Haptens liposomes

Figure 22.16 SMPB-activated liposomes may be modified with peptide hapten molecules containing cysteine thiol groups. The resultant immunogen may be used for immunization purposes to generate an antibody...

Protocol for the Coupling of Peptide Haptens Containing Sulfhydryl Groups to Liposomal Vesicles... 

Dissolve a sulfhydryl-containing peptide hapten at a concentration of 25 pmol/ml in degassed, nitrogen-purged lOmM HEPES, 0.15M NaCl, pH 7.0. Add the peptide solution to the liposome suspension at a molar ratio necessary to obtain at least a 5 1 excess of thiol groups to the amount of maleimide groups present (as MPB-DPPE). 

Tatsu et a/.(106) reported a novel immunosensor using immobilized liposomes doped with carboxyfluorescein and dinitrophenyl (DNP) hapten on the tip of an optical fiber. On complement-mediated immunolysis by anti-DNP-antibody, the fluorescent signal of the liberated carboxyfluorescein was measured. 

The recognition of hapten-free phospholipid liposomes as nonself, when introduced into the bloodstream, still seems to me to be very important. I cannot believe that antitumor drugs will be successfully delivered until this problem is solved. 

Yasuda, T., Kanegasaki, Sh.f Tsumita, T., Tadakuma, T., Homma, 3.Y., Inage, M., Kusumoto, S., and Shiba, T. (1982). Biological activity of chemically synthesized lipid A analogues. Demonstration of adjuvant effect in hapten-sensitized liposomal system. Eur. 3. Biochem., 124, 405-007... 

F2. Freytag, J. W., and Litchfield, W. J., Liposome-mediated immunoassays for small haptens (digoxin) independent of complement. J. Immunol. Methods 70, 133-140 (1984). 

Monroe, D. (1989). Novel Liposome Immunoassays for Detecting Antigens, Antibodies, and Haptens. J. Liposome Res. 1 339 - 377. 

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