Amphiphilic copolymers composed of styrene and maleic acid (SMA) are newly developed tools with the ability to form lipid-polymer complexes when mixed with biological membranes. These complexes, termed native nanodiscs or SMALPs, are discoidal nanoparticles capable of solubilising and stabilising both lipids and integral membrane proteins in solution without the aid of conventional detergents. Although the structural features of these particles have been partially unveiled, the kinetics governing trans-SMALP lipid exchange remain unknown. This is of utmost importance to fully exploit this new technology and understand the kinetics and, thus, the mechanism of (i) SMA-mediated lipid extraction from vesicles into SMALPs, (ii) the inter-SMALP lipid transfer and (iii) the reincorporation of lipids from nanodiscs into vesicular membranes. We will produce SMA-stabilised nanodiscs composed of hydrogenated SMA and either hydrogenated (H-) or deuterated (D-) phospholipid. We propose the use of time-resolved small-angle neutron scattering to investigate the interbilayer exchange kinetics among D-SMALPs and H-SMALPs in solution at various temperatures.