Surface interaction and behavior of poly(amidoamine) dendrimers: deformability and lipid bilayer disruption.

Dendrimers are synthetically built macromolecules that, through the conjugation of various functional moieties, have become the basis of the emerging field of nanomedicine. However, research is beginning to show that the dynamic interactions between PAMAM dendrimers and cellular lipid membranes can stimulate membrane hole formation and expansion. These membrane disruptions are not unique to dendrimers and are the observed functions of natural proteins such as MSI-78 (pexiganan) and Trans-Activator of Transcription protein (TAT). Membrane interactions can also affect the dendrimers, causing structural deformations and encapsulation within a lipid bilayer vesicle. Acetamide capping of the positively charged PAMAM terminal end groups neutralizes the dendrimer, and many of these effects can be minimized or eliminated. Knowledge gained from these studies will indeed have an impact on the future designs of dendrimer-based nanodevices.