Executive Summary : | Live-cell imaging is a powerful tool for observing pathological and therapeutic processes, identifying complex molecular mechanisms responsible for various diseases. Fluorescent signals, which are a key component of these sensory systems, have high sensitivity, selectivity, in-situ analysis, low cost, and "naked eye" detection. Fluorophores, such as methylene blue, indocyanine green, and fluorescein, play a crucial role in altering photophysical properties during selective interaction with specific analytes. To achieve in vivo studies, fluorophores should be biocompatible, photostable, and highly bright. Traditional FDA-approved small organic fluorophores with emission in the visible to NIR-I (700-900 nm) range have limitations such as limited tissue penetration depth and strong tissue autofluorescence. NIR-II fluorescence imaging, on the other hand, has low autofluorescence, minimal tissue absorption, and less scattering, resulting in deeper tissue penetration and a higher signal-to-background ratio. To overcome these limitations, nanoparticles based on conjugated polymers (CPs) have emerged as an inimitable solution for NIR-II fluorescence bioimaging. These nanoparticles have ultrahigh fluorescence brightness, excellent photostability, good water dispersibility, and high biocompatibility. Different CPs, such as poly(3,4-ethylenedioxythiophene), polythiophene, polypyrrole, and polyaniline, have been used due to their great technological potential. The proposed study focuses on developing functionalized fluorescent conjugated polymeric nanoparticles for NIR-II live-cell imaging and ¹O₂ generation for photodynamic therapy. |