Milewska Adrianna, Sigurjonsson Olafur E, Leosson Kristjan
Innovation Center Iceland, Árleynir 2-8, 112 Reykjavík, Iceland.
The Blood Bank, Landspitali University Hospital, Snorrabraut 60, 105 Reykjavík, Iceland.
ACS Appl Bio Mater. 2021 Jun 21;4(6):4999-5007. doi: 10.1021/acsabm.1c00286. Epub 2021 Jun 7.
Understanding the process of mesenchymal stromal cell (MSC) osteogenic differentiation is essential for a wide range of medical applications. However, these primary cells vary significantly from donor to donor, making it difficult to fully exploit their therapeutic potential. Although osteogenic differentiation has been studied extensively, there is still a shortage of standardized methods for the evaluation of the degree of differentiation. Here, we employ noninvasive surface-enhanced Raman scattering (SERS) for studying such cells, offering a better understanding of cellular processes in situ. We present the long-term differentiation of MSCs on biocompatible gold nanoisland SERS substrates, combining imaging of cells with spectroscopic detection of molecular species and chemical events occurring on the cellular membrane adjacent to the surface of the SERS substrate. We detect multiple signs of bone tissue formation, from an early stage to mature osteoblasts, without labeling. We show that the results correlate very well with classical differentiation-detecting assays, indicating that the SERS imaging technique alone is sufficient to study the progress of osteogenic differentiation of such cells, paving a way toward continuous label-free screening of live cells.
了解间充质基质细胞（MSC）的成骨分化过程对于广泛的医学应用至关重要。然而，这些原代细胞在不同供体之间差异很大，这使得难以充分发挥其治疗潜力。尽管对成骨分化进行了广泛研究，但评估分化程度的标准化方法仍然不足。在此，我们采用非侵入性表面增强拉曼散射（SERS）来研究此类细胞，以便更好地原位了解细胞过程。我们展示了MSC在生物相容性金纳米岛SERS基底上的长期分化情况，将细胞成像与分子物种的光谱检测以及在SERS基底表面相邻细胞膜上发生的化学事件相结合。我们在未进行标记的情况下检测到从早期到成熟成骨细胞的骨组织形成的多个迹象。我们表明，结果与经典的分化检测分析非常吻合，这表明仅SERS成像技术就足以研究此类细胞的成骨分化进程，为活细胞的连续无标记筛选铺平了道路。
