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Sol-gel-derived glass scaffold with high pore interconnectivity and enhanced bioactivity

Published online by Cambridge University Press:  31 January 2011

Ana C. Marques ,
Rui M. Almeida ,
Amath Thiema ,
Shaojie Wang ,
Matthias Falk  and
Himanshu Jain
Ana C. Marques
Affiliation:
Departamento de Engenharia de Materiais/ICEMS, Instituto Superior Técnico/TULisbon, Lisboa, Portugal
Rui M. Almeida
Affiliation:
Departamento de Engenharia de Materiais/ICEMS, Instituto Superior Técnico/TULisbon, Lisboa, Portugal
Amath Thiema
Affiliation:
Department of Physics, University Cheikh Anta Diop de Dakar, Dakar, Senegal
Shaojie Wang
Affiliation:
Department of Materials Science and Engineering, Lehigh University, Bethlehem, Pennsylvania 18015
Matthias Falk
Affiliation:
Department of Biological Sciences, Lehigh University, Bethlehem, Pennsylvania 18015
Himanshu Jain*
Affiliation:
Department of Materials Science and Engineering, Lehigh University, Bethlehem, Pennsylvania 18015
*
c) Address all correspondence to this author. e-mail: [email protected]
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Abstract

We report on the preparation of a bioactive CaO–SiO2 monolithic scaffold with interconnected bimodal nanomacro porosity, which simulates the morphology of a natural trabecular bone, by a newly developed modified sol-gel process. This method inherently creates nanopores, whose average diameter can be tailored to approximately 5–20 nm by solvent exchange. To achieve interconnected macroporosity (pores ∼5–300 μm in size), a polymer [poly(ethylene oxide)] is added, which causes phase separation simultaneously with the sol-gel transition. High-resolution scanning electron microscopy and mercury intrusion porosimetry demonstrate a high degree of three-dimensional interconnectivity and sharp distributions of pore size. In vitro bioactivity tests in simulated body fluid (SBF) show bioactivity of the material after soaking for approximately 5 h, as verified by the formation of a hydroxyapatite layer deep into the scaffold structure. Analysis of the SBF after the reaction indicates the dissolution of the samples, another desired feature of temporary scaffolds for bone regeneration. MG63 osteoblast-like cells seeded on our sol-gel glass samples responded better to samples with nanopores enlarged by a solvent exchange process than to the one with normal nanopores. Thus, the benefits of the high surface area achieved by sol-gel and solvent exchange procedures are most clearly demonstrated for the first time.

Keywords

BiomaterialPorositySol-gel
Type
Articles
Information
Journal of Materials Research , Volume 24 , Issue 12 , December 2009 , pp. 3495 - 3502
Copyright
Copyright © Materials Research Society 2009

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References

REFERENCES

1.Jones, J.R., Ehrenfried, L.M., and Hench, L.L.: Optimizing bioac-tive glass scaffolds for bone tissue engineering. Biomaterials 11. 964 (2006).CrossRefGoogle Scholar
2.Hench, L.L., Splinter, R.J., Allen, W.C., and Greenlee, T.K. Jr: Bonding mechanisms at the interface of ceramic prosthetic materials. J. Biomed. Mater. Res. 2, 117 (1971).Google Scholar
3.Pereira, M.M. and Hench, L.L.: Mechanisms of hydroxyapatite formation on porous gel-silica substrates. J. Sol-Gel Sci. Technol. 7, 59 (1996).Google Scholar
4.Freyman, T.M., Yannas, I.V., and Gibson, L.J.: Cellular materials as porous scaffolds for tissue engineering. Prog. Mater. Sci. 46, 273 (2001).Google Scholar
5.Nakanishi, K.: Pore structure control of silica gels based on phase separation. J. Porous Mater. 4, 67 (1997).Google Scholar
6.Takahashi, R., Sato, S., Sodesawa, T., Goto, T., Matsutani, K., and Mikami, N.: Bending strength of silica gel with bimodal pores: Effect of variation in mesopore structure. Mater. Res. Bull. 40, 1148 (2005).Google Scholar
7.Sepulveda, P., Jones, J.R., and Hench, L.L.: Bioactive sol-gel foams for tissue repair. J. Biomed. Mater. Res. 59, 340 (2002).Google Scholar
8.Jones, J.R., Tsigkou, O., Coates, E.E., Stevens, M.M., Polak, J.M., and Hench, L.L.: Extracellular-matrix formation and mineralization on a phosphate-free porous bioactive glass scaffold using primary human osteoblast (HOB) cells. Biomaterials 28, 1653 (2007).Google Scholar
9.Maekawa, H., Esquena, J., Bishop, S., Solans, C., and Chmelka, B.F.: Meso/macroporous inorganic oxide monoliths from polymer foams. Adv. Mater. 15, 591 (2003).Google Scholar
10.Liang, W. and Russel, C.: Resorbable, porous glass scaffolds by a salt sintering process. J. Mater. Sci. 41, 3787 (2006).Google Scholar
11.Yun, H.S., Kim, S.E., and Hyun, Y.T.: Fabrication of hierarchically porous bioactive glass ceramics. Key Eng. Mater. 361–363, 285 (2008).Google Scholar
12.Lofton, C.M., Milz, C.B., Huang, H., and Sigmund, W.M.: Bicon-tinuous porosity in ceramics utilizing polymer spinodal phase separation. J. Eur. Ceram. Soc. 25, 883 (2005).Google Scholar
13.Marques, A.C., Jain, H., and Almeida, R.M.: Sol-gel derived nano/ macroporous monolithic scaffolds. Phys. Chem. Glasses: Eur. J. Glass Sci. Technol. B 48, 65 (2007).Google Scholar
14.Marques, A.C., Jain, H., and Almeida, R.M.: Nano/macroporous monolithic scaffolds prepared by the sol-gel method. J. Sol-Gel Sci. Technol. 51, 42 (2009).Google Scholar
15.Kokubo, T. and Takadama, H.: How useful is SBF in predicting in vivo bone bioactivity? Biomaterials 27, 2907 (2006).CrossRefGoogle ScholarPubMed
16.Almeida, R.M. and Marques, A.C.: Characterization of sol-gel materials by infrared spectroscopy, in Handbook of Sol-Gel Science and Technology, edited by Sakka, S. (Kluwer Academic Publishers, London, 2005).Google Scholar
17.Pereira, M.M., Clark, A.E., and Hench, L.L.: Calcium phosphate formation on sol-gel-derived bioactive glasses in vitro. J. Biomed. Mater. Res. 28, 693 (1994).CrossRefGoogle ScholarPubMed
18.Olmo, N., Martín, A.I., Salinas, A.J., Turnay, J., Vallet-Regi, M., and Lizarbe, M.A.: Bioactive sol-gel glasses with and without a HCA layer as substrates for osteoblast cells adhesion and proliferation. Biomaterials 24, 3383 (2003).CrossRefGoogle ScholarPubMed
19.Zhong, J. and Greenspan, D.C.: Processing and properties of sol-gel bioactive glasses. J. Biomed. Mater. Res. 53, 694 (2000).Google Scholar