methacrylates was less than that for acrylates. Increased incident light intensity resulted in increased shrinkage rate, but not in statistically significant increases of the volume shrinkage. Conversion was calculated from shrinkage data and compared to data from monomer extraction experiments. Results indicate that although double bond conversion is low, conversion of monomer units is significantly higher.

  4. Chalcogenide amorphous nanoparticles doped poly (methyl methacrylate) with high nonlinearity for optical waveguide

    NASA Astrophysics Data System (ADS)

    Xue, Xiaojie; Nagasaka, Kenshiro; Cheng, Tonglei; Deng, Dinghuan; Zhang, Lei; Liu, Lai; Suzuki, Takenobu; Ohishi, Yasutake

    2015-03-01

    Nonlinear optical polymers show promising potential applications in photonics, for example, electro-optical devices. Poly (methyl methacrylate) (PMMA) is widely used in optical waveguides, integrated optics and optical fibers. However, PMMA has not been used for nonlinear optical waveguides since it has a low nonlinear refractive index. We successfully prepared chalcogenide amorphous nanoparticles doped PMMA that had a high nonlinearity. The As3S7 bulk glass was dissolved in propylamine to form a cluster solution. Then the As3S7/propylamine solution was added into methyl methacrylate (MMA) containing photoinitiator Irgacure 184 about 0.5 wt%. After well mixing the As3S7 nanoparticle doped MMA was transparent. Under the irradiation by a 365 nm UV lamp, As3S7 nanoparticles doped PMMA was obtained with yellow color. The third-order nonlinear optical susceptibility of As3S7 nanoparticles doped PMMA was investigated. An optical waveguide array based on the As3S7 nanoparticles doped PMMA composite of high nonlinearity was fabricated.

  5. Role of thiol-complex formation in 2-hydroxyethyl- methacrylate-induced toxicity in vitro.

    PubMed

    Samuelsen, J T; Kopperud, H M; Holme, J A; Dragland, I S; Christensen, T; Dahl, J E

    2011-02-01

    Methacrylate monomers that are found to leach from cured resin-based dental materials induce biological effects in vitro. The underlying mechanisms have not been fully elucidated although involvement of increased cellular reactive oxygen species (ROS) and DNA-damage has been suggested. In this in vitro study we have elucidated the impact of a commonly used methacrylate monomer, HEMA, on the level and oxidation state of cellular glutathione, intracellular ROS level, as well as the formation of complex between HEMA and glutathione. HEMA exposure rapidly led to increased level of ROS and reduced level of GSH (reduced form of glutathione). Antioxidants effectively counteracted the ROS increase, but had no effect on the GSH depletion. No change in glutathione-disulphide (GSSG; oxidized form of glutathione) concentration was detected in the HEMA treated cells, showing that oxidation of glutathione was not responsible for the reduced GSH concentration. Further we demonstrated spontaneous formation of a complex between HEMA and GSH. In conclusion, we showed that exposure to HEMA led to drop in cellular glutathione level probably caused by complex formation with HEMA. A similar covalent binding of HEMA to macromolecules combined with increased level of cellular ROS due to lower levels of GSH is suggested to be important factors triggering the toxic response.

  6. Host reaction to poly(2-hydroxyethyl methacrylate) scaffolds in a small spinal cord injury model.

    PubMed

    Li, Hong Ying; Führmann, Tobias; Zhou, Yue; Dalton, Paul D

    2013-08-01

    Tissue engineered scaffolds and matrices have been investigated over the past decade for their potential in spinal cord repair. They provide a 3-D substrate that can be permissive for nerve regeneration yet have other roles including neuroprotection, altering the inflammatory cascade and mechanically stabilizing spinal cord tissue after injury. In this study we investigated very small lesions (approx. 0.25 μL in volume) of the dorsal column into which a phase-separated poly(2-hydroxyethyl methacrylate) hydrogel scaffold is implanted. Using fluorescent immunohistochemistry to quantify glial scarring, the poly(2-hydroxyethyl methacrylate) scaffold group showed reduced intensity compared to lesion controls for GFAP and the chondroitin sulfate proteoglycan neurocan after 6 days. However, the scaffold and tissue was also pushed dorsally after 6 days while the scaffold was not integrated into the spinal cord after 28 days. Overall, this small-lesion spinal cord injury model provided information on the host tissue reaction of a TE scaffold while reducing animal discomfort and care.

  7. Cell toxicity of 2-hydroxyethyl methacrylate (HEMA): the role of oxidative stress.

    PubMed

    Morisbak, Else; Ansteinsson, Vibeke; Samuelsen, Jan T

    2015-08-01

    2-Hydroxyethyl methacrylate (HEMA) is a methacrylate monomer used in polymer-based dental-restorative materials. In this study, the viability of human lung epithelial cells, BEAS-2B, was investigated after exposure to this monomer. Exposure to HEMA reduced the viability of the BEAS-2B cells as a result of increased apoptosis, interruption of the cell cycle, and decreased cell proliferation. Depletion of cellular glutathione and increased levels of reactive oxygen species (ROS) were seen after exposure of BEAS-2B cells to HEMA. The glutathione synthase inhibitor, L-buthioninesulfoximine (BSO), was used to study whether the reduced viability was caused by glutathione depletion and increased levels of ROS. Similarly to incubation with HEMA, incubation with BSO resulted in glutathione depletion and increased ROS levels, without increasing cell death or inhibiting cell growth. The results indicate that HEMA-induced cell damage is not caused exclusively by these mechanisms. Mechanisms other than glutathione depletion and ROS formation seem to be of importance for the toxic effect of HEMA on lung epithelial cells.

  8. Synthesis and Examination of Nanocomposites Based on Poly(2-hydroxyethyl methacrylate) for Medicinal Use.

    PubMed

    Kukolevska, Olena S; Gerashchenko, Igor I; Borysenko, Mykola V; Pakhlov, Evgenii M; Machovsky, Michal; Yushchenko, Tetyana I

    2017-12-01

    Preparation of poly(2-hydroxyethyl methacrylate) (PHEMA) based nanocomposites using different approaches such as synthesis with water as the porogen, filling of polymer matrix by silica and formation of interpenetrating polymer networks with polyurethane was demonstrated. Incorporation of various biologically active compounds (BAC) such as metronidazole, decamethoxin, zinc sulphate, silver nitrate or amino acids glycine and tryptophan into nanocomposites was achieved. BAC were introduced into the polymer matrix either (1) directly, or (2) with a solution of colloidal silica, or (3) through immobilization on silica (sol-densil). Morphology of prepared materials was investigated by laser scanning microscopy and low-vacuum scanning electron microscopy. In vacuum freeze-drying, prior imaging was proposed for improving visualization of the porous structure of composites. The interaction between PHEMA matrix and silica filler was investigated by IR spectroscopy. Adsorption of 2-hydroxyethyl methacrylate and BAC from aqueous solution on the silica surface was also examined. Phase composition and thermal stability of composites were studied by the differential thermogravimetry/differential thermal analysis. Release of BAC into water medium from prepared composites were shown to depend on the synthetic method and differed significantly. Obtained PHEMA-base materials which are characterized by controlled release of BAC have a strong potential for application in manufacturing of different surgical devices like implants, catheters and drainages.

  9. Binding of leachable components of polymethyl methacrylate (PMMA) and peptide on modified SPR chip

    NASA Astrophysics Data System (ADS)

    Szaloki, M.; Vitalyos, G.; Harfalvi, J.; Hegedus, Cs

    2013-12-01

    Many types of polymers are often used in dentistry, which may cause allergic reaction, mainly methyl methacrylate allergy due to the leachable, degradable components of polymerized dental products. The aim of this study was to investigate the interaction between the leachable components of PMMA and peptides by Fourier-transform Surface Plasmon Resonance (FT SPR). In our previous work binding of oligopeptides (Ph.D.-7 and Ph.D.-12 Peptide Library Kit) was investigated to PMMA surface by phage display technique. It was found that oligopeptides bounded specifically to PMMA surface. The most common amino acids were leucine and proline inside the amino acids sequences of DNA of phages. The binding of haptens, as formaldehyde and methacrylic acid, to frequent amino acids was to investigate on the modified gold SPR chip. Self assembled monolayer (SAM) modified the surface of gold chip and ensured the specific binding between the haptens and amino acids. It was found that amino acids bounded to modified SPR gold and the haptens bounded to amino acids by creating multilayer on the chip surface. By the application of phage display and SPR modern bioanalytical methods the interaction between allergens and peptides can be investigated.

  10. Photoinduced graft-copolymer synthesis and characterization of methacrylic acid onto natural biodegradable lignocellulose fiber.

    PubMed

    Khan, Ferdous

    2004-01-01

    UV radiation induced graft copolymerization of methacrylic acid onto natural lignocellulose (jute) fiber was carried out both by "simultaneous irradiation and grafting" and by preirradiation methods using 1-hydroxycyclohexyl-phenyl ketone as a photoinitiator. In the "simultaneous irradiation and grafting" method, the variation of graft weight with UV-radiation time, monomer concentration, and the concentration of photoinitiator was investigated. In the case of the preirradiation method, the incorporation of 2-methyl-2-propene 1-sulfonic acid, sodium salt, into the grafting reaction solution played a most important role in suppressing the homopolymer/gel formation and facilitating graft copolymerization. The optimum value of the reaction parameters on the percentage of grafting was evaluated. In comparison, results showed that the method of graft-copolymer synthesis has significant influence on graft weight. The study on the mechanical and thermal properties of grafted samples was conducted. The results showed that the percentage of grafting has a significant effect on the mechanical and thermal properties in the case of grafted samples. Considering the water absorption property, the jute-poly(methacrylic acid)-grafted sample showed a maximum up to 42% increase in hydrophilicity with respect to that of the "as received" sample. Attenuated total reflection infrared studies indicate that the estimation of the degree of grafting could be achieved by correlating band intensities with the percent graft weight.

  11. Synthesis and Examination of Nanocomposites Based on Poly(2-hydroxyethyl methacrylate) for Medicinal Use

    NASA Astrophysics Data System (ADS)

    Kukolevska, Olena S.; Gerashchenko, Igor I.; Borysenko, Mykola V.; Pakhlov, Evgenii M.; Machovsky, Michal; Yushchenko, Tetyana I.

    2017-02-01

    Preparation of poly(2-hydroxyethyl methacrylate) (PHEMA) based nanocomposites using different approaches such as synthesis with water as the porogen, filling of polymer matrix by silica and formation of interpenetrating polymer networks with polyurethane was demonstrated. Incorporation of various biologically active compounds (BAC) such as metronidazole, decamethoxin, zinc sulphate, silver nitrate or amino acids glycine and tryptophan into nanocomposites was achieved. BAC were introduced into the polymer matrix either (1) directly, or (2) with a solution of colloidal silica, or (3) through immobilization on silica (sol-densil). Morphology of prepared materials was investigated by laser scanning microscopy and low-vacuum scanning electron microscopy. In vacuum freeze-drying, prior imaging was proposed for improving visualization of the porous structure of composites. The interaction between PHEMA matrix and silica filler was investigated by IR spectroscopy. Adsorption of 2-hydroxyethyl methacrylate and BAC from aqueous solution on the silica surface was also examined. Phase composition and thermal stability of composites were studied by the differential thermogravimetry/differential thermal analysis. Release of BAC into water medium from prepared composites were shown to depend on the synthetic method and differed significantly. Obtained PHEMA-base materials which are characterized by controlled release of BAC have a strong potential for application in manufacturing of different surgical devices like implants, catheters and drainages.

  12. Effect of Nanoclay on Thermal Conductivity and Flexural Strength of Polymethyl Methacrylate Acrylic Resin

    PubMed Central

    Ghaffari, Tahereh; Barzegar, Ali; Hamedi Rad, Fahimeh; Moslehifard, Elnaz

    2016-01-01

    Statement of the Problem The mechanical and thermal properties of polymethyl methacrylate (PMMA) acrylic resin should be improved to counterweigh its structural deficiencies. Purpose The aim of this study was to compare the flexural strength and thermal conductivity of conventional acrylic resin and acrylic resin loaded with nanoclay. Materials and Method The methacrylate monomer containing the 0.5, 1 and 2 wt% of nanoclay was placed in an ultrasonic probe and mixed with the PMMA powder. Scanning electron microscopy was used to verify homogeneous distribution of particles. Twenty-four 20×20×200-mm cubic samples were prepared for flexural strength test; 18 samples containing nanoclay and 6 samples for the control group. Another 24 cylindrical samples of 38×25 mm were prepared for thermal conductivity test. One-way ANOVA was used for statistical analysis, followed by multiple-comparison test (Scheffé’s test). Statistical significance was set at p< 0.05. Results Increasing the concentration of nanoclay incorporated into the acrylic resin samples increased thermal conductivity but decreased flexural strength (p< 0.05). Conclusion Based on the results of this study, adding nanoclay particles to PMMA improved its thermal conductivity, while it had a negative effect on the flexural strength. PMID:27284557

  13. Quaternary ammonium silane-functionalized, methacrylate resin composition with antimicrobial activities and self-repair potential.

    PubMed

    Gong, Shi-qiang; Niu, Li-Na; Kemp, Lisa K; Yiu, Cynthia K Y; Ryou, Heonjune; Qi, Yi-Pin; Blizzard, John D; Nikonov, Sergey; Brackett, Martha G; Messer, Regina L W; Wu, Christine D; Mao, Jing; Bryan Brister, L; Rueggeberg, Frederick A; Arola, Dwayne D; Pashley, David H; Tay, Franklin R

    2012-09-01

    The design of antimicrobial polymers to address healthcare issues and minimize environmental problems is an important endeavor with both fundamental and practical implications. Quaternary ammonium silane-functionalized methacrylate (QAMS) represents an example of antimicrobial macromonomers synthesized by a sol-gel chemical route; these compounds possess flexible Si-O-Si bonds. In present work, a partially hydrolyzed QAMS co-polymerized with 2,2-[4(2-hydroxy 3-methacryloxypropoxy)-phenyl]propane is introduced. This methacrylate resin was shown to possess desirable mechanical properties with both a high degree of conversion and minimal polymerization shrinkage. The kill-on-contact microbiocidal activities of this resin were demonstrated using single-species biofilms of Streptococcus mutans (ATCC 36558), Actinomyces naeslundii (ATCC 12104) and Candida albicans (ATCC 90028). Improved mechanical properties after hydration provided the proof-of-concept that QAMS-incorporated resin exhibits self-repair potential via water-induced condensation of organic modified silicate (ormosil) phases within the polymerized resin matrix.

  14. Chemically induced graft copolymerization of 2-hydroxyethyl methacrylate onto polyurethane surface for improving blood compatibility

    NASA Astrophysics Data System (ADS)

    He, Chunli; Wang, Miao; Cai, Xianmei; Huang, Xiaobo; Li, Li; Zhu, Haomiao; Shen, Jian; Yuan, Jiang

    2011-11-01

    To improve hydrophilicity and blood compatibility properties of polyurethane (PU) film, we chemically induced graft copolymerization of 2-hydroxyethyl methacrylate (HEMA) onto the surface of polyurethane film using benzoyl peroxide as an initiator. The effects of grafting temperature, grafting time, monomer and initiator concentrations on the grafting yields were studied. The maximum grafting yield value was obtained 0.0275 g/cm2 for HEMA. Characterization of the films was carried out by attenuated total reflection Fourier transform infrared spectroscopy (ATR-FTIR), water contact angle measurements. ATR-FTIR data showed that HEMA was successfully grafted onto the PU films surface. Water contact angle measurement demonstrated the grafted films possessed a relatively hydrophilic surface. The blood compatibility of the grafted films was preliminarily evaluated by a platelet-rich plasma adhesion test and hemolysis test. The results of platelet adhesion experiment showed that polyurethane grafted polymerization with monomer of 2-hydroxyethyl methacrylate had good blood compatibility featured by the low platelet adhesion. Hemolysis rate of the PU-g-PHEMA films was dramatically decreased than the ungrafted PU films. This kind of new biomaterials grafted with HEMA monomers might have a potential usage for biomedical applications.

  15. Synthesis of poly(sorbitan methacrylate) hydrogel by free-radical polymerization.

    PubMed

    Jeong, Gwi-Taek; Lee, Kyoung-Min; Yang, Hee-Seung; Park, Seok-Hwan; Park, Jae-Hee; Sunwoo, Changshin; Ryu, Hwa-Won; Kim, Doman; Lee, Woo-Tae; Kim, Hae-Sung; Cha, Wol-Seog; Park, Don-Hee

    2007-04-01

    Hydrogels are materials with the ability to swell in water through the retention of significant fractions of water within their structures. Owing to their relatively high degree of biocompatibility, hydrogels have been utilized in a host of biomedical applications. In an attempt to determine the optimum conditions for hydrogel synthesis by the free-radical polymerization of sorbitan methacrylate (SMA), the hydrogel used in this study was well polymerized under the following conditions: 50% (w/v) SMA as monomer, 1% (w/w) alpha, alpha'-azo-bis(isobutyro-nitrile) as thermal initiator, and 1% (w/w) ethylene glycol dimethacrylate as cross-liking agent. Under these conditions, the moisture content of the polymerized SMA hydrogel was higher than in the other conditions. Moreover, the moisture content of the poly(SMA) hydrogel was also found to be higher than that of the poly(methyl methacrylate [MMA]) hydrogel. When the Fourier transform-infrared spectrum of poly(SMA) hydrogel was compared with that of poly(MMA) hydrogel, we noted a band at 1735-1730/cm, which did not appear in the Fourier transform-infrared spectrum of poly(MMA). The surface of the poly(SMA) hydrogel was visualized through scanning electron microscopy, and was uniform and clear in appearance.

  16. Cellulose nanocrystal-poly(oligo(ethylene glycol) methacrylate) brushes with tunable LCSTs.

    PubMed

    Grishkewich, Nathan; Akhlaghi, Seyedeh Parinaz; Zhaoling, Yao; Berry, Richard; Tam, Kam C

    2016-06-25

    This paper reports on the synthesis of poly(oligoethylene glycol) methyl ether acrylate (POEGMA) grafted cellulose nanocrystals (CNCs) via surface initiated atom transfer radical polymerization (ATRP). An ATRP initiator (α-Bromoisobutyryl bromide) was covalently bonded to the surface of CNCs, followed by copolymerizing di(ethylene glycol) methyl ether methacrylate (MEO2MA) and oligoethylene glycol methyl ether methacrylate (OEGMA300) monomers from the surface using Cu(I)Br/2,2-dipyridal. Multiple POEGMA-g-CNC systems with varying MEO2MA/OEGMA300 content were synthesized, and they displayed a range of lower critical solution temperatures (LCSTs) in aqueous medium. μDSC endotherms and microstructural analysis indicated the collapse of POEGMA chains, followed by the aggregation of nanoparticles above their LCSTs. Cloud point measurements demonstrated a hysteresis in the heating and cooling of the POEGMA-g-CNC systems. It was found that the LCST of the nanoparticles could be tuned to between 23.8 to 63.8°C by adjusting the OEGMA300 content of the POEGMA brushes.

  17. Synthesis of methyl methacrylate from coal-derived syngas: Quarterly report,, October 1-December 31, 1997

    SciTech Connect

    1998-09-01

    Research Triangle Institute (RTI), Eastman Chemical Company, and Bechtel collectively are developing a novel process for the synthesis of methyl methacrylate (MMA) from coal-derived syngas that consists of three steps of synthesis of a propionate, its condensation with formaldehyde, and esterification of resulting methacrylic acid (MAA) with methanol to produce MMA. Over the last quarter, Eastman developed two new processes which have resulted in two new invention reports. One process deals with carbonylation of benzyl ether which represents a model for coal liquefaction and the second focuses on the acceleration of carbonylation rates for propionic acid synthesis, via use of polar aprotic solvents. These two inventions are major improvements in the novel Mo-catalyzed homogeneous process for propionic acid synthesis technology, developed by Eastman. Over the last quarter, RTI completed three reaction cycles and two regeneration cycles as a part of long-term reaction regeneration cycle study on a 10% Nb{sub 2}O{sub 5}/Si0{sub 2} catalyst, for vapor phase condensation reaction of formaldehyde with propionic acid.

  18. Synthesis of acrylates and methacrylates from coal-derived syngas. Quarterly report, October--December 1996

    SciTech Connect

    1997-05-02

    Research Triangle Institute (RTI), Eastman Chemical Company, and Bechtel collectively are developing a novel process for the synthesis of methyl methacrylate (MMA) from coal-derived syngas, under a contract from the US Department of Energy, Federal Energy Technology Center. This three-step process consists of synthesis of a propionate, its condensation with formaldehyde, and esterification of resulting methacrylic acid (MAA) with methanol to produce MMA. Eastman has focused on the propionate synthesis step. the resultant Mo catalysts work efficiently at much less severe conditions (170{degrees}C and 30 atm) than the conventional Ni catalysts (270{degrees}C and 180 atm). Bechtel has performed an extensive cost analysis which shows that Eastman`s propionate synthesis step is competitive with other technologies to produce the anhydride. In the second step, RTI and Eastman have developed active and stable V-Si-P ternary metal oxide catalysts Nb/SiO{sub 2} and Ta/SiO{sub 2} catalysts for the condensation of propionic anhydride and acid with formaldehyde. RTI has demonstrated a novel correlation among the catalyst acid-base properties, condensation reaction yield, and long-term catalyst activity. Current research focuses on enhancing the condensation reaction yields by better understanding of the acid-base property correlation, in situ condensation in a high-temperature, high- pressure (HTHP) slurry reactor, and alternate formaldehyde feedstocks. Based on Eastman and RTI laboratory data, a cost estimate is also being developed for the integrated process.

  19. From the N-Heterocyclic Carbene-Catalyzed Conjugate Addition of Alcohols to the Controlled Polymerization of (Meth)acrylates.

    PubMed

    Ottou, Winnie Nzahou; Bourichon, Damien; Vignolle, Joan; Wirotius, Anne-Laure; Robert, Fredéric; Landais, Yannick; Sotiropoulos, Jean-Marc; Miqueu, Karinne; Taton, Daniel

    2015-06-22

    Among various N-heterocyclic carbenes (NHCs) tested, only 1,3-bis(tert-butyl)imidazol-2-ylidene (NHC(tBu) ) proved to selectively promote the catalytic conjugate addition of alcohols onto (meth)acrylate substrates. This rather rare example of NHC-catalyzed 1,4-addition of alcohols was investigated as a simple means to trigger the polymerization of both methyl methacrylate and methyl acrylate (MMA and MA, respectively). Well-defined α-alkoxy poly(methyl (meth)acrylate) (PM(M)A) chains, the molar masses of which could be controlled by the initial [(meth)acrylate]0/[ROH]0 molar ratio, were ultimately obtained in N,N-dimethylformamide at 25 °C. A hydroxyl-terminated poly(ethylene oxide) (PEO-OH) macro-initiator was also employed to directly access PEO-b-PMMA amphiphilic block copolymers. Investigations into the reaction mechanism by DFT calculations revealed the occurrence of two competitive concerted pathways, involving either the activation of the alcohol or that of the monomer by NHC(tBu) .

  20. Click synthesis of quaternized poly(dimethylaminoethyl methacrylate) functionalized graphene oxide with improved antibacterial and antifouling ability.

    PubMed

    Tu, Qin; Tian, Chang; Ma, Tongtong; Pang, Long; Wang, Jinyi

    2016-05-01

    A quaternized poly(dimethylaminoethyl methacrylate) functionalized graphene oxide (GO-QPDMAEMA) was successfully prepared in this study via click chemistry. Alkyne-functionalized graphene oxide (GO-alkyne) was first synthesized through a two-step amidation reaction of GO-COOH. Meanwhile, azide-terminated poly(dimethylaminoethyl methacrylate) (PDMAEMA-N3) was prepared via the atom-transfer radical-polymerization of dimethylaminoethyl methacrylate (DMAEMA). Subsequently, PDMAEMA-N3 was grafted onto the GO-alkyne through click chemistry to obtain PDMAEMA modified graphene oxide (GO-PDMAEMA). Finally, the tertiary amino groups of GO-PDMAEMA were quaternized by ethyl bromide to provide a quaternized poly(dimethylaminoethyl methacrylate) functionalized graphene oxide (GO-QPDMAEMA). Various characterization techniques, including Fourier-transform infrared spectroscopy, X-ray photoelectron spectroscopy, UV-vis spectrometry, ζ potential, Raman, contact angle analyses and field emission scanning electron microscope were used to ascertain the successful preparation of the quaternized GO-QPDMAEMA. Furthermore, antibacterial and antifouling activities of GO-QPDMAEMA were investigated via protein adsorption, as well as bacterial and cell adhesion studies. The results suggest that the GO-QPDMAEMA surface exhibited significant antibacterial and antifouling properties, compared with the GO-COOH and GO-PDMAEMA surfaces.