LIPID CARRIER COMPOSITIONS WITH PROTECTED SURFACE REACTIVE FUNCTIONS

摘要

The liposomes of the invention have a reactive surface that demonstrates reduced interaction with macromolecules and increased blood circulation time . The reactive surface may comprise phosphatidylserine. The liposomes are protected by the presence of high levels of a hydrophilic polymer conjugated to a lipid. The invention further provides means for adjusting the appropria te ratio of hydrophilic polymer to a reactive lipid by a) determining the reactivity of the lipid; b) determining the time required for the carrier to reach its desired target location; c) determining the affinity of desired interactions with the reactive surface; and d) incorporating in the liposome or lipid carrier the amount of polyethylene glycol required to protect the reactive surface.