Human serum albumin (HSA) is a depot and carrier for many endogenous and exogenous molecules in blood. Many studies have demonstrated that the transport of HSA in tumor microenvironments contributes to tumor development and progression. In this report, we set up a multimodal nonlinear optical microscope system, combining two-photon excitation fluorescence, second harmonic generation, and two-photon fluorescence lifetime imaging microscopy. The fluorescence lifetime of a small squaraine dye (SD) is used to evaluate HSA concentrations in tumor tissue based on specific binding between SD and HSA. We used SD to stain the cryosections from serous ovarian cancer patients in high-grade (HGSOC) and low-grade (LGSOC), respectively, and found a gradient descent of HSA concentration from normal connective tissue to extracellular matrix to tumor masses from 13 to 2 µM for LGSOC patients and from 36 to 12 µM for HGSOC patients. We demonstrated that multimodal nonlinear optical microscopy can obtain similar results as those from traditional histologic staining, thus it is expected to move to clinical applications.

中文翻译：

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荧光寿命测定浆液性卵巢癌冷冻切片中人血清白蛋白梯度

人血清白蛋白（HSA）是血液中许多内源性和外源性分子的贮库和载体。许多研究表明，HSA在肿瘤微环境中的转运有助于肿瘤的发展和进展。在本报告中，我们建立了一个多模态非线性光学显微镜系统，将双光子激发荧光，二次谐波生成和双光子荧光寿命成像显微镜相结合。小方酸菁染料（SD）的荧光寿命可用于根据SD和HSA之间的特异性结合来评估肿瘤组织中的HSA浓度。我们使用SD分别对高级别（HGSOC）和低级别（LGSOC）的浆液性卵巢癌患者的冷冻切片染色，并且发现LGSOC患者从正常结缔组织到细胞外基质到肿瘤块的HSA浓度从13到2 µM下降，而HGSOC患者从36到12 µM下降。我们证明了多峰非线性光学显微镜可以获得与传统组织学染色相似的结果，因此有望进入临床应用。