Fullerene-based amino acid ester chlorides self-assembled as spherical nano-vesicles for drug delayed release.

Fullerenes with novel structures find numerous potential applications, particularly in the fields of biology and pharmaceutics. Among various fullerene derivatives, those exhibiting amphiphilic character and capable of self-assembly into vesicles are particularly interesting, being suitable for delayed drug release. Herein, we report the synthesis and self-assembly of biocompatible hollow nanovesicles with bilayer shells from amphiphilic functionalized fullerenes C60R5Cl (R=methyl ester of 4-aminobutyric/glutamic acid or phenylalanine). The thus prepared vesicles exhibit sizes of 80-135nm (depending on R) and can be used as delayed-release carriers of anti-cancer drugs such as 5-fluorouracil, cyclophosphamide, and cisplatin, with the time of 5-fluorouracil release from drug-containing vesicles exceeding that of non-encapsulated forms by a factor of three. We further reveal the effect of R on the loading amount and release rate/amount of vesicle-encapsulated drugs, demonstrating a potential pharmaceutical application of the prepared nanovesicles depending on the nature of R.

Formation of Curvature Subunit of Carbon in Combustion.

Curvature prevalently exists in the world of carbon materials (e.g., fullerenes, buckyl bowls, carbon nanotubes, and onions), but traditional C2-addition mechanisms fail to elucidate the mechanism responsible for the formation of carbon curvature starting from a pentagonal carbon ring in currently available chemical-physical processes such as combustion. Here, we show a complete series of nascent pentagon-incorporating C5-C18 that are online produced in the flame of acetylene-cyclopentadiene-oxygen and in situ captured by C60 or trapped as polycyclic aromatic hydrocarbons for clarifying the growth of the curved subunit of C20H10. A mechanism regarding C1-substitution and C2-addition has been proposed for understanding the formation of curvature in carbon materials, as exemplified by the typical curved molecule containing a single pentagon completely surrounded by five hexagons. The present mechanism, supported by the intermediates characterized by X-ray crystallography as well as NMR, has been experimentally validated for the rational synthesis of curved molecule in the commercially useful combustion process.