Figure 6.

Cellular uptake and permeability of LIP by hCMEC/D3 cell monolayers. 10⁶ cells were incubated with dual-radiolabeled RI-PA-LIP for 2 hours at 37°C, 5% CO₂. (A) Cellular uptake of RI-PA-LIP. After incubation, the amount of radioactivity incorporated into the cells was measured and the nmols of total lipids uptaken from the cells calculated for b/s-RI-PA-LIP (squares) or cov-RI-PA-LIP (triangles), for both radiotracers used ([³H]-Sm, black; [¹⁴C]-PA, red). (B) Transcytosis of RI-PA-LIP through hCMEC/ D3 cell monolayers. Dual-radiolabeled LIP were added to the upper chamber of the transwell monolayers and incubated for 120 minutes at 37°C, 5% CO₂. The permeability of LIP across the cell monolayer was calculated for both radiotracers used, [³H]-Sm (dark bars) and [¹⁴C]-PA (red bars).

Notes: Each value is the mean of at least three independent experiments and the SDs of means are presented as bars. *P < 0.05.

Abbreviations: b/s, biotin/streptavidin; cov, covalent; LIP, liposomes; PA, phosphatidic acid; RI, RI7217 antibody; Sm, sphingomyelin.