Research Of PEG-modified Binary Rare-earth Nano-contrast Agents For MRI/CT Dual-mode Imaging

Malignant tumors threaten human health in today’s society,and precision medicine is increasingly advocated for their treatment,that is:the ability to accurately and dynamically detect tumor development,the detection of tumor classification,and then formulate individualized plans for patients to achieve prevention and treatment against tumor.Integrating multi-modal imaging technology into multifunctional probes on the same platform can provide more comprehensive information for the diagnosis and dynamic changes of tumors and other diseases.For example,MRI（magnetic resonance imaging）and CT（X-ray electronic tomography）,which are commonly used in clinical therapy,can make up for the defects of imaging methods and achieve complementary advantages.Therefore,this article intends to synthesize a nanoprobe suitable for MRI and CT dual-mode imaging conditions（PEG-Gd/Lu（OH）CO₃NPs）,and explore whether it can be used as a dual-mode MRI/CT for imaging probe applications.In this paper,the PEG-modified binary rare-earth nano-contrast agents（PEG-Gd/Lu（OH）CO₃NPs）were constructed by a one-pot homogeneous precipitation method.Through the structure identification of its synthesis and analysis of physical and chemical properties:field emission scanning electron microscopy（FE-SEM）analysis.The results show that the nanocontrast agent is spherical and uniform in size;Fourier transform infrared spectroscopy（FTIR）experimental results show that PEG is successfully modified to the surface of the nano-contrast agent.Due to the PEG modification,the nano-contrast agent shows good stability and dispersibility in the solution.In vitro cytotoxicity assay（WST-1 method）results show that the probe has lower cytotoxicity;and the nanocontrast agent has efficient T1-weighted MRI and CT imaging capabilities.In vivo experiments showed that,nanocontrast agent can be used for T1-weighted MR imaging when applying on 4T1 subcutaneous tumor-bearing mice.HE staining results show that oral administration of the probe to mice（1 mg/mL）did not cause liver in experimental animals for 4 weeks,kidney tissue damage.To sum up,the PEG modified binary rare-earth nano-contrast agents have a chance to become a new generation of the dual-mode contrast agents for application in clinic.