PAPER 42: COMPARATIVE ANALYSIS OF DIFFERENT GRAFTING MATERIALS IN VITRO

Abstract

Introduction: Different grafting materials for the filling of large bony defects are used in clinic. Aim of the present study was the comparative analyses of different bony grafting materials concerning their growth factor composition and osteoinductivity in vitro.

Materials & Methods: Different allograft preparations from the tissue bank of the Charité and two commercial demineralized bone matrices (DBM; DBX putty and Allomatrix) were analyzed. Using ELISA-kits following growth factors were quantified: VEGF, IGF-I, FGFa/b, TGF-β1, BMP-2/4, PDGF. Osteoinductivity was investigated by the induction of alkaline phosphatase activity in C2C12-cells.

Results: BMP-2 had the highest quantity within the different materials without differences between the materials. Differences in the quantity of the other growth factors were found between the investigated materials but also a high variability between the different batches was observable. The investigated materials showed individual differences which are donor related concerning their osteoinductive potential. A significant enhancement of osteogenic differentiation (AP) was seen for the two commercial DBM-products. For PES processed spongiosa from the tissue bank, 2 of the 5 materials had a negative effect on the AP-activity in the first incubation period but no effect in the second incubation period.

Discussion: The results of the present study revealed, that the different investigated grafting materials contain growth factors important for bone regeneration and an osteoinductive potential of the DBMs. A high batch/donor related variability, however, was detectable in both analysis. Important for the use in vivo is beside the osteoinductivity also the osteoconductivity and further comparative studies are necessary.