title: A unique and potent protein binding nature of liposome containing polyethylenimine and polyethylene glycol: a nondisplaceable property.
abstract: Most of the currently available targeting vectors are produced via the linkage of targeting molecules. However, the coupling process is complicated, and the covalent linkage may attenuate the activity of certain targeting molecules. In this study, we have developed a cationic liposome complexed with polyethylenimine and polyethylene glycol polymers (LPPC) that can capture various proteins without covalent conjugation. Characterizations of prepared LPPC revealed that the maximal-binding capacity was about 170 µg of bovine serum albumin to 40 µg of sphere-shaped LPPC (180 nm). The proteins were essentially located at or near the surface when analyzed by atomic force or transmission electron microscopy. We demonstrate that polyethylenimine was an essential component to bind the proteins. Upon the saturation of captured proteins, a given protein could not be displaced by other additional proteins and still retained its biological activity. Using a variety of functional proteins, we show some typical examples of the utility of incorporated beta-glucuronidase and antibodies onto the LPPC. The beta-glucuronidase can be used for the study of antigen-antibody interactions, whereas in studies with the antibody complex, we used anti-CD3 as an agonist to stimulate the proliferation of peripheral blood mononuclear cells via a receptor-mediated mechanism and anti-VEGFR for cell staining. In conclusion, the prepared LPPC can provide a platform to capture biologically and biochemically functional proteins on its surface for various applications, such as cell signaling, cell profiling, noncovalent enzyme-linked immunoassays, and others not mentioned.
authors.affiliation: Institute of Molecular Medicine and Bioengineering, National Chiao Tung University, Hsin-Chu, 30068, Taiwan, Republic of China.
authors.forename: Yen-Ku
authors.initials: YK
authors.lastname: Liu
authors.forename: Yu-Ling
authors.initials: YL
authors.lastname: Lin
authors.forename: Chia-Hung
authors.initials: CH
authors.lastname: Chen
authors.forename: Ching-Min
authors.initials: CM
authors.lastname: Lin
authors.forename: Kuan-Lun
authors.initials: KL
authors.lastname: Ma
authors.forename: Fu-Hsuan
authors.initials: FH
authors.lastname: Chou
authors.forename: Jin-Sheng
authors.initials: JS
authors.lastname: Tsai
authors.forename: Hsin-Yu
authors.initials: HY
authors.lastname: Lin
authors.forename: Fu-Rong
authors.initials: FR
authors.lastname: Chen
authors.forename: Tian-Lu
authors.initials: TL
authors.lastname: Cheng
authors.forename: Chia-Ching
authors.initials: CC
authors.lastname: Chang
authors.forename: Kuang-Wen
authors.initials: KW
authors.lastname: Liao
mesh_terms: D000818:Animals; D041702:BALB 3T3 Cells; D002417:Cattle; D002478:Cells, Cultured; D006801:Humans; D008081:Liposomes / Q000378:metabolism; D051379:Mice; D011092:Polyethylene Glycols / Q000378:metabolism*; D011094:Polyethyleneimine / Q000378:metabolism*; D011485:Protein Binding; D011506:Proteins / Q000378:metabolism*; D012710:Serum Albumin, Bovine / Q000378:metabolism
chemical_list: D008081:Liposomes; D011506:Proteins; D012710:Serum Albumin, Bovine; D011092:Polyethylene Glycols; D011094:Polyethyleneimine