Immunoliposome preparation

Brendas G, Krause A, Bakowsky U et al (1999) Targetability of novel immunoliposomes prepared by a new antibody conjugation technique. Int J Pharm 181 79—93... 

Carrion C, Domingo JC, de Madariaga MA. Preparation of long-circulating immunoliposomes using PEG-cholesterol conjugates effect of the spacer arm between PEG and cholesterol on liposomal characteristics. Chem Phys Lipids 2001 113 97. 

Long-circulating immunoliposomes can also be prepared (see Figure 5.8). The antibody can be coupled directly to the liposomal surface, however the PEG chains may provide steric hindrance to antigen binding. Alternatively, a bi-functional PEG linker can be used, to couple liposomes to one end of PEG chains and antibodies to the other end of these chains. Steric hindrance is not a problem in the latter approach. 

Liposomes can be targeted to the brain by exploiting receptor-mediated transcytosis systems. For example, a bi-functional PEG-linker has been used to couple anti-transferrin (0X26) receptor antibodies to one end of the PEG strands and liposomes at the other end of the PEG strands (Figure 13.6). Classically, immunoliposomes are prepared by attaching the MAb to the surface of the liposomes (see Section 5.3.1.3). However, this can lead to steric hindrance by the PEG strands with respect to antibody binding to the appropriate receptor. The use of the bifunctional PEG linker overcomes this problem. 

ATP-immunoliposomes (ATP-IL) are prepared using the micelle transfer method by modification of the ATP-L with anti-myosin antibody 2G4. 

Immunoliposomes were prepared by conjugating an anticarcinoembryonic antigen monoclonal antibody with liposomes containing °B compound by Yanagie et al. (1997). BNCT with intratu-moral injection of such immunoliposomes was found to be able to destroy malignant cells and cancer tissues from the side of He generation. 

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