Division of Engineering in Medicine, Department of Medicine, Brigham and Women's Hospital, Harvard Medical School , Cambridge, Massachusetts 02139, United States.
Anal Chem. 2017 Sep 19;89(18):9758-9766. doi: 10.1021/acs.analchem.7b01623. Epub 2017 Aug 25.
Three-dimensional (3D) molecular imaging enables the study of biological processes in both living and nonviable systems at the molecular level and has a high potential on early diagnosis. In conjunction with specific molecular probes, optical coherent tomography (OCT) is a promising imaging modality to provide 3D molecular features at the tissue level. In this study, we introduced (gold triangular nanoprism core)/(polyaniline shell) nanoparticles (GTNPs@PANI) as an OCT contrast agent and pH-responsive nanoprobe for 3D imaging of pH distribution. These core/shell nanoparticles possessed significantly different extinction and scattering properties in acidic and basic microenvironments. The switch of the optical features of the nanoparticles upon pH change was reversible, and the response time was less than 1.0 s. The nanoprobe successfully indicated the acid regions of a mimic tumor from the basic region in a gelatin-based phantom under OCT imaging. As a demonstration of practical applications, real-time 3D OCT imaging of pH and lactic acid in the anterior chamber of a fish eye was realized by GTNPs@PANI nanoparticles. Using GTNPs@PANI nanoparticles as the contrast probes for OCT imaging, noninvasive and real-time molecular imaging in both living and nonviable systems at the microscale can be achieved.
三维（3D）分子成像能够在分子水平上研究活体和非活体系统中的生物过程，具有早期诊断的巨大潜力。与特定的分子探针结合，光学相干断层扫描（OCT）是一种很有前途的成像方式，可以在组织水平上提供 3D 分子特征。在这项研究中，我们引入了（金三角纳米棱镜核）/（聚苯胺壳）纳米粒子（GTNPs@PANI）作为 OCT 造影剂和 pH 响应性纳米探针，用于 pH 分布的 3D 成像。这些核/壳纳米粒子在酸性和碱性微环境中具有明显不同的消光和散射特性。纳米粒子的光学特性在 pH 变化时发生可逆变化，响应时间小于 1.0 s。该纳米探针在 OCT 成像下，成功地从基于明胶的模型中的碱性区域指示出了模拟肿瘤的酸性区域。作为实际应用的一个例子，通过 GTNPs@PANI 纳米粒子实现了对鱼眼前房 pH 值和乳酸的实时 3D OCT 成像。使用 GTNPs@PANI 纳米粒子作为 OCT 成像的对比探针，可以在微观尺度上对活体和非活体系统进行非侵入性和实时的分子成像。
