For liposome preparation, DPPC (dipalmitoylphosphatidylcholin) as the main lipid, [1] 2+ and the PEGylated lipid 14:0 PEG2000 PE were combined in the desired molar ratio of 100 :1 :1. DPPC liposomes were chosen because they are not permeable for larger water-soluble molecules at room temperature, which is the operating temperature during the experiments. In addition to DPPC, 1 mol% of 14:0 PEG2000 PE was added to the lipid mixture to increase stability and to prevent aggregation of the liposome via steric repulsion by the PEG chains on the liposome surface. Membrane integration of [1] 2+ into DPPC lipid bilayer was achieved via lipid film hydration, as described in detail in Section S2. Lipid film hydration yielded giant vesicles. When lipid film hydration was followed by extrusion, it yielded unilamellar vesicles with a typical diameter of 110 for empty liposomes and 140 nm average with encapsulated NADH according to dynamic light scattering (DLS).