Synthesis of Co@Au (superparamagnetics) and CdSe@Zn (quantum dots) core@shell nanostructures for applications as antineoplasia agents

Abstract

Recently, magnetic and quantum dot nanoparticles are intensively studied as new materials for cancer diagnostic and therapy due to their unique properties, mainly such as magnetic, optical, electric and photoluminescent. In the case of nanomaterials, these properties are also size-dependent or size-tunable, which justified the strongest interest in this materials science scale range. For biomedical applications, in a new area called as nanomedicine, superparamagnetic behavior at room temperature and colloidal stability, as well as surface biocompatible and low toxicity, are necessary for magnetic materials. In this way, there are several advantages of core/shell nanostructure uses, for example Co/Au, for cancer therapy. Advantages consist basically to connect the high saturation magnetization (~ 1422 emu.cm-3) and superparamagnetic behavior of the Co core with size up to 8 nm, and the gold coating that confer large surface functionalization possibilities, low toxicity and high colloidal and chemical stabilities. Similarly, core/shell quantum dots of CdSe/ZnS present enhanced photoluminescent properties for application in cancer image and photodynamic therapy due to their efficient electronic structure which confer superior photostability and longer photoluminescent lifetime. However, applications of these nanomaterials in biomedicine require rigorous size and shape control, and narrow size distribution to adjust their properties. In addition, materials surface must have non-toxicity and selectivity by cancer cells membranes that can be obtained by using specific, synthetic or natural, biocompatible macromolecules. Consequently, the goal of this project is developing synthetic methods for obtaining monodisperse core/shell nanostructures of Co/Au and CdSe/ZnS with size, shape, and chemical composition control. After that, colloidal stability and specificity by cancer cells will be investigated by appropriate surface functionalization of these systems using biocompatible polymers and biologically active molecules.