Sterically stabilized liposome mechanism

Figure 1 Facing page) (A) Mechanism of remote loading of doxorubicin by transmembrane ammonium sulfate gradient. (B) Collapse of transmembrane ammonium ion gradient in SSL by nonactine induces doxorubicin release. (C) Collapse of transmembrane proton gradient in SSL by nigericin induces collapse of transmembrane ammonium ion gradient followed by release of DOX. Abbreviations. DOX, doxorubicin SSL, sterically stabilized liposome.

That these mechanisms may operate in the body has been mentioned and certainly could account for the paradox noted earlier. However, from a practical standpoint, delivery of VIP as a drug in sterically stabilized phospholipid liposomes would be very attractive and may find future application. 

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