(449d) Preparation, Characterization and Properties of Janus Magnetic Liposomes

The use of magnetic nanoparticles for drug delivery applications has been a subject of many investigations in recent years. Among the different formulations proposed in the literature, the incorporation of particles into liposomes offers many advantages. However, a major contemporary concern in developing effective liposomenanoparticle hybrids is the present inclusion size limitation of nanoparticles between vesicle bilayers, which is considered to be around 6.5 nm in diameter. In this work, we present experimental observations backed by theoretical considerations which show that large amount of magnetic nanocrystals can be incorporated within vesicle membranes by promoting the clustering of nanoparticles before liposome formation. Cryo-transmission electron microscopy and cryo-electron tomography confirm these observations at unprecedented detail and underpin that the liposome membranes can accommodate flexible structures of up to 60 nm in size, very often assuming a Janus-like conformation. These results imply that this material is more versatile in terms of inclusion capabilities and consequently widens the opportunities in developing multivalent vesicles for nanobiotechnology applications. The magnetic properties of the prepared liposomes for hyperthermia applications have also been investigated.