RESUMO
Composition control is a powerful tool for obtaining high-performance lanthanide (Ln) luminescent materials with adjustable optical outputs. This strategy is well-established for hierarchically structured nanoparticles, but it is rarely applied to molecular compounds due to the limited number of metal centers within a single unit. In this work, we present a series of molecular cluster-aggregates (MCAs) with an icosanuclear core {Ln2Eu2Tb16} (Ln = Ce, Pr, Nd, Sm, Gd, Dy, Ho, Er, Tm, and Yb) in which we explore composition control, akin to nanoparticles, to modulate the optical output. More specifically, we target to understand how the presence of a third LnIII doping ion would impact the well-known TbIII â EuIII energy transfer and the ratiometric optical thermometry performance based on the TbIII/EuIII pair. Photophysical properties at room and at varying temperatures were investigated. Based on experimental data and well-established intrinsic features, such as spin-orbit coupling strength and LnIII 4f energy levels' structure, we discuss the possible luminescent processes present in each MCA and provide insight into qualitative trends that can be rationally correlated throughout the series.
RESUMO
Gold nanorods (AuNRs) have been studied extensively in biomedicine due to their biocompatibility and their unique properties. Some studies reported that AuNRs selectively accumulate on cancer cell mitochondria causing its death. However, the immediate effects of this accumulation needed further investigations. In this context, we evaluated the effect of AuNRs on the mitochondrial integrity of isolated rat liver mitochondria. We verified that AuNRs decreased the mitochondrial respiratory ratio by decreasing the phosphorylation and maximal states. Additionally, AuNRs caused a decrease in the production of mitochondrial ROS and a delay in mitochondrial swelling. Moreover, even with cyclosporine A treatment, AuNRs disrupted the mitochondrial potential. With the highest concentration of AuNRs studied, disorganized mitochondrial crests and intermembrane separation were observed in TEM images. These results indicate that AuNRs can interact with mitochondria, disrupting the electron transport chain. This study provides new evidence of the immediate effects of AuNRs on mitochondrial bioenergetics.
