In Vitro Assessment of Porous Glass Scaffolds for Bone Tissue Engineering

Two types of glass scaffolds fabricated from silicate-based 13-93 glass were tested for possible use in bone tissue engineering. The two scaffold types included constructs prepared by a polymer foam infiltration procedure to simulate trabecular bone and sintered glass fiber construct. These scaffolds were seeded with mouse MLO-AS cells, an established line of osteogenic cells used as a model of developing bone tissue. Assays were conducted to assess growth and function of the seeded cells over incubation times ranging from two to six days. Cell adhesion to the scaffolds was confirmed by scanning electron microscopy. Quantitative measurements of total cellular protein indicate that the rate of cell growth on the scaffolds is similar to that on standard tissue culture plates. MTT assays showed significant penetration and proliferation of cells within the interior of the scaffolds. Alkaline phosphatase, a marker enzyme of bone cell differentiation, was assayed to assess cell function of the scaffolds. Alkaline activity of this marker enzyme increased linearly during the six-day incubation on both scaffolds indicating they both support differentiation. The results obtained suggest that 13-93 sponge and fiber scaffolds are effective frameworks for bone tissue engineering.