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Peroxalate CL as an energy source to excite photosensitizers has attracted tremendous attention in photodynamic therapy (PDT). In this work, peroxyoxalate CPPO and hypocrellin B (HB)‐based nanoparticles (CBNPs) for ultrasound (US)‐enhanced self‐exciting PDT were designed and prepared. CBNPs showed an excellent therapeutic effect against cancer cells with the assistance of US. This US‐enhanced‐chemiluminescence system avoids the dependence on external light and provides an example for inspiring more effective and precise strategies for cancer treatment. [ABSTRACT FROM AUTHOR]

Hypocrellin B (HB) derived from naturally produced hypocrellins has attracted considerable attention in photodynamic therapy (PDT) because of its excellent photosensitive properties. However, the weak absorption within a "phototherapy window" (600–900 nm) and poor water solubility of HB have limited its clinical application. In this study, two HB derivatives (i. e., HE and HF) were designed and synthesized for the first time by introducing two different substituent groups into the HB structure. The obtained derivatives showed a broad absorption band covering the near‐infrared (NIR) region, NIR emission (peaked at 805 nm), and singlet oxygen quantum yields of 0.27/0.31. HE‐PEG‐NPs were also prepared using 2‐distearoyl‐sn‐glycero‐3‐phosphoethanolamine‐N‐[methoxy(polyethyleneglycol)‐2000] (DSPE‐mPEG2000) to achieve excellent dispersion in water and further explored their practical applications. HE‐PEG‐NPs not only retained their 1O2‐generating ability, but also exhibited a photothermal conversion efficiency of 25.9%. In vitro and in vivo therapeutic results revealed that the synergetic effect of HE‐PEG‐NPs on PDT and photothermal therapy (PTT) could achieve a good performance. Therefore, HE‐PEG‐NPs could be regarded as a promising phototheranostic agent. [ABSTRACT FROM AUTHOR]

Carbon dots (CDs), a kind of phototheranostic agent with the capability of simultaneous bioimaging and phototherapy [i.e. photodynamic therapy (PDT) or photothermal therapy (PTT)], have received considerable attention because of their remarkable properties, including flexibility for surface modification, high biocompatibility, low toxicity and photo‐induced activity for malignant tumor cells. Among numerous carbon sources, it has been found that natural biomass are good candidates for the preparation of CD phototheranostic agents. In this study, pheophytin, a type of Mg‐free chlorophyll derivative and also a natural product with low toxicity, was used as a raw carbon source for the synthesis of CDs by using a microwave method. The obtained hydrophobic CDs exhibited a maximum near‐infrared (NIR) emission peak at approximately 680 nm, and high singlet oxygen (1O2) generation with a quantum yield of 0.62. The self‐assembled CDs from the as‐prepared CDs with DSPE‐mPEG2000 retained efficient 1O2 generation. The obtained carbon dot assembly was not only an efficient fluorescence (FL) imaging agent but also a smart PDT agent. Our studies indicated that the obtained hydrophilic CD assembly holds great potential as a new phototheranostic agent for cancer therapy. This work provides a new route for synthesis of CDs and proposes a readily available candidate for tumor treatment. [ABSTRACT FROM AUTHOR]

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]

Abstract: Conjugated polymer dots (Pdots, also named polymer nanoparticles, PNPs), which consist of π‐conjugated organic polymers, are novel organic nanomaterials with size in the range of 1–100 nm. Compared with traditional organic small molecules, semiconductor quantum dots and inorganic nanomaterials, the Pdots exhibit significant potential applications in biological imaging, sensing and detection, drug delivery and theranostics, due to their advantages of special optical properties, diverse structure, easy surface modification and good biocompatibility. In this short review, we present a brief summary of the current development in Pdots as phototheranostic agents, including fluorescence imaging, photoacoustic imaging, photodynamic therapy and photothermal therapy. Current challenges in Pdot research and future directions in the field are proposed. [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]

As phototheranostic agents, carbon dots (CDs), have recently drawn considerable attention due to their excellent physicochemical properties. However, the complex synthetic route and high-cost of CDs greatly limit their practical application. To address this issue, given their nearly infinite supply from nature, Hypocrella bambusae is used as the precursor for the preparation of CDs in this study. The obtained Hypocrella bambusae CDs (HBCDs) possess good water solubility, broad absorption (350–800 nm), red-light emission (maximum peak at 610 nm), and low biotoxicity. Moreover, HBCDs can highly generate 1 O 2 (0.38) and heat (27.6%) under 635 nm laser irradiation. These excellent properties of HBCDs capacitate them to be utilized for bimodal fluorescence/photoacoustic imaging-guided synergistic photodynamic therapy (PDT)/photothermal therapy (PTT). This work provides a new candidate for tumor treatment with the combination of PDT and PTT, and explores a novel approach for the preparation of CD-based phototheranostic agents with natural biomass as raw carbon sources. [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]

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]