Controlling Cellular Uptake and Toxicity of Polyphenylene Dendrimers by Chemical Functionalization.

Polyphenylene dendrimers (PPDs) represent a unique class of macromolecules based on their monodisperse and shape-persistent nature. These characteristics have enabled the synthesis of a new genre of "patched" surface dendrimers, where their exterior can be functionalized with a variety of polar and nonpolar substituents to yield lipophilic binding sites in a site-specific way. Although such materials are capable of complexing biologically relevant molecules, show high cellular uptake in various cell lines, and low to no toxicity, there is minimal understanding of the driving forces to these characteristics. We investigated whether it is the specific chemical functionalities, relative quantities of each moiety, or the "patched" surface patterning on the dendrimers that more significantly influences their behavior in biological media.