3,479 research outputs found
Evaluation Of In Vitro Calcification Of Pristine And Sulfonated Chitosan For Use On Stents
No full text[No abstract available]26SUPPL.6155Beppu, M.M., Santana, C.C., (2003) Mater. Sci. Eng, 23, p. 651Amiji, M.M., (1998) Colloids Surfaces B: Biointerfaces, 10, pp. 263-271Aimoli, C.G., Torres, M.A., Beppu, M.M., (2006) Mater Sci and Eng C, 26, pp. 78-86Park, K.D., Lee, W.K., (1997) Biomaterials, 18, pp. 47-51Lee, W.K., Park, K.D., (2001) J Biomed Mater Res (Appl Biomater), 58, pp. 27-3
In Situ X-ray Diffraction Study Of Phase Development During Hardening Of β-tricalcium Phosphate Bone Cements With Chitosan
No full textThe aim of this work was to study the phase transformation during the setting reaction of beta tricalcium phosphate (β-TCP) and phosphoric acid with chitosan solution added. To follow the kinetics of the phase transformation, two methods were used: x-ray diffraction (XRD) was used to study the phase evolution during the hardening process in real time, and was also used in samples where the reaction was supposedly stopped in different times using acetone, as indicated in literature. The setting reaction occurs so fast that the phase transformation could not be observed, but it was possible to invalidate the second mentioned method for this system, as it induces the final product dicalcium phosphate dihydrate DCPD (brushite) to be converted into his anhydrous form dicalcium phosphate DCP (monetite). The addition of chitosan in order to improve biocompatibility was successfully done, it could be observed that chitosan inhibits brushite crystallization in the first moment of the reaction, but the final product was not affected by it. © (2014) Trans Tech Publications, Switzerland.587109114Galembeck, F., Lima, E.C.O., Beppu, M.M., Polyphosphate nanoparticles and gels-from macroscopic monoliths to nanoparticles (1996) Nato Advanced Science Institute Series, 12, pp. 267-279Legeros, R.Z., Chohayeb, A., Shulman, A., Apatitic calcium phosphates: Possible dental restorative materials (1982) J. Dent. Res, 61Dorozhkin, S.V., Calcium orthophosphate cements and concretes (2009) Materials, 27, pp. 221-291Tonoli, M.S., Leal, C.V., Zavaglia, C.A., Beppu, M.M., Development and characterization of β-tricalcium phosphate cements containing chitosan (2006) Key Engineering Materials, 309, pp. 845-848Beppu, M.M., Santana, C.C., PAA influence on chitosan membrane calcification (2003) Materials Science and Engineering C, 23, pp. 651-658Aimoli, C.G., Beppu, M.M., Precipitation of calcium phosphate and calcium carbonate induced over chitosan membranes: A quick method to evaluate the influence of polymeric matrix on heterogeneous calcification (2006) Colloids and Surfaces B, 53, pp. 15-22Aimoli, C.G., Torres, M.A., Beppu, M.M., Investigations into the early stages of "in vitro" calcification on chitosan films (2006) Materials Science and Engineering C, 26, pp. 78-86Beppu, M.M., Aimoli, C.G., Influence on in vitro chitosan membrane biomineralization (2004) Key Engineering Materials, 254, pp. 311-314Aimoli, C.G., Nogueira, G.M., Nascimento, L.S., Lyiophilized bovine pericardium treated with a phenetilamine-diepoxide as na alternative to preventing calcification of cardiovascular bioprosthesis: Preliminary results (2007) Artificial Organs, 31, pp. 278-283Bohner, M., Reactivity of calcium phosphate cements (2007) Journal of Materials Chemistry, 17, pp. 3980-3986Rau, J.V., Energy dispersive X-ray diffraction study of phase development during hardening of calcium phosphate bone cements with addition of chitosan (2008) Acta Biomaterialia, 4, pp. 1089-1094Grover, L., Temperature dependent setting kinetics and mechanical properties of β-TCP-pyrophosphoric acid bone cement (2005) J. Mater. Chem, 15, pp. 4955-4962Ginebra, M.P., Desarrolo y caracterización de un cemento óseo basado en fosfato tricálcico-α para aplicaciones quirurgicas (1996) Dissertação (Doutorado em Ciências, Especialidade Física)-Departament de Ciências Dels Materials i Enginyeria Metalurgica, , Universitat Politécnica de Catalunya 1996Bohner, M., Lemaître, J., Hydraulic properties of tricalcium phosphate-phosphoric acid-water mixtures (1993) Journal of Materials Science Materials in Medicine, 8Jinlong, N., Zhenxi, Z., Dazong, J., Investigation of phase evolution during the thermochemical synthesis of tricalcium phosphate (2002) Journal of Materials Synthesis and Processing, 9, pp. 235-240ASTM-C266-04: Standard Test Method for Time of Setting of Hydraulic-cement Paste by Gillmore NeedlesDosen, A., Giese, R.F., Thermal decomposition of brushite CaHPO4, 2H 2O to monetite CaHPO4 and the formation of an amorphous phase (2011) American Minearalogist, 96, pp. 368-373Bohner, M., Merkle, H.P., Lemaître, J., In vitro aging of a calcium phosphate cement (2000) Journal of Materials Science Materials in Medicine, 11, pp. 155-16
"in Vitro" Calcification Of Silk Fibroin Hydrogel
No full textSilk fibroin hydrogels were prepared and their potential to deposit calcium phosphates in vitro was observed. Pristine and lyophilized samples were tested in 1.5×SBF and 1.5×SBF. The results showed that silk fibroin hydrogels can induce calcium phosphate deposits both in the pristine and lyophilized form. However, the pristine silk fibroin hydrogel after calcification presented a fragile structure making it difficult to handle, while the lyophilized samples presented better resistance to handling. Calcium phosphates deposits were intense in samples submitted to tests in 1.5×SBF, however, few and isolated deposits were observed on samples submitted to tests in 1×SBF. The 3-D porous structure and the ability to deposit calcium phosphates, turn silk fibroin hydrogel a potential material suitable to use in biomimetic processes.361-363 I503506Takeuchi, A., Ohtsuki, C., Miyasaki, T., (2003) J. Biomed. Mater. Res., A, 65, p. 283Takeuchi, A., Ohtsuki, C., Miyasaki, T., (2003) Key Eng. Mater, 240-242, p. 31Aimoli, C.G., Torres, M.A., Beppu, M.M., (2006) Mater. Sci. Eng., C, 26, p. 78Nazarov, R., Jin, H., Kaplan, D.L., (2004) Biomacromolecules, 5, p. 718Meinel, L., Betz, O., Fajardo, R., (2006) Bone, 39, p. 922Altiman, G.H., Diaz, F., Jacuba, C., (2003) Biomaterials, 24, p. 401Beppu, M.M., Torres, M.A., Aimoli, C.G., (2005) J. Mater. Res, 20, p. 3303Aimoli, C.G., Beppu, M.M., (2006) Colloids Surf., B, 53, p. 1
Influence Of Acetylation On In Vitro Chitosan Membrane Biomineralization
No full textIn a previous work of this research group, we studied the in vitro calcification of dense and porous chitosan membranes. Chemical modifications had been promoted, but further investigations were needed to better understand the role of some chemical groups in the process of calcification. In the present study, we proposed the acetylation of the already-molded chitosan membranes, producing a "pseudo-chitin", to be used in calcification. The acetylated chitosan was submitted to mineralization by soaking the membranes in simulated body fluids (SBF) with 1x and 1.5x the concentration of ions found in human serum, for 7 days at 36.5°C. Morphological characterization was performed using SEM and compositional analyses were done using SEM-EDX and FTIR-ATR techniques. The results showed that acetyl groups induce calcification, forming deposits that present a Ca:P ratio different of those formed on pristine chitosan.254-256311314Calvert, P., Rieke, P., (1996) Chem. Mater., 8, p. 1715Beppu, M.M., Santana, C.C., (2000) Key Eng. Mater., 125-129, p. 34Beppu, M.M., Santana, C.C., (2002) Mater. Sci., 5, p. 47Beppu, M.M., (1999) Estudo da Calcificação in Vitro da Quitosana, , PhD thesis - FEQ - State University of Campinas. BrazilHirano, S., (1987) Industrial Polysaccharides, , Elsevir Science Publishers. AmsterdamZhang, S., Gonsalves, K.E., (1995) J. Appl. Polym. Sci., 56, p. 68
Effects Of Sterilization Methods On The Physical, Chemical, And Biological Properties Of Silk Fibroin Membranes
No full textSilk fibroin has been widely explored for many biomedical applications, due to its biocompatibility and biodegradability. Sterilization is a fundamental step in biomaterials processing and it must not jeopardize the functionality of medical devices. The aim of this study was to analyze the influence of different sterilization methods in the physical, chemical, and biological characteristics of dense and porous silk fibroin membranes. Silk fibroin membranes were treated by several procedures: immersion in 70% ethanol solution, ultraviolet radiation, autoclave, ethylene oxide, and gamma radiation, and were analyzed by scanning electron microscopy, Fourier-transformed infrared spectroscopy (FTIR), X-ray diffraction, tensile strength and in vitro cytotoxicity to Chinese hamster ovary cells. The results indicated that the sterilization methods did not cause perceivable morphological changes in the membranes and the membranes were not toxic to cells. The sterilization methods that used organic solvent or an increased humidity and/or temperature (70% ethanol, autoclave, and ethylene oxide) increased the silk II content in the membranes: the dense membranes became more brittle, while the porous membranes showed increased strength at break. Membranes that underwent sterilization by UV and gamma radiation presented properties similar to the nonsterilized membranes, mainly for tensile strength and FTIR results. © 2013 Wiley Periodicals, Inc.1024869876Vepari, C., Kaplan, D.L., Silk as a biomaterial (2007) Progress in Polymer Science (Oxford), 32 (8-9), pp. 991-1007. , DOI 10.1016/j.progpolymsci.2007.05.013, PII S0079670007000731, Polymers in Biomedical ApplicationsHakimi, O., Knight, D.P., Vollrath, F., Vadgama, P., Spider and mulberry silkworm silks as compatible biomaterials (2007) Composites Part B: Engineering, 38 (3), pp. 324-337. , DOI 10.1016/j.compositesb.2006.06.012, PII S1359836806001284Jin, H.-J., Kaplan, D.L., Mechanism of silk processing in insects and spiders (2003) Nature, 424 (6952), pp. 1057-1061. , DOI 10.1038/nature01809Nogueira, G.M., Rodas, A.C.D., Leite, C.A.P., Giles, C., Higa, O.Z., Polakiewicz, B., Beppu, M.M., Preparation and characterization of ethanol-treated silk fibroin dense membranes for biomaterials application using waste silk fibers as raw material (2010) Bioresour Technol, 101, pp. 8446-8451Altman, G.H., Diaz, F., Jakuba, C., Calabro, T., Horan, R.L., Chen, J., Lu, H., Kaplan, D.L., Silk-based biomaterials (2003) Biomaterials, 24 (3), pp. 401-416. , DOI 10.1016/S0142-9612(02)00353-8, PII S0142961202003538Um, I.C., Kweon, H., Park, Y.H., Hudson, S., Structural characteristics and properties of the regenerated silk fibroin prepared from formic acid (2001) International Journal of Biological Macromolecules, 29 (2), pp. 91-97. , DOI 10.1016/S0141-8130(01)00159-3, PII S0141813001001593Macintosh, A.C., Kearns, V.R., Crawford, A., Hatton, P.V., Skeletal tissue engineering using silk biomaterials (2008) J Tissue Eng Regen Med, 2, pp. 71-80Lee, K.H., Ki, C.S., Back, D.H., Kang, G.D., Ihm, D.-W., Park, Y.H., Application of electrospun silk fibroin nanofibers as an immobilization support of enzyme (2005) Fibers and Polymers, 6 (3), pp. 181-185Vangsness Jr., C.T., Wagner, P.P., Moore, T.M., Roberts, M.R., Overview of Safety Issues Concerning the Preparation and Processing of Soft-Tissue Allografts (2006) Arthroscopy - Journal of Arthroscopic and Related Surgery, 22 (12), pp. 1351-1358. , DOI 10.1016/j.arthro.2006.10.009, PII S0749806306013144Fuchs, S., Motta, A., Migliaresi, C., Kirkpatrick, C.J., Outgrowth endothelial cells isolated and expanded from human peripheral blood progenitor cells as a potential source of autologous cells for endothelialization of silk fibroin biomaterials (2006) Biomaterials, 27 (31), pp. 5399-5408. , DOI 10.1016/j.biomaterials.2006.06.015, PII S0142961206005722Gotoh, Y., Tsukada, M., Minoura, N., Imai, Y., Synthesis of poly(ethylene glycol)-silk fibroin conjugates and surface interaction between L-929 cells and the conjugates (1997) Biomaterials, 18 (3), pp. 267-271. , DOI 10.1016/S0142-9612(96)00137-8, PII S0142961296001378Yang, Y., Chen, X., Ding, F., Zhang, P., Liu, J., Gu, X., Biocompatibility evaluation of silk fibroin with peripheral nerve tissues and cells in vitro (2007) Biomaterials, 28 (9), pp. 1643-1652. , DOI 10.1016/j.biomaterials.2006.12.004, PII S0142961206010192Panilaitis, B., Altman, G.H., Chen, J., Jin, H.-J., Karageorgiou, V., Kaplan, D.L., Macrophage responses to silk (2003) Biomaterials, 24 (18), pp. 3079-3085. , DOI 10.1016/S0142-9612(03)00158-3Fini, M., Motta, A., Torricelli, P., Giavaresi, G., Nicoli Aldini, N., Tschon, M., Giardino, R., Migliaresi, C., The healing of confined critical size cancellous defects in the presence of silk fibroin hydrogel (2005) Biomaterials, 26 (17), pp. 3527-3536. , DOI 10.1016/j.biomaterials.2004.09.040, PII S0142961204008695Marreco, P.R., Da Luz Moreira, P., Genari, S.C., Moraes, A.M., Effects of different sterilization methods on the morphology, mechanical properties, and cytotoxicity of chitosan membranes used as wound dressings (2004) Journal of Biomedical Materials Research - Part B Applied Biomaterials, 71 (2), pp. 268-277. , DOI 10.1002/jbm.b.30081Siritientong, T., Srichana, T., Aramwit, P., The effect of sterilization methods on the physical properties of silk sericin scaffolds (2011) Aaps Pharmscitech, 12, pp. 771-781Von Woedtke, T., Julich, W.-D., Hartmann, V., Stieber, M., Abel, P.U., Sterilization of enzyme glucose sensors: Problems and concepts (2002) Biosensors and Bioelectronics, 17 (5), pp. 373-382. , DOI 10.1016/S0956-5663(01)00310-4, PII S0956566301003104Lee, M.H., Kim, H.-L., Kim, C.H., Lee, S.H., Kim, J.K., Lee, S.J., Park, J.-C., Effects of low temperature hydrogen peroxide gas on sterilization and cytocompatibility of porous poly(d,l -lactic-co-glycolic acid) scaffolds (2008) Surf Coat Technol, 202, pp. 5762-5767Block, S.S., (2001) Disinfection, Sterilization, and Preservation, , Baltimore: Lippincott Williams & WilkinsPalsule, A.S., Clarson, S.J., Widenhouse, C.W., Gamma irradiation of silicones (2008) J Inorg Organomet Polym Mater, 18, pp. 207-221BR200601975-A, Unicamp Univ Estadual Campinas, invs.: M. M. Beppu, B. Polakiewicz, G. M. Nogueira2008Lv, Q., Cao, C., Zhang, Y., Ma, X.L., Zhu, H., Preparation of insoluble fibroin films without methanol treatment (2005) Journal of Applied Polymer Science, 96 (6), pp. 2168-2173. , DOI 10.1002/app.21682Miyaguchi, Y., Hu, J., Physicochemical properties of silk fibroin after solubilization using calcium chloride with or without ethanol (2005) Food Science and Technology Research, 11 (1), pp. 37-42Rusa, C.C., Bridges, C., Ha, S.-W., Tonelli, A.E., Conformational changes induced in Bombyx mori silk fibroin by cyclodextrin inclusion complexation (2005) Macromolecules, 38 (13), pp. 5640-5646. , DOI 10.1021/ma050340aUm, I.C., Ki, C.S., Kweon, H., Lee, K.G., Ihm, D.W., Park, Y.H., Wet spinning of silk polymer: II. Effect of drawing on the structural characteristics and properties of filament (2004) International Journal of Biological Macromolecules, 34 (1-2), pp. 107-119. , DOI 10.1016/j.ijbiomac.2004.03.011, PII S0141813004000145Zuo, B., Liu, L., Wu, Z., Effect on properties of regenerated silk fibroin fiber coagulated with aqueous methanol/ethanol (2007) Journal of Applied Polymer Science, 106 (1), pp. 53-59. , DOI 10.1002/app.26653Lawrence, B.D., Omenetto, F., Chui, K., Kaplan, D.L., Processing methods to control silk fibroin film biomaterial features (2008) J Mater Sci, 43, pp. 6967-6985Tamada, Y., New process to form a silk fibroin porous 3-D structure (2005) Biomacromolecules, 6 (6), pp. 3100-3106. , DOI 10.1021/bm050431fMoonsri, P., Watanesk, R., Watanesk, S., Niamsup, H., Deming, R.L., Fibroin membrane preparation and stabilization by polyethylene glycol diglycidyl ether (2008) Journal of Applied Polymer Science, 108 (3), pp. 1402-1406. , DOI 10.1002/app.27528Li, M., Lu, S., Wu, Z., Tan, K., Minoura, N., Kuga, S., Structure and properties of silk fibroin-poly(vinyl alcohol) gel (2002) International Journal of Biological Macromolecules, 30 (2), pp. 89-94. , DOI 10.1016/S0141-8130(02)00007-7, PII S0141813002000077Kim, S.H., Nam, Y.S., Lee, T.S., Park, W.H., Silk fibroin nanofiber. Electrospinning, properties, and structure (2003) Polym J, 35, pp. 185-190Lv, Q., Cao, C., Zhang, Y., Man, X., Zhu, H., The preparation of insoluble fibroin films induced by degummed fibroin or fibroin microspheres (2004) Journal of Materials Science: Materials in Medicine, 15 (11), pp. 1193-1197. , DOI 10.1007/s10856-004-5918-yPutthanarat, S., Zarkoob, S., Magoshi, J., Chen, J.A., Eby, R.K., Stone, M., Adams, W.W., Effect of processing temperature on the morphology of silk membranes (2002) Polymer, 43 (12), pp. 3405-3413. , DOI 10.1016/S0032-3861(02)00161-1, PII S0032386102001611Nogueira, G.M., Rodas, A.C.D., Weska, R.F., Aimoli, C.G., Higa, O.Z., Maizato, M., Leiner, A.A., Beppu, M.M., Bovine pericardium coated with biopolymeric films as an alternative to prevent calcification: In vitro calcification and cytotoxicity results (2010) Mater Sci Eng C Mater Biol Appl, 30, pp. 575-582Wang, X., Kim, H.J., Xu, P., Matsumoto, A., Kaplan, D.L., Biomaterial coatings by stepwise deposition of silk fibroin (2005) Langmuir, 21 (24), pp. 11335-11341. , DOI 10.1021/la051862mNogueira, G.M., Weska, R.F., Vieira, W.C., Polakiewicz, B., Rodas, A.C.D., Higa, O.Z., Beppu, M.M., A new method to prepare porous silk fibroin membranes suitable for tissue scaffolding applications (2009) J Appl Polym Sci, 114, pp. 617-623Weska, R.F., Nogueira, G.M., Vieira, Jr.W.C., Beppu, M.M., Porous silk fibroin membrane as a potential scaffold for bone regeneration (2009) Key Eng Mater, 396-398, pp. 187-19
Chromium Removal On Chitosan-based Sorbents - An Exafs/xanes Investigation Of Mechanism
No full textChitosan is known to be a good sorbent for metal-containing ions as the presence of amino groups and hydroxyl functions act as effective binding sites. Its crosslinking, employing glutaraldehyde or epichlorohydrin, may change the sorption properties (sorption capacity or diffusion properties) of this biopolymer, since the available functional groups are different in each case. X-ray absorption spectroscopy (XAS), including extended X-ray absorption fine structure (EXAFS) and X-ray absorption near-edge structure (XANES), Fourier-transformed infrared spectroscopy with attenuated total reflectance device (FTIR-ATR) was used along with speciation diagrams, in order to identify the binding groups involved in chromate sorption and its mechanisms. In pristine chitosan and epichlorohydrin-crosslinked chitosan membranes, amino groups are most likely responsible for adsorption, although the contribution of hydroxyl groups cannot be excluded (especially for metal-sorbent stabilization). In this case, when adsorbed about 70% of chromate ions remain in the Cr(VI) oxidation state. In the case of glutaraldehyde-crosslinked membranes, the functional groups involved are different. Carbonyl groups and imino bonds - resulting from the reaction of the crosslinking agent and amino groups - may be involved in the adsorption mechanism. Additionally, a higher fraction of chromate anions, around 44% are reduced to Cr(III) oxidation state in loaded sorbent. The presence of free aldehyde groups may explain this partial reduction. © 2014 Elsevier B.V. All rights reserved.1463412417Snow, E.T., (1991) Environ. Health Perspect., 92, pp. 75-80Wase, J., Foster, C., (1997) Biosorbents for Metal Ions, , Taylor & Francis Ltd UKKratochvil, D., Pimentel, P., Volesky, B., (1998) Environ. Sci. Technol., 32, pp. 2693-2698Machado, R., Carvalho, J.R., Correia, M.J.N., (2002) J. Chem. Technol. Biotechnol., 77, pp. 1340-1348Ng, J.C.Y., Cheung, W.H., Mckay, G., (2002) J. Colloid Interface Sci., 255, pp. 64-74Chu, K.H., (2002) J. Hazard. Mater., B90, pp. 77-95Guibal, E., (2004) Sep. Purif. Technol., 38, pp. 43-74Merrifield, J.D., Davids, W.G., MacRae, J.D., Amirbahman, A., (2004) Water Res., 38, pp. 3132-3138Zhou, D., Zhang, L., Shenglian, L.G., (2005) Water Res., 39, pp. 3755-3762Vieira, R.S., Beppu, M.M., (2006) Colloids Surf. A Physicochem. Eng. Asp., 279, pp. 196-207Vieira, R.S., Beppu, M.M., (2006) Water Res., 40, pp. 726-734Baroni, P., Vieira, R.S., Meneghetti, E., Da Silva, M.G.C., Beppu, M.M., (2008) J. Hazard. Mater., 152, pp. 1155-1163Kurita, K., (2006) Mar. Biotechnol., 8, pp. 203-226Mourya, V.K., Inamdar, N.N., (2008) React. Funct. Polym., 68, pp. 1013-1051Becker, T., Schlaak, M., Strasdeit, H., (2000) React. Funct. Polym., 44, pp. 289-298Webster, A., Halling, M.D., Grant, D.M., (2007) Carbohydr. Res., 342, pp. 1189-1201Dambies, L., Guimon, C., Yiacoumi, S., Guibal, E., (2001) Colloids Surf. A Physicochem. Eng. Asp., 177, pp. 203-214Vieira, R.S., Oliveira, M.L.M., Guibal, E., Rodríguez-Castellón, E., Beppu, M.M., (2011) Colloids Surf. A Physicochem. Eng. Asp., 374, pp. 108-114Peirano, F., Vincent, T., Quignard, F., Robitze, M., Guibal, E., (2009) J. Membr. Sci., 329, pp. 30-45Fras, L., Johansson, L.S., Stenius, P., Laine, J., Stana-Kleinschek, K., Ribitsch, V., (2005) Colloids Surf. A Physicochem. Eng. Asp., 260, pp. 101-108Bhatia, S.C., Ravi, N.A., (2000) Biomacromolecules, 1, pp. 413-417Gardea-Torresdey, J.L., Peralta-Videa, J.R., De La Rosa, G., Parsons, J.G., (2005) Coord. Chem. Rev., 249, pp. 1797-1810Kramareva, N.V., Stakheev, A.Y., Tkachenko, O.P., Klementiev, K.V., Grünert, W., Finashina, E.D., Kustov, L.M., (2004) J. Mol. Catal. A Chem., 209, pp. 97-106Gardea-Torresdey, J.L., Tiemann, K.J., Armendariz, V., Bess-Oberto, L., Chianelli, R.R., Rios, J., Parsons, J.G., Gamez, G., (2000) J. Hazard. Mater., B80, pp. 175-188Gardea-Torresdey, J.L., Dokkena, K., Tiemann, K.J., Parsons, J.G., Ramos, J., Pingitor, N.E., Gamez, G., (2002) Microchem. J., 71, pp. 157-166Parsons, J.G., Hejazia, M., Tiemann, K.J., Henning, J., Gardea-Torresdeya, J.L., (2002) Microchem. J., 71, pp. 211-219Gardea-Torresdey, J.L., Tiemann, K.J., Peralta-Videa, I.R., Parsons, J.G., Delgado, M., (2004) Microchem. J., 76, pp. 65-76Sawalha, M.F., Gardea-Torresdey, J.L., Parsons, J.G., Geoffrey, S., Peralta-Videab, J.R., (2005) Microchem. J., 81, pp. 122-132Parsons, J.G., Dokken, K., Peralta-Videa, I.R., Romero-Gonzalez, J., Gardea-Torresdey, J.L., (2007) Appl. Spectrosc., 61, pp. 338-345Lv, J., Luo, L., Zhang, J., Christie, P., Zhang, S., (2012) Environ. Pollut., 162, pp. 255-261Zhao, X.T., Zeng, T., Li, X.Y., Hu, Z.J., Gao, H.W., Xie, Z., (2012) Carbohydr. Polym., 89, pp. 185-192Wang, S.L., Lee, J.F., (2011) Chem. Eng. J., 174, pp. 289-295Flogeac, K., Guillon, E., Aplincourt, M., (2007) Geoderma, 139, pp. 180-189Kim, C.S., Rytuba, J.J., Brown Jr., G.E., (2004) J. Colloid Interface Sci., 271, pp. 1-15Bosinco, S., Roussy, J., Guibal, E., Lecloirec, P., (1996) Environ. Technol., 17, pp. 55-62Guibal, E., Roussy, J., Le Cloirec, P., (1996) Water SA, 22, pp. 19-26Beppu, M.M., Santana, C.C., (2003) Mater. Sci. Eng. C, 23, pp. 651-658Newville, M., (2001) J. Synchrotron Rad., 8, pp. 322-324I. Puigdomenech, Royal Institute of Technology, Sweden, 2004Requejo, F.G., Ramallo-López, J.M., Rosas-Salas, R., Domínguez, J.M., Dominguez, J.A., Kim, J.Y., Quijada, R., (2005) Catal. Today, 107-108, pp. 750-758Peterson, M.L., Brown, G.E., Parks, G.A., Stein, L.C., (1997) Geochim. Cosmochim. Acta, 61, pp. 3399-3412Park, D., Yeoung-Sang, Y., Park, J.M., (2008) J. Colloid Interface Sci., 317, pp. 54-6
Authority and Personality in M.M. Bakhtin\u27s Author and Hero in Aesthetic Activity
No full textM.M. Bakhtin\u27s fundamental claim in his seminal essay Author and Hero in Aesthetic Activity situates verbal action as the most essential constituent of human personality. A careful reading of this text reveals important truths about the relationship between free individual personhood and the nature of the speech utterance. Bakhtin connects the human experience of speech to the life and person of Jesus Christ emphasizing the incarnation and the Trinitarian view of God as essential principles for understanding the creative power of the word and consequent liabilities. Bakhtin develops these theological and philosophical coordinates around a discussion of the author-hero relationship in the novel asserting that the verbal utterance is creatively involved in building and sustaining the inner personhood of those it addresses. Bakhtin\u27s critical conclusion substantiates that from whom a word is received, and to whom the spoken word appeals has weighty influence on the type and character of human personality, and that personality\u27s relationship to authority
Layer-by-layer Thin Films Of Alginate/chitosan And Hyaluronic Acid/chitosan With Tunable Thickness And Surface Roughness
No full textLayer-by-layer (LbL) is a bottom-up technique used for construction of films with selfassembly and self-organizing properties. In most cases, the fundamental driving force for the formation of these films is originated from the electrostatic interaction between oppositely charged species. The charged segments of polyelectrolytes behave as small building units and their orientation and position can be designed to target structures of great complexity. Furthermore, the technique enables the use of various materials, including natural polymers. In this work, we chose the cationic biopolymer chitosan (CHI) and the negative polyelectrolytes sodium alginate (ALG) and hyaluronic acid (HA). The aim of this study was to evaluate the effect of ionic strength (0 versus 200 mM) and pH (3 versus 5) on ALG/CHI and HA/CHI nanostructured multilayered thin films properties. From profilometry and atomic force microscopy (AFM) analyses, changes in thickness and roughness of the coatings were monitored. The presence of salt in polyelectrolyte solutions induced the polymer chains to adopt conformations with more loops and tails and this arrangement in solution was transmitted to films, resulting in rougher surfaces. Furthermore, the film thickness can be precisely controlled by adjusting the pH of the polyelectrolyte solution. The variation of these parameters shows that it is possible to molecularly control chemical and structural properties of nanostructured coatings, thus opening up new possibilities of application (e.g. cell adhesion). © (2014) Trans Tech Publications, Switzerland.783-78612261231CDMM,Dynamic systems Inc.,et al,National Science Foundataion (NSF),Office of Naval Research (ONR),POSCODecher, G., Nanoassemblies, F., Toward Layered Polymeric Multicomposites (1997) Science, 277, pp. 1232-1237Voigt, U., Jaeger, W., Findenegg, G.H., Klitzing, R.V., Charge Effects on the Formation of Multilayers Containing Strong Polyelectrolytes (2003) The Journal of Physical Chemistry B, 107, pp. 5273-5280Delcea, M., Möhwald, H., Skirtach, A.G., Stimuli-responsive LbL capsules and nanoshells for drug delivery (2011) Advanced Drug Delivery Reviews, 63, pp. 730-747Vasconcellos, F.C., Swiston, A.J., Beppu, M.M., Cohen, R.E., Rubner, M.F., Bioactive Polyelectrolyte Multilayers: Hyaluronic Acid Mediated B Lymphocyte Adhesion (2010) Biomacromolecules, 11, pp. 2407-2414Etienne, O., Gasnier, C., Taddei, C., Voegel, J.-C., Aunis, D., Schaaf, P., Metz-Boutigue, M.-H., Egles, C., Antifungal coating by biofunctionalized polyelectrolyte multilayered films (2005) Biomaterials, 26, pp. 6704-6712Lichter, J.A., van Vliet, K.J., Rubner, M.F., Design of Antibacterial Surfaces and Interfaces: Polyelectrolyte Multilayers as a Multifunctional Platform (2009) Macromolecules, 42, pp. 8573-8586Tsuge, Y., Kim, J., Sone, Y., Kuwaki, O., Shiratori, S., Fabrication of transparent TiO2 film with high adhesion by using self-assembly methods: Application to super-hydrophilic film (2008) Thin Solid Films, 516, pp. 2463-2468Richert, L., Lavalle, P., Payan, E., Shu, X., Prestwich, G., Stoltz, J., Schaaf, P., Picart, C., Layer by layer buildup of polysaccharide films: Physical chemistry and cellular adhesion aspects (2004) Langmuir, 20, pp. 448-458Rinaudo, M., Main properties and current applications of some polysaccharides as biomaterials (2008) Polymer International, 57, pp. 397-430Alves, N.M., Picart, C., Mano, J.F., Self Assembling and Crosslinking of Polyelectrolyte Multilayer Films of Chitosan and Alginate Studied by QCM and IR Spectroscopy (2009) Macromolecular Bioscience, 9, pp. 776-785Jin, R.-H., Yuan, J.-J., Biomimetically Controlled Formation of Nanotextured Silica/Titania Films on Arbitrary Substrates and Their Tunable Surface Function (2009) Advanced Materials, 21, pp. 3750-3753Lavalle, P., Gergely, C., Cuisinier, F.J.G., Decher, G., Schaaf, P., Voegel, J.C., Picart, C., Comparison of the Structure of Polyelectrolyte Multilayer Films Exhibiting a Linear and an Exponential Growth Regime: An in Situ Atomic Force Microscopy Study (2002) Macromolecules, 35, pp. 4458-4465Box, G.E.P., Hunter, W.G., Hunter, J.S., (1978) Statistics For Experimenters: An Introduction to Design, Data Analysis, , and model building, WileyShiratori, S.S., Rubner, M.F., PH-Dependent Thickness Behavior of Sequentially Adsorbed Layers of Weak Polyelectrolytes (2000) Macromolecules, 33, pp. 4213-4219Ikeda, A., Takemura, A., Ono, H., Preparation of low-molecular weight alginic acid by acid hydrolysis (2000) Carbohydrate Polymers, 42, pp. 421-425Voigt, U., Khrenov, V., Thuer, K., Hahn, M., Jaeger, W., von Klitzing, R., The effect of polymer charge density and charge distribution on the formation of multilayers (2003) Journal of Physics- Condensed Matter, 15, pp. S213-S218Dubas, S.T., Schlenoff, J.B., Polyelectrolyte Multilayers Containing a Weak Polyacid: Construction and Deconstruction (2001) Macromolecules, 34, pp. 3736-3740Rojas, O.J., Claesson, P.M., Muller, D., Neuman, R.D., The Effect of Salt Concentration on Adsorption of Low-Charge-Density Polyelectrolytes and Interactions between Polyelectrolyte- Coated Surfaces (1998) Journal of Colloid and Interface Science, 205, pp. 77-88McAloney, R.A., Sinyor, M., Dudnik, V., Goh, M.C., Atomic Force Microscopy Studies of Salt Effects on Polyelectrolyte Multilayer Film Morphology (2001) Langmuir, 17, pp. 6655-6663Ren, K., Wang, Y., Ji, J., Lin, Q., Shen, J., Construction and deconstruction of PLL/DNA multilayered films for DNA delivery: Effect of ionic strength (2005) Colloids and Surfaces B: Biointerfaces, 46, pp. 63-69Bohmer, M.R., Evers, O.A., Scheutjens, J.M.H.M., Weak polyelectrolytes between two surfaces: Adsorption and stabilization (1990) Macromolecules, 23, pp. 2288-2301Fery, A., Schöler, B., Cassagneau, T., Caruso, F., Nanoporous Thin Films Formed by Salt- Induced Structural Changes in Multilayers of Poly(acrylic acid) and Poly(allylamine) (2001) Langmuir, 17, pp. 3779-378
Factors Controlling The Deposition Of Silk Fibroin Nanofibrils During Layer-by-layer Assembly
No full textThe layer-by-layer technique has been used as a powerful method to produce multilayer thin films with tunable properties. When natural polymers are employed, complicated phenomena such as self-aggregation and fibrilogenesis can occur, making it more difficult to obtain and characterize high-quality films. The weak acid and base character of such materials provides multilayer systems that may differ from those found with synthetic polymers due to strong self-organization effects. Specifically, LbL films prepared with chitosan and silk fibroin (SF) often involve the deposition of fibroin fibrils, which can influence the assembly process, surface properties, and overall film functionality. In this case, one has the intriguing possibility of realizing multilayer thin films with aligned nanofibers. In this article, we propose a strategy to control fibroin fibril formation by adjusting the assembly partner. Aligned fibroin fibrils were formed when chitosan was used as the counterpart, whereas no fibrils were observed when poly(allylamine hydrochloride) (PAH) was used. Charge density, which is higher in PAH, apparently stabilizes SF aggregates on the nanometer scale, thereby preventing their organization into fibrils. The drying step between the deposition of each layer was also crucial for film formation, as it stabilizes the SF molecules. Preliminary cell studies with optimized multilayers indicated that cell viability of NIH-3T3 fibroblasts remained between 90 and 100% after surface seeding, showing the potential application of the films in the biomedical field, as coatings and functional surfaces. (Figure Presented).16197104Stockton, W.B., Rubner, M.F., Molecular-level processing of conjugated polymers 0.4. Layer-by-layer manipulation of polyaniline via hydrogen-bonding interactions (1997) Macromolecules, 30, pp. 2717-2725Kotov, N.A., Layer-by-layer self-assembly: The contribution of hydrophobic interactions (1999) Nanostruct. Mater., 12, pp. 789-796Zhang, Y.J., Yang, S.G., Guan, Y., Cao, W.X., Xu, J., Fabrication of stable hollow capsules by covalent layer-by-layer self-assembly (2003) Macromolecules, 36, pp. 4238-4240Decher, G., Fuzzy nanoassemblies: Toward layered polymeric multicomposites (1997) Science, 277, pp. 1232-1237Wang, X.Y., Kim, H.J., Xu, P., Matsumoto, A., Kaplan, D.L., Biomaterial coatings by stepwise deposition of silk fibroin (2005) Langmuir, 21, pp. 11335-11341Jiang, C.Y., Wang, X.Y., Gunawidjaja, R., Lin, Y.H., Gupta, M.K., Kaplan, D.L., Naik, R.R., Tsukruk, V.V., Mechanical properties of robust ultrathin silk fibroin films (2007) Adv. Funct. Mater., 17, pp. 2229-2237Shchepelina, O., Drachuk, I., Gupta, M.K., Lin, J., Tsukruk, V.V., Silk-on-silk layer-by-layer microcapsules (2011) Adv. Mater., 23, pp. 4655-4660Kozlovskaya, V., Baggett, J., Godin, B., Liu, X., Kharlampieva, E., Hydrogen-bonded multilayers of silk fibroin: From coatings to cell-mimicking shaped microcontainers (2012) Acs Macro Lett., 1, pp. 384-387Cai, K., Hu, Y., Jandt, K.D., Surface engineering of titanium thin films with silk fibroin via layer-by-layer technique and its effects on osteoblast growth behavior (2007) J. Biomed. Mater. Res., Part A, 82 A, pp. 927-935Nogueira, G.M., Swiston, A.J., Beppu, M.M., Rubner, M.F., Layer-by-layer deposited chitosan/silk fibroin thin films with anisotropic nanofiber alignment (2010) Langmuir, 26, pp. 8953-8958Cooper, A., Jana, S., Bhattarai, N., Zhang, M., Aligned chitosan-based nanofibers for enhanced myogenesis (2010) J. Mater. Chem., 20, pp. 8904-8911Pelaez-Vargas, A., Gallego-Perez, D., Ferrell, N., Fernandes, M.H., Hansford, D., Monteiro, F.J., Early spreading and propagation of human bone marrow stem cells on isotropic and anisotropic topographies of silica thin films produced via microstamping (2010) Microsc. Microanal., 16, pp. 670-676Lu, Q., Zhu, H., Zhang, C., Zhang, F., Zhang, B., Kaplan, D.L., Silk self-assembly mechanisms and control from thermodynamics to kinetics (2012) Biomacromolecules, 13, pp. 826-832Greving, I., Cai, M., Vollrath, F., Schniepp, H.C., Shear-induced self-assembly of native silk proteins into fibrils studied by atomic force microscopy (2012) Biomacromolecules, 13, pp. 676-682Jin, H.J., Kaplan, D.L., Mechanism of silk processing in insects and spiders (2003) Nature, 424, pp. 1057-1061Chen, P., Kim, H.S., Park, C.Y., Chin, I.J., Jin, H.J., pH-triggered transition of silk fibroin from spherical micelles to nanofibrils in water (2008) Macromol. Res., 16, pp. 539-543Gong, Z., Huang, L., Yang, Y., Chen, X., Shao, Z., Two distinct beta-sheet fibrils from silk protein (2009) Chem. Commun., 48, pp. 7506-7508Payne, G.F., Raghavan, S.R., Chitosan: A soft interconnect for hierarchical assembly of nano-scale components (2007) Soft Matter, 3, pp. 521-527Choi, J., Rubner, M.F., Influence of the degree of ionization on weak polyelectrolyte multilayer assembly (2005) Macromolecules, 38, pp. 116-124Vasconcellos, F.C., Swiston, A.J., Beppu, M.M., Cohen, R.E., Rubner, M.F., Bioactive polyelectrolyte multilayers: Hyaluronic acid mediated B lymphocyte adhesion (2010) Biomacromolecules, 11, pp. 2407-2414Lee, D., Rubner, M.F., Cohen, R.E., All-nanoparticle thin-film coatings (2006) Nano Lett, 6, pp. 2305-2312Lee, H., Mensire, R., Cohen, R.E., Rubner, M.F., Strategies for hydrogen bonding based layer-by-layer assembly of poly(vinyl alcohol) with weak polyacids (2012) Macromolecules, 45, pp. 347-355Li, G.Y., Zhou, P., Shao, Z.Z., Xie, X., Chen, X., Wang, H.H., Chunyu, L.J., Yu, T.Y., The natural silk spinning process - A nucleation-dependent aggregation mechanism? (2001) Eur. J. Biochem., 268, pp. 6600-6606Richert, L., Lavalle, P., Payan, E., Shu, X.Z., Prestwich, G.D., Stoltz, J.F., Schaaf, P., Picart, C., Layer by layer buildup of polysaccharide films: Physical chemistry and cellular adhesion aspects (2004) Langmuir, 20, pp. 448-458Svensson, O., Lindh, L., Cardenas, M., Arnebrant, T., Layer-by-layer assembly of mucin and chitosan - Influence of surface properties, concentration and type of mucin (2006) J. Colloid Interface Sci., 299, pp. 608-616Jin, H.J., Park, J., Valluzzi, R., Cebe, P., Kaplan, D.L., Biomaterial films of Bombyx mori silk fibroin with poly(ethylene oxide) (2004) Biomacromolecules, 5, pp. 711-717Amornsudthiwat, P., Mongkolnavin, R., Kanokpanont, S., Panpranot, J., Wong, C.S., Damrongsakkul, S., Improvement of early cell adhesion on Thai silk fibroin surface by low energy plasma (2013) Colloids Surf., B, 111, pp. 579-586Lee, J.-H., Hwang, H.J., Bhak, G., Jang, Y., Paik, S.R., Char, K., In situ fibril formation of kappa-casein by external stimuli within multilayer thin films (2013) Acs Macro Lett., 2, pp. 688-693Yan, X., Zhu, P., Li, J., Self-assembly and application of diphenylalanine-based nanostructures (2010) Chem. Soc. Rev., 39, pp. 1877-1890Hwang, W., Kim, B.-H., Dandu, R., Cappello, J., Ghandehari, H., Seog, J., Surface induced nanofiber growth by self-assembly of a silk-elastin-like protein polymer (2009) Langmuir, 25, pp. 12682-12686Um, I.C., Kweon, H.Y., Park, Y.H., Hudson, S., Structural characteristics and properties of the regenerated silk fibroin prepared from formic acid (2001) Int. J. Biol. Macromol., 29, pp. 91-97Qiang, L., Cao, C.B., Zhang, Y., Man, X.L., Zhu, H.S., The preparation of insoluble fibroin films induced by degummed fibroin or fibroin microspheres (2004) J. Mater. Sci.: Mater. Med., 15, pp. 1193-1197Nogueira, G.M., Rodas, A.C.D., Leite, C.A.P., Giles, C., Higa, O.Z., Polakiewicz, B., Beppu, M.M., Preparation and characterization of ethanol-treated silk fibroin dense membranes for biomaterials application using waste silk fibers as raw material (2010) Bioresour. Technol., 101, pp. 8446-8451Kawahara, Y., Furukawa, K., Yamamoto, T., Self-expansion behavior of silk fibroin film (2006) Macromol. Mater. Eng., 291, pp. 458-462Jin, H.J., Park, J., Karageorgiou, V., Kim, U.J., Valluzzi, R., Kaplan, D.L., Water-stable silk films with reduced beta-sheet content (2005) Adv. Funct. Mater., 15, pp. 1241-124
In Vitro Biomineralization Of Chitosan
No full textThe influence of chemical treatments of porous and non-porous chitosan membranes on biomineralization was studied. These treatments are: 1) the crosslinking using glutaraldehyde and 2) the adsorption of poly(acrylic acid) (PAA) on chitosan. The first one blocks chitosan amino groups, inducing a more hydrophobic character to the substrate, and the second one turns the membrane surface polyanionic instead of the polycationic natural character of chitosan. Substrates (membranes) of chitosan treated in both ways were used to undergo mineralization by soaking them in simulated body fluids (SBF), with 1x or 1.5x the concentration of ions found in human serum, for 7 at 36.5°C. SEM-EDS and FTIR-ATR techniques showed that glutaraldehyde tends to inhibit calcium compound deposition on substrates while PAA induces a more homogeneous and intense deposition.192-1953134Pathak, Y., Shoen, F.J., Levy, R.J., Pathologic calcification of biomaterials (1996) Biomaterials Science, An Introduction to Materials in Medicine, pp. 272-282. , Ed. Ratner, B.D., Hoffman, A.S., Schoen, F.J. e Lemons, J.E., Academic Press, California-USASandford, P.A., Chitosan: Commercial uses and potential applications (1989) Chitin and Chitosan, pp. 51-69. , Ed. Skjaek-Braek, G et al., Elsevier Applied Science, New YorkGolomb, G., Wagner, D., (1991) Biomaterials, 12, p. 397Mucalo, M.R., Toriyama, M., Yokogawa, Y., Suzuki, T., Kawamoto, Y., Nagata, F., Nishizawa, K., (1995) J. Mater. Sci. Mater. Medicine, 6, pp. 409-419Tanahashi, M., Yao, T., Kokubo, T., Minoda, M., Miyamoto, T., Nakamura, T., Yamamuro, T., (1995) J. Mater. Sci. Mater. Medicine, 6, pp. 319-326Koutsopoulos, S., Kontogeorgergou, A., Ptroheilos, J., Dalas, E., (1998) J. Mater. Sci. Mater. Medicine, 9, pp. 421-424Golomb, G., (1992) J. Mater. Sci. Mater. Medicine, 3, pp. 272-377Kokubo, T., Ito, S., Huang, Z.T., Hayashi, T., Sakka, S., Kitsugi, T., Yamamuro, T., (1990) Journal of Biomed, Mater. Res., 24, pp. 331-343Davies, J.E., Mechanisms of endosseous integration (1998) Conference, 1st COLAOB, , Belo-Horizonte, BrazilBeppu, M.M., Estudo da Calcificação in Vitro de Quitosana, , PhD Thesis in print. Unicamp Brazi
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