Background and Purpose: Non-invasive imaging methodologies, especially nuclear imaging techniques, have undergone an extraordinary development over the last years. Interest in the development of innovative tracers has prompted the emergence of new nanomaterials with a focus on nuclear imaging and therapeutical applications. Among others, organic nanoparticles are of the highest interest due to their translational potential related to their biocompatibility and biodegradability. Our group has developed a promising new type of biocompatible nanomaterials, sphingomyelin nanoemulsions (SNs). The aim of this study is to explore the potential of SNs for nuclear imaging applications.
Methods: Ready-to-label SNs were prepared by a one-step method using lipid derivative chelators and characterized in terms of their physicochemical properties. Stability was assessed under storage and after incubation with human serum. Chelator-functionalized SNs were radiolabeled with ⁶⁷Ga and ⁶⁸Ga, and the radiochemical yield (RCY), radiochemical purity (RCP) and radiochemical stability (RCS) were determined. Finally, the biodistribution of ^67/68Ga-SNs was evaluated in vivo and ex vivo.
Results: Here, we describe a simple and mild one-step method for fast and efficient radiolabeling of SNs with ⁶⁸Ga and ⁶⁷Ga radioisotopes. In vivo experiments showed that ^67/68Ga-SNs can efficiently and indistinctly be followed up by PET and SPECT. Additionally, we proved that the biodistribution of the ^67/68Ga-SNs can be conveniently modulated by modifying the surface properties of different hydrophilic polymers, and therefore the formulation can be further adapted to the specific requirements of different biomedical applications.
Conclusion: This work supports ^67/68Ga-SNs as a novel probe for nuclear imaging with tunable biodistribution and with great potential for the future development of nanotheranostics.

Keywords: sphingomyelin nanoemulsions, biodistribution, gallium-68/67, nuclear imaging, nanotheranostics


中文翻译：

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通过 PET 和 SPECT 成像对 68/67Ga 放射性标记的鞘脂纳米乳液进行生物分布

背景和目的：非侵入性成像方法，尤其是核成像技术，在过去几年中取得了非凡的发展。对开发创新示踪剂的兴趣促使新纳米材料的出现，重点是核成像和治疗应用。其中，有机纳米颗粒因其与生物相容性和生物降解性相关的转化潜力而备受关注。我们小组开发了一种很有前途的新型生物相容性纳米材料——鞘磷脂纳米乳液（SNs）。本研究的目的是探索 SN 在核成像应用中的潜力。
方法：通过使用脂质衍生物螯合剂的一步法制备可立即标记的 SN，并根据其物理化学性质进行表征。在储存下和与人血清一起温育后评估稳定性。螯合剂功能化的 SN 用⁶⁷ Ga 和⁶⁸ Ga 进行放射性标记，并测定了放射化学产率 (RCY)、放射化学纯度 (RCP) 和放射化学稳定性 (RCS)。最后，在体内和体外评估了^{67/68 Ga-SNs 的生物分布。}
结果：在这里，我们描述了一种简单而温和的一步法，用于快速有效地对具有⁶⁸ Ga 和⁶⁷ Ga 放射性同位素的 SN 进行放射性标记。体内实验表明，^67/68Ga-SNs 可以通过 PET 和 SPECT 有效且模糊地跟踪。此外，我们证明了通过改变不同亲水聚合物的表面性质可以方便地调节^67/68 Ga-SNs 的生物分布，因此该配方可以进一步适应不同生物医学应用的特定要求。
结论：这项工作支持^67/68 Ga-SNs 作为一种新型核成像探针，具有可调节的生物分布，在纳米治疗学的未来发展中具有巨大潜力。

关键词：鞘磷脂纳米乳，生物分布，镓68/67，核成像，纳米治疗