Fabrication of GM3-enriched sphingomyelin/cholesterol solid-supported lipid membranes on Au/SiO2 plasmonic substrates

The fabrication of solid-supported artificial lipid bilayers enriched with biological agents is an important step for acquiring more insights into their behavior from in vitro studies. In this work we demonstrate the formation of lipid artificial membranes enriched with ganglioside GM3, whose role in the cell proliferation and tumor angiogenesis is still an object of extensive investigation. The membranes are formed by fusion of small unilamellar vesicles (SUV) obtained from the sonication of multi-lamellar vesicles (MLV) formed from a hydrated mixture of GM3, brain sphingomyelin and cholesterol. The effective formation of SUV was confirmed by Dynamic light scattering (DLS) measurements. The recognition of the ganglioside in the biomimetic raft like biomembranes is accomplished via surface plasmon resonance (SPR) by exploiting the ganglioside affinity with wheat germ agglutinin (WGA). The affinity constant of the binding between the inglobated GM3 and WGA has been measured for three different GM3 molar concentrations. Beside the effective generation of GM3-enriched biomimetic membranes, our results indicate a decrease in the apparent WGA-GM3 dissociation constant at increasing GM3 concentrations up to 20 mol%, consistent with clustering effects of the ganglioside in the fabricated biomembranes.