J. Biomed. Mater. Res. 2003, 66A, 860-869

 

Effects of Materials Parameters on Mineralization and Degradation of Sol-gel Bioactive Glasses with 3D-Ordered Macroporous (3DOM) Structures

 

Kai Zhang¹, Hongwei Yan², David C. Bell³,

Andreas Stein^{2 *}, Lorraine F. Francis^{1 *}

 

¹Department of Chemical Engineering and Materials Science

²Department of Chemistry

³Institute of Technology Characterization Facility

University of Minnesota, Minneapolis, MN 55455

 

Abstract

 

Bioactive glasses (BGs) with three-dimensionally ordered macroporous (3DOM) structures were prepared by combining a sol-gel synthesis with colloidal crystal templating. 3DOM sol-gel BGs with two compositions (20mol% CaO–80% SiO₂ and 20mol% CaO–4% P₂O₅–76% SiO₂) and three macropore sizes (average: 345, 440, and 790 nm) were prepared. Glasses were separated into two particle sizes (212 mm < small < 355 mm and 600 mm < large < 1000 mm). The glasses were soaked in simulated body fluid (SBF) at 37°C for 2 or 4 days and the effects of composition, particle size, and macropore size on the formation of apatite and glass degradation were characterized. Within the parameter range of the experiments, several comparisons could be made. First, the formation of apatite and degradation of the glass were slightly enhanced for the phosphate containing composition. Second, large particles formed less apatite and degraded less completely as compared with small particles. Lastly, an increase in macropore size slowed down the glass degradation and apatite formation processes, an effect related to the decreased internal surface area of the larger pore materials.