Anti-Aβ-MAb (Aβ-MAb)-decorated immunoliposomes (LIP) and dually decorated ones (dd-LIP) with OX-26 and Aβ-MAb were constructed. In both cases, the biotin-streptavidin ligation method was applied. All LIP types were characterized for size distribution, zeta potential, and integrity during incubation with serum proteins. Uptake and transcytosis of both LIP types and control vesicles by human brain endothelial hCMEC/D3 cells were measured. All LIP types had mean diameters below 150-200 nm and low polydispersity. Aβ-MAb-LIP uptake was higher than control PEGylated liposomes, while uptake of dd-LIP was similar to that of OX-26-LIP. Aβ-MAb-LIP and dd-LIP uptake increased significantly when cells were pre-incubated with Aβ1-42 peptides; OX-26-LIP uptake was not modulated. Transcytosis of Aβ-MAb-LIP through monolayers was 2.5 times higher when monolayers were pre-incubated with Aβ1-42. Transport of both probes, FITC-dextran and rhodamine-lipid, was equivalent, indicating that Aβ-MAb-LIP are transferred intact through the BBB model. The Aβ peptide-induced increase in binding (and transport) is regulated by the membrane receptors for Aβ1-42 peptides (RAGE), as proven after blocking RAGE by a specific MAb. Aβ1-42 peptides did not modulate the barrier tightness and integrity, as determined by transendothelial resistance and Lucifer Yellow permeability. Additionally, hCMEC/D3 cell viability was not affected by Aβ peptides or by Aβ-MAb-LIP.
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