University of California at Berkeley and Howard Hughes Medical Institute researchers have developed a means of making CNTs biocompatible by coating them with synthetic synthetic glycopolymers that mimic mucin, the substance on cell surfaces that serves as a lubricant.

They were able to customize the coatings so that carbon nanotubes could be induced to bind only to the surfaces of specific types of cells via ligand receptors. To do this, they complexed one of their mucin mimics with a sticky cell-surface protein found in snails, called Helix pomatia agglutinin, or HPA, which not only features binding specificity but is also capable of crosslinking cells and glycoproteins.

The glycopolymer coating (C18-á-MM, an á-N-acetylgalactosamine sugar with a C18 lipid tail) remained adhered to the carbon nanotubes for several months and kept cells safe from CNT cytotoxicity. Through the introduction of a variety of alternative ligands and sugars to the glycopolymers, the technology essentially makes it possible to program CNTs to selectively interact with target cells.

Source: University of California at Berkeley news release