Nunes Antonio, Pansare Vikram J, Beziere Nicolas, Ntoukas Argiris Kolokithas, Reber Josefine, Bruzek Matthew, Anthony John, Prud'homme Robert K, Ntziachristos Vasilis
Institute for Biological and Medical Imaging, Helmholtz Zentrum München and Technische Universität München, Ingolstädter Landstr. 1, D-85764 Neuherberg, Germany.
J Mater Chem B. 2018 Jan 7;6(1):44-55. doi: 10.1039/c7tb02633a. Epub 2017 Nov 3.
Optoacoustic (photoacoustic) imaging enables high-resolution optical imaging at depths well beyond optical microscopy, revolutionizing optical interrogation of tissues. Operation in the near-infrared (NIR) is nevertheless necessary to capitalize on the technology potential and reach depths of several centimeters. Using Flash NanoPrecipitation for highly-scalable single-step encapsulation of hydrophobic hexacene at self-quenching concentrations, we propose quenched fluorescence-dye nanoparticles as a potent alternative to NIR metal nanoparticles for strong optoacoustic signal generation. Comprehensive hexacene-based nanoparticle characterization was based on a 5-step approach that examined the physicochemical features (Step 1), optoacoustic signal generation (Step 2), stability (Step 3), biocompatibility (Step 4) and spectral sensitivity (Step 5). Using this characterization framework we showcase the discovery of two nanoparticle formulations, QH-50 nm and QH-100 nm that attain superior stability characteristics and optimal optoacoustic properties compared to gold standards commonly employed for near-infrared optoacoustics. We discuss encapsulation and self-quenching (ESQ) of organic dyes as a promising strategy to generate optimal optoacoustic particles.
光声成像能够在远超光学显微镜的深度进行高分辨率光学成像，彻底改变了对组织的光学检测方式。然而，为了充分利用该技术的潜力并达到几厘米的深度，在近红外（NIR）波段进行操作是必要的。我们利用快速纳米沉淀法在自猝灭浓度下对疏水性并六苯进行高度可扩展的单步封装，提出将猝灭荧光染料纳米颗粒作为近红外金属纳米颗粒的有力替代品，用于产生强烈的光声信号。基于并六苯的纳米颗粒的全面表征基于一种五步方法，该方法考察了物理化学特征（第一步）、光声信号产生（第二步）、稳定性（第三步）、生物相容性（第四步）和光谱敏感性（第五步）。使用这个表征框架，我们展示了两种纳米颗粒配方QH - 50 nm和QH - 100 nm的发现，与近红外光声常用的金标准相比，它们具有卓越的稳定性特征和最佳的光声性能。我们讨论了有机染料的封装和自猝灭（ESQ）作为生成最佳光声颗粒的一种有前景的策略。
