Liposomes and lipid disks traverse the BBB and BBTB as intact forms as revealed by two-step Förster resonance energy transfer imaging

Fluorophores (DiO, DiI and DiD) were loaded into liposomes and disks to form Förster resonance energy transfer (FRET) nano-drug delivery systems. Using this method, we investigated the integrity of liposomes and disks traversing BBB and BBTB both in vitro and in vivo.117