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The combination of photothermal and chemodynamic therapy (PTT/CDT) has promising anticancer effect. Nonetheless, the large-scale preparation of multifunctional nanotherapeutics with good water-solubility and biocompatibility using simple methods remains a major challenge. Herein, we prepared multifunctional nanoparticles (Fe–Ba NPs) by combining Fe3+ with baicalin via a simple coordination assisted self-assembly method, as the carbonyl and phenolic hydroxyl groups in baicalin have strong coordination interaction with Fe3+. The obtained NPs exhibit a broad absorption spectrum extending to near-infrared region and have an excellent photothermal conversion efficiency of 91.1 %. In addition, glutathione (GSH), which is highly expressed in tumor, can reduce Fe3+ in Fe–Ba NPs to Fe2+. On the one hand, Fe2+ can further react with H2O2 to generate hydroxy radical, resulting in CDT. Conversely, depletion of GSH in tumors can disrupt redox homeostasis and upregulate CDT-mediated oxidative damage, leading to enhanced CDT effect. By integrating PTT and CDT, Fe–Ba NPs can greatly improve the therapeutic efficacy. This research introduces a strategy for the design and synthesis of multifunctional nanotherapeutic reagents. [ABSTRACT FROM AUTHOR]

Imaging-guided photodynamic therapy (PDT) represents an advantage in cancer therapy because of its optically controlled selectivity, negligible side effects, and ability to monitor the therapeutic effect in situ in real time. However, the photosensitizers currently in use have poor water solubility and an inability to target tumors, whereas semiconductor quantum dots and metal-based complexes that have excellent water dispersity have the disadvantage of exerting a potential toxicity because of the heavy metals. Therefore, this work describes the preparation of the red fluorescent N,S-doped carbon dots (N,S-CDs) from a polythiophene derivate that generate singlet oxygen (1O2) with a quantum yield of ∼8% under light irradiation. Moreover, these CDs possess the ability to penetrate tumor cells and mainly accumulate into the lysosome and mitochondria, as well as excellent biocompatibility, chemostability, and a large Stokes shift (215 nm). Hence, the N,S-CDs may be used as a potential effective photosensitizer for imaging-guided PDT. [ABSTRACT FROM AUTHOR]

Near-infrared (NIR)-II fluorescence and photoacoustic (PA) dual-model imaging-guided photothermal therapy (PTT) can precisely diagnose and treat tumors and evaluate the therapeutic efficacy in real-time. Herein, we utilized a donor-π-acceptor (D-π-A) structured hemicyanine dye (named M1) with a large conjugated structure and strong intramolecular charge transfer effect and demonstrated that the aggregation of M1 could significantly enhance its photophysical performance by improving its photostability and photothermal conversion capability as compared with M1 in a single molecular state. Furthermore, we prepared water-dispersible NIR-II fluorescent nanoparticles (M1 NPs) by wrapping M1 with DSPE-PEG2000-NH 2 . The obtained M1 NPs exhibit strong NIR-I absorption and NIR-II fluorescence with their maxima at 734 and 1040 nm, respectively, with a fluorescence quantum yield of 2.84%. Moreover, M1 NPs also exhibit excellent biocompatibility, good photostability, and high photothermal conversion efficiency of 77.5%. In vitro and in vivo experiments reveal that M1 NPs can effectively image tumors through NIR-II fluorescence and PA signals, inhibit DNA replication, trigger cytoskeleton collapse, and eventually induce tumor cell apoptosis under 808 nm laser irradiation. Based on these outstanding properties, the application of M1 NPs in PA and NIR-II fluorescence imaging-guided PTT of tumors is demonstrated., Competing Interests: The authors declare no competing financial interest., (© 2023 The Authors. Co-published by Nanjing University and American Chemical Society.)

Positively charged water-soluble polythiophene (PT0) that could self-assemble into nanoparticles in pure water solution was designed and synthesized. PT0 exhibited high photostabilities and pH stabilities, excellent biocompatibility, strong 1 O 2 generation capability, and large two-photon absorption cross sections. Moreover, we showed that the fluorescence of PT0 was unaffected by the interference of biomolecules and metal ions. As an example application, PT0 was demonstrated to be capable of simultaneous cell imaging and photodynamic therapy under either one-photon or two-photon excitation modes.

Nitrogen and sulfur codoped carbon dots (CDs) were prepared from garlic by a hydrothermal method. The as-prepared CDs possess good water dispersibility, strong blue fluorescence emission with a fluorescent quantum yield of 17.5%, and excellent photo and pH stabilities. It is also demonstrated that the fluorescence of CDs are resistant to the interference of metal ions, biomolecules, and high ionic strength environments. Combining with low cytotoxicity properties, CDs could be used as an excellent fluorescent probe for cellular multicolor imaging. Moreover, the CDs were also demonstrated to exhibit favorable radical scavenging activity.