Mesenchymal stem cell ingrowth and differentiation on coralline hydroxyapatite scaffolds

Culture of osteogenic cells on a porous scaffold could offer a new solution to bone grafting using autologous human mesenchymal stem cells (hMSC) from the patient. We compared coralline hydroxyapatite scaffolds with pore sizes of 200 and 500 microm for expansion and differentiation of hMSCs. We cultivated the hMSC statically or in spinner flasks for 1, 7, 14 and 21 days and found that the 200-microm pore scaffolds exhibited a faster rate of osteogenic differentiation than did the 500-microm pore scaffolds as shown by an alkaline phosphatase activity assay and real-time reverse transcriptase polymerase chain reaction for 10 osteogenic markers. The 500-microm scaffolds had increased proliferation rates and accommodated a higher number of cells (shown by DNA content, scanning electron microscopy and fluorescence microscopy). Thus the porosity of a 3D microporous biomaterial may be used to steer hMSC in a particular direction. We found that dynamic spinner flask cultivation of hMSC/scaffold constructs resulted in increased proliferation, differentiation and distribution of cells in scaffolds. Therefore, spinner flask cultivation is an easy-to-use inexpensive system for cultivating hMSCs on small to intermediate size 3D scaffolds.