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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: hj00@lehigh.edu
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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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