engleski

AFM and FTIR spectroscopy studies on the interaction of flavonoids with model cell membranes

Interactions of flavonoids with membranes exposed to the oxidative stress are investigated with the respect to their influence on the membrane structure, elasticity and its functionality, especially regarding lipid ordering. In addition, liposome zeta potential and hydrodynamic diameter measurements before and after induced lipid peroxidation were performed to gain more insight into flavonoid1, 2 protective mechanism of membrane during reaction. The mechanisms of interactions were investigated on model membranes made of a lipid unsaturated phosphatidylcholine (DOPC) with and without embedded flavonoids with increasing molar ratio. Aim of this work is to study flavonoid interactions with model lipid membranes in vitro before and after induced oxidative stress i.e. lipid peroxidation by addition of H2O2 and Fe2+. By combining AFM imaging data, force spectroscopy (FS), and HATR FTIR spectroscopy, local altered nanomechanical and structural reorganization of membrane induced by peroxidation are recorded. The new aspect of this study showed that the time needed to complete the oxidative reaction might be considered as the measure of flavonoid protective power. It highlights the potential of combining AFM, FS and FTIR spectroscopy in revealing the mechanism of flavonoid protection. The nanomechanics (elasticity), surface topography (roughness) of model lipid membranes that result from the oxidative damage are quantified.

atomic force microscopy ; roughness ; Young’s modulus ; elasticity ; FTIR ; Lipid peroxidation

Hrvatsko-slovenska bilateralna suradnja