Ix51w

For the macroscopic observation, an epi-fluorescence microscope (IX51W, Olympus, Inc., Tokyo, Japan) equipped with 60× water immersion objective (N.A. 1.00) was used. The spatial resolution at a wavelength of 560 nm was approximately 350 nm based on the Rayleigh criterion. For SPT, an inverted fluorescence microscope (IX-71, Olympus, Inc.) equipped with 100× oil immersion objective (N.A. 1.45) was used. With the light excitation by 532 nm laser, the obtained diffusion of fluorescent probes in the bilayer was recorded by EM-CCD camera (iXon DU-897, Andor Technology, Ltd., Belfast, UK) at the frame rate of 30 frames/s (fps) or 500 fps. The effective pixel size of the SPT recording was 275.86 nm. We observed the surface structure of the PI+PC-SLBs by AFM (5500 Scanning Probe Microscope, Agilent Technologies, Inc., Santa Clara, CA, USA) with magnetic AC mode before and after addition of FBP-17. For AFM imaging, TYPE VI MAC Lever (Agilent Technologies, Inc.) with typical spring constant of 0.2 N/m was used. The epi-fluorescence microscope and AFM observations were performed at an ambient temperature of 23 °C.

In anesthetized mice, a craniotomy (3 mm in diameter) was made over the sensory motor cortex. The dura was left intact and the craniotomy was covered with aCSF and sealed with a glass coverslip. To visualize the vasculature, 0.1 ml BBB impermeable Texas Red-dextran 70 (MW 70kD; 1% in saline, Invitrogen) was injected intravenously immediately before imaging. A Mai Tai laser (SpectraPhysics) attached to a confocal scanning system (Fluoview 300, Olympus) and an upright microscope (IX51W, Olympus) was used for in vivo imaging as described [26 (link), 27 (link)]. A 20X (0.9NA) water immersion lens was used to image the cortex, from the surface to a depth of ~150 μm at every 5 μm z-steps. We used 870 nm as excitation wavelength and emission was collected at 575-645 nm. The cerebral vasculature was imaged at a resolution of 512 × 512px. FITC-apoE3 was administered intracisternally at 1 μL/min for 5 min and images acquired at 15 min after the injection.