Bioactive glass as precursor of designed-architecture scaffolds for tissue engineering

Abstract

In this work, the conditions to obtain concentrated and fluid suspensions from a bioactive glass (55-SiO2; 41-CaO; 4-P2O 5; mol %) were investigated. The influence of the heat treatment of the glass on the specific surface area, solubility, bioactivity, and finally on their dispersion characteristics was studied. Zeta potential and viscosity measurements were carried out, and based on the obtained results, the best dispersant was selected. The optimum concentration of dispersant, maximum content of solid and time of mixing were also investigated. Slurries containing 50 vol % could be obtained calcining the glass at 1100°C and using Darvan 811 (sodium polyacrylate) as dispersant. Scaffolds with designed architecture were prepared from these suspensions combining the gelcasting method and the stereo-lithography technique. A polymeric negative (replica of the desired structure) was previously obtained by stereolithography. The slurry was cast into the molds and then polymerized (gelcasting method). The negative was eliminated by heat treatment. After sintering at 1300°C, scaffolds with interconnected porosity and three-dimensional channels of 400-470 μm and macropores of 1.4 μm were obtained. © 2006 Wiley Periodicals, Inc.