Rational design of a multifunctional molecular dye for dual-modal NIR-II/photoacoustic imaging and photothermal therapy

Abstract

Small-molecule based multifunctional probes play significant roles in biomedical science and possess high clinical translational ability. However, the preparation of these promising probes without complicated synthetic procedures remains a challenging task. Herein, we rationally designed a high-performance DD-A-DD scaffold molecular dye (<b>SYL</b>) with an intrinsic multifunctional ability and then incorporated it into DSPE-mPEG5000 to facilely construct biocompatible NIR-II fluorescent and photoacoustic (PA) dual-modal theranostic nanoprobes (<b>SYL</b> NPs) (∼120 nm). <i>In vivo</i> studies confirmed that <b>SYL</b> NPs exhibited bright NIR-II fluorescence and PA signals in the tumor region with a promising signal to background ratio (S/B). Meanwhile, <b>SYL</b> NPs demonstrated significantly inhibited tumor growth under laser irradiation with no noticeable side effects. These promising results highlighted <b>SYL</b> NPs as a potential theranostic platform for cancer diagnosis (NIR-II region) and therapy.