Theranostics 2019; 9(14):4168-4181. doi:10.7150/thno.34390

Research Paper

Gadolinium-Chelated Conjugated Polymer-Based Nanotheranostics for Photoacoustic/Magnetic Resonance/NIR-II Fluorescence Imaging-Guided Cancer Photothermal Therapy

Xiaoming Hu1, Yufu Tang1, Yuxuan Hu2, Feng Lu1, Xiaomei Lu3, Yuqi Wang2, Jie Li1, Yuanyuan Li1, Yu Ji1, Wenjun Wang4, Deju Ye2, Quli Fan1✉, Wei Huang1,3,5

1. Key Laboratory for Organic Electronics and Information Displays (KLOEID) & Institute of Advanced Materials (IAM), Jiangsu National Synergetic Innovation Center for Advanced Materials (SICAM), Nanjing University of Posts & Telecommunications, Nanjing 210023, China.
2. State Key Laboratory of Analytical Chemistry for Life Science, School of Chemistry and Chemical Engineering, Nanjing University, Nanjing, 210093, China
3. Key Laboratory of Flexible Electronics (KLOFE) & Institute of Advanced Materials (IAM), Jiangsu National Synergetic Innovation Center for Advanced Materials (SICAM), Nanjing Tech University (NanjingTech), Nanjing 211816, China
4. Key Lab of Optical Communication Science and Technology of Shandong Province & School of Physics Science and Information Engineering, Liaocheng University, Liaocheng 252059, China
5. Shaanxi Institute of Flexible Electronics (SIFE), Northwestern Polytechnical University (NPU), Xi'an 710072, China.

Abstract

Our exploiting versatile multimodal theranostic agent aims to integrate the complementary superiorities of photoacoustic imaging (PAI), second near-infrared (NIR-II, 1000-1700) fluorescence and T1-weighted magnetic resonance imaging (MRI) with an ultimate objective of perfecting cancer diagnosis, thus improving cancer therapy efficacy. Herein, we engineered and prepared a water-soluble gadolinium-chelated conjugated polymer-based theranostic nanomedicine (PFTQ-PEG-Gd NPs) for in vivo tri-mode PA/MR/NIR-II imaging-guided tumor photothermal therapy (PTT).

Methods: We firstly constructed a semiconducting polymer composed of low-bandgap donor-acceptor (D-A) which afforded the strong NIR absorption for PAI/PTT and long fluorescence emission to NIR-II region for in vivo imaging. Then, the remaining carboxyl groups of the polymeric NPs could effectively chelate with Gd3+ ions for MRI. The in vitro characteristics of the PFTQ-PEG-Gd NPs were studied and the in vivo multimode imaging as well as anti-tumor efficacy of the NPs was evaluated using 4T1 tumor-bearing mice.

Results: The obtained theranostic agent showed excellent chemical and optical stability as well as low biotoxicity. After 24 h of systemic administration using PQTF-PEG-Gd NPs, the tumor sites of living mice exhibited obvious enhancement in PA, NIR-II fluorescence and positive MR signal intensities. Better still, a conspicuous tumor growth restraint was detected under NIR light irradiation after administration of PQTF-PEG-Gd NPs, indicating the efficient photothermal potency of the nano-agent.

Conclusion: we triumphantly designed and synthesized a novel and omnipotent semiconducting polymer nanoparticles-based theranostic platform for PAI, NIR-II fluorescence imaging as well as positive MRI-guided tumor PTT in living mice. We expect that such a novel organic nano-platform manifests a great promise for high spatial resolution and deep penetration cancer theranostics.

Keywords: conjugated polymer, second near-infrared fluorescence imaging, photoacoustic imaging, magnetic resonance imaging, photothermal therapy

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How to cite this article:
Hu X, Tang Y, Hu Y, Lu F, Lu X, Wang Y, Li J, Li Y, Ji Y, Wang W, Ye D, Fan Q, Huang W. Gadolinium-Chelated Conjugated Polymer-Based Nanotheranostics for Photoacoustic/Magnetic Resonance/NIR-II Fluorescence Imaging-Guided Cancer Photothermal Therapy. Theranostics 2019; 9(14):4168-4181. doi:10.7150/thno.34390. Available from http://www.thno.org/v09p4168.htm