Revisiting gold nanoshells as multifunctional biomedical nanotools

Abstract

The application of gold nanoparticles in the biomedical field has been widely explored in the last decades owing to their high biocompatibility, easy functionalization, and their structurally highly dependent optical properties. Among the different types of gold-based nanostructures, gold nanoshells (GNSs) are a particularly interesting option due to their complex dual structure, which allows the integration of several functionalities and a wide tunability of their optical response. Despite the remarkable progress made for the design of GNSs with the optimal characteristics for the intended application, the development of nanosystems that display the desired functionalities and preserve them in biological environments while showing effective targeting capability is still a challenge. In this review, the different synthetic routes proposed for the design of GNSs, their most remarkable optical properties, and the most relevant concerns associated with their interaction with biological systems are discussed. The application of these nanostructures for different diagnostic and/or therapeutic purposes is also reviewed. Finally, major remaining barriers to the clinical translation of GNSs and potential future directions of research in this field are critically commented. Graphical abstract