The Effect of a Fibirn-Collagen Sponge Scaffold on Osteogenic Differentiation of Rabbit Mesenchymal Stem Cells / 대한정형외과연구학회지

ABSTRACT

PURPOSE: To investigate whether collagen sponge with or without fibrin reinforcement can be used as a biocompatible scaffold for in vitro osteogenic differentiation of bone marrow-derived mesenchymal stem cells of rabbit (rBMSC). MATERIALS AND METHODS: rBMSC were isolated and expanded from the femur of New Zealand White rabbit. The nucleated cells were separated from red blood cells by Percoll(R) -gradient centrifuge. The porous collagen sponge with pore size 150~250 mm (Collacote(R), Sulzer Dental Inc. Carlsbad, CA) was used. rBMSC were seeded at a density of 2x10(5)/cm2 on two types of scaffold. In this study, type I scaffold consisted of collagen sponge without fibrin, while type II scaffold consisted of collagen sponge with fibrin. Fibrin composition used in this experiment was 0.5% fibrinogen and 0.5 unit/ml thrombin solution (Tisseel kit(R), Baxter AG, Vienna, Austria). After rBMSC seeded into scaffold, cells were induced into osteogenic differentiation by dexamethasone, -glycerol phosphate, and ascorbic acid. The contraction rate of the scaffold and pore size were measured by photoplanimetric method. Cell-mediated contraction rate was calculated by after normalization by DNA content in scaffold. The alkaline phosphatase activity and calcium content were measured by colorimetric method. The degree of mineralization and cellular distribution within the scaffold were analyzed by histomorphologic method. RESULTS: The contraction rate of scaffold was similar during the first 3 days in culture. The type II scaffold was contracted less than 20 % and type I scaffolds was contracted more than 20 %. After 7 days in culture, the type I scaffold was markedly decreased in size than type II scaffold (p<0.05). Type II scaffold showed more resistance to cell-mediated contraction than type I scaffold (p<0.05). The pore size of scaffold was markedly decreased on 14 days after culture in type I scaffold, but structure and size of pore in type II scaffold were well preserved. The degree of osteogenic differentiation of rBMSC did not showed any difference in both types of scaffold biochemically. However, cells were more evenly distributed and mineral intensity was more increased in type II scaffold than those of type I scaffold. CONCLUSION: The fibrin reinforcement into collagen sponges could prevent cell-mediated contraction of scaffold and could support in vitro osteogenic differentiation of rBMSC.