Dendrimers Show Antibiotic Activity

A new class of dendrimers has promising antibiotic activity, killing prokaryotic bacteria cells while remaining largely nontoxic to eukaryotic human cells (J. Am. Chem. Soc., DOI: 10.1021/ja806912a). Chemistry and biomedical engineering professor Mark W. Grinstaff, postdoc Steven R. Meyers, and colleagues at Boston University synthesized two anionic amphiphilic dendrimers, based in part on past evidence that dendrimers with anionic charges are relatively nontoxic to animals. The group patched the dendrimers together from succinic acid, glycerol, and myristic acid, and then tested the resulting molecules' toxicity. One dendrimer in particular was 36 times more toxic to a strain of the gram-positive bacterium Bacillus subtilis than to human umbilical vein endothelial cells. The dendrimers form supramolecular structures in solution, which appear to be correlated with their toxicity, Grinstaff says. The researchers believe the dendrimers could prove to be useful leads in the search for more effective antibiotics.