Photoacoustic (PA) imaging is an emerging non-invasive diagnostic modality with many potential clinical applications in oncology, rheumatology and the cardiovascular field. For this purpose, there is a high demand for exogenous contrast agents with high absorption coefficients in the optical window for tissue imaging, i.e. the near infrared (NIR) range between 680 and 950 nm. We herein report the photoacoustic properties of quinone-fused porphyrins inserted with different transition metals as new highly promising candidates. These dyes exhibit intense NIR absorption, a lack of fluorescence emission, and PA sensitivity in concentrations below 3 nmol mL–1. In this context, the highest PA signal was obtained with a Zn(ii) inserted dye. Furthermore, this dye was stable in blood serum and free thiol solution and exhibited negligible cell toxicity. Additionally, the Zn(ii) probe could be detected with an up to 3.2 fold higher PA intensity compared to the clinically most commonly used PA agent, ICG. Thus, further exploration of the ‘quinone-fusing’ approach to other chromophores may be an efficient way to generate highly potent PA agents that do not fluoresce and shift their absorption into the NIR range.
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机译:光声(PA)成像是一种新兴的非侵入性诊断方式,在肿瘤学,风湿病学和心血管领域具有许多潜在的临床应用。为此,迫切需要用于组织成像的光学窗中具有高吸收系数的外源造影剂,即在680至950nm之间的近红外(NIR)范围。我们在本文中报道了插入有不同过渡金属的醌融合卟啉的光声性质,它们是新的很有前途的候选物。这些染料在低于3 nmol mL –1 sup>的情况下表现出强烈的NIR吸收,缺乏荧光发射和PA敏感性。在这种情况下,用插入Zn(ii)的染料可获得最高的PA信号。此外,该染料在血清和游离硫醇溶液中稳定,并且细胞毒性可忽略不计。此外,与临床上最常用的PA试剂ICG相比,可以检测到的Zn(ii)探针具有高达3.2倍的PA强度。因此,对其他生色团进行“醌融合”方法的进一步探索可能是生成高效的,不会发荧光并将其吸收转移到NIR范围内的PA试剂的有效方法。
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