Influência de nanobastões de ouro na cadeia transportadora de elétrons

Abstract

Nanomaterials have distinct properties that depend strongly on the shape and size of the particles that make them up. Because of these properties, more and more researchers are exploring new applications for these structures. Some of them have therapeutic purposes, mainly in some types of neoplasias, and such mechanism is often linked to the induction of cell death. Considering that mitochondria are the main machinery responsible for cell metabolism and are directly involved in cell death, either through necrosis or apoptosis, they are an excellent research target. Thus, this work aims to investigate the influence of gold nanorods (AuNRs) on these organelles, specifically evaluating the operation of the electron transport chain and possible structural modifications. To this end, mitochondria of rat liver were isolated, and then this mitochondrial suspension was exposed to gold nanorods (AuNRs) coated with bovine serum albumin (BSA) at different concentrations (6.25, 12.5, 25, 50 and 100 μM) where the electron transport chain was evaluated through mitochondrial oxygen consumption and transmission electron microscopy to identify possible structural changes. The results indicated that AuNRs were able to lead to impairment of mitochondrial oxygen uptake through decreased phosphorylation state (V3) and decoupled state (VCCCP). These events consequently reduced the respiratory control of mitochondria, a parameter that measures mitochondrial viability. The results also showed that the deleterious capacity of AuNRs is expressed in a dose-dependent manner. In addition, the nanorods were able to cause a disorganization of the mitochondrial ridges and detachment of the membranes. This interruption of mitochondrial function may induce cell death, demonstrating, however initial a possible therapeutic application.