4T1 Cell Membrane-Coated\nPdots with NIR-II Absorption\nand Fluorescence Properties for Targeted Phototheranostics of Breast\nTumors

Designing highly biocompatible organic semiconducting\nconjugated\npolymer dots (Pdots) with bright fluorescence and superior absorption\nproperties in the second near-infrared window (NIR-II: 1000–1700\nnm) remains a huge challenge for tumor phototheranostics. In this\nstudy, we constructed 4T1 cell membrane-coated <i>m</i>-PBTQ4F\nPdots (CPdots) with enhanced NIR-II photoacoustic (PA) and fluorescence\n(FL) imaging capability for NIR-II photothermal therapy (PTT) of breast\ntumors. Our findings demonstrated that CPdots could specifically target\nbreast tumors, leading to enhanced tumor accumulation after systemic\nadministration in living mice. In addition, CPdots can not only serve\nas contrast agents for NIR-II PA and FL imaging for improved breast\ntumor detection but also generate more cytotoxic heat to improve PTT\nefficacy. Therefore, this pilot study opens an option avenue for developing\nnew NIR-II Pdots with homologous targeting capability for enhanced\nphototheranostics of breast tumors.