gms | German Medical Science

Deutscher Kongress für Orthopädie und Unfallchirurgie (DKOU 2014)

28.10. - 31.10.2014, Berlin

Effects of Perfusion, Cyclic Compression and Bone Morphogenetic Protein-7 on the Proliferation and Differentiation of Human Bone Marrow Stromal Cells Seeded on the Polyurethane Scaffolds

Meeting Abstract

  • presenting/speaker Songsong Teng - Hannover Medical School, Hannover, Germany
  • Chaoxu Liu - Hannover Medical School, Hannover, Germany
  • Christian Krettek - Hannover Medical School, Hannover, Germany
  • Michael Jagodzinski - Hannover Medical School, Hannover, Germany

Deutscher Kongress für Orthopädie und Unfallchirurgie (DKOU 2014). Berlin, 28.-31.10.2014. Düsseldorf: German Medical Science GMS Publishing House; 2014. DocPO12-771

doi: 10.3205/14dkou597, urn:nbn:de:0183-14dkou5977

Published: October 13, 2014

© 2014 Teng et al.
This is an Open Access article distributed under the terms of the Creative Commons Attribution License (http://creativecommons.org/licenses/by-nc-nd/3.0/deed.en). You are free: to Share – to copy, distribute and transmit the work, provided the original author and source are credited.


Outline

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Objective: The purpose of this study was to investigate the proliferation and differentiation of human bone marrow stromal cells(hBMSCs) that were seeded on the polyurethane scaffolds under the influence of continuous perfusion, cyclic compression and bone morphogenetic protein-7 (BMP-7) in a perfusion-mechanical bioreactor system that simulated the condition of human bone marrow.

Method: 10^6 hBMSCs of the third passage suspended in 400 ul culture medium were seeded on one polyurethane scaffold (5×20 mm, Actific®, Orteq, Groningen, The Netherlands). After 24h incubation, the polyurethane scaffolds with hBMSCs were cultured under 5 different conditions in the bioreactors: 10% cyclic compression at 0.5 Hz and 5Hz (perfusion rate:1 ml/min, 0.5 Hz group and 5 Hz group), continuous perfusion(perfusion rate: 10 ml/min, 10 ml/min group), BMP-7 (100 ng/ml, perfusion rate:1 ml/min, BMP-7 group) and control (perfusion rate: 1 ml/min). The scaffolds were harvested on day 7 and day 14. Then the MTS assay and qPCR (Runx2, COL1A1 and osteocalcin mRNA) were conducted to determine the proliferation and osteogenic differentiation of hBMSCs on the scaffolds, respectively. Comparison among groups were performed by one-way ANOVA with the Student-Newman-Keuls test (SPSS 15.0), and p<0.05 was considered statistically significant (n=3).

Results and conclusion: Proliferation in all the groups was increased over time. On day 7, BMP-7 group had the highest cell number, compared with the other 4 groups (p<0.05), and the minimum cell number was observed in the 5Hz group on day 14 (p<0.05). There was no significant difference among control, 0.5Hz group and 10 ml/min group at each time point. During 14 days of dynamic culture, although no significant difference of the Runx2 level was found among groups, there was an upward trend on the whole, and the 5 Hz group exhibited the lowest level on both day 7 and day 14. COL1A1 expression was significantly upregulated in the 0.5 Hz, 5 Hz and BMP-7 groups on day 7 (p<0.05), compared with that in the control group, but on day 14, no significant difference was shown among 5 groups. After 14 days, the stimulation of BMP-7 resulted in the highest osteocalcin expression (p<0.05), and the osteocalcin level in 0.5 Hz group was significantly higher than that in the control and 5 Hz group (p<0.05). During the 14 days, no significant change of osteocalcin expression was observed in the 5 Hz group.

In conclusion,cyclic compression of low frequency enhanced the osteogenic differentiation of hBMSCs without affecting their proliferation on the polyurethane scaffolds, whereas high frequency compression inhibited their proliferation. Different from the results of our previous study, high perfusion rate did not result in the enhanced proliferation of hBMSCs which may be attributed to the distinct material and porosity of the scaffolds utilized between two studies. BMP-7 was demonstrated to be the most excellent stimulation factor that promoted both the proliferation and osteogenic differentiation of hBMSCs