Construction Of Hydrophilic Micellar Aggregation With Alkylbenzene Sulfonate Gadolinium-Dendritic Macromolecules Pamam And Controlled Release Of Gadolinium Ions

Gadolinium (?) chloride and sodium dodecylbenzenesulfonate were used to prepare alkyl gadolinium (Gd) surfactants. The non-ionic surfactant alcohol ethoxylate (AEO-25) was selected to solubilize and disperse the Gd surfactants in water to form the solubilizing system.When the ratio of AEO-25 and Gd was more than 1.5, the solution was transparent and stable, and the white snowflake solid was get after the freeze drying of this solution. An ordered supramolecular micellar aggregate (4G-PAMAM/AEO-25/LASGd) was constructed through self-assembly by adding four generations of polyamide-amine dendritic macromolecular (4.0G-PAMAM) to the solubilizing system through the weak interaction among intermoleculars and the synergistic effect. By the analysis methods of elemental analysis, thermogravimetric, infrared,nuclear magnetic, transmission electron microscope, and inductively coupled plasma atomic emission spectrometry, the dodecylbenzene-sulfonate acid gadolinium, solubilizing mode and the structure and properties of the aggregation were characterized.The alkyl gadoliniums were in the core of the mixed micelle fabricated by AEO-25, and PAM AM moleculers were existed around the micelles in aqueous solution. The solution of freeze-dried aggregate was dialysised by deionized water, and the acid or alkali was added to adjust the pH value. We found that the concentration of gadolinium ions in the dialysis bag was changed. It is indicated that the release of gadolinium ions in the micelle were controlled by pH value. We also found the changing ratio of 4.0G-PAMAM and mixed micelle and the temperature of the aggregate aqueous solution were both controlled the release of gadolinium ions.It was concluded that a kind of good water-soluble aggregate was prepared in this thesis, and we can control the release of Gd ions by adjusting the solution pH or the ratio between ingredients or system temperature. This micellar aggregate shows promise in applications as a pH-sensitive magnetic resonce imaging (MRI) contrast agent.