Publication I September 15, 2020
Biophysical analysis of liposomes and antibody-receptor interactions on VLPs with the switchSENSE® Biosensor
We report a novel approach to study the interaction between an antibody (anti-human CXCR4) and the membrane receptor CXCR4 expressed on intact VLPs on a microfluidic biochip using the switchSENSE® dual color technology. Antibodies immobilized on the measurement spot via conjugated DNA nanolevers were used to target specific overexpressed receptors on the VLP membrane. This immobilization technique resulted in a robust and receptor-specific binding of VLPs on the biochip surface. Furthermore, binding of fluorescently labeled antibodies to the membrane receptor CXCR4 of immobilized VLPs could be measured in real-time. Additionally, we present a new technique to characterize liposomes using the switchSENSE® platform. Immobilization of liposomes on the measurement spot was performed using a cholesterol modified DNA monolayer. Lipid phase transition temperatures of immobilized liposomal formation were monitored in real-time by applying a controlled temperature ramp to the chip surface. Liposomes are ideal model structures to study on-chip behavior of cell membranes and for the use as novel drug delivery systems. These results demonstrate the successful integration of membrane-bound structures on electro-switchable DNA microelectrodes. This method offers a convenient approach to on-chip characterization of membrane proteins, vaccine platforms, therapeutic antibodies and liposome-based drug delivery systems using the switchSENSE® technology.