Investigation of the interaction between the luminescent complex cis-(Ru(phen)2(Apy))2 and liposomes as mimetic membrane models

Abstract

Our laboratory has been working on the development of luminescent complexes as teranostic agents for Alzheimer's disease. Recently, we prepared the luminescent complexes cis-[Ru(phen)2(Apy)]2+ (RuApy) in which phen = 1,10-phenanthroline and Apy = 4aminopyridine, 3,4-aminopyridine. For example, the complex containing the 3,4-Apy ligand is absorbed by neuronal cells reaching the cytoplasmic region (Neuro2A, PC12, SH-S5Y5) with no apparent toxicity. The studies with PC12 cells indicated a protective effect of the complex even in high concentrations of the complex with increase in cell viability. These results motivated us to begin studies of the interaction of this complex with the cell membrane. The transport of compounds through cell membrane is a complex biological process, often difficult to understand due to its dynamic nature. A viable alternative is the use of artificial membranes, which mimic the natural process and assist in the elucidation of membrane-compound interactions. In this project we intend to investigate the interaction of RuApy complex with mimetic membranes of LUV type composed of neutral, cationic and anionic phospholipids using stationary spectroscopic techniques and resolved in time (measurements of emission intensity, emission life time and anisotropy). From the relationship between the membrane penetration ability and the lipid membrane structure changes with the presence of the complex, we hope to obtain results that contribute to the elucidation of the transport of these complexes by the cell membrane.