A General and Facile Strategy to Fabricate Multifunctional Nanoprobes for Simultaneous F-19 Magnetic Resonance Imaging, Optical/Thermal Imaging, and Photothermal Therapy

摘要

F-19 magnetic resonance imaging (MRI), due to its high sensitivity and negligible background, is anticipated to be a powerful noninvasive, sensitive, and accurate molecular imaging technique. However, the major challenge of F-19 MRI is to increase the number of F-19 atoms while maintaining the solubility and molecular mobility of the probe. Here, we successfully developed a facile and general strategy to synthesize the multifunctional F-19 MRI nanoprobes by encapsulating the hydrophobic inorganic nano particles (NPs) into a hybrid polymer micelle consisting of hydrolysates of 1H,1H,2H,2H-perfluorodecyltriethoxysilane (PDTES) and oleylamine-functionalized poly(succinimide) (PSIOAm). Due to their good water dispersibility, excellent molecular mobility resulting from the ultrathin coating, and high F-19 atom numbers, these nanoprobes generate a separate sharp singlet of F-19 nuclear magnetic resonance (NMR) signal (at -82.8 ppm) with half peak width of similar to 28 Hz, which is highly applicable for F-19 MRI. Significantly, by varying the inorganic core from metals (Au), oxides (Fe3O4), fluorides (NaYF4:Yb3+/Er3+), and phosphates (YPO4) to semiconductors (Cu7S4 and Ag2S, ZnS:Mn2+) NPs, which renders the nanoprobes' multifunctional properties such as photothermal ability (Au; Cu7S4), magnetism (Fe3O4), fluorescence (ZnS:Mn2+), near-infrared (NIR) fluorescence (Ag2S), and upconversion (UC) luminescence. Meanwhile, the as prepared nanoprobes possess relatively small sizes (about 50 nm), which is beneficial for long-time circulation. The proof-of-concept in vitro F-19 NMR and photothermal ablation of ZnS:Mn2+@PDTES/PSIOAm, and Cu7S4@PDTES/PSIOAm nanoprobes further suggest that these nanoprobes hold wide potentials for multifunctional applications in biomedical fields.