Tumor Extracellular pH-Driven Cancer-Selective Artificial Receptor-Mediated Tumor-Targeted Fluorescence Imaging.

Biomarker receptors on cancer cells can sense and recruit extracellular ligands and ligand-conjugated imaging agents/drugs, providing a critical basis upon which to develop an active tumor-targeting strategy. However, such a strategy can be confounded by both the limited number of cancer biomarker receptors and the inherent heterogeneity of cancer cells. Therefore, we herein report a simple strategy to deploy an exogenous physical label on the surface of cancer cells as an artificial receptor (AR) for active tumor targeting. It can be driven by the tumor extracellular acidic microenvironment to insert into the plasma membrane of cancer cells. Our studies demonstrated that an AR could efficiently sense and recruit the extracellular imaging agent Cy5-streptavidin conjugate to cancer cells, cancer cell spheroids, and an in vivo tumor. Based on the easy synthesis and chemical modification diversity of the peptide, our AR holds promise as a novel tumor-targeted strategy.