Cadherin-integrated liposomes with potential application in a drug delivery system.

N-cadherin (CDH2) proteins were reconstituted with liposomes using a baculovirus expression-liposome fusion method. CDH2 budded viruses were fused with giant liposomes containing dioleoylphophogycerol/dioleoylphosphatidylcholine (DOPG/DOPC) at pH 4.5 and the localization of CDH2 on the liposome membrane was observed by confocal laser scanning microscopy. CDH2 liposomes showed Ca(2+)-dependent association. CDH2-mediated association/dissociation in CDH2 liposomes was specific to Ca(2+) and reversible. CDH2-expressing LN-229 cells (human glioblastoma cell) adhered to CDH2 liposomes and small CDH2 liposomes (diameter approximately 150 nm), in particular, were internalized by endocytosis and partly escaped endosomes. Cadherin-containing liposomes show high potential as a new cell-specific proteoliposome. The baculovirus expression-liposome fusion method is useful as a new enabling technology for biomedical applications of functional proteoliposomes.