Search

Organic molecules that are active in the near-infrared (NIR) bio-window for photo-to-heat energy-converting theranostics have attracted much attention in cancer therapy. However, current organic NIR-absorbing molecules are still suffering from the inefficient non-radiative decay or serious photobleaching under light irradiation. Herein, we design a convenient strategy to load a new kind of NIR-absorbing nonlinear optical (NLO) chromophore FTC-3f with the biocompatible polymer, methoxy poly(ethylene glycol)-poly(lactideco-glycolide) (mPEG-PLGA). The resulted FTC-3f/PLGA nanoparticles showed excellent stability, high photothermal conversion efficiency (∼51.11%) and good photoacoustic performance. Moreover, in vitro anticancer experiments demonstrated that the FTC-3f/PLGA nanoparticles possess a high PTT (photothermal therapy) efficiency under NIR laser irradiation. This work thus provides an insight into the exploration of versatile organic NIR-absorbing nanoparticles toward future practical PTT application. [Display omitted] • A new kind of FTC-3f chromophores were synthesized with a strong absorption in the spectral region of 600–1100 nm. • FTC-3f/PLGA nanoparticles possess high stability when dispersed in water, PBS solution and DMEM solution. • FTC-3f/PLGA shows a high photothermal conversion efficiency and excellent photoacoustic/photostability performance. • In vitro antitumor result revealed a high photothermal therapy efficiency under 750 nm NIR light irradiation. [ABSTRACT FROM AUTHOR]

Two asymmetrical benzoxanthene dyes (BP-1 and BP-2) were designed and synthesized by a convenient one-step procedure from naphthaldehyde and m -aminophenol precursors. These dyes showed long-wavelength absorption, near-infrared emission (>650 nm), and large Stokes shifts (>90 nm) because of the asymmetrical introduction of the benzene ring into the xanthene structure. BP-1 exhibited high fluorescence quantum yield in organic solvents, whereas BP-2 showed very weak fluorescence due to the photoinduced electron transfer of 9-substituted groups. Cell experiments indicated that BP-1 with crescent-shape structure showed lower cytotoxicity and higher photostability than BP-2 and could rapidly stain RNA in nucleoli at low concentration. [Display omitted] • Two asymmetrical benzoxanthene dyes were synthesized by a convenient one-step procedure. • The dyes showed long-wavelength absorption, near-infrared emission and large Stokes shifts. • BP-1 could stained RNA in nucleoli rapidly with low cytotoxicity and good photostability. • BP-2 showed a very weak fluorescence and cytotoxicity due to 9-substituted groups. [ABSTRACT FROM AUTHOR]