Boyan B D, Schwartz Z, Lohmann C H, Sylvia V L, Cochran D L, Dean D D, Puzas J E
Department of Biomedical Engineering, Georgia Institute of Technology, Atlanta, GA 30332, USA.
J Orthop Res. 2003 Jul;21(4):638-47. doi: 10.1016/S0736-0266(02)00261-9.
Implant surface morphology regulates osteoblast phenotypic expression. Osteoblast sensitivity to non-biologic surfaces suggests that native bone surface features may also affect osteoblast response. To test this, MG63 osteoblast-like cells were grown for 7 days on bovine cortical bone wafers pretreated with rat bone marrow osteoclasts for 0, 10 or 20 days. Response to osteoclast-treated surfaces was compared to the response of MG63 cells to titanium surfaces with smooth and rough microtopographies. Cell number, differentiation (alkaline phosphatase activity and osteocalcin levels), and local factors (PGE(2) and TGF-beta1) were measured in confluent cultures. Compared to culture on plastic, cell number was reduced on all three types of bone wafers; this effect was dose-dependent with increasing resorption of the surface. Alkaline phosphatase specific activity was increased (P<or=0.05) on all three surfaces compared with plastic, but this increase was not dependent on resorption time, indicating this parameter was sensitive to the surface (bovine bone vs. plastic) but not to osteoclast-resorption. There was a direct correlation between the area of the bone surface resorbed and the amount of osteocalcin, TGF-beta1 and PGE(2) (R(2)=0.8025, 0.8689, 0.8896, respectively). With 20 days of osteoclast pretreatment, there was a 20-fold increase in osteocalcin over plastic and a 7-fold increase over cultures on untreated bone wafers. Similar increases were found for TGF-beta1 and PGE(2). Thus, surface changes resulting from osteoclast pretreatment have a strong effect on osteoblast phenotypic expression, and suggest that microtopography may play a role.
植入物表面形态调节成骨细胞的表型表达。成骨细胞对非生物表面的敏感性表明，天然骨表面特征也可能影响成骨细胞的反应。为了验证这一点，将MG63成骨样细胞在经大鼠骨髓破骨细胞预处理0、10或20天的牛皮质骨薄片上培养7天。将对破骨细胞处理表面的反应与MG63细胞对具有光滑和粗糙微观形貌的钛表面的反应进行比较。在汇合培养物中测量细胞数量、分化（碱性磷酸酶活性和骨钙素水平）以及局部因子（前列腺素E2和转化生长因子β1）。与在塑料上培养相比，在所有三种类型的骨薄片上细胞数量均减少；这种效应呈剂量依赖性，随着表面吸收增加而增强。与塑料相比，在所有三种表面上碱性磷酸酶比活性均增加（P≤0.05），但这种增加不依赖于吸收时间，表明该参数对表面（牛骨与塑料）敏感，而对破骨细胞吸收不敏感。骨表面吸收面积与骨钙素、转化生长因子β1和前列腺素E2的量之间存在直接相关性（R2分别为0.8025、0.8689、0.8896）。经过20天破骨细胞预处理后，骨钙素比在塑料上培养增加了20倍，比在未处理的骨薄片上培养增加了7倍。转化生长因子β1和前列腺素E2也有类似的增加。因此，破骨细胞预处理导致的表面变化对成骨细胞表型表达有强烈影响，并表明微观形貌可能起作用。
