Signal ampflication using nanoplatform cluster formation

Abstract

Multifunctional nanoplatforms are being developed for targeted delivery of imaging and therapeutic agents. The nanoscale size of these platforms allows a large carrying capacity, which translates to a high ratio of targeted agent for each ligand–receptor interaction. Here we used a simple in vitro system to show that the targeting ratio can be further amplified by controlled cluster formation using multiple cycles of coupling reactions. As the receptor sites become more sparse the relationship between the amplification of the signal from an imaging agent and the reaction cycles approaches a cubic relationship, which is the theoretical limit for this relationship. These results demonstrate that this approach has the potential to significantly enhance the capacity of multifunctional platforms to be used for targeted delivery of imaging agents or drugs.