A Comparative Study Between α-tcp And Si-α-tcp Calcium Phosphate Cement

On this study the influence of silicon dopping on the properties of the final calcium phosphate cement were analysed and compared to the ones of the conventional Si and Mg-free αTCP cement. In spite of silicon doping, Si-α-TCP calcination temperature (1400°C) was higher than the one used for conventional a-TCP (1300°C) as a result of Mg contamination on the commercial precursor used on the Si-α-TCP synthesis. Because of the high temperature used, Si-α-TCP sample was difficult to mill. Even after 1 week milling, the particle size achieved was 12μm while Si-free α-TCP reached 7.7μm. Consequently, the reactivity of both powders was different. In conclusion, the properties of Si-αα-TCP cement were not satisfactory for clinical application. In order to do it so, it is essential to enhance the powder reactivity by reducing Mg contamination, lowering the sintering temperature and reducing the particle size to, then, achieve the desired reactivity and compressive strength.396-398201204Dorozhkin, S.V., (2008) J Mater. Sci, 43, p. 3028Pietak, A.M., et., Al., (2007) Biomaterials, 28, p. 4023Langstaff, S., et., al., (1999) Biomaterials, 20, p. 1727Langstaff, S., et., al., (2001) Biomaterials, 22, p. 135Reid, J.W., et., al., (2005) Biomaterials, 26, p. 2887Reid, J.W., et., al., (2006) Biomaterials, 27, p. 2916Fernández, E., et., al., (1995) Proceedings of the 4th Euro Ceramics Conference, p. 103Camiré, C.L., et., al., (2006) J. Biomed. Mater. Res. Part B: Appl. Biomater, 76 B, p. 424Arcos, D., et., al., (2006) J. Biomed. Mater. Res. Part A, 78 A, p. 762Carrodeguas, R.G., et., al., (2008) Key Eng. Mater, 361-363, p. 237Motisuke, M., et., al., (2008) Key Eng. Mater, 361-363, p. 199Reid, J.W., et., al., (2007) Mater. Lett, 61, p. 3851Carrodeguas, R.G., et., al., (2008) J Amer. Ceram. Soc, 91, p. 1281Cullity, B.D., (1977) Elements of X-Ray Diffraction, , Addion-Wesley Publishing Company, In

Si-tcp Synthesized From "mg-free" Reagents Employed As Calcium Phosphate Cement

The influence of silicon doping on calcium phosphate cement were explored in this work. α-TCP and Si-α-TCP were prepared by solid state reaction employing "Mg-free" CaHPO 4, CaCO 3 and CaSiO 3 as precursors. It was possible to obtain TCP powders with low contents of β phase as contaminant. Cement liquid phase was an aqueous solution containing 2.5 wt. (%) of Na 2HPO 4 and 1.5 wt. (%) of citric acid. The liquid-to-powder ratio was 0.6 mL.g -1. Chemical, physical and mechanical properties of the cement samples were determined by means of XRD, FTIR, XRF, compressive strength and SEM. The calcium phosphate cements obtained achieved satisfactory properties; however, Si-α-TCP presented a decrease on the rate of setting reaction.154568572Döeblin, N., Luginbühl, R., Bohner, M., Synthetic calcium phosphate ceramics for treatment of bone fractures (2010) Mineralogy, 64, pp. 723-729Dorozhkin, S.V., Bioceramics of calcium orthophosphates (2010) Biomaterials, 31, pp. 1465-1485. , http://dx.doi.org/10.1016/j.biomaterials.2009.11.050, PMid:19969343Ginebra, M.P., Espanol, M., Montufar, E.B., Perez, R.A., Mestres, G., New processing approaches in calcium phosphate cements and their applications in regenerative medicine (2010) Acta Biomaterialia, 6, pp. 2863-2873. , http://dx.doi.org/10.1016/j.actbio.2010.01.036, PMid:20123046Pietak, A.M., Reid, J.W., Stott, M.J., Sayer, M., Silicon substituition in the calcium phosphate bioceramics (2007) Biomaterials, 28, pp. 4023-4032. , http://dx.doi.org/10.1016/j.biomaterials.2007.05.003, PMid:17544500Reid, J.W., Tuck, L., Sayer, M., Fargo, K., Hendry, J.A., Shynthesis and characterization of single-phase silicon-substituted α-tricalcium phosphate (2006) Biomaterials, 27, pp. 2916-2925. , http://dx.doi.org/10.1016/j.biomaterials.2006.01.007, PMid:16448694Carlise, E., Si: A possible factor in bone calcification (1970) Science, 167Carlisle, E.M., A silicon requirement for normal skull formation in chicks (1980) Journal of Nutrition, 110Camiré, C.L., Saint-Jean, S.J., Mochales, C., Nevsten, P., Wang, J.S., Lidgren, L., Material characterization and in vivo behavior of silicon substituted α-tricalcium phosphate cement (2006) Journal of Biomedical Materials Research Part B: Applied Biomaterials, 76 B, pp. 424-431. , http://dx.doi.org/10.1002/jbm.b.30385, PMid:16184531Arcos, D., Sánchez-Salcedo, S., Izquierdo-Barba, I., Ruiz, L., González-Calbet, J., Vallet-Regí, M., Crystallochemistry, textural properties, and in vitro biocompatibility of different silicon-doped calcium phosphates (2006) Journal of Biomedical Materials Research Part A, 78 A, pp. 762-771. , http://dx.doi.org/10.1002/jbm.a.30790, PMid:16739108Carrodeguas, R.G., De Aza, A.H., Jimenez, J., De Aza, P.N., López-Bravo, A., De Aza, S., Preparation and in vitro characterization of wollastonite doped tricalcium phosphate bioceramics (2008) Key Engineering Materials, 361-363, pp. 237-240. , http://dx.doi.org/10.4028/www.scientific.net/KEM.361-363.237Wei, X., Akinc, M., Resorption rate tunable bioceramic: Si&Zn-modified tricacium phosphate (2008) Ceramic Engineering and Science Proceedings, 26, pp. 129-136. , http://dx.doi.org/10.1002/9780470291269.ch16Bohner, M., Silicon-substituted calcium phosphates - A critical view (2009) Biomaterials, 30, pp. 6403-6406. , http://dx.doi.org/10.1016/j.biomaterials.2009.08.007, PMid:19695699Carrodeguas, R.G., De Aza, S., α-Tricalcium phosphate: Synthesis, properties and biomedical applications (2011) Acta Biomaterialia, (7), pp. 3536-3546. , http://dx.doi.org/10.1016/j.actbio.2011.06.019, PMid:21712105Mestres, G., Van C, L., Ginebra, M.P., Silicon-stabilized α-tricalcium phosphate and its use in a calcium phosphate cement: Characterization and cell response (2011) Acta Biomaterialia, , http://dx.doi.org/10.1016/j.actbio.2011.11.021, PMid:22154863Reid, J.W., Pietak, A., Sayer, M., Dunfield, D., Smith, T.J.N., Phase formation and evolution in the silicon substituted tricalcium phosphate/apatite system (2005) Biomaterials, 26, pp. 2887-2897. , http://dx.doi.org/10.1016/j.biomaterials.2004.09.005, PMid:15603784Motisuke, M., Carrodeguas, R.G., Zavaglia, C.A.C., Mg-free precursors for the synthesis of pure phase Si-doped α-Ca 3(PO 4) 2 (2008) Key Engineering Materials, 361-363, pp. 199-202. , http://dx.doi.org/10.4028/www.scientific.net/KEM.361-363.199Camiré, C.L., Saint-Jean, S.J., McCarthy, I., Mochales-Palau, C., Lidgren, L., Planell, J.A., Production methodology and reactivity of silica substituted α phase tricalcium phosphate (2004) Proceedings of the 7th WBC, pp. 17-21. , 2004SydneyCullity, B.D., (1956) Elements of X-Ray Diffraction, , Indiana: Addion-Wesley Publishing Company IncC266-04: Standard Test Method for Time of Setting of Hydraulic-Cement Paste by Gillmore Needles, , American Society for Testing and Materials - ASTMGinebra, M.P., Fernandez, E., De Maeyer, E.A.P., Verbeeck, R.M.H., Boltong, M.G., Ginebra, J., Setting reaction and hardening of an apatitic calcium phosphate cement (1997) Journal of Disability Research, 76, pp. 905-912Dos Santos, L.A., Carrodeguas, R.G., Rogero, S.O., Higa, O.Z., Boschi, A.O., Arruda, A.C.F., Alpha-tricalcium phosphate cement: In vitro cytotoxicity (2002) Biomaterials, 23, pp. 2035-2042. , http://dx.doi.org/10.1016/S0142-9612(01)00333-7Motisuke, M., Carrodeguas, R.G., Zavaglia, C.A.C., Si-Tricalcium phosphate cement: Preparation, characterization and bioactivity in SBF (2011) Materials Research, 14, pp. 493-498. , http://dx.doi.org/10.1590/S1516-14392011005000065Langstaff, S., Sayer, M., Smith, T.J.M., Pugh, S.M., Resorbable bioceramics based on stabilized calcium phosphates. Part I: Rational design, sample preparation and material characterization (1999) Biomaterials, 20, pp. 135-150. , http://dx.doi.org/10.1016/S0142-9612(99)00086-1Carrodeguas, R.G., De Aza, A.H., Turrillas, X., Pena, P., De Aza, S., New approach to the β → α polymorphic transformation in magnesium-substituted tricalcium phosphates and its pratical implications (2008) Journal of the American Ceramic Society, 91, pp. 1281-1286. , http://dx.doi.org/10.1111/j.1551-2916.2008.02294.xGinebra, M.P., Fernandez, E., Fcm, D., Boltong, M.G., Muntasell, J., Font, J., The effects of temperature on the behavior of an apatitic calcium phosphate cement (1995) Journal of Materials Science: Materials in Medicine, 6, pp. 857-860. , http://dx.doi.org/10.1007/BF00134332Sarda, S., Fernández, E., Nilsson, M., Balcells, M., Planell, J.A., Kinetic study of citric acid influence on calcium phosphate bone cement as water-reducing agent (2002) Journal of Biomedical Materials Research, p. 6

Mg-free Precursors For The Synthesis Of Pure Phase Si-doped A-ca 3(po4)2

On this paper, methods to obtain Mg-free reagents for synthesizing pure phase Sistabilized α-TCP were established. The Mg contents of synthesized reagents were considerably lower than those in commercially available reactants. Pure Si-doped (2.5 at.-% of P by Si substitution) a-TCP was obtained by solid state reaction from synthetic reagents at temperature as low as 1200°C When commercial reagents were employed for the solid state synthesis, a mixture of α- and β-TCP was obtained even when the solid state reaction was conducted at 1300 °C.361-363 I199202Langstaff, S., Sayer, M., Smith, T.J.N., Pugh, S.M., Hesp, S.A.M., Thompson, W.T., (1999) Biomaterials, 20, p. 1727Langstaff, S., Sayer, M., Smith, T.J.N., Pugh, S.M., (2001) Biomaterials, 22, p. 135Reid, J.W., Pietak, A., Sayer, M., Dunfield, D., Smith, T.J.N., (2005) Biomaterials, 26, p. 2887Reid, J.W., Tuck, L., Sayer, M., Fargo, K., Hendry, J.A., (2006) Biomaterials, 27, p. 2916E. Fernández, M.G. Boltong, M.P. Ginebra, J.A. Planìli and F.C.M. Driessens, in: Proceedings of the 4th Euro Ceramics Conference (Oct. 2-6, 1995, Riccione, Italy), 8, p. 103, edited by A. Ravaglioli, Faenza Editrice S.p.A. (1995)Camiré, C.L., Saint-Jean, S.J., Mochales, C., Nevsten, P., Wang, J.-S., Lidgren, L., McCarthy, I., Ginebra, M.-P., (2006) J. Biomed. Mater. Res. Part B: Appl. Biomater, 76 B, p. 424Arcos, D., Sánchez-Salcedo, S., Izquierdo-Barba, I., Ruiz, L., González-Calbet, J., Vallet-Regí, M., (2006) J. Biomed. Mater. Res, 78 A (PART A), p. 762Carrodeguas, R.G., De Aza, A.H., Jiménez, J., De Aza, P.N., Pena, P., López-Bravo, A., De Aza, S., (2007) Key Eng. Mater, 20, pp. XXXI.R. Gibson, M. Akao, S.M. Best and W. Bonfield, in: Bioceramics 9, Proceedings of the 9th International Symposium on Ceramics in Medicine (Nov. 1996, Otsu, Japan), p. 173., edited by T. Kokubo, T. Nakamura and F. Miyaji, Pergamon (1996)TenHuisen, K.S., Brown, P., (1999) J. Am. Ceram. Soc, 82, p. 2813Enderle, R., Götz-Neunhoeffer, F., Göbbels, M., Müller, F.A., Greil, P., (2005) Biomaterials, 26, p. 3379Marchi, J., Dantas, A.C., Greil, P., Bressiani, J.C., Bressiani, A.H.A., Müller, F.A., (2007) Mater. Res. Bull, 42, pp. 1040-1050J.W. Reid, K. Fargo, J.A. Hendry and M. Sayer: Mater. Lett. (2007), doi: 10.1016/j.matlet.2006.12.046 (in press)Flaschka, H.A., (1959) EDTA Titrations, , Pergamon, LondonLevin, E.M., Robbins, C.R., McMurdie, H.F., (1964) Phase Diagrams for Ceramists, p. 246. , edited by M.K. Reser, Fig, American Ceramic Societ

Si-tricalcium Phosphate Cement: Preparation, Characterization And Bioactivity In Sbf

There are evidences considering the effectiveness of Si on enhancing biological properties of calcium phosphates; however, there are not many works relating to the Si-alpha-TCP bone cement. The influence of silicon doping on the properties of α-TCP cement was analyzed. Si-TCP was obtained by a solid state reaction employing CaCO 3, CaHPO 4 and CaSiO 3 and powder was analyzed by XRD, FTIR, XRF and BET specific area. Cement samples were analyzed for their surface of fracture morphology, mechanical resistance and SBF bioactivity. Cement mechanical resistance was not satisfactory for biomedical application; nonetheless, sample's surface was coated by an apatite layer after immersion in SBF. Notwithstanding, to ensure that silicon is the element responsible for increasing the material's bioactivity it is necessary to evaluate the in vivo performance of the bone cement obtained in this work.144493498Wei, X., Ozan, U., Ankit, A., Acar, H.Y., Akinc, M., Dissolution behavior of Si, Zn-codoped tricalcium phosphate (2009) Materials Science and Engineering C, 29 (1), pp. 126-135. , http://dx.doi.org/10.1016/j.msec.2008.05.020Matsumoto, N., Yoshida, K., Hashimoto, K., Toda, Y., Thermal stability of β-tricalcium phospahte doped with monovalent metal ions (2009) Materials Research Bulletin, 44 (9), pp. 1889-1894. , http://dx.doi.org/10.1016/j.materresbull.2009.05.012Li, X., Ito, A., Sogo, Y., Wang, X., Le Geros, R.Z., Solubility of Mg-containing β-tricalcium phosphate at 25°C (2009) Acta Biomaterialia, 5 (1), pp. 508-517. , http://dx.doi.org/10.1016/j.actbio.2008.06.010Pietak, A.M., Reid, J.W., Stott, M.J., Sayer, M., Silicon substitution in the calcium phosphate bioceramics (2007) Biomaterials, 28 (28), pp. 4023-4032. , DOI 10.1016/j.biomaterials.2007.05.003, PII S014296120700381XArcos, D., Sanchez-Salcedo, S., Izquierdo-Barba, I., Ruiz, L., Gonzalez-Calbet, J., Vallet-Regi, M., Crystallochemistry, textural properties, and in vitro biocompatibility of different silicon-doped calcium phosphates (2006) Journal of Biomedical Materials Research - Part A, 78 (4), pp. 762-771. , DOI 10.1002/jbm.a.30790Camiré, C.L., Saint-Jean, S.J., McCarthy, I., Mochales-Palau, C., Lidgren, L., Planell, J.A., Production methodology and reactivity of silica substituted α phase tricalcium phosphate (2004) Proceedings Ofth 7th World Biomaterials Congress, , Sydney, Australia. Sydney2004Camire, C.L., Saint-Jean, S.J., Mochales, C., Nevsten, P., Wang, J.-S., Lidgren, L., McCarthy, I., Ginebra, M.-P., Material characterization and in vivo behavior of silicon substituted a-tricalcium phosphate cement (2006) Journal of Biomedical Materials Research - Part B Applied Biomaterials, 76 (2), pp. 424-431. , DOI 10.1002/jbm.b.30385Reid, J.W., Pietak, A., Sayer, M., Dunfield, D., Smith, T.J.N., Phase formation and evolution in the silicon substituted tricalcium phosphate/apatite system (2005) Biomaterials, 26 (16), pp. 2887-2897. , DOI 10.1016/j.biomaterials.2004.09.005, PII S0142961204008014Reid, J.W., Tuck, L., Sayer, M., Fargo, K., Hendry, J.A., Synthesis and characterization of single-phase silicon-substituted a-tricalcium phosphate (2006) Biomaterials, 27 (15), pp. 2916-2925. , DOI 10.1016/j.biomaterials.2006.01.007, PII S0142961206000184Langstaff, S., Sayer, M., Smith, T.J.N., Pugh, S.M., Hesp, S.A.M., Thompson, W.T., Resorbable bioceramics based on stabilized calcium phosphates. Part I: Rational design, sample preparation and material characterization (1999) Biomaterials, 20 (18), pp. 1727-1741. , DOI 10.1016/S0142-9612(99)00086-1, PII S0142961299000861Carrodeguas, R.G., De Aza, S., Alpha-tricalcium phosphate: Synthesis, properties and biomedical applications (2011) Acta Biomateriallia, , in pressGaspar, A.M.M., Saska, S., Carrodeguas, R.G., De Aza, A.H., Pena, P., De Aza, P.N., Biological response to wollastonite doped α-tricalcium phosphate implants in hard and soft tissues in rats (2009) Key Engineering Materials, 396-398, pp. 7-10Motisuke, M., Carrodeguas, R.G., Zavaglia, C.A.C., Mg-free precursors for the synthesis of pure phase Si-doped (X-Ca3 (PO4) 2 (2008) Key Engineering Materials, 361-363, pp. 199-202. , http://dx.doi.org/10.4028/www.scientific.net/KEM.361-363.199Carrodeguas, R.G., De Aza, A.H., Jimenez, J., De Aza, P.N., Pena, P., López-Bravo, A., Preparation and in vitro characterization of wollastonite doped tricalcium phosphate bioceramics (2008) Key Engineering Materials, 361-363, pp. 237-240. , http://dx.doi.org/10.4028/www.scientific.net/KEM.361-363.237Reid, J.W., Fargo, K., Hendry, J.A., Sayer, M., The influence of trace magnesium content on the phase composition of silicon-stabilized calcium phosphate powders (2007) Materials Letters, 61 (18), pp. 3851-3854. , DOI 10.1016/j.matlet.2006.12.046, PII S0167577X06015291Carrodeguas, R.G., De Aza, A.H., Turrillas, X., Pena, P., De Aza, S., New approach to the β → α polymorphic transformation in magnesiumsubstituted tricalcium phosphates and its pratical implications. Journal of the American Ceramic Society (2008) Journal of the American Ceramic Society, 91 (4), pp. 1281-1286. , DOI 10.1111/j.1551-2916.2008.02294.xCullity, B.D., (1977) Elements of X-ray Diffraction, , Indiana: Addion-Wesley Publishing Company, IncGinebra, M.P., Fernandez, E., De Maeyer, E.A.P., Verbeeck, R.M.H., Boltong, M.G., Ginebra, J., Driessens, F.C.M., Planell, J.A., Setting reaction and hardening of an apatitic calcium phosphate cement (1997) Journal of Dental Research, 76 (4), pp. 905-912Dunfield, D., Sayer, M., Shurvell, H.F., Total attenuated reflection infrared analysis of silicon-stabilized tri-calcium phosphate (2005) Journal of Physical Chemistry B, 109 (42), pp. 19579-19583. , DOI 10.1021/jp0519823Ginebra, M.P., Driessens, F.C.M., Planell, J.A., Effect of the particle size on the micro and nanostructural features of a calcium phosphate cement: A kinetic analysis (2004) Biomaterials, 25 (17), pp. 3453-3462. , DOI 10.1016/j.biomaterials.2003.10.049, PII S0142961203009943Ginebra, M.P., Fernandez, E., Driessens, F.C.M., Planell, J.A., Modeling of the hydrolysis of α-tricalcium phosphate (1999) Journal of the American Ceramic Society, 82 (10), pp. 2808-2812. , http://dx.doi.org/10.1111/j.1151-2916.1999.tb02160.

Preparação e caracterização de microesferas defosfato tricálcico obtidas por spray drying

[EN] α-TCP microspheres were obtained by atomizing aqueous slurries containing 50 wt% of low crystallinity α-TCP and 1 wt% of citric acid. Poly(ethylene glycol) and poly(vinyl alcohol) were tested as a binder. The spray drying process yielded to microspheres with mean diameter around 20 μm and sphericity (horizontal and vertical length ratio) closest to one, which is essential to many applications, such as drug delivery and injectability of cements. The addition of binders was necessary to decrease the amount of loose particles and to improve powder flowability but it also caused a reduction in wettability and surface area. Best results were achieved with 3 wt% of PVA, as the microspheres presented the highest specific surface area, wettability, and sphericity. The microspheres prepared in this study may be used as injectable bone cements precursor since their geometry and flowability would favor paste homogeneity and injectability overcoming many drawbacks of today's injectable bone cements.[PT] Microesferas de α-TCP foram obtidas atomizando uma suspensão aquosa contendo 50% em massa de α-TCP com baixa cristalinidade e 1% em massa de ácido cítrico. Poli(etileno glicol) e poli(álcool vinílico) foram testados como ligantes. O processo de spray drying resultou em microesferas com diâmetros médios de aproximadamente 20 μm e esfericidade (razão de comprimentos na horizontal e na vertical) próxima a um, características essenciais para várias aplicações, como a liberação controlada de drogas e cimentos ósseos injetáveis. A adição dos ligantes foi necessária para reduzir a quantidade de partículas soltas e aumentar a fluidez do pó, mas também resultou em uma redução na molhabilidade e na área superficial das microesferas. Os melhores resultados foram obtidos com 3% de PVA já que as microesferas apresentaram a maior área superficial, molhabilidade e esfericidade. As microesferas preparadas neste estudo podem ser utilizadas como precursoras de cimentos ósseos injetáveis, já que a sua geometria esférica e sua fluidez favorecem a homogeneidade e injetabilidade das pastas sobrepujando as principais dificuldades dos cimentos injetáveis atuais.C.O. Reno thanks FAPESP, São Paulo, Brazil, for the scholarships (Process No. 2013/03208-1, 2013/26248-9). Authors would like to thank FAPESP, São Paulo, Brazil for the financial support (Process No 2013/19642-2). R.G. Carrodeguas thanks CNPq, Brazil, for DCR Grant Process No. 351182/2013-6. Authors recognize the financial support from the Ministry of Economy and Competitiveness of Spain provided through projects BIOJER (MAT2013-48426-C2-1-R). Authors would like to thank Prof. Anderson de Oliveira Lobo, PhD from Universidade do Vale do Paraíba. (UNIVAP) for permitting contact angle analysis

Bonelike Apatite Coating On Ti6al4v: Novel Nucleation Process Using Sodium Silicate Solution

Despite the well known biocompatibility and bioactivity of synthetic hydroxyapatite (HA), its use, as structural biomaterial has been limited because of intrinsic low mechanical properties. In order to avoid this problem, metallic implants are commonly coated with a thin HA layers. Among the various techniques used to produce coatings on metals, the biomimetic process has gained increasing attention in the last years. In this work, a metallic substrate (Ti6Al4V) was coated using a variation of the traditional biomimetic method. The HA coatings were characterised by diffused reflectance spectroscopy (DRIFT) and scanning electron microscopy (SEM).416-4181658662Dhert, W.J.A., Plasma-sprayed coatings and hard-tissue compatibility (1992) A Comparative Study on Fluorapatite, Magnesiumwhitlockite and Hydroxyapatite, pp. 4-6. , Offsetdrukkerij Haveka B. U., AblasserdamJarcho, M., (1992) Dent. Clin. North Am., 36 (1), p. 19Fisher, G., (1986) Ceram. Bull., 65 (2), p. 283Abe, Y., Kokubo, T., Yamamuro, T., (1990) J. Mater. Sci. Mater. Med., 1, p. 233Lacefield, W.R., Hydroxyapatite coating (1993) An Introduction to Bioceramics. Advanced Series in Ceramics, 1, pp. 223-238. , L L Hench and J Wilson, Eds., World Scientific Publishing Co. Pte. Ltda., SingaporeKlee, W.E., Engel, G., (1970) Inorg. Nucl. Chem., 32, p. 1837Stoch, A., Jastrzebski, W., Brozek, A., Stoch, J., Szaranice, J., Trybalska, B., Kmita, G., (2000) J. Molecular Structure, 555, p. 375Kokubo, T., Kim, H.M., Miyaji, F., Takadama, H., Miyazaki, T., (1999) Composite: Part A: Applied Science and Manufacturing, 30, p. 405Hench, L.L., (1991) Ceramic Glasses and Glasses Ceramics in Biomaterials Science: An Introductory Text, , B D Ratuer and A S Hoffman, Eds., Academic Press, Orland

Dual-setting Calcium Phosphate Cement Modified With Ammonium Polyacrylate

α-Tricalcium phosphate bone cement, as formerly designed and developed by Driessens et al., consists of a powder composed by α-tricalcium phosphate (α-TCP) and hydroxyapatite (HA) seeds, and an aqueous solution of Na2HPO4 as mixing liquid. After mixing powder and liquid, α-TCP dissolves into the liquid and calcium deficient hydroxyapatite (CDHA), more insoluble than the former, precipitates as an entanglement of crystals, which causes the setting and hardening of the cement, α-TCP bone cement offers several advantages in comparison to calcium phosphate bioceramics and acrylic bone cements as bone graft and repairing material, like perfect adaptability to the defect size and shape, osteotransductibility, and absence of thermal effect during setting. The main handicap is its low mechanical strength. Therefore, approaching its mechanical strength to that of human bone could considerably extend its applications. In the present work, an in situ polymerization system based on acrylamide (AA) and ammonium polyacrylate (PA) as liquid reducer was added to α-TCP cement to increase its mechanical strength. The results showed that the addition of 20 wt% of acrylamide and 1 wt% AP to the liquid increased the compressive and tensile strength of α-TCP bone cement by 149 and 69% (55 and 21 MPa), respectively. The improvement in mechanical strength seems to be caused by a decrease of porosity and the reinforcing effect of a polyacrylamide network coexisting with the entanglement of CDHA crystals. The studied additives do not affect the nature of the final product of the setting reaction, CDHA, but promote the reduction of its crystal size.275412418Gruninger, S.E., Siew, C., Chow, L.C., Oyoung, A., Tsao, N.K., Brown, W.E., Evaluation of the biocompatibility of a new calcium phosphate setting cement (1984) J Dent Res, 63, p. 200Yu, D., Wong, J., Matsuda, Y., Fox, J.L., Higuchi, W.I., Otsuka, M., Self-setting hydroxyapatite cement: A novel skeletal drug delivery system for antibiotics (1992) J Pharm Sci, 81 (6), pp. 529-531Ginebra, M.P., Boltong, M.G., Fernández, E., Planell, J.A., Driessens, F.C.M., Effect of various additives and temperature on some properties of an apatitic calcium phosphate cement (1995) J Mater Sci Mater Med, 6, pp. 612-616Ginebra, M.P., Fernández, E., Driessens, F.C.M., Planell, J.A., The effect of Na2HPO4 addition on the setting reaction kinetics of an α-TCP cement (1998) Bioceramics, 11, pp. 243-246. , LeGeros RZ, LeGeros JP, eds., (Proceedings of the 11th International Symposium on Ceramics in Medicine), New York: World Scientific Publishing Co. Pte. LtdGinebra, M.P., Fernández, E., Driessens, F.C.M., Boltong, M.G., Muntasell, J., Font, J., Planell, J.A., The effects of temperature on the behaviour of an apatitic calcium phosphate cement (1995) J Mater Sci Mater Med, 6, pp. 857-860Santos, L.A., Oliveira, L.C., Rigo, E.C.S., Carrodéguas, R.G., Boschi, A.O., Arruda, A.C.F., Influence of polymeric additives on the mechanical properties of α-tricalcium phosphate cement (1999) Bone, 25 (2), pp. 99S-102SCarrodéguas, R.G., Oliveira, L.C., Santos, L.A., Rigo, E.C.S., Boschi, A.O., Mondéjar, S.P., Cementos de α-fosfato tricálcico de fraguado doble (1999) Revista CNIC. Serie Ciencias Químicas (Cuba), 30 (3), pp. 153-158Driessens, F.C.M., Fernández, E., Ginebra, M.P., Boltong, M.G., Planell, J.A., Calcium phosphates and ceramic bone cements vs. acrylic cements (1997) Anal Quire Int, 93, pp. S38-S43Monma, H., Goto, M., Kohmura, T., Effect of additives on hydration and hardness of tricalcium phosphate (1984) Gypsum and Lime, 188, pp. 11-16Jenkins, R., Vries, J.L., (1971) An Introduction to X-ray Powder Diffractometry, , N. V. Philips Gloeilampenfabrieken - Eindhoven HolandaGinebra, M.P., Fernández, E., De Maeyer, E.A.P., Verbeeck, R.M.H., Boltong, M.G., Ginebra, J., Driessens, F.C.M., Planell, J.A., Setting reaction and hardening of an apatitic calcium phosphate cement (1997) J Dent Res, 76 (4), pp. 905-912Fernández, E., Ginebra, M.P., Boltong, M.G., Verbeeck, R.M.H., Planell, J.A., Kinetic study of the setting reaction of a calcium phosphate bone cement (1996) J Biomed Mater Res, 32, pp. 367-374Bermúdez, O., Boltong, M.G., Driessens, F.C.M., Planell, J.Á., Development of an octacalcium phosphate cement (1994) J Mater Sci Mater Med, 5, pp. 144-146Tampieri, A., Celotti, G., Szontagh, F., Landi, E., Sintering and characterization of HA and TCP bioceramics with control of their strength and phase purity (1997) J Mater Sci Mater Med, 8, pp. 29-37Famery, R., Richard, N., Boch, P., Preparation of α- and β-tricalcium phosphate ceramics with and without magnesium addition (1994) Ceramics International, 20, pp. 327-336Chow, L.C., Hirayama, S., Takagi, S., Parry, E., Diametral tensile strength and compressive strength of a calcium phosphate cement: Effect of applied pressure (2000) J Biomed Mater Res, 53, pp. 511-517Miyamoto, Y., Ishikawa, K., Takechi, M., Toh, T., Yuasa, T., Nagayama, M., Suzuki, K., Basic properties of calcium phosphate cement containing atelocollagen in its liquid or powder phases (1998) Biomaterials, 19, pp. 707-715Miyazaki, K., Horibe, T., Antonucci, J.M., Takagi, S., Chow, L.C., Polymeric calcium phosphate cements: Analysis of reaction products and properties (1993) Dent Mater, 9, pp. 41-45Matsuya, Y., Antonucci, J.M., Matsuya, S., Takagi, S., Chow, L.C., Polymeric calcium phosphate cements derived from poly(methyl vinyl ether-maleic acid) (1996) Dent Mater, 12, pp. 2-7Cherng, A., Takagi, S., Chow, L.C., Effects of hxydroxypropyl methylcellulose and other gelling agents on the handling properties of calcium phosphate cement (1997) J Biomed Mater Res, 35, pp. 273-277Sawamura, T., Hattori, M., Calcium Phosphate Composition and a Setting Solution Therefore, , US Patent 5,980,625, November 9, 1999Sawamura, T., Hattori, M., Okuyama, M., Calcium Phosphate Cement and Calcium Phosphate Cement Composition, , US Patent 5,993,535, November 30, 1999LeGeros, R.Z., (1991) Calcium Phosphates in Oral Biology and Medicine Monography in Oral Science, 15. , Switzerland: S. 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α-tricalcium Phosphate Cement: "in Vitro" Cytotoxicity

Calcium phosphate-based bioceramics have revolutionized orthopedic and dental repair of damaged parts of the bone system. Among these materials, calcium phosphate-based cements, with hydraulic setting, stand out due to their biocompatibility and in situ hardening, which allow easy manipulation and adaptation to the shape and dimensions of bone defects. An investigation was made of the in vitro cytotoxic effect of calcium phosphate cement based on α-tricalcium phosphate, immersed for different lengths of time in simulated body fluid (SBF), based on the ISO-10993 "Biological Evaluation of Medical Devices" standard. The culture medium was Chinese hamster ovary (CHO) cells in contact with diluted cement extracts. The results revealed that the calcium phosphate cement used was cytotoxic and that the material's cytotoxicity decreased the longer the cement was immersed in SBF. © 2002 Elsevier Science Ltd. All rights reserved.23920352042Gruninger, S.E., Siew, C., Chow, L.C., O'Young, A., Ts'ao, N.K., Brown, W.E., Evaluation of the biocompatibility of a new calcium-phosphate setting cement (1984) J Dent Res, pp. 63-200Yu, D., Wong, J., Matsuda, Y., Fox, J.L., Higuchi, W.I., Otsuka, M., Self-setting hydroxyapatite cement: A novel skeletal drug delivery system for antibiotics (1992) J Pharm Sci, 81 (6), pp. 529-531Driessens, F.C.M., Fernández, E., Ginebra, M.P., Boltong, M.G., Planell, J.A., Calcium phosphates and ceramic bone cements vs. acrylic cements (1997) Anal Quim Int Ed, 93, pp. S38-S43Monma, H., Goto, M., Kohmura, T., Effect of additives on hydration and hardness of tricalcium phosphate (1984) Gypsum lime, 188, pp. 11-16Ginebra, M.P., Fernández, E., Driessens, F.C.M., Planell, J.A., The effect of Na2HPO4 addition on the setting reaction kinetics of an α-TCP cement (1998) Biomaterials, 11, pp. 243-246Jenkins, R., Vries, J.L., (1971) An introduction to X-ray powder diffractometry, , Eindhoven, Holanda: N.V. Philips Gloeilampenfabrieken(1992) International standard: Biological evaluation of medical devices - Part 5: tests for cytotoxicity: in vitro methods, , ISO 10993-5Nakamura, A., Ikarashi, Y., Tshuchiya, T., Kaniwa, M., Radiation vulcanized natural rubber latex is not cytotoxic (1989) Proceedings of the International Symposium on Radiation Vulcanization of Natural Rubber Latex, pp. 79-87. , Japan Atomic Research Institute JAERI-M 89-228, Takasaki, JapanDriessens, F.C.M., Boltong, M.G., Bermudez, O., Planell, J., Efective formulations for the preparation of calcium phosphate bone cements (1994) J Mater Sci Mater Med, 5, pp. 164-170Fernández, E., Ginebra, M.P., Bermudez, O., Boltong, M.G., Driessens, F.C.M., Dimensional and thermal behaviour of calcium phosphate cements during setting compared to PMMA bone cements (1995) J Mater Sci Lett, 14, pp. 4-5Carrodéguas, R.G., Rigo, E.C., Oliveira, L.C., Santos, L.A., Boschi, A.O., Recubrimiento de hidroxiapatita sobre ceramica de titanato de bario BIOMAT'97 - Congresso Internacional de Biomateriales, , 4 de Maio/1997, Universidad de La Habana, CubaLi, P., Ohtswki, C., Kokubo, T., Apatite formation induced by silica gel in a simulated body fluid (1992) J Am Ceram Soc, 75, pp. 2094-2097Fresa, R., Constantini, A., Buri, A., Apatite formation on (2-x)CaO·x/3M2O3·2SiO2 glasses (M=La, Y0<x<0.6) in a simulated body fluid (1995) Biomaterials, 16, pp. 849-854Oliveira, J.M., Correia, R., Fernandes, M.H., Surface modifications of a glass and a glass-ceramic of the MgO-3CaO·P2O5-SiO2 system in a simulated body fluid (1995) Biomaterials, 16, pp. 849-854Santos, L.A., Oliveira, L.C., Rigo, E.C.S., Carrodéguas, R.G., Boschi, A.O., Arruda, A.C.F., Influence of polymeric additives on the mechanical properties of α-tricalcium phosphate cement (1999) Bone, 25 (2), pp. 99S-102SSantos, L.A., Oliveira, L.C., Rigo, E.C.S., Carrodéguas, R.G., Boschi, A.O., Arruda, A.C.F., Fiber reinforced calcium phosphate cement (2000) Artif Organs, 24 (3), pp. 212-216Carrodéguas, R.G., Santos, L.A., Rigo, E.C.S., Mondéjar, S.P., Arruda, A.C.F., Boschi, A.O., Improvement of mechanical strength of calcium phosphate cement by dual-setting principle J Mater Sci Mater Med, , submitted for publicationBermúdez, O., Boltong, M.G., Driessens, F.C.M., Planell, J.A., Development of an octacalcium phosphate cement (1994) J Mater Sci Mater Med, 5, pp. 144-146Tampieri, A., Celotti, G., Szontagh, F., Landi, E., Sintering and characterization of HA and TCP bioceramics with control of their strength and phase purity (1997) J Mater Sci Mater Med, 8, pp. 29-37Famery, R., Richard, N., Boch, P., Preparation of α- and β-tricalcium phosphate ceramics with and without magnesium addition (1994) Ceram Int, 20, pp. 327-336Fernández, E., Ginebra, M.P., Boltong, M.G., Verbeeck, R.M.H., Planell, J.A., Kinetic study of the setting reaction of a calcium phosphate bone cement (1996) J Biomed Mater Res, 32, pp. 367-374Ginebra, M.P., Fernández, E., De Maeyer, E.A.P., Verbeeck, R.M.H., Boltong, M.G., Ginebra, J., Driessens, F.C.M., Planell, J.A., Setting reaction and hardening of an apatitic calcium phosphate cement (1997) J Dent Res, 76 (4), pp. 905-912Driessens, F.C.M., Boltong, M.G., Bermúdez, O., Planell, J.A., Ginebra, M.P., Fernández, E., Effective formulations for the preparation of calcium phosphate bone cements (1994) J Mater Sci Mater Med, 5, pp. 164-170Bermúdez, O., Boltong, M.G., Driessens, F.C.M., Planell, J.A., Development of some calcium phosphate cements from combinations of α-TCP, MCPM and CaO (1994) J Mater Sci Mater Med, 5, pp. 160-163Fernández, E., Gil, J.F., Ginebra, M.P., Driessens, F.C.M., Planell, J.A., Production and characterization of new calcium phosphate bone cements in the CaHPO4-α-Ca3(PO4)2 system: pH, workability and setting times (1999) J Mater Sci Mater Med, 10, pp. 223-230Chow, L.C., Development of self-setting calcium phosphate cements (1991) J Ceram Soc Jpn (The Centennial Memorial Issue), 99 (10), pp. 954-964Ishikawa, K., Miyamoto, Y., Suzuki, K., Nagayama, M., Mechanism of inflamatory response to calcium phosphate cement (1998) J Dent Res, 1446, p. 812Miyamoto, Y., Ishikawa, K., Takechi, M., Toh, T., Yuasa, T., Nagayama, M., Suzuki, K., Histological and composicional evaluations of three types of calcium phosphate cements when implanted in subcutaneous tissue immediately after mixing (1999) J Biomed Mater Res, 48, pp. 36-4