| Yolk-shell nanomaterials is a special structure based on the core-shell structure,which is similar to the space structure of ellipsoid capsule drugs and spherical liposome drugs.Compared with the traditional core-shell structure,the yolk-shell nanomaterials have controllable cavities,which can be widely used in various fields.Multi-mode composite nanoplatform based on yolkshell structure have become an important object in the field of tumor diagnosis and treatment,and have been widely mentioned in the field of drug carrier behavior.However,the synthesis methods of yolk-shell nanoparticles are often complicated,and there is a lack of general and efficient preparation route.At the same time,there is a lack of universal nanoplatform design method for the integration of cancer diagnosis and treatment.Firstly,a simple method for synthesis of yolk-shell structure was developed and the related synthesis mechanism was explained.The synthetic method has good universality and extensibility,and several kinds of yolk-shell nanoparticles were synthesized based on different materials.In this regard,a general synthesis method of yolk-shell nanostructures with adjustable shell thickness was studied in the aqueous phase.This method is mainly based on the principle that inorganic/organic hybrid silicon precursors have homology in chemical structure,but different ability to resist etching.The two kinds of silicon sources hydrolyzed gradually around the metal core to generate the hybrid structure of the double shell,and the difference in properties was used to etch the internal silane by strong alkali,and the yolk-shell nanoparticles with excellent morphology are obtained.By adjusting the ratio of silane and the intensity of etched base,the shell thickness and cavity size of nanoparticles can be adjusted,which is conducive to substance exchange.Secondly,gold nanorods and dye were encapsulated inside the yolk-shell nanoparticles to achieve real-time photothermal therapy guided by fluorescent dye contrast agent.On the basis of this above methodology,the hetero-shaped gold nanorods yolk-shell nanoparticles(AuNRs@YSiO2)were further developed and extended.The photothermal functional metal core and the cavity structure which can be used to load small molecules were constructed.At the same time,the toxic positive charge cetyl trimethyl ammonium bromide(CTAB)was simultaneously removed by etching solution,and the non-toxic AuNRs@YSiO2 was obtained.To achieve fluorescent tracer imaging,two cyanine dyes IR798 and CyN were designed and synthesized.Sulfonate and carboxyl groups were introduced to enhance their water solubility.The composite nanoplatform AuNRs@YSiO2-dye was prepared by loading the dye into the cavity of AuNRs@YSiO2 with high infiltrability,and the fluorescence interaction between the composite nanoplatform and the dye loaded with different wavelengths and potential properties was investigated.Gold nanorods showed fluorescence quenching effect on IR798 dyes with similar absorption wavelength,while the composite nanoplatforms of AuNRs@YSiO2-CyN and AuNRs@YSiO2-RB could be used for tracer imaging of intracellular particles by lighting up targeted cells.The study also showed that due to the molecular structure and charge differences between CyN and RB,AuNRs@YSiO2-CyN had a higher dye loading capacity,and the evaluation effect of biotherapy was better.The dye encapsulated by the composite nanoplatform can be used to track its endocytosis process.When the nanomaterial entered the cell,under the irradiation of 808 nm laser,the gold nanorods had excellent photothermal effect and could effectively kill cancer cells and achieved excellent treatment effect. |
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