Multifunctional Nanoprobe For ¹⁹F Magnetic Resonance Imaging Mediated Synergetic Therapy

For the past few years,the consistent nanotechnology development has provided new ideas for researchers to construct biomedical platforms using new multifunctional nanomaterials.Nanomaterials could be used in precision medicine and clinical disease diagnosis,in virtue of their unique properties in physical and chemical field.¹⁹F magnetic resonance imaging(¹⁹F MRI)not only retains the advantages of ¹H magnetic resonance imaging（¹H MRI）as non-invasive and deep tissue penetration,but also has the characteristics of zero background interference due to the absence of endogenous fluorine atoms in organisms,which is a new imaging method with high spatial resolution.The combination of imaging technology and treatment can further provide people with detailed information about the disease,helping to establish an accurate and efficient visual diagnosis and treatment platform.However,the preparation of fluorinated nanoprobes with high fluoride content that can be used for in vivo imaging presents some challenges.In this paper,we propose a method for in-situ synthesis of copper sulfide nanoassemblies inside fluorine-containing nanoprobes loaded with taxol,and prepare multifunctional nanoprobes CFPP NPs that can be used in ¹⁹F MRI and photoacoustic imaging（PAI）.By changing the reaction conditions,the local surface plasmon resonance（LSPR）absorption peak of the copper sulfide nanoassembly was regulated to obtain good photothermal effect.The self-assembly results in further improvement of the photothermal performance,and the photothermal conversion efficiency（PEC）reaches 43.2%.Due to the high ¹⁹F MRI signal intensity and good in vivo circulation stability of CFPP NPs,nanoprobes were injected into the tail vein of tumor-bearing mice.The results showed that these CFPP NPs were suitable for multi-mode imaging with high penetration depth and low background,and had good chemotherapy photothermal synergic effect.The results of metabolic experiments in mice showed that the assembly was easy to dissociate and the dissolved small particles were basically discharged from the body within 10 days,which avoided long-term retention of large nanoparticles to the organism and had high biosafety.This method broadens the application space of multifunctional nanoplatform in the field of biomedicine and has great potential in image-guided tumor therapy.