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Abstract Photoactive agents based on natural products have attracted substantial attention in clinical applications because of their distinct biological activity, molecular structure multiformity, and low biotoxicity. Herein, we initially modify hypocrellin B (HB) with 1,2-diamino-2-methyl propane to form near-infrared (NIR) light (>700 nm)-responsive amino-substituted HB derivative (DPAHB). The DPAHB exhibit broad absorption (400–800 nm), NIR emission (maximum emission peak at 710 nm), and high singlet oxygen (1O 2) quantum yield (∼0.33) under NIR light (721 nm) irradiation. After self-assembly by using DPAHB with PEG-PLGA, the as-prepared nanovesicles (DPAHB NVs) retain efficient 1O 2 generation, more interestingly, show high photothermal conversion efficiency (∼0.24) under NIR light (721 nm) irradiation for synergistic photodynamic therapy (PDT) and photothermal therapy toward hypoxic tumor. The DPAHB NVs can not only be as a fluorescence/photoacoustic imaging agent but also exhibit an even stronger PDT efficiency than that of chlorin e6 (a widely used classic photosensitizer). In vitro and in vivo studies demonstrate that DPAHB NVs possess high photothermal stability, enhanced tumor accumulation, and suitable biodegradation rate, thus, show a highly promising clinical potential as a new photoactive agent for cancer therapy. [ABSTRACT FROM AUTHOR]

A novel phototheranostic platform based on tri -malonate derivative of fullerene C 70 (TFC 70 )/photosensitizer (Chlorin e6, Ce6) nanovesicles (FCNVs) has been developed for effective tumor imaging and treatment. The FCNVs were prepared from amphiphilic TFC 70 -oligo ethylene glycol -Ce6 molecules. The developed FCNVs possessed the following advantages: (i) high loading efficiency of Ce6 (up to ∼57 wt%); (ii) efficient absorption in near-infrared light region; (iii) enhanced cellular uptake efficiency of Ce6 in vitro and in vivo ; (iv) good biocompatibility and total clearance out from the body. These unique properties suggest that the as-prepared FCNVs could be applied as an ideal theranostic agent for simultaneous imaging and photodynamic therapy of tumor. This finding may provide a good solution to highly efficient phototheranostic applications based on fullerene derivatives fabricated nanostructures. [ABSTRACT FROM AUTHOR]

Abstract: A facile hydrothermal approach based on n-nonyl alcohol mediated process has been developed to synthesize self-assembled Fe3O4 hierarchical nanostructures. The as-synthesized hierarchical nanostructured Fe3O4 could be easily transformed to γ-Fe2O3 and α-Fe2O3 without changing its original morphology by calcination in air. X-ray powder diffraction (XRD), field emission scanning electron microscopy (FESEM), transmission electron microscopy (TEM) and high-resolution transmission electron microscopy (HRTEM) were performed to investigate the evolution process of Fe3O4 hierarchical nanostructures. The growth mechanism of the as-prepared Fe3O4 nanostructure and the subsequently hierarchical nanostructures are suggested. The as-obtained iron oxide nanomaterials were used as adsorbent in water treatment, and were found an excellent ability to remove organic pollutants such as Orange II in waste water. [Copyright &y& Elsevier]

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]

Graphical abstract Highlights • Multifunctional liposomes with tumor targeted drug delivery and imaging. • Enhanced photoluminescence emission of carbon dots. • Enhanced anti-cancer efficacy of cinobufagin after loading into liposomes. Abstract Integrating the optical properties of near-infrared fluorescent carbon dots into liposomes may construct a multifunctional nano-system with the potential as a drug carrier, tracer and efficacy intensifier of the anticancer agent. In this study, the liposomes loaded with hydrophilic near-infrared carbon dots as a nano-carrier and tracer of lipophilic anticancer agent cinobufagin were developed. Prepared liposomes were characterized by particle size, morphology and entrapment efficiency. The drug release behavior, the tracer function, the anticancer effect and the side effect were investigated in vitro and in vivo. It was observed that the photoluminescence emission of carbon dots could be strongly enhanced up to 5 times by nano-liposomes. Due to this property, the bio-imaging of CDs + CB liposomes in vitro and in vivo could be clearly obtained. Our results also showed that the CDs + CB liposomes could be uptaken by cells (the lysosomes targeted) and delivered to the tumor site, and undoubtedly, the CDs + CB liposomes demonstrated sustained drug release, enhanced anticancer efficacy and low side effects in vivo. With the assistance of imaging function of CDs, the CDs + CB liposomes can easily display the distribution of drugs, which is very helpful for drug development and may open a novel avenue for drug delivery. [ABSTRACT FROM AUTHOR]

The distance-dependent based sensing mechanism, such as fluorescence resonance energy transfer (FRET) and surface plasmon resonance (SPR) absorption of gold nanoparticles, has been used widely in visual detection. In this work, we report another distance-dependent detection method for nucleoside triphosphates (NTPs) based on carbon dots (CDs) ( 1 O 2 donor) and 9, 10-diphenylanthracene-2-boronic acid (DABA, 1 O 2 acceptor). The CDs can generate singlet oxygen ( 1 O 2 ) which allows diffusion within 200 nm. Thus, the distance between CDs and DABA decreased through binding of NTPs (<200 nm), leading to absorption changes of DABA under light irradiation due to 1 O 2 trapping. This sensing system (CDs@DABA) has high selectivity for the detection of NTPs due to the double molecular recognition and a linear response in the 0–80 μM concentration range was accomplished with the detection limit as low as 4.35 μM. [ABSTRACT FROM AUTHOR]

A new water-soluble fluorescent probe 1 based on hemicyanine dye is designed for selective detection of glutathione (GSH). Probe 1 shows a tremendous colorimetric and ratiometric fluorescence response toward GSH with high selectivity over cysteine/homocysteine. After nucleophilic aromatic substitution reaction with GSH, probe 1 undergoes an intramolecular aldimine condensation that leads to forming a ring, which is accompanied by 107 and 41 nm red-shifts in the absorption and fluorescence spectra, respectively. Subsequent experiments in living cells indicate that probe 1 has a good photostability and response to mitochondrial GSH level in a ratiometric manner. [ABSTRACT FROM AUTHOR]

A novel fluorescent probe O-hNRSel based on tetralin-xanthene fused dye O-hNR was designed and synthesized by introducing 2,4-dinitrobenzenesulfonate functionality. This probe is able to detect selenocysteine (Sec) with rapid response time (2 min) and a large fluorescence enhancement at 624 nm (124-fold). O-hNRSel exhibited selective response to Sec over many other analy and high sensitivity with the detection limit as low as 17 nM. Furthermore, O-hNRSel has been used for fluorescent imaging of Sec in living cells with good biocompatibility. [ABSTRACT FROM AUTHOR]

Carbon dots (CDs) have emerged as promising nanomaterials for bioimaging-guided photodynamic therapy (PDT). However, designing red-emissive CDs (RCDs) with tunable type I and type II reactive oxygen species (ROS) generation to simultaneously meet PDT applications in aerobic and hypoxic scenarios still remain major challenges. Herein, three types of RCDs with maximum emission at approximately 680 nm are successfully prepared. It is noteworthy that they exhibit the adjustable ROS production with equal superoxide anion (via type I PDT) and incremental singlet oxygen (via type II PDT). Detailed structural and optical characterizations along with theoretical calculation reveal that the unique type I/II ROS formation mainly depends on the core sizes and surface states of RCDs, which determine their identical redox potentials and tapering energy gaps between singlet- and triplet states, respectively. Additionally, due to the inherent mitochondria targeting capability, RCDs enable themselves to induce cell programmed death via activating mitochondrion-mediated apoptotic pathways. This work exploits the unprecedented RCDs with tunable type I and type II ROS generation that could ensure highly efficient tumor eradication both in vitro and in vivo, even under the harsh tumor microenvironment, providing a new prospect for CDs as nanophotosensitizers to conquer the limitations of single type PDT. Red emissive carbon dots with tunable reactive oxygen species generation are prepared to achieve highly efficient fluorescence imaging-guided type I/II photodynamic therapy via activating mitochondrion-mediated apoptotic pathways of cancer cells, providing a new prospect for carbon dots as nanophotosensitizers to conquer the limitations of single type PDT. [Display omitted] [ABSTRACT FROM AUTHOR]

Nanozymes are artificial enzymes that mimic natural enzyme-like activities and show great promise for tumor catalytic therapy. However, new nanozymes with multiple catalytic activities for multifunctional nanotheranostic use remain challenging to design. Herein, for the first time, iron phthalocyanine (Fe(II)Pc) was assembled with poly(l -lactide-co-glycolide)-block-poly(ethylene glycol) to prepare an Fe(II)Pc assembly (denoted as Fe(II)Pc-A). The obtained Fe(II)Pc-A could be applied as a smart near-infrared (NIR) light-responsive nanotheranostic for simultaneous photoacoustic imaging-guided photothermal therapy. Notably, Fe(II)Pc-A possessed peroxidase, catalase, and oxidase mimicking activities, which could not only catalyze the conversion of intratumoral H 2 O 2 to •OH, but also degrade H 2 O 2 to generate O 2 and continuously catalyze the conversion of O 2 to cytotoxic O 2 •-. Impressively, the dual reactive oxygen species (ROS) generation of Fe(II)Pc-A was further remarkably enhanced by the endogenous acidity of the tumor microenvironment and the exogenous NIR light-responsive photothermal effect. Moreover, the O 2 self-supplying ability of Fe(II)Pc-A led to increased generation of O 2 •- for enhancing catalytic therapy in hypoxic tumor. These collective properties of Fe(II)Pc-A nanozyme enabled it to be a dual ROS generation accelerator for photothermally enhanced tumor catalytic therapy. Thus, a new type of high-performance nanozyme for multifunctional nanotheranostic use toward cancer was presented. Fe(II)Pc-derived nanozyme with three enzyme-mimicking activities as dual reactive oxygen species generation accelerator for photothermally enhanced tumor catalytic therapy was designed and prepared, thereby providing a new type of high-performance nanozyme for multifunctional nanotheranostic use toward cancer. [Display omitted] [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]

Abstract: C60-carboxyfullerene, C60[C(COOH)2]2, has been proven to function as peroxidase mimetics that can catalyze the reaction of peroxidase substrate 3,3',5,5'-tetramethylbenzidine (TMB) in the presence of H2O2 to produce a blue color reaction. Kinetic studies further indicate that C60[C(COOH)2]2 has an even higher affinity to TMB than that of the natural enzyme, horseradish peroxidase (HRP). C60[C(COOH)2]2/glucose oxidase (GO x )/TMB system provides a novel colorimetric sensor for glucose and shows good response toward glucose detection over a range of 1.0–40μM with a limit of detection 0.5μM (3σ/slope). Moreover, this sensitive and selective sensor can be successfully applied for the quantitative determination of glucose in human serum. The results indicate that it is a simple, cheap, convenient, highly selective, sensitive, and easy handling colorimetric assay. [Copyright &y& Elsevier]

Efficient treatment of primary tumor and preventing cancer metastasis present intriguing alternatives to cancer therapy. Herein, for the first time, we reported the photo-triggered nano-gadofullerene (Gd@C 82 -Ala, abbreviated Gd-Ala) induced malignant tumor vascular disruption by shortening the light interval between Gd-Ala administration and light illumination, where oxygen in blood vessels was employed efficiently to produce cytotoxic reactive oxygen species (ROS). The produced ROS could not only destroy the tumor cells but also devastate the vascular endothelial cells corresponding to the loss of intercellular junctions and vessels disruption. Notably, the irradiated Gd-Ala could enhance dendritic cells (DCs) maturation, which further secreted tumor necrosis factor-α (TNF-α) and interleukin-12 (IL)-12, and then activated T lymphocytes by up-regulation of cluster of differentiation CD4+ and CD8+ T lymphocytes. Furthermore, the down-regulation of matrix metalloprotein 2 (MMP2) and MMP9 also reduce the rate of tumor metastasis. This work explored a new biomedical application of gadofullerene, thereby providing a smart carbon nanomaterial candidate for tumor ablation and inhibition of cancer metastasis. [ABSTRACT FROM AUTHOR]