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Hypoxia is a critical factor for restricting photodynamic therapy (PDT) of tumor, and it becomes increasingly severe with increasing tissue depth. Thus, the relief of deep tumor hypoxia is extremely important to improve the PDT efficacy. Herein, tumor microenvironment (TME)‐responsive size‐switchable hyaluronic acid‐hybridized Ru nanoaggregates (HA@Ru NAs) were developed via screening reaction temperature to alleviate deep tumor hypoxia for improving the tumor‐specific PDT by the artful integration multiple bioactivated chemical reactions in situ and receptor‐mediated targeting (RMT). In this nanosystem, Ru NPs not only enabled HA@Ru NAs to have near infrared (NIR)‐mediated photothermal/photodynamic functions, but also could catalyze endogenous H2O2 to produce O2in situ. More importantly, hyaluronidase (HAase) overexpressed in the TME could trigger disassembly of HA@Ru NAs via the hydrolysis of HA, offering the smart size switch capability from 60 to 15 nm for enhancing tumor penetration. Moreover, the RMT characteristics of HA ensured that HA@Ru NAs could specially enter CD44‐overexpressed tumor cells, enhancing tumor‐specific precision of phototherapy. Taken together these distinguishing characteristics, smart HA@Ru NAs successfully realized the relief of deep tumor hypoxia to improve the tumor‐specific PDT. [ABSTRACT FROM AUTHOR]

Herein, we describe an energy balance strategy between fluorescence and photoacoustic effects by sulfur substitution to transform existing hemicyanine dyes (Cy) into optimized NIRF/PA dual ratiometric scaffolds. Based on this optimized scaffold, we reported the first dual‐ratio response of nitroreductase probe AS‐Cy‐NO2, which allows quantitative visualization of tumor hypoxia in vivo. AS‐Cy‐NO2, composed of a new NIRF/PA scaffold thioxanthene‐hemicyanine (AS‐Cy‐1) and a 4‐nitrobenzene moiety, showed a 10‐fold ratiometric NIRF enhancement (I773/I733) and 2.4‐fold ratiometric PA enhancement (PA730/PA670) upon activation by a biomarker (nitroreductase, NTR) associated with tumor hypoxia. Moreover, the dual ratiometric NIRF/PA imaging accurately quantified the hypoxia extent with high sensitivity and high imaging depth in xenograft breast cancer models. More importantly, the 3D maximal intensity projection (MIP) PA images of the probe can precisely differentiate the highly heterogeneous oxygen distribution in solid tumor. Thus, this study provides a promising NIRF/PA scaffold that may be generalized for the dual ratiometric imaging of other disease‐relevant biomarkers. [ABSTRACT FROM AUTHOR]

The selection of suitable nanozymes with easy synthesis, tumor specificity, multifunction, and high therapeutics is meaningful for tumor therapy. Herein, a facile one‐step assembly approach was employed to successfully prepare a novel kind of natural polyphenol tannic acid (TA) hybrid with mixed valence vanadium oxide nanosheets (TA@VOx NSs). In this system, VOx is assembled with TA through metal–phenolic coordination interaction to both introduce superior peroxidase‐like activity and high near infrared (NIR) absorption owing to partial reduction of vanadium from V5+ to V4+. The presence of mixed valence vanadium oxide in TA@VOx NSs is proved to be the key for the catalytic reaction of hydrogen peroxide (H2O2) to.OH, and the corresponding catalytic mechanism of H2O2 by TA@VOx NSs is proposed. Benefitting from such peroxidase‐like activity of TA@VOx NSs, the overproduced H2O2 of the tumor microenvironment allows the realization of tumor‐specific chemodynamic therapy (CDT). As a valid supplement to CDT, the NIR absorption enables TA@VOx NSs to have NIR light‐mediated conversion ability for photothermal therapy (PTT) of cancers. Furthermore, in vitro and in vivo experiments confirmed that TA@VOx NSs can effectively inhibit the growth of tumors by synergistic CDT/PTT. These results offer a promising way to develop novel vanadium oxide‐based nanozymes for enhanced synergistic tumor‐specific treatment. [ABSTRACT FROM AUTHOR]

Carbon nanomaterials have received great attention from the scientific community over the past few decades because of their unique physical and chemical properties. In this minireview, we will summarize the recent progress of the use of various carbon nanomaterials in the field of cancer phototherapy. The structural characteristics of each category and the surface functionalization strategies of these nanomaterials will be briefly introduced before focusing on their therapeutic applications. Recent advances on their use in photothermal therapy, photodynamic therapy, and combined phototherapies are presented. Moreover, a few challenges and perspectives on the development of carbon nanomaterials for future theranostics are also discussed. The many dimensions of carbon nanomaterials: The recent progress of carbon nanomaterials in the field of cancer phototherapy is reviewed. A few challenges, perspectives on the development of carbon nanomaterials for future phototheranostics are also discussed. [ABSTRACT FROM AUTHOR]

Abstract: Indocyanine green (ICG) is an effective light absorber for laser‐mediated photodynamic therapy. However, applications of ICG are limited due to its rapid degradation and poor photostability in water. Herein, we report the development of a multifunctional nanoplatform by coating ICG on the surface of single‐walled carbon nanohorns (SWNHs) through π–π stacking, obtaining SWNH‐ICGs with high solubility and stability under physiological conditions. The SWNH‐ICGs could be used as a single nanoplatform to simultaneously produce satisfactory hyperthermia and reactive oxygen species under near‐infrared (NIR) laser irradiation. In addition, the SWNH‐ICGs not only improved the photostability of ICG in different media, but also protected it from light degradation. The SWNH‐ICGs exhibited highly efficient thermal/photoacoustic (PA) imaging‐guided photothermal therapy (PTT) and photodynamic therapy (PDT) effects, even under low‐power laser irradiation (0.3 W cm−2) in vitro. Combined PTT and PDT effectively killed triple‐negative breast cancer 4T1 cells, demonstrating a markedly improved and synergistic therapeutic effect compared to PTT or PDT alone. Furthermore, significant tumor growth inhibition as well as tumor cell death were observed following PTT/PDT at 808 nm laser irradiation, confirming the synergistic effects of SWNH‐ICGs over free ICG in vivo. This facile and simple methodology for thermal/PA imaging‐guided PTT/PDT suggests that SWNH‐ICGs may serve as an effective nanoplatform for cancer therapy. [ABSTRACT FROM AUTHOR]

Cover Feature: Natural Polyphenol-Vanadium Oxide Nanozymes for Synergistic Chemodynamic/Photothermal Therapy (Chem. Eur. J. 66/2020) Keywords: chemodynamic therapy; nanoenzymes; photothermal therapy; tumor microenvironments; vanadium oxide EN chemodynamic therapy nanoenzymes photothermal therapy tumor microenvironments vanadium oxide 15048 15048 1 11/28/20 20201126 NES 201126 B One-step assembly of tannic acid and metavanadate b led to the formation of a type of nanozyme comprising natural polyphenol-hybrided mixed valence vanadium oxide nanosheets (TA@VO SB I x i sb NSs). Chemodynamic therapy, nanoenzymes, photothermal therapy, tumor microenvironments, vanadium oxide. [Extracted from the article]

The structural characteristics of various carbon nanomaterials, their surface functionalization strategies, and recent advances in the field of cancer phototherapy are summarized in the Minireview by X.‐C. Shen et al. on page 3993 ff. Their excellent NIR absorption, large surface area, and appropriate size make carbon nanomaterials attractive and promising nanoplatforms for phototherapeutic applications. Despite many significant advances in this field have been made, several challenges remain to be addressed to promote their practical clinical applications. [ABSTRACT FROM AUTHOR]

The mechanism of the surface chemistry of carbon dots (CDs) is revealed in the solid state by X.‐C. Shen and co‐workers in the Full Paper on page 18993 ff. Red‐emitting CDs (RCDs) are prepared, and further used to serve as solid‐state fluorescence sensory material for gaseous ammonia. More importantly, they confirm that the fluorescence response of the RCDs results from ammonia‐induced Michael addition via insertion of N into the CC group and deprotonation of the carboxyl group. [ABSTRACT FROM AUTHOR]

Herein, we describe an energy balance strategy between fluorescence and photoacoustic effects by sulfur substitution to transform existing hemicyanine dyes (Cy) into optimized NIRF/PA dual ratiometric scaffolds. Based on this optimized scaffold, we reported the first dual‐ratio response of nitroreductase probe AS‐Cy‐NO2, which allows quantitative visualization of tumor hypoxia in vivo. AS‐Cy‐NO2, composed of a new NIRF/PA scaffold thioxanthene‐hemicyanine (AS‐Cy‐1) and a 4‐nitrobenzene moiety, showed a 10‐fold ratiometric NIRF enhancement (I773/I733) and 2.4‐fold ratiometric PA enhancement (PA730/PA670) upon activation by a biomarker (nitroreductase, NTR) associated with tumor hypoxia. Moreover, the dual ratiometric NIRF/PA imaging accurately quantified the hypoxia extent with high sensitivity and high imaging depth in xenograft breast cancer models. More importantly, the 3D maximal intensity projection (MIP) PA images of the probe can precisely differentiate the highly heterogeneous oxygen distribution in solid tumor. Thus, this study provides a promising NIRF/PA scaffold that may be generalized for the dual ratiometric imaging of other disease‐relevant biomarkers. [ABSTRACT FROM AUTHOR]