Synergy in Nanomedicine: What It Is Not, and What It Might Be.

Interactions between nanoformulations delivering two or more drugs-or a drug and some other therapeutic modality-are often described as synergistic. In fact, synergy is a specific term of art, with important therapeutic implications. The term is often misused in the nanoscience literature. Here we discuss what synergy is and an approach to demonstrating it rigorously.