Brain Targeting Using Immunoliposomes

In conclusion, the use of an immunoliposome-based drug delivery system allows for targeted delivery of a small molecule such as daunomycin or plasmids to the rat brain in vivo. Further experiments will be needed to clarify the subcellular routes and compartments involved in the transcytosis mechanism, as well as the eventual release mechanism in the target cell. 

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. 

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