Broadband Absorbing Semiconducting Polymer Nanoparticles for Photoacoustic Imaging in Second Near-Infrared Window
Broadband Absorbing Semiconducting Polymer Nanoparticles for Photoacoustic Imaging in Second Near-Infrared Window
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DOI：
10.1021/acs.nanolett.7b02106
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发表时间：
2017-08-01
期刊：
影响因子：
10.8
通讯作者：
Pu, Kanyi
中科院分区：
文献类型：
--
作者：
Jiang, Yuyan;Upputuri, Paul Kumar;Pu, Kanyi
光声成像在临床前研究和临床实践中有着广阔的前景。然而，大多数研究依赖于第一个近红外窗口(NIR-I，650-950 nm)的激光波长，而对于第二个近红外窗口(NIR-II，nm)的研究很少，这主要是由于缺乏NIR-II吸收造影剂。本文报道了一种基于半导体聚合物纳米颗粒的宽带吸收PA造影剂(SPN-II)的合成，并将其应用于近红外窗口的PA成像。SPN-II在NIR-I和NIR-II两个区域都有吸收，为直接比较750 nm和1064 nm的PA成像提供了可行性。由于在NIR-II窗口中来自生物组织的背景PA信号较弱，SPN-II结果PA图像在1064 nm处的信噪比(SNR)可比在3 cm成像深度时的750 nm高1.4倍。NIR-II PA成像在活体大鼠脑血管成像中得到了概念验证应用，其信噪比是NIR-I PA成像的1.5倍。我们的研究不仅介绍了第一种在近红外-I和近红外-II窗口都适用于PA成像的宽带吸收有机造影剂，而且揭示了NIR-II在PA成像中相对于NIR-I的优势。
Photoacoustic (PA) imaging holds great promise for preclinical research and clinical practice. However, most studies rely on the laser wavelength in the first near infrared (NIR) window (NIR-I, 650-950 nm), while few studies have been exploited in the second NIR window (NIR-II, nm), mainly due to the lack of NIR-II absorbing contrast agents. We herein report the synthesis of a broadband absorbing PA contrast agent based on semi-conducting polymer nanoparticles (SPN-II) and apply it for PA imaging in NIR-II window. SPN-II can absorb in both NIR-I and NIR-II regions, providing the feasibility to directly compare PA imaging at 750 nm with that at 1064 nm. Because of the weaker background PA signals from biological tissues in NIR-II window, the signal-to-noise ratio (SNR) of SPN-II resulted PA images at 1064 nm can be 1.4-times higher than that at 750 nm when comparing at the imaging depth of 3 cm. The proof-of-concept application of NIR-II PA imaging is demonstrated in in-vivo imaging of brain vasculature in living rats, which showed 1.5-times higher SNR as compared with NIR-I PA imaging. Our study not only introduces the first broadband absorbing organic contrast agent that is applicable for PA imaging in both NIR-I and NIR-II windows but also reveals the advantages of NIR-II over NIR-I in PA imaging.