Study On Mesoporous Silicon Modified Gadolinium-based Nano-Contrast Agent For Improving The Performance Of Magnetic Resonance Imaging

At present,the treatment of oral tumor,mainly surgical treatment,through the removal of diseased tissue to completely remove the lesion,to achieve the therapeutic effect.Although,the maxillofacial soft tissue is rich in blood circulation and strong tissue regeneration ability.However,surgical resection will cause facial soft and hard tissue defects to a certain extent,affect the integrity of facial contours,and easily cause secondary injury to patients psychologically.Therefore,it is urgent to make early diagnosis and treatment through early instruments and other auxiliary detection in the early stage of tumor and other diseases.Magnetic resonance imaging?MRI?is suitable for early screening of soft tissue lesions such as tumors because of its good soft tissue resolution and no ionizing radiation.Clinically,more than 30%of the tests used contrast media to enhance the imaging effect.However,the main clinical use of single-mode small molecular contrast agent,will be quickly removed in vivo,affecting the effectiveness of magnetic resonance imaging.In order to achieve the desired imaging results,a large number of geomagnetic resonance contrast agents are used throughout the body to increase the risk of side effects,such as renal fibrosis.To this end,researchers have developed nano-contrast agents,which last longer in the body,use smaller doses,and have better magnetic resonance imaging results.Solid tumor has rich blood supply in oral and maxillofacial region through high permeability and retention effect?EPR effect?,and the blood supply in tumor area is relatively abundant.Nano-contrast medium tends to gather in tumor tissue through the blood vessel wall in tumor area.Enhanced radiography in the tumor area.Nano-contrast agent itself does not produce contrast signal,through contact with water molecules,affect the movement of hydrogen protons in water molecules,and produce contrast effect.Therefore,this paper is mainly studied in the following two directions:?1?increase the exchange between nanomaterials and water molecules.Paramagnetic gadolinium oxide nanoparticles are integrated into the surface of mesoporous silica,and the water molecules on the surface of mesoporous silica are relatively active,and the gadolinium atoms can be in full contact with the water molecules around mesoporous silica.Enhanced magnetic resonance imaging.?2?increase the hydrophilicity of nanomaterials.By modifying a layer of hydrophilic loose silica on the surface of nano-contrast medium,the interaction between gadolinium atom and sufficient water molecules in nano-materials was obtained.Through the experimental study,it is found that MRI can be enhanced in both directions.The first method can enhance the effect of magnetic resonance T1 imaging significantly,the second way can also increase the effect of magnetic resonance T₁ imaging,the enhancement effect is stronger,but has little effect on T₂ imaging.This experiment provides a certain basic research for the development of nano-contrast agent in the future,and provides a new research idea for the early diagnosis of oral tumor.