Construction,Performance Control And Application Research Of Multi-functional Rare-earth Gd-based Nanoprobes Based On NIR-? Imaging

In the past decade,multi-functional nanomaterials have been widely used as bioprobes in efficient diagnosis and effective treatment of tumor.The multi-functional nanomaterials integrating the multi-modal imaging such as optical imaging,magnetic resonance?MR?imaging and effective treatment?such as photothermal therapy?functions have become one of the research hotspots due to its broad applications in nanomedicine.In addition,in recent years,compared with the traditional rare-earth fluorescent probes,the rare-earth fluorescent probes holding fluorescence emission in the second near-infrared?NIR-??window have opened up a new field for the development of optical bioimaging technology for promoting early detection and diagnosis of tumor and attracted a great research attention due to the large tissue penetration depth,low auto-fluorescence,high sensitivity and spatial resolution.Therefore,it is of great significance to design a novel multi-functional nanoprobe with NIR-? emission for simultaneous realization of the diagnosis and treatment functions.To this end,we mainly construct the rare-earth Gd-based multi-functional nanomaterials by integrating the NIR-? and X-ray/MR multi-modal imaging with therapy functions.The main contents are as follows:?1?We successfully synthesized hexagonal phase Nd³⁺doped GdPO₄nanoprobes with yolk-shell structure.And the morphology and properties were characterized.The effects of Nd³⁺doping and particle size on the NIR-? luminescence properties of the samples were investigated.The nanoprobe presents excellent NIR-? emission under 808 nm laser excitation.And the best NIR-? emission intensity of the GdPO₄ sample is obtained via doping 2%Nd³⁺,demonstrating the optimal doping content.?2?The GdPO₄:2%Nd³⁺probe was further used for NIR-? optical and X-ray dual-modal bioimaging,and pH-dependent drug releasing properties were systematically studied.The results demonstrated that the probe was mainly accumulated in the liver and spleen of mice.In addition,our designed GdPO₄:2%Nd³⁺probe presented superior X-ray imaging contrast than the clinically used contrast agent?iohexol?.And the designed GdPO₄:Nd³⁺probe can also be used for drug loading and pH response drug release,which indicates that GdPO₄:Nd³⁺probe has potential applications in tumor-targeted drug delivery.?3?The multi-functional Fe₃O₄@PDA@NaGdF₄:Yb/Er probes were successfully synthesized.The explored nanocomposites present excellent magnetic properties and binary T₁/T₂ weighted MR imaging.And under808 nm laser excitation,the nanocomposites hold excellent photothermal conversion effect,indicating its potential application in photothermal therapy of tumor.In addition,in vivo NIR-? optical bioimaging was successfully performed by using the designed nanocomposites,demonstrating the excellent NIR-? emission.Therefore,it is expected that the designed Fe₃O₄@PDA@NaGdF₄:Yb/Er nanocomposites have potential applications in MR/NIR-? dual-mode bioimaging and magnetic targeting photothermal therapy of tumors.