O3125 OPTIMISATION OF HYDROXYAPATITE BY THE ADDITION OF HUMAN MESENCHYMAL STEM CELLS, AND RECOMBINANT HUMAN OSTEOGENIC PROTEIN- 1 (BMP-7)

Abstract

Aim: Mesenchymal stem cells (MSCñs) attach to hydroxyapaptite surfaces (HA) surfaces and given appropriate stimuli from human Bone Morphogenetic Protein 7 (OP -1), will differentiate into osteogenic cells. Our hypothesis is that combining HA/MSC/BMP-7 will provide a superior osseoinductive property compared to HA alone. Methods: Porous hydroxyapatite (74.6% porosity, and 0.65% closed porosity) loaded with MSCñs (2 x 105) were compared to samples loaded with rhBMP-7 (400 ng/0.1g HA,) of the same MSC concentration over a fourteen day period. Quantitative analysis (Cell proliferation, measured by total DNA and the Alamar blue assay and Cell differentiation- alkaline phosphatase activity) and qualitative (Light and Scanning Electron Microscopy) were performed. The Students T-test was performed. Ethical approval for the use of human tissue was obtained prior to experimentation Results: Cell proliferation as indicated by total DNA, and Alamar blue was signiþcantly enhanced (P< 0.05) in the BMP-7 loaded composite at all time points. ALP production and release was enhanced in loaded samples. ALP production per unit DNA was also enhanced in the loaded samples and was signiþ-cant at day fourteen. Conclusion: Results indicate that the loaded composites showed enhanced cell proliferation, and ALP production and release. SEM analysis also demonstrated enhanced cell attachment and an increase number of proliferative cells. Thus the HA/MSC/BMP-7 composite displayed superior osseo-inductive properties in comparison to the HA/MSC composite.