Superglue For Cells

The cells of all eukaryotes, and of a good fraction of bacteria, build their membranes with lipids ending in phosphatidylcholine groups. Now, by flipping the order of the phosphate and choline, researchers have created an adhesive for cells (Nat. Mater., DOI: 10.1038/nmat3272). Donald E. Brooks and colleagues at the University of British Columbia, Vancouver, used a variation on click chemistry to attach dozens of choline phosphate (CP) groups to hyperbranched polyglycerol, a star-shaped, biocompatible molecule. The researchers found that, on average, hundreds of thousands of the resulting CP-decorated polymers bound to each human red blood cell in plasma and that the bound cells aggregated. When labeled with fluorescent dye, the star-shaped polymers converged on the cells’ surface. By doing the analogous experiment with cells from hamster ovaries, the researchers demonstrated that the cells took the molecules into their cytoplasm. The researchers used electrospray time-of-flight mass spectro­metry to show that the mirrored head groups attract. The researchers made simplified lipids attached to phosphatidylcholine or to CP and found that the lipids formed heterodimers. Brooks and his team suggest the adhesive could play a role in drug delivery or as a tissue sealant.