Self-Assembly of Hierarchical Nanostructures from Dopamine and Polyoxometalate for Oral Drug Delivery

The preparation of 3D hierarchical nanostructures by a simple and versatile strategy of self-assembly of dopamine (DA) and phosphotungstic acid (PTA) is described. The size and morphology of the hierarchical nanostructures could be simply controlled by varying the ratio of the two components, their concentrations, and the pH of the initial Tris-HCl solution. The self-assembly of the flowerlike micro-spheres has been found to involve a two-stage growth process. Moreover, use of the hierarchical nanostructures as a possible carrier for an anticancer drug in chemotherapy has been explored. The nanostructures showed an intriguing pH-dependent release behavior, making them promising for applications in biomedical science.