title: Mono and dually decorated nanoliposomes for brain targeting, in vitro and in vivo studies.
abstract: OBJECTIVE
  Mono- and dual-decorated (DUAL) liposomes (LIP) were prepared, by immobilization of MAb against transferrin (TfR[OX26 or RI7217]) and/or a peptide analogue of ApoΕ3 (APOe) -to target low-density lipoprotein receptor(LPR)-, characterized physicochemically and investigated for BBB-targeting, in-vitro and in-vivo.
  
  
  METHODS
  Human microvascular endothelial cells (hCMEC/D3) were used as BBB model, and brain targeting was studied by in-vivo imaging of DiR-labelled formulations (at two doses and surface ligand densities), followed by ex-vivo organ imaging.
  
  
  RESULTS
  LIP diameter was between 100 nm and 150 nm, their stability was good and they were non-cytotoxic. LIP uptake and transport across the hCMEC/D3 cell monolayer was significantly affected by decoration with APOe or MAb, the DUAL exerting an additive effect. Intact vesicle-transcytosis was confirmed by equal transport of hydrophilic and lipophilic labels. In-vivo and ex-vivo results confirmed MAb and DUAL-LIP increased brain targeting compared to non-targeted PEG-LIPs, but not for APOe (also targeting ability of DUAL-LIP was not higher than MAb-LIP). The contradiction between in-vitro and in-vivo results was overruled when in-vitro studies (uptake and monolayer transport) were carried out in presence of serum proteins, revealing their important role in targeted-nanoformulation performance.
  
  
  CONCLUSIONS
  A peptide analogue of ApoΕ3 was found to target BBB and increase the targeting potential of TfR-MAb decorated LIP, in-vitro, but not in-vivo, indicating that different types of ligands (small peptides and antibodies) are affected differently by in-vivo applying conditions. In-vitro tests, carried out in presence of serum proteins, may be a helpful predictive "targetability" tool.
authors: Laboratory of Pharmaceutical Technology, Department of Pharmacy, University of Patras, Rio, Patras, 26510, Greece.
authors: E
authors: E
authors: Markoutsa
authors: K
authors: K
authors: Papadia
authors: A D
authors: AD
authors: Giannou
authors: M
authors: M
authors: Spella
authors: A
authors: A
authors: Cagnotto
authors: M
authors: M
authors: Salmona
authors: G T
authors: GT
authors: Stathopoulos
authors: S G
authors: SG
authors: Antimisiaris
mesh_terms: D001812:Blood-Brain Barrier; D001921:Brain / Q000378:metabolism*; D002461:Cell Line, Transformed; D004730:Endothelium, Vascular / Q000378:metabolism*; D006801:Humans; D066298:In Vitro Techniques; D008081:Liposomes; D046529:Microscopy, Electron, Transmission; D049329:Nanostructures
chemical_list: D008081:Liposomes