Department of Pharmacy, School of Pharmaceutical Science, Shanxi Medical University, Taiyuan, Shanxi, People's Republic of China.
Radiology Department, The Affiliated Bethune Hospital of Shanxi Medical University, Taiyuan, Shanxi, People's Republic of China.
Int J Nanomedicine. 2020 Jul 14;15:5017-5026. doi: 10.2147/IJN.S238679. eCollection 2020.
Molecular imaging is of great benefit to early disease diagnosis and timely treatment. One of the most striking innovations is the development of multimodal molecular imaging technology, which integrates two or more imaging modalities, largely in view of making the best of the advantages of each modality while overcoming their respective shortcomings. Hence, engineering a versatile and easily prepared nanomaterial with integrating multimodal molecular imaging function holds great promise, but is still a great challenge.
We firstly designed and synthesized a BDT-DPP conjugated polymer and then noncovalent self-assembly with phospholipid-polyethylene glycol endowed BDT-DPP with water solubility and biocompatibility. Followed by [Cu] labeling, the acquired multifunctional nanoparticles (NPs) were studied in detail for the photophysical property. The cytotoxicity and biocompatibility of DPP-BDT NPs were examined through MTT assay and H&E stained analysis. In addition, we investigated the accumulation of the NPs in HepG2 tumor models by positron emission tomography (PET) and photoacoustic (PA) dual-mode imaging.
The DPP-BDT NPs exhibited excellent optical stability, strong near-infrared (NIR) light absorption as well as fine biocompatibility. After tail vein injection into the living mice, the PA signals in the neoplastic tissues were gradually increased and reached to the maximum at the 4-h post-injection, which was consistent with the PET analysis. Such strong PA and PET signals were attributed to the efficient NPs accumulation resulting from the enhanced permeability and retention (EPR) effect.
The biocompatible DPP-BDT NPs demonstrated to be strong NIR absorption property and PAI sensitivity. Besides, these novel DPP-BDT NPs can act not only as a PA imaging contrast agent but also as an imaging agent for PET.
分子成像对疾病的早期诊断和及时治疗具有重要意义。其中最引人注目的创新之一是开发了多模态分子成像技术，它集成了两种或更多种成像模式，主要是为了充分利用每种模式的优势，同时克服各自的缺点。因此，设计和制备一种多功能且易于制备的纳米材料，同时具有整合多模态分子成像功能，具有很大的应用前景，但仍然是一个巨大的挑战。
我们首先设计并合成了一种 BDT-DPP 共轭聚合物，然后通过非共价自组装与磷脂-聚乙二醇结合，赋予 BDT-DPP 水溶性和生物相容性。随后进行[Cu]标记，详细研究了获得的多功能纳米颗粒（NPs）的光物理性质。通过 MTT 检测和 H&E 染色分析，研究了 DPP-BDT NPs 的细胞毒性和生物相容性。此外，我们通过正电子发射断层扫描（PET）和光声（PA）双模式成像研究了 NPs 在 HepG2 肿瘤模型中的积累情况。
DPP-BDT NPs 表现出优异的光学稳定性、强近红外（NIR）光吸收和良好的生物相容性。尾静脉注射到活小鼠体内后，肿瘤组织中的 PA 信号逐渐增加，在注射后 4 小时达到最大值，与 PET 分析一致。这种强的 PA 和 PET 信号归因于增强的通透性和保留（EPR）效应导致的 NPs 有效积累。
生物相容性的 DPP-BDT NPs 表现出强的近红外吸收特性和 PAI 灵敏度。此外，这些新型 DPP-BDT NPs 不仅可以作为 PA 成像造影剂，还可以作为 PET 的成像剂。
