Photothermal ablation (PTA) therapy has a great potential to revolutionize conventional therapeutic approaches for cancers, but it has been limited by difficulties in obtaining biocompatible photothermal agents that have low cost, small size (<100 nm), and high photothermal conversion efficiency. Herein, we have developed hydrophilic plate-like Cu(9)S(5) nanocrystals (NCs, a mean size of ∼70 nm × 13 nm) as a new photothermal agent, which are synthesized by combining a thermal decomposition and ligand exchange route. The aqueous dispersion of as-synthesized Cu(9)S(5) NCs exhibits an enhanced absorption (e.g., ∼1.2 × 10(9) M(-1) cm(-1) at 980 nm) with the increase of wavelength in near-infrared (NIR) region, which should be attributed to localized surface plasmon resonances (SPR) arising from p-type carriers. The exposure of the aqueous dispersion of Cu(9)S(5) NCs (40 ppm) to 980 nm laser with a power density of 0.51 W/cm(2) can elevate its temperature by 15.1 °C in 7 min; a 980 nm laser heat conversion efficiency reaches as high as 25.7%, which is higher than that of the as-synthesized Au nanorods (23.7% from 980 nm laser) and the recently reported Cu(2-x)Se NCs (22% from 808 nm laser). Importantly, under the irradiation of 980 nm laser with the conservative and safe power density over a short period (∼10 min), cancer cells in vivo can be efficiently killed by the photothermal effects of the Cu(9)S(5) NCs. The present finding demonstrates the promising application of the Cu(9)S(5) NCs as an ideal photothermal agent in the PTA of in vivo tumor tissues.

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Photothermal nanomaterials have recently attracted significant research interest due to their potential applications in biological imaging and therapeutics. However, the development of small-sized photothermal nanomaterials with high thermal stability remains a formidable challenge. Here, we report the rational design and synthesis of ultrasmall (<10 nm) Fe3O4@Cu2-xS core-shell nanoparticles, which offer both high photothermal stability and superparamagnetic properties. Specifically, these core-shell nanoparticles have proven effective as probes for T2-weighted magnetic resonance imaging and infrared thermal imaging because of their strong absorption at the near-infrared region centered around 960 nm. Importantly, the photothermal effect of the nanoparticles can be precisely controlled by varying the Cu content in the core-shell structure. Furthermore, we demonstrate in vitro and in vivo photothermal ablation of cancer cells using these multifunctional nanoparticles. The results should provide improved understanding of synergistic effect resulting from the integration of magnetism with photothermal phenomenon, important for developing multimode nanoparticle probes for biomedical applications.

Fluorescence targeted imaging in vivo has proven useful in tumor recognition and drug delivery. In the process of in vivo imaging, however, a high autofluorescence background could mask the signals from the fluorescent probes. Herein, a high contrast upconversion luminescence (UCL) imaging protocol was developed for targeted imaging of tumors based on RGD-labeled upconversion nanophosphors (UCNPs) as luminescent labels. Confocal Z-scan imaging of tissue slices revealed that UCL imaging showed no autofluorescence signal even at high penetration depth (approximately 600 microm). More importantly, region of interest (ROI) analysis of the UCL signal in vivo showed that UCL imaging achieved a high signal-to-noise ratio (approximately 24) between the tumor and the background. These results demonstrate that the UCL imaging technique appears particularly suited for applications in tracking and labeling components of complex biological systems.

A new photothermal coupling agent for photothermal ablation (PTA) therapy of tumors is developed based on ultrathin PEGylated W18O49 nanowires. After being injected with the nanowire solution, the in vivo tumors exhibit a rapid temperature rise to 50.0 ± 0.5 °C upon irradiation with NIR laser light at a safe, low intensity (0.72 W cm(-2)) for 2 min (left-hand mouse in the figure),), resulting in the efficient PTA of cancer cells in vivo in 10 min.

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A novel flower-like Bi 2 WO 6 superstructure was successfully realized by a facile hydrothermal process without any surfactant or template. Based on the evolution of this morphology as a function of hydrothermal time, the formation mechanism was proposed to be as follows: (1) self-aggregation of nanoparticles; (2) formation of crystalline nanoplates by Ostwald ripening; and (3) organization of the in situ-formed nanoplates into spherical superstructures. The pretty flower-like superstructure of Bi 2 WO 6 was retained after calcination at 550 uC for 4 h. Both the uncalcined and calcined Bi 2 WO 6 exhibited excellent visible-light-driven photocatalytic efficiencies for the degradation of Rhodamine B (RhB), up to 84 and 97% within 60 minutes, respectively, which were much higher than those of TiO 2 (P-25) and Bi 2 WO 6 sample prepared by solid-state reaction (SSR-Bi 2 WO 6 ). Close investigation indicated that plenty of pores with different sizes existed in the Bi 2 WO 6 superstructures, which could serve as hierarchical transport paths for small molecules and might greatly improve their photocatalytic activities.

the copper chalcogenide@mSiO 2 core-shell nanostructures not only possess high biocompatibility, but also are a potential multifunctional platform for effective photothermal and chemotherapy and infrared thermal imagining applications.Herein, we report the rational design and successful synthesis of the Cu 9 S 5 @mSiO 2 -PEG core-shell nanostructures by a thermal decomposition reaction and a sol-gel reaction, followed by surface modifi cation. As-prepared Cu 9 S 5 @mSiO 2 -PEG coreshell nanostructures show a low cytotoxicity and excellent blood compatibility in vitro, and can also be effective photothermal ablation of cancer cells and infrared thermal imaging. Moreover, anticancer drug of doxorubicin (DOX) -loaded Cu 9 S 5 @ mSiO 2 -PEG core-shell nanostructures can effectively delivery DOX into cancer cells with pH sensitive release profi le and be employed for chemotherapy of cancer cells. Importantly, the combination of photothermal-and chemotherapies demonstrates better therapy effects on cancer cells than individual therapy approaches in vitro and in vivo. Results and DiscussionThe Cu 9 S 5 @mSiO 2 -PEG core-shell nanostructures were synthesized by combining a modifi ed thermal decomposition reaction and a sol-gel reaction, followed by surface modifi cation. Figure 1 a illustrates the synthetic procedure of the Cu 9 S 5 @ mSiO 2 -PEG core-shell nanocomposites. First, hydrophobic Cu 9 S 5 nanocrystals were transferred into an aqueous phase by utilizing cetyltrimethylammonium bromide (CTAB). Subsequently, CTAB-stabilized Cu 9 S 5 nanocrystals (Cu 9 S 5 /CTAB) were coated with mesoporous silica shells through hydrolysis and condensation of tetraethylorthosilicate (TEOS) processes, forming Cu 9 S 5 @mSiO 2 core-shell composite nanoparticles. As-obtained Cu 9 S 5 @mSiO 2 core-shell nanoparticles were then nanoplates [ 1c ] are effi cient 980-nm laser-driven photothermal agents and can effectively kill cancer cells in vitro and in vivo. As we know, the PPT agents as a platform for therapy applications should fulfi ll the following requirements: strong absorbance in NIR region and effi cient conversion of the laser energy into heat, and high biocompatibility for a successful applications in vivo therapy. [ 13 ] Thus, it is necessary that the copper chalcogenides should possess good hydrophilicity and low toxicity in a biological environment. However, as-prepared copper chalcogenides are hydrophobic and thus less biocompatible when synthesized via thermal decomposition. [ 1c , 12b ] Though several surface modifi cation methods such as ligands exchange [ 1c ] or polymer coating [ 12b ] have been adopted to make these copper chalcogenides hydrophilic properties, they still show a considerable toxicity in vitro, [ 1c ] thus limiting their wide applications in vivo therapy. Therefore, new methodologies of surface modifi cation are still developed to further reduce the toxicity of the copper chalcogenides as PTT agents.An alternative strategy for reducing the toxicity is to coat the copper chalcogenide nanomaterial...