Miktoarm star conjugated multifunctional gold nanoshells: synthesis and an evaluation of biocompatibility and cellular uptake

Synthetic Methodologies to Gold Nanoshells: An Overview

Gold nanostructures that can be synthetically articulated to adapt diverse morphologies, offer a versatile platform and tunable properties for applications in a variety of areas, including biomedicine and diagnostics. Among several conformational architectures, gold nanoshells provide a highly advantageous combination of properties that can be fine-tuned in designing single or multi-purpose nanomaterials, especially for applications in biology. One of the important parameters for evaluating the efficacy of gold nano-architectures is their reproducible synthesis and surface functionalization with desired moieties. A variety of methods now exist that allow fabrication and chemical manipulation of their structure and resulting properties. This review article provides an overview and a discussion of synthetic methodologies to a diverse range of gold nanoshells, and a brief summary of surface functionalization and characterization methods employed to evaluate their overall composition.

Conjugation of multivalent ligands to gold nanoshells and designing a dual modality imaging probe

Design and synthesis of branched tetraethylene glycol (TEG) based ligands for subsequent conjugation to gold nanoshells are reported. TEG enhances the aqueous solubility of hollow gold nanoshells (HAuNShs), and the branched architecture provides stability. An examination of the supernatant of the surface displacement reaction shows that the structure of the ligand plays an important role in the functionalization of HAuNShs. The binding of multivalent ligands leads to rupturing of the gold nanoshell architecture; most probably due to the large dendron not compensating the replacement of small citrate capping agents. The construction of a probe with dual imaging capabilities is demonstrated by covalent linking of a dendron containing Cy5.5_A dye to gold nanoshells. It leads to fluorescence quenching of Cy5.5_A by the gold nanoshells, as evidenced in solution and in cellular internalization studies with J774 and bEnd.3 cells.