Effective co-encapsulation of doxorubicin and irinotecan for synergistic therapy using liposomes prepared with triethylammonium sucrose octasulfate as drug trapping agent.

The combination regimen of irinotecan (IRI) and doxorubicin (DOX) for cancer treatment has been frequently exploited in clinical studies, but face challenges in design of efficacious combination drug delivery systems. Here we demonstrate a novel nanoliposome constructed by triethylammonium sucrose octasulfate gradient loading method for co-delivering the two therapeutic agents. In vitro cytotoxicity of IRI, DOX and their combinations against breast cancer cells (4T-1), non-small cell lung cancer cells (A549) and colon cancer cells (HT-29) was evaluated to screen optimal synergistic ratio of the two drugs.

Crystallographic evidence of an unusual, pentagon-shaped folding pattern in a circular aromatic pentamer.

Introduction of a continuous hydrogen-bonding network suppressed the conformational flexibility of an oligomeric backbone. Cyclization of a rigidified, suitably sized oligomer led to a circular aromatic pentamer. Its crystal structure determined by X-ray crystallography reveals a pseudo five-fold symmetric planarity in the solid state, which is quite unusual among all the previously described shape-persistent macrocycles and synthetic foldamers with biased conformations enforced by noncovalent forces.