Protease-Responsive Bitext Editing Biopolymer for Breast Cancer Imaging In Vivo

Despite the fact that peptide substrate-assisted protease-specific recognition has flourished in the field of disease diagnostics, the introduction of nonbiocompatible nanoparticles poses safety hazards and hampers their further widespread application, and a homogeneous system loaded and delivered exclusively by functional DNA is still unrealized. Herein, we propose a protease-responsive bitext editing peptide-loaded multifunctional DNA nanoflower (ppDNF) for in vivo protease activity assay in situ. This ppDNF biopolymer provides precise target recognition and high signal gain for the expression abundance and spatiotemporal distribution of a specific protease by rationally designing the recognition text and loading the response text. In this work, cathepsin B, which is overexpressed in breast cancer cells, is chosen as a model protease. Systematic investigation of ppDNF in vivo carries out and realizes robust tumor imaging in living cells and mice. Thus, this work demonstrates the potential of functional DNA-coupled peptide substrates to enable precision biomedical applications.