Label-free imaging of lipid-rich biological tissues by mid-infrared photoacoustic microscopy.
Label-free imaging of lipid-rich biological tissues by mid-infrared photoacoustic microscopy.
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DOI：
10.1117/1.jbo.25.10.106506
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发表时间：
2020-10
影响因子：
3.5
通讯作者：
Wang LV
中科院分区：
文献类型：
--
作者：
He Y;Shi J;Pleitez MA;Maslov K;Wagenaar DA;Wang LV
意义：基于生物分子振动跃迁的中红外(IR)成像在生物组织的无标记成像中提供了良好的化学特异性对比度，使其成为生物医学研究和临床应用的常用工具。然而，目前的技术通常需要薄的、干燥的或非常平的样品，其复杂的处理限制了该技术的更广泛的翻译。目的：为了解决这个问题，我们报告了中红外光声显微镜(PAM)，它可以很容易地处理新鲜和厚重的组织样本，即使它们有粗糙的表面。方法：我们研制了一种透射式中红外PAM系统，该系统采用光学参数振荡激光器，工作在2.5到2.5的波长范围内。由于其对光吸收的高敏感性和组织的低超声衰减，我们的PAM实现了比傅立叶变换红外光谱更大的探测深度，从而能够成像具有粗糙表面的新鲜和厚重的组织样本。结果：在我们的光谱学研究中，在3508 nm处的对称伸展被发现是一个很好的内源性脂质对比的来源。在这个波数，我们展示了在新鲜的，手工切割的，和未处理的3毫米厚的组织切片中，脂质成分的无标记成像。结论：我们的技术不需要耗时的样品制备过程，在快速临床组织学分析和基础生物学研究方面都具有很大的潜力。
Significance: Mid-infrared (IR) imaging based on the vibrational transition of biomolecules provides good chemical-specific contrast in label-free imaging of biology tissues, making it a popular tool in both biomedical studies and clinical applications. However, the current technology typically requires thin and dried or extremely flat samples, whose complicated processing limits this technology’s broader translation. Aim: To address this issue, we report mid-IR photoacoustic microscopy (PAM), which can readily work with fresh and thick tissue samples, even when they have rough surfaces. Approach: We developed a transmission-mode mid-IR PAM system employing an optical parametric oscillation laser operating in the wavelength range from 2.5 to . Due to its high sensitivity to optical absorption and the low ultrasonic attenuation of tissue, our PAM achieved greater probing depth than Fourier transform IR spectroscopy, thus enabling imaging fresh and thick tissue samples with rough surfaces. Results: In our spectroscopy study, the symmetric stretching at (3508 nm) was found to be an excellent source of endogenous contrast for lipids. At this wavenumber, we demonstrated label-free imaging of the lipid composition in fresh, manually cut, and unprocessed tissue sections of up to 3-mm thickness. Conclusions: Our technology requires no time-consuming sample preparation procedure and has great potential in both fast clinical histological analysis and fundamental biological studies.