Mineo Hashizume

Stable vesicular nanoparticle 'Cerasome' as an organic-inorganic hybrid formed with organoalkoxysilane lipids having a hydrogen-bonding unit

Abstract Cerasomes, liposomal membranes covered with ceramic surface, were prepared from double-chain organoalkoxysilane lipids with a hydrogen-bonding unit by using ethanol sol injection method. The Cerasomes thus prepared were characterized by means of various physical measurements such as scanning and transmission electron microscopy, light scattering and differential scanning calorimetry. As compared with liposomes formed with a lipid having a quaternary ammonium head in place of the inorganic moiety, the Cerasomes were more stable to maintain their vesicular structures even in the presence of excessive amounts of a surfactant, in which the conventional liposomes were completely dissolved. Potential of the Cerasome as an organic–inorganic hybrid material for nano-device fabrications were discussed.

Photodynamic Activity of C70 Caged within Surface‐Cross‐Linked Liposomes

[70]Fullerene (C(70)) encapsulated into a surface-cross-linked liposome, a so-called cerasome, was prepared by an exchange reaction incorporating C(70)gamma-cyclodextrin complexes into lipid membranes. Fullerene exchange in a cerasome-incorporated C(70) (CIC(70)), as well as in a lipid-membrane-incorporated C(70) (LMIC(70)), was completed within 1 min with stirring at 25 degrees C. CIC(70) was more resistant to lysis than LMIC(70) towards lysing agents such as surfactants. Furthermore, the photodynamic activity of CIC(70) in HeLa cells was similar to that of LMIC(70), indicating that C(70) can act as a photosensitizing drug (PS) without release from cerasome membranes. Thus, in contrast with general drug-delivery systems (DDSs), which require the drug to be released from the interior of liposomes, carriers for PSs for use in photodynamic therapy (PDT) do not necessarily need to release the drug. These results indicate that DDSs with high morphological stability can increase the residence time in blood and achieves tumor-selective drug delivery by the enhanced permeability and retention (EPR) effect.

Controlled propagation in molecular communication using tagged liposome containers

Molecular communication is an emerging research area in the bio and nano science. Molecular communication uses molecules as a communication medium and allows nanomachines to communicate over a short distance. A key design challenge in molecular communication is controlling the propagation direction of information-carrying molecules towards their destination. This paper presents results of the experiment for transporting liposome containers to the designated receivers. In the experiments, molecular tags were used to identify the destination of the liposome containers

Size-Selective Organization of Silica and Silica-Like Particles on Solid Interfaces through Layer-by-Layer Assembly

Employing a layer-by-layer assembly technique, we created three-dimensional architectures of silica and silica-like particles on solid interfaces. Atomic force and scanning electron microscopy confirmed a size-selection effect for assembling a mixture of two kinds of monodispersed silica particles prepared through the sol-gel process. Size-selective assembly was also applied for layer-by-layer organization of Cerasomes, which are organic-inorganic vesicular hybrids with a silica-like structure on the lipid bilayer surface. This study obtained an alternating layer-by-layer assembly of Cerasomes with a relatively uniform size on solid interfaces from polydispersed aqueous colloids of a surface-modified cationic Cerasome with an unmodified anionic Cerasome or an anionic poly(vinyl sulfate). Quartz crystal microbalance measurements and atomic force microscopy were used to evaluate this assembly process.