The purpose of this research was to investigate the sensitivity of a system for the detection of circulating melanoma cells based on the thermoelastic properties of melanoma. The method employs photoacoustic (PA) excitation coupled with an optical transducer capable of determining the presence of cells within the circulating system in vitro. The transducer is based on stress wave-induced changes of the optical reflectance of a glass–water interface, probed with a continuous laser beam that is incident at an angle close to the critical angle of total internal reflection. A frequency tripled Nd:YAG laser pumping an optical parametric oscillator was employed to provide 532nm and 620nm laser light with a pulse duration of 10ns. A custom-made flow chamber was used as an excitation and acoustic wave collection device. The targets were a human melanoma cell line HS 936 with an average diameter of about 15μm. Melanoma cells were suspended in 10mL of two types of media. The first one was Tyrode’s buffer in concentrations ranging from 10 to 50 cells per μL, and the second one included 106 healthy white blood cells per mL of Tyrode’s buffer. PA pressure waves were detected by an optical stress transducer. Detection trials resulted in a detection threshold of the order of one individual cell, indicating the effectiveness of the proposed mechanism. Results imply the potential to assay simple blood samples, from healthy and metastatic patients, to test the presence of cancerous melanoma providing an unprecedented method for screening metastatic disease.

中文翻译：

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体外循环黑色素瘤细胞的光学光声检测

本研究的目的是基于黑色素瘤的热弹性特性，研究检测循环黑色素瘤细胞的系统的灵敏度。该方法采用光声 (PA) 激发与光学换能器相结合，能够确定体外循环系统中细胞的存在。该换能器基于应力波引起的玻璃-水界面光学反射率的变化，用连续激光束探测，该激光束以接近全内反射临界角的角度入射。采用三倍频 Nd:YAG 激光泵浦光学参量振荡器，以提供脉冲持续时间为 10ns 的 532nm 和 620nm 激光。定制的流动室用作激发和声波收集装置。目标是平均直径约为 15μm 的人类黑色素瘤细胞系 HS 936。黑色素瘤细胞悬浮在 10mL 的两种培养基中。第一个是 Tyrode 缓冲液，浓度范围为每微升 10 到 50 个细胞，第二个包括每毫升 Tyrode 缓冲液 106 个健康白细胞。PA 压力波由光学应力传感器检测。检测试验产生了一个单个细胞数量级的检测阈值，表明所提出机制的有效性。结果意味着有可能对来自健康和转移性患者的简单血液样本进行分析，以测试癌性黑色素瘤的存在，从而提供一种前所未有的筛查转移性疾病的方法。第一个是 Tyrode 缓冲液，浓度范围为每微升 10 到 50 个细胞，第二个包括每毫升 Tyrode 缓冲液 106 个健康白细胞。PA 压力波由光学应力传感器检测。检测试验产生了一个单个细胞数量级的检测阈值，表明所提出机制的有效性。结果意味着有可能对来自健康和转移性患者的简单血液样本进行分析，以测试癌性黑色素瘤的存在，从而提供一种前所未有的筛查转移性疾病的方法。第一个是 Tyrode 缓冲液，浓度范围为每微升 10 到 50 个细胞，第二个包括每毫升 Tyrode 缓冲液 106 个健康白细胞。PA 压力波由光学应力传感器检测。检测试验产生了一个单个细胞数量级的检测阈值，表明所提出机制的有效性。结果意味着有可能对来自健康和转移性患者的简单血液样本进行分析，以测试癌性黑色素瘤的存在，从而提供一种前所未有的筛查转移性疾病的方法。检测试验产生了一个单个细胞数量级的检测阈值，表明所提出机制的有效性。结果意味着有可能对来自健康和转移性患者的简单血液样本进行分析，以测试癌性黑色素瘤的存在，从而提供一种前所未有的筛查转移性疾病的方法。检测试验产生了一个单个细胞数量级的检测阈值，表明所提出机制的有效性。结果意味着有可能对来自健康和转移性患者的简单血液样本进行分析，以测试癌性黑色素瘤的存在，从而提供一种前所未有的筛查转移性疾病的方法。