Schliephake H, Zghoul N, Jäger V, van Griensven M, Zeichen J, Gelinsky M, Wülfing T
Department of Oral and Maxillofacial Surgery, George-Augusta-University, Göttingen, Germany.
J Biomed Mater Res A. 2009 Aug;90(2):429-37. doi: 10.1002/jbm.a.32104.
The aim of the present study was to test the hypothesis that both scaffold material and the type of cell culturing contribute to the results of in vivo osteogenesis in tissue-engineered constructs in an interactive manner. CaCO3 scaffolds and mineralized collagen scaffolds were seeded with human trabecular bone cells at a density of 5 x 10(6) cells/cm(3) and were left to attach under standard conditions for 24 h. Subsequently, they were submitted to static and dynamic culturing for 14 days (groups III and IV, respectively). Dynamic culturing was carried out in a continuous flow perfusion bioreactor. Empty scaffolds and scaffolds that were seeded with cells and kept under standard conditions for 24 h served as controls (groups I and II, respectively). Five scaffolds of each biomaterial and from each group were implanted into the gluteal muscles of rnu rats for 6 weeks. Osteogenesis was assessed quantitatively by histomorphometry and expression of osteocalcin (OC) and vascular endothelial growth factor (VEGF) was determined by immunohistochemistry. CaCO3 scaffolds exhibited 15.8% (SD 3.1) of newly formed bone after static culture and 22.4% (SD 8.2) after dynamic culture. Empty control scaffolds did not show bone formation, and scaffolds after 24 h of standard conditions produced 8.2% of newly formed bone (SD 4.0). Differences between the controls and the scaffolds cultured for 14 days were significant, but there was no significant difference between static and dynamic culturing. Mineralized collagen scaffolds did not show bone formation in any group. There was a significant difference in the expression of OC within the scaffolds submitted to static versus dynamic culturing in the CaCO3 scaffolds. VEGF expression did not show significant differences between static and dynamic culturing in the two biomaterials tested. It is concluded that within the limitations of the study the type of biomaterial had the dominant effect on in vivo bone formation in small tissue-engineered scaffolds. The culture period additionally affected the amount of bone formed, whereas the type of culturing may have had a positive effect on the expression of osteogenic markers but not on the quantity of bone formation.
支架材料和细胞培养类型以交互方式对组织工程构建体的体内成骨结果产生影响。将碳酸钙支架和矿化胶原支架以5×10(6)个细胞/cm(3)的密度接种人松质骨细胞，并在标准条件下放置24小时使其附着。随后，分别对它们进行静态和动态培养14天（分别为III组和IV组）。动态培养在连续流动灌注生物反应器中进行。空支架以及接种细胞并在标准条件下放置24小时的支架分别作为对照（分别为I组和II组）。将每组生物材料的五个支架植入裸大鼠的臀肌中6周。通过组织形态计量学对成骨进行定量评估，并通过免疫组织化学测定骨钙素（OC）和血管内皮生长因子（VEGF）的表达。碳酸钙支架在静态培养后显示新形成骨为15.8%（标准差3.1），动态培养后为22.4%（标准差8.2）。空对照支架未显示骨形成，在标准条件下放置24小时后的支架产生新形成骨8.2%（标准差4.0）。对照与培养14天的支架之间的差异显著，但静态和动态培养之间无显著差异。矿化胶原支架在任何组中均未显示骨形成。在碳酸钙支架中，静态培养与动态培养的支架内OC表达存在显著差异。在所测试的两种生物材料中，VEGF表达在静态和动态培养之间未显示显著差异。得出结论，在本研究的局限性内，生物材料类型对小型组织工程支架的体内骨形成具有主导作用。培养时间额外影响形成的骨量，而培养类型可能对成骨标志物的表达有积极影响，但对骨形成量无影响。
