Trauma Surgery and Paraplegiology, Clinic for Orthopedics and Trauma Surgery, Center for Orthopedics, University Hospital Heidelberg, 69120 Heidelberg, Germany.
Department of Nuclear Medicine, University Hospital Heidelberg, 69120 Heidelberg, Germany.
Int J Mol Sci. 2020 Oct 17;21(20):7692. doi: 10.3390/ijms21207692.
In bone tissue engineering, there is a constant need to design new methods for promoting in vitro osteogenic differentiation. Consequently, there is a strong demand for fast, effective and reliable methods to track and quantify osteogenesis in vitro. In this study, we used the radiopharmacon fluorine-18 (F) to evaluate the amount of hydroxylapatite produced by mesenchymal stem cells (MSCs) in a monolayer cell culture in vitro. The hydroxylapatite bound tracer was evaluated using µ-positron emission tomography (µ-PET) scanning and activimeter analysis. It was therefore possible to determine the amount of synthesized mineral and thus to conclude the osteogenic potential of the cells. A Student's -test revealed a highly significant difference regarding tracer uptake between the osteogenic group and the corresponding control group (µ-PET = 0.043; activimeter analysis = 0.012). This tracer uptake showed a highly significant correlation with the gold standard of quantitative Alizarin Red staining (ARS) (r = 0.86) as well as with the absolute calcium content detected by inductively coupled plasma mass spectrometry (r = 0.81). The results showed that F labeling is a novel method to prove and quantify hydroxyapatite content in MSC monolayer cultures. The mineral layer remains intact for further analysis. This non-destructive in vitro method can be used to rapidly investigate bone tissue engineering strategies in terms of hydroxylapatite production, and could therefore accelerate the process of implementing new strategies in clinical practice.
在骨组织工程中，人们不断需要设计新的方法来促进体外成骨分化。因此，迫切需要快速、有效和可靠的方法来跟踪和量化体外成骨。在这项研究中，我们使用放射性药物氟-18（F）来评估间充质干细胞（MSCs）在体外单层细胞培养中产生的羟磷灰石的量。使用µ-正电子发射断层扫描（µ-PET）扫描和活度计分析评估结合的羟磷灰石示踪剂。因此，可以确定合成的矿物质的量，并由此得出细胞的成骨潜力。学生 t 检验显示，成骨组和相应对照组之间的示踪剂摄取量存在高度显著差异（µ-PET = 0.043；活度计分析 = 0.012）。这种示踪剂摄取与定量茜素红染色（ARS）的金标准高度显著相关（r = 0.86），与电感耦合等离子体质谱法检测到的绝对钙含量也高度显著相关（r = 0.81）。结果表明，F 标记是一种证明和量化 MSC 单层培养物中羟磷灰石含量的新方法。矿物质层保持完整，以便进一步分析。这种非破坏性的体外方法可用于快速研究骨组织工程策略在羟磷灰石产生方面的情况，从而加速在临床实践中实施新策略的过程。
