Biocontainer Transport

When molecular cargo needs to be shipped to precise locations around a cell, biology often uses molecular motors that walk along molecular tracks with their load in tow. Scientists have been aiming to hijack these cellular highways to deliver drugs and other goods. A team led by Youichi Tsuchiya of Japan’s RIKEN and Seiji Shinkai of the Institute of Systems, Information Technologies & Nanotechnologies, in Fukuoka, Japan, has now designed a molecular container that can encapsulate long, tubular cargo (Angew. Chem. Int. Ed., DOI: 10.1002/anie.200904909). The researchers employed a triple-stranded helical sugar called schizophyllan as the container and showed that the polysaccharide can hold a carbon nanotube. Schizophyllan is a convenient container material because it falls apart in dimethyl sulfoxide solvent and re-forms in water with the load encapsulated. The team observed that the nanotube-laden container is transported by the motor protein myosin at a speed of 95 nm per second along actin protein highways in cells. Because actin filaments connect to a cell’s nucleus, the researchers believe the myosin motors and sugar containers could be commandeered to deliver gene therapies directly to their target.