1,296 research outputs found
Injectable Biodegradable Polycaprolactone-sebacic Acid Gels For Bone Tissue Engineering
No full textTissue engineering constitutes a promising alternative technology to transplantation medicine by creating viable substitutes for failing tissues or organs. The ability to manipulate and reconstitute tissue function has tremendous clinical implications and will most likely play a key role in cell and gene therapies in the coming years. In the present work, a novel injectable and biodegradable biomaterial is reported that could be injected on the human body with a surgical syringe. The material prepared is a blend of polycaprolactone (PCL), a biodegradable and elastic biomedical polymer, and sebacic acid, a natural polymer part of castor oil with low molecular weight to accelerate the slow degradation rate of PCL. The biocompatibility of the blend was evaluated in vitro and its in vivo behavior was also assessed through subcutaneous and bone implantation in rats to evaluate its tissue-forming ability and degradation rate. The results allowed the conclusion that the gel is biocompatible, promotes the differentiation of mesenchymal stem cells, and presents an adequate degradation rate for use in bone tissue engineering. In vivo the gel blends promoted tissue regeneration and adverse reactions were not observed on subcutaneous and bone implants. © 2012 Mary Ann Liebert, Inc.181-2137146Payne, R.G., Yaszemski, M.J., Yasko, A.W., Mikos, A.G., Development of an injectable, in situ crosslinkable, degradable polymeric carrier for osteogenic cell populations. Part 1. 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Boca Raton, FL: CRC PressRatner, B.D., New ideas in biomaterials science-a path to engineered biomaterials (1993) J Biomed Mater Res, 27, p. 837Luciano, R.M., Zavaglia, C.A.C., Duek, E.A.R., Alberto-Rincon, M.C., Synthesis and characterization of poly(L-lactic acid) membranes: Studies in vivo and in vitro (2003) J Mater Sci Mater Med, 14, p. 87Williams, J.M., Adewunmi, A., Schek, R.M., Flanagan, C.L., Krebsbach, P.H., Feinberg, S.E., Hollister, S.J., Das, S., Bone tissue engineering using polycaprolactone scaffolds fabricated via selective laser sintering (2005) Biomaterials, 23, p. 4817Mano, J.F., Sousa, R.A., Boesel, L.F., Neves, N.M., Reis, R.L., Bloinert, biodegradable and injectable polymeric matrix composites for hard tissue replacement: State of the art and recent developments (2004) Compos Sci Technol, 64, p. 789Barbanti, S.H., Santos, A.R., Zavaglia, C.A.C., Duek, E.A.R., Porous and dense poly(L-lactic acid) and poly(D,Llactic acid co-glycolic acid) scaffolds: In vitro degradation in culture medium and osteoblasts culture (2004) J Mater Sci Mater Med, 15, p. 1315Li, S.M., Chen, X.H., Gross, R.A., McCarthy, S.P., Hydrolytic degradation of PCL/PEO copolymers in alkaline media (2000) J Mater Sci Mater Med, 11, p. 227Vert, M., Li, S.M., Spenlehauer, G., Guerin, P., Bioresorbability and biocompatibility of aliphatic polyesters (1992) J Mater Sci Mater Med, 3, p. 432Lam, C.X.F., Hutmacher, D.W., Schantz, J.T., Woodruff, M.A., Teoh, S.H., Evaluation of polycaprolactone scaffold degradation for 6 months in vitro and in vivo (2009) J Biomed Mater Res Part A, 90 A, p. 906Salgado, C.L., Sanchez, E.S., Zavaglia, C.A.C., Granja, P.L., (2009) Método de Confecção de Polímero Biodegradável Injeta ́vel Brazil, , Brazilian submitted patent: PI 018080059526(1999) Standardization of Biological Evaluation of Medical Devices. Part 5: Tests for Cytotoxicity: In Vitro Methods, Volume 10993-5, , ISO, ed. Geneva, SwitzerlandAshton, B.A., Abdullah, F., Cave, J., Williamson, M., Sykes, B.C., Couch, M., Characterization of cells with high alkaline-phosphatase activity derived from human-bone and marrow-preliminary assessment of their osteogenicity (1985) Bone, 6, p. 313Barrias, C.C., Lamghari, M., Granja, P.L., Sa Miranda, M.C., Barbosa, M.A., Biological evaluation of calcium alginate microspheres as a vehicle for the localized delivery of a therapeutic enzyme (2005) J Biomed Mater Res, 72, p. 57Ciapetti, G., Ambrosio, L., Marletta, G., Baldini, N., Giunti, A., Human bone marrow stromal cells: In vitro expansion and differentiation for bone engineering (2006) Biomaterials, 27, p. 6150Vitte, J., Benoliel, A.M., Pierres, A., Bongrand, P., Is there a predictable relationship between surface physical-chemical properties and cell behaviour at the interface? 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K., Kitayama, T., and Vogl, O., eds New York, Basel, Hong Kong: Marcel Dekker IncJabbari, E., Wang, S.F., Lu, L.C., Gruetzmacher, J.A., Ameenuddin, S., Hefferan, T.E., Synthesis, material properties, and biocompatibility of a novel self-crosslinkable poly(caprolactone fumarate) as an injectable tissue engineering scaffold (2005) Biomacromolecules, 6, p. 2503Martina, M., Hutmacher, D.W., Biodegradable polymers applied in tissue engineering research: A review (2007) Polym Int, 56, p. 145Shikanov, A., Vaisman, B., Krasko, M.Y., Nyska, A., Domb, A.J., Poly(sebacic acid-co-ricinoleic acid) biodegradable carrier for paclitaxel: In vitro release and in vivo toxicity (2004) J Biomed Mater Res Part A, 69 A, p. 47Shikanov, A., Domb, A.J., Poly(sebacic acid-co-ricinoleic acid) biodegradable injectable in situ gelling polymer (2006) Biomacromolecules, 7, p. 288Modi, S., Jain, J.P., Domb, A.J., Kumar, N., Copolymers of pharmaceutical grade lactic acid and sebacic acid: Drug release behavior and-biocompatibility (2006) Eur J Pharm Biopharm, 64, p. 277Clark, R.A.F., Ghosh, K., Tonnesen, M.G., Tissue engineering for cutaneous wounds (2007) J Invest Dermatol, 127, p. 1018Salgado, A.J., Coutinho, O.P., Reis, R.L., Bone tissue engineering: State of the art and future trends (2004) Macromol Biosci, 4, p. 743Sawyer, A.A., Song, S.J., Susanto, E., Chuan, P., Lam, C.X.F., Woodruff, M.A., The stimulation of healing within a rat calvarial defect by mPCL-TCP/collagen scaffolds loaded with rhBMP-2 (2009) Biomaterials, 30, p. 247
Silver sheaves; gathered through clouds and sunshine. In two parts. Part 1st: Civil and military life of the author. Part 2d: Miscellaneous collection of prose and poetry.
No full text2d ed.2 p.l., [9]-360 p
Steady-state kinetics of the tungsten containing aldehyde: Ferredoxin oxidoreductases from the hyperthermophilic archaeon Pyrococcus furiosus
No full textThe tungsten containing Aldehyde:ferredoxin oxidoreductases (AOR) offer interesting opportunities for biocatalytic approaches towards aldehyde oxidation and carboxylic acid reduction. The hyperthermophilic archaeon Pyrococcus furiosus encodes five different AOR family members: glyceraldehyde-3-phosphate oxidoreductase (GAPOR), aldehyde oxidoreductase (AOR), and formaldehyde oxidoreductase (FOR), WOR4 and WOR5. GAPOR functions as a glycolytic enzyme and is highly specific for the substrate glyceraldehyde-3-phosphate (GAP). AOR, FOR and WOR5 have a broad substrate spectrum, and for WOR4 no substrate has been identified to date. As ambiguous kinetic parameters have been reported for different AOR family enzymes the steady state kinetics under different physiologically relevant conditions was explored. The GAPOR substrate GAP was found to degrade at 60 °C by non-enzymatic elimination of the phosphate group to methylglyoxal with a half-life t1/2 = 6.5 min. Methylglyoxal is not a substrate or inhibitor of GAPOR. D-GAP was identified as the only substrate oxidized by GAPOR, and the kinetics of the enzyme was unaffected by the presence of L-GAP, which makes GAPOR the first enantioselective enzyme of the AOR family. The steady-state kinetics of GAPOR showed partial substrate inhibition, which assumes the GAP inhibited form of the enzyme retains some activity. This inhibition was found to be alleviated completely by a 1 M NaCl resulting in increased enzyme activity at high substrate concentrations. GAPOR activity was strongly pH dependent, with the optimum at pH 9. At pH 9, the substrate is a divalent anion and, therefore, positively charged amino acid residues are likely to be involved in the binding of the substrate. FOR exhibited a significant primary kinetic isotope effect of the apparent Vmax for the deuterated substrate, formaldehyde-d2, which shows that the rate-determining step involves a C[sbnd]H bond break from the aldehyde. The implications of these results for the reaction mechanism of tungsten-containing AORs, are discussed.Accepted Author ManuscriptBT/Biocatalysi
Legislative amendments, 1996
No full textAn annotated copy of Senate Bill No. 349: an Act concerning the regulation of hazardous substances, amending P.L.1983. c383, and amending and supplementing P.L.1983, c.315
The English hermit; or, Unparalleled sufferings and surprising adventures of Mr. Philip Quarll, who was lately discovered on an uninhabited island in the South sea; where he had lived about fifty years without any human assistance.
No full textAn issue of the 1727 edition in the British museum has the initials P.L. in the title and a dedication, in which the writer claims the authorship of the work, signed Peter Longueville. In the preface (signed P.L.) he denounces the bookseller for having substituted Edward Dorrington's name for his own. For a discussion of the authorship of A. Esdaile's "Author and publisher in 1727: The English hermit", in the Library, 4th ser., v. 2, p. 185-192. Ascribed by some authorities to Alexander Bicknell.Signed: Edward Dorrington.Running title: The English hermit.Mode of access: Internet
Historic old Rhinebeck, echoes of two centuries; a Hudson River and post road colonial town.
No full text[1st ed.]4 p.l., 448 p
Dogs: their management and treatment in disease. A study of the theory and practice of canine medicine. By Ashmont [pseud.]
No full text1 p.l., v, 208 p
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