Optimising the strength of macroporous bioactive glass scaffolds

Resorbable 3D macroporous bioactive scaffolds have been produced for tissue engineering applications by foaming sol-gel-derived bioactive glasses of the 70S30C (70mol% SiO2, 30mol% CaO) composition. The foams exhibit a hierarchical structure with interconnected macropores (10-500mum in diameter), which provide the potential for tissue ingrowth, and mesopores (2-50nm in diameter) that enhance bioactivity and resorbability. The effect of sintering temperature on the compressive strength of bioactive glass scaffolds was investigated. Compressive strength generally increased as sintering temperature increased to 800degreesC, due to a decrease in the textural mesopore diameter and a thickening of the macropore walls. The compressive strength of the foams did not increase as sintering temperature increased from 800degreesC to 1000degreesC, even though the mesoporosity was eliminated. The modal interconnected macropore diameter decreased as sintering temperature increased, but remained above 100mum until the sintering temperature exceeded 800degreesC. Sintering the bioactive glass foam at 800degreesC was the optimum treatment for the production of a macroporous scaffold for tissue engineering.