同步辐射红外光谱成像技术对细胞的研究

Application of Synchrotron FTIR Imaging for Cells

同步辐射红外显微光谱技术凭借其超高亮度和高空间分辨率的优势,已经在多学科领域中取得了大量的研究成果。特别是在生物医学领域,同步辐射红外显微光谱可以对无染色、无标记的生物样品进行无损检测并可获得生物分子的大量结构信息,因此得到广泛应用。随着同步辐射红外显微光谱技术的发展,生物化学家和光谱学家已经将研究的重点从组织层次的红外光谱成像(组织红外光谱成像)扩展到细胞层次的红外光谱成像(细胞红外光谱成像),并在近十年的研究中取得了大量的研究成果,但同时也暴露出一些问题,例如(1)细胞或介质中的水在红外光谱酰胺Ⅰ谱带具有很强的吸收;(2)不平整的细胞表面会导致红外光谱中产生Mie散射;(3)细胞红外光谱的复杂性和不确定性会影响数据分析的有效性和准确性。另一方面,生化学家和光谱学家也为解决这些问题采取了许多有用的策略。因此,本综述首先从样品制备、实验设计以及数据分析等方面对最近十年来细胞同步辐射红外光谱成像技术取得的成果进行了总结,随后介绍了目前细胞红外成像技术面临的问题以及解决策略。我们相信,通过多束同步辐射红外光与焦平面阵列(FPA)探测器的结合,同步辐射红外光谱成像技术在对细胞的结构和功能研究中以及其他领域不同材料的研究中都会逐步显示出独特的作用。

Thanks to the ultra-high brightness and high spatial resolution of synchrotron infrared light source, synchrotron radiation based Fourier-transform infrared（ SR-FTIR） microspectroscopy is w idely used in multidisciplinary field. Especially in the biomedical field,SR-FTIR has been w idely employed in the structural and functional characterization of unstained and unlabeled biomolecules as a non-destructive technique. In the recent ten years,w ith the development of SR-FTIR microspectroscopic technique,biochemists and spectral scientists have expanded their interests from the tissue level FTIR imaging（ tissue FTIR imaging,w hich normally focus on imaging a tissue section） to single cell level FTIR imaging（ cell FTIR imaging,w hich focus on imaging of a single functional or live cell）. How ever,there are several problems need to be overcome in cell FTIR imaging. For example,（ 1） w ater in cell and / or in medium has strong absorption in amide Ⅰ band;（ 2） uneven surface of cell leads to Mie scattering of FTIR spectra;（ 3） complexity and uncertainty of FTIR spectra of cell affect the validity and accuracy of the data analysis. On the other hand,biochemists and spectral scientists have designed fruitful strategies to solve these problems. Therefore,w e summarized the studies about cell SR- FTIR imaging in the past ten years in this review. We firstly describe the sample preparation,experimental design and data analysis methods in these published w orks,and then put forw ard the problems and the corresponding solutions on cell SR-FTIR imaging. We believe w ith the development of multibeam synchrotron source / focal plane array（ FPA） system,SR-FTIR imaging w ill become a very promising tool to detect structures and functions not only for cells,but also for many other materials in different fields