CHARACTERIZATION OF MACROPHAGE MEMBRANES ASSOCIATED WITH GOLD NANORODS

The synthesis of gold nanorods (GNRs) has opened possibilities for applications in many fields such as phototherapies due to the optical properties originating from the surface plasmon resonance. Each GNR has a longitudinal plasmon resonance peak (LSPR), which, upon irradiation, can convert NIR light into heat, a process known as plasmon photothermal therapy (FADEEL; GARCIA-BENNETT, 2010). Therefore, GNR-based solutions are used in studies evaluating damage and destruction of cells, pathogens, and diseases relevant to public health (LAGE et al., 2022). However, it is still necessary to understand how the physicochemical properties of GNRs affect cell motility to clarify the action of nanoparticles on cytotoxic interactions with cell membranes for appropriate phototherapy applications. For such an analysis, Defocusing Microscopy (DM) was used to study and characterize changes in membrane-cytoskeleton interactions on the surface of macrophages, immune system cells, associated with GNRs. DM uses the formalism of angular spectrum propagation to describe the phase object contrast (AGERO, 2003). Based on the contrast, it is possible to study dynamic and mechanical properties of the cytoskeleton. Moreover, it is possible to correlate viscoelastic properties with fluctuations using spatial and temporal autocorrelation functions, which allow to obtain the decay time of these membrane fluctuations. Thus, we analyzed the reactions of GNRs applications. The aim is to analyze changes in cell motility and evaluate the susceptibility of GNRs against parasites and diseases without damaging macrophages, to deepen the understanding of GNRs' performance, their interactions with cells, and the potential damage and cytotoxicity. This enables the implementation of phototherapy and facilitates the understanding of the biophysical system under study.