Materials Science

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Science  10 Mar 2006:
Vol. 311, Issue 5766, pp. 1349
DOI: 10.1126/science.311.5766.1349b

Liposomes—microscopic compartments surrounded by a phospholipid bilayer shell—are of interest for targeted drug delivery. However, their high surface curvature renders them vulnerable to fusing when they collide, which can result in the premature release of their contents; many efforts to address this deficiency have relied on significant modifications of the liposome surface structure.

Zhang and Granick have stabilized 200-nm-diameter liposomes against fusion through a minor modification: the adhesion of negatively charged nanoparticles (polystyrene functionalized with carboxylate groups) to the outer membrane surface. Although only one-quarter of the surface was occluded by the nanoparticles, charge repulsion was sufficient to prevent fusion, stabilizing a 16% by volume liposome suspension for 50 days. The authors further demonstrated the robustness of the structures by filling them with a fluorescent dye and observing no leakage over 4 days. — PDS

Nano Lett. 6, 10.1021/nl052455y (2006).

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