State Key Laboratory of Systems Medicine for Cancer, School of biomedical engineering, Shanghai Jiao Tong University, Shanghai 200030, P. R. China.
Shanghai Key Laboratory of Gynecologic Oncology, Ren Ji Hospital, School of Medicine, Shanghai Jiao Tong University, Shanghai 200127, P. R. China.
ACS Appl Mater Interfaces. 2023 Sep 27;15(38):44665-44675. doi: 10.1021/acsami.3c07792. Epub 2023 Sep 13.
Locating distinct objects within a thick scattering medium remains a long-standing challenge in the fields of materials science, health, and engineering. Transmission Raman spectroscopy (TRS) with the use of surface-enhanced Raman scattering (SERS) nanoparticles has proven to be an effective approach to detect deep-seated lesions inside thick biological tissues. However, it has not yet been proven to spatially locate deep lesions in three dimensions using optical modalities. Herein, we present the concept of tomographic TRS and report its successful use for accurately locating SERS nanoparticles in elongated rod-like thick tissues. Our work starts with theoretical simulations of Raman photon propagation in tissues. We discovered a linear relationship between the Raman spectral peak ratio and propagation distance of Raman photons in tissues, allowing us to predict the location of lesions tagged by SERS NPs. Based on this, we propose a two-step tomographic TRS strategy, which includes axial scanning and ring scanning. We demonstrate the robustness of our approach using thick tissue (4.5 cm in thickness) and locate an embedded SERS phantom lesion, with a ring scanning step of 10-30°. We successfully locate multiple SERS phantom lesions in the porcine muscle stack with high accuracy (absolute error of <2 mm). Our method is rapid, efficient, and of low cost compared to current tomographic medical imaging techniques. This work advances Raman techniques for three-dimensional positioning and offers new insights toward practical diagnosis applications.
在材料科学、健康和工程领域，在厚散射介质中定位不同的物体仍然是一个长期存在的挑战。使用表面增强拉曼散射（SERS）纳米粒子的传输拉曼光谱（TRS）已被证明是一种有效的方法，可以检测厚生物组织内的深层病变。然而，它尚未被证明可以使用光学模式在三维空间中定位深层病变。本文提出了层析 TRS 的概念，并报告了其成功用于准确定位厚组织中伸长棒状 SERS 纳米粒子的用途。我们的工作从组织中拉曼光子传播的理论模拟开始。我们发现组织中拉曼光子的拉曼光谱峰比与传播距离之间存在线性关系，这使我们能够预测被 SERS NPs 标记的病变的位置。基于此，我们提出了两步层析 TRS 策略，包括轴向扫描和环扫描。我们使用厚组织（4.5 厘米厚）证明了我们方法的稳健性，并定位了嵌入的 SERS 幻影病变，环扫描步长为 10-30°。我们成功地以高精度（<2 毫米的绝对误差）定位了猪肌肉堆栈中的多个 SERS 幻影病变。与当前的层析医学成像技术相比，我们的方法快速、高效且成本低。这项工作推进了拉曼技术在三维定位方面的应用，并为实际诊断应用提供了新的见解。
