FeSe₂‐Decorated Bi₂Se₃ Nanosheets Fabricated via Cation Exchange for Chelator‐Free ⁶⁴Cu‐Labeling and Multimodal Image‐Guided Photothermal‐Radiation Therapy

Abstract

Multifunctional theranostic agents have become rather attractive to realize image-guided combination cancer therapy. Herein, we develop a novel method to synthesize Bi2Se3 nanosheets decorated with mono-dispersed FeSe2 nanoparticles (FeSe2/Bi2Se3) for tetra-modal image-guided combined photothermal & radiation tumor therapy. Interestingly, upon addition of Bi(NO3)3, pre-made FeSe2 nanoparticles via cation exchange would be gradually converted into Bi2Se3 nanosheets, on which remaining FeSe2 nanoparticles are decorated. The yielded FeSe2/Bi2Se3 composite-nanostructures were then modified with polyethylene glycol (PEG). Taking advantages of the high r2 relaxivity of FeSe2, the X-ray attenuation ability of Bi2Se3, the strong near-infrared (NIR) optical absorbance of the whole nanostructure, as well as the chelate-free radiolabeling of 64Cu on FeSe2/Bi2Se3-PEG, in vivo magnetic resonance (MR)/computer tomography (CT)/photoacoustic (PA)/position emission tomography (PET) multimodal imaging was carried out, revealing efficient tumor homing of FeSe2/Bi2Se3-PEG after intravenous injection. Utilizing the intrinsic physical properties of FeSe2/Bi2Se3-PEG, in vivo photothermal & radiation therapy to achieve synergistic tumor destruction was then realized, without causing obvious toxicity to the treated animals. Our work presents a unique method to synthesize composite-nanostructures with highly integrated functionalities, promising not only for nano-biomedicine, but also potentially for other different nanotechnology fields.

Dual-Modality Positron Emission Tomography/Optical Image-Guided Photodynamic Cancer Therapy with Chlorin e6-Containing Nanomicelles

“…Data acquisition, image reconstruction, and ROI analysis of the PET data were performed as described previously. 52 After the PET scans at 24 h and 48 h p.i., ex vivo biodistribution studies were carried out to ensure the %ID/g values determined by PET imaging truly represented the radioactivity distribution in tumor-bearing mice. Mice were euthanized, and blood, tumor, and major organs/tissues were collected and wet-weighed.…”

Harnessing the Power of Nanotechnology for Enhanced Radiation Therapy

“…25 Several studies have since reported the use of more effective or less costly nanoformulations composed of high atomic weight nanomaterials alone or in conjunction with nanoparticulate photosensitizers for enhanced combination therapy of tumors. 24,26–28 Despite extensive advances in combined RT/PTT in the preclinical setting, logistical problems associated with the simultaneous delivery of heat and radiation, nonspecific accumulation of the nanomaterials, and difficulty in photoirradiation of deep-seated tumors, etc ., have impeded the clinical translation of this promising paradigm. To circumvent the latter, Li and coworkers have reported ultrasmall Bi nanoparticles that have the ability to absorb both the ionizing and second near-infrared (NIR-II) window laser irradiations, for effective and synergistic treatment of tumors.…”

Mitochondria‐Targeted Artificial “Nano‐RBCs” for Amplified Synergistic Cancer Phototherapy by a Single NIR Irradiation

“…Especially, the rational integration of diverse imaging modalities to achieve multiple imaging can provide more precise information 13. As one of the most commonly adopted diagnostic tools in clinic, computed tomography (CT) imaging can provide 3D images to illustrate the anatomic structures around tumor region with high spatial resolutions and deep tissue penetration 14. However, the diagnostic accuracy of CT is limited by its low sensitivity, leading to poor contrast for soft‐tissue 15.…”