Engineered Gold-Based Nanomaterials: Morphologies and Functionalities in Biomedical Applications. A Mini Review

Abstract

In the last decade, several engineered gold-based nanomaterials, such as spheres, rods, stars, cubes, hollow particles, and nanocapsules have been widely explored in biomedical fields, in particular in therapy and diagnostics. As well as different shapes and dimensions, these materials may, on their surfaces, have specific functionalizations to improve their capability as sensors or in drug loading and controlled release, and/or particular cell receptors ligands, in order to get a definite targeting. In this review, the up-to-date progress will be illustrated regarding morphologies, sizes and functionalizations, mostly used to obtain an improved performance of nanomaterials in biomedicine. Many suggestions are presented to organize and compare the numerous and heterogeneous experimental data, such as the most important chemical-physical parameters, which guide and control the interaction between the gold surface and biological environment. The purpose of all this is to offer the readers an overview of the most noteworthy progress and challenges in this research field.

Gold Nanoparticles and Nanorods in Nuclear Medicine: A Mini Review

“…AuNPs can be synthesized by means of several processes such as chemical, physical, and biological methods [24,[49][50][51]65]. A well-known bottom-up approach is a wet reduction in the presence of a capping agent [55,57,[59][60][61][62]64].…”

“…The chemical synthesis is a strong tool for the bottom-up approach in gold-based materials preparations [49,63]. In particular for AuNRs, by the strict control of chemical procedures, it can be possible to control dimensions and monodispersity, as reported in Figure 3.…”

“…While dissimilar passive targeting demonstrates low tumor selectivity, active targeting produces a higher intratumoral accumulation of a nanocarrier and drug. Consequently, it is positive to develop active targeting systems that can selectively identify specific cells or tissues, attaching specific ligands such as antibodies, aptamers, peptides, and so forth, on nanocarrier surfaces [48,49].Among others, the gold-based nanomaterials have amazing features that make them very suitable and valuable in nanomedicine. In fact, they show remarkable chemical-physical properties, such as an easy modifiable morphology/size/surface, modulable optical absorption and scattering, photothermal and photoacoustic enhancements, and a wide surface/volume ratio that is suitable for interaction with the environment [50][51][52][53].…”

“…While dissimilar passive targeting demonstrates low tumor selectivity, active targeting produces a higher intratumoral accumulation of a nanocarrier and drug. Consequently, it is positive to develop active targeting systems that can selectively identify specific cells or tissues, attaching specific ligands such as antibodies, aptamers, peptides, and so forth, on nanocarrier surfaces [48,49].…”

Visualization photofragmentation‐induced rhodamine B release from gold nanorod delivery system by combination two‐photon luminescence imaging with correlation spectroscopy

“…The gold‐based optical nanomaterials have widely applied in drug delivery, imaging and biosensor because of their tunable surface plasmon resonance, shape‐dependent optical and electrical properties . In particular, the gold nanorod (AuNR) has an tunable intensive absorption in the near‐infrared (NIR) region (650‐900 nm), large surface and the excellent photothermal conversion efficiency, which are widely designed to graft photosensitizers or chemotherapy drug for in vivo NIR‐responsive drug delivery .…”