Phase‐Transition Induced Conversion into a Photothermal Material: Quasi‐Metallic WO 2.9 Nanorods for Solar Water Evaporation and Anticancer Photothermal Therapy

Full-spectrum plasmonic semiconductors for photocatalysis

Localized surface plasmon resonance (LSPR) of noble metal nanoparticles can focus surrounding light onto the particle surface to boost photochemical reactions and solar energy utilization. However, the rarity and high cost of noble metals limit their applications in plasmonic photocatalysis, forcing researchers to seek low-cost alternatives. Recently, some heavily doped semiconductors with high free carrier density have garnered attention due to their metal-like LSPR properties. However, plasmonic semiconductors have complex surface structures characterized by the presence of a depletion layer, which poses challenges for active site exposure and hot carrier transfer, resulting in low photocatalytic activity. In this review, we introduce the essential characteristics and types, synthesis methods, and characterization techniques of full-spectrum plasmonic semiconductors, elucidate the mechanism of full-spectrum nonmetallic plasmonic photocatalysis, including the local electromagnetic field, hot carrier generation and transfer, the photothermal effect, and the solutions for the surface depletion layer, and summarize the applications of plasmonic semiconductors in photocatalytic environmental remediation, CO2 reduction, H2 generation, and organic transformations. Finally, we provide a perspective on full-spectrum plasmonic photocatalysis, aiming to guide the design and development of plasmonic photocatalysts.

Plasmon-Enhanced Light Absorption Below the Bandgap of Semiconducting SnS2 Microcubes for Highly Efficient Solar Water Evaporation

Semiconducting materials show high potential for solar energy harvesting due to their suitable bandgaps, which allow the efficient utilization of light energy larger than their bandgaps. However, the photon energy smaller than their bandgap is almost unused, which significantly limits their efficient applications. Herein, plasmonic Pd/SnS2 microcubes with abundant Pd nanoparticles attached to the SnS2 nanosheets are fabricated by an in situ photoreduction method. The as-prepared Pd/SnS2 microcubes extend the light-harvesting ability of SnS2 beyond its cutoff wavelength, which is attributed to the localized surface plasmon resonance (LSPR) effect of the Pd nanoparticles and the 3D structure of the SnS2 microcubes. Pd nanoparticles can also enhance the light absorption of TiO2 nanoparticles and NiPS3 nanosheets beyond their cutoff wavelengths, revealing the universality for promoting absorption above the cutoff wavelength of the semiconductors. When the plasmonic Pd/SnS2 microcubes are integrated into a hydrophilic sponge acting as the solar evaporator, a solar-to-vapor efficiency of up to 89.2% can be achieved under one sun. The high solar-to-vapor conversion efficiency and the broad applicability of extending the light absorption far beyond the cutoff wavelength of the semiconductor comprise the potential of innovative plasmonic nanoparticle/semiconductor composites for solar desalination.

Copper tannate nanosheets-embedded multifunctional coating for antifouling and photothermal bactericidal applications

Implant-associated infections (IAIs), triggered by pathogenic bacteria, are a leading cause of implant failure. The design of functionalized coatings on biomedical materials is crucial to address IAIs. Herein, a multifunctional coating with good antifouling effect and antibacterial photothermal therapy (aPTT) performance was developed. The copper tannate nanosheets (CuTA NSs) were formed via coordination bonding of Cu2+ ions and tannic acid (TA). The CuTA NSs were then integrated into the TA and poly(ethylene glycol) (PEG) network to form the TCP coating for deposition on the titanium (Ti) substrates via surface adhesion of TA and gravitational effect. The resulting Ti-TCP substrate exhibited good antifouling property, reactive oxygen species (ROS) scavenging capability and cytocompatibility. The TCP coating exhibited antifouling efficacy in conjunction with aPTT, curtailing the surface adhesion and biofilm formation of pathogens, such as Staphylococcus aureus and Escherichia coli. Notably, the Ti-TCP substrate also exhibited the ability to prevent bacterial infection in vivo in a subcutaneous implantation model. The present work demonstrated a promising approach in designing high-performance antifouling and photothermal bactericidal coatings to combat IAIs.

Heat-Localized and Salt-Resistant 3D Hierarchical Porous Ceramic Platform for Efficient Solar-Driven Interfacial Evaporation

Solar-driven interfacial evaporation (SDIE) is a highly promising approach to achieve sustainable desalination and tackle the global freshwater crisis. Despite advancements in this field, achieving balanced thermal localization and salt resistance remains a challenge. Herein, the study presents a 3D hierarchical porous ceramic platform for SDIE applications. The utilized alumina foam ceramics (AFCs) exhibit remarkable corrosion resistance and chemical stability, ensuring a prolonged operational lifespan in seawater or brines. The millimeter-scale air-filled pores in AFCs prevent thermal losses through conduction with bulk water, resulting in heat-localized interfaces. The hydrophilic nature of macroporous AFC skeletons facilitates rapid water replenishment on the evaporating surface for effective salt-resistant desalination. Benefiting from its self-radiation adsorption and side-assisted evaporation capabilities, the AFC-based evaporators exhibit high indoor evaporation rates of 2.99 and 3.54 kg m-2 h-1 under one-sided and three-sided illumination under 1.0 sun, respectively. The AFC-based evaporator maintains a high evaporation rate of ≈2.77 kg m-2 h-1 throughout the 21-day long-term test. Furthermore, it achieves a daily water productivity of ≈10.44 kg m-2 in outdoor operations. This work demonstrates the potential of 3D hierarchical porous ceramics in addressing the trade-off between heat localization and salt resistance, and contributes to the development of durable solar steam generators.

Inorganic nanoparticles for photothermal treatment of cancer

In recent years, inorganic nanoparticles (NPs) have attracted increasing attention as potential theranostic agents in the field of oncology. Photothermal therapy (PTT) is a minimally invasive technique that uses nanoparticles to produce heat from light to kill cancer cells. PTT requires two essential elements: a photothermal agent (PTA) and near-infrared (NIR) radiation. The role of PTAs is to absorb NIR, which subsequently triggers hyperthermia within cancer cells. By raising the temperature in the tumor microenvironment (TME), PTT causes damage to the cancer cells. Nanoparticles (NPs) are instrumental in PTT given that they facilitate the passive and active targeting of the PTA to the TME, making them crucial for the effectiveness of the treatment. In addition, specific targeting can be achieved through their enhanced permeation and retention effect. Thus, owing to their significant advantages, such as altering the morphology and surface characteristics of nanocarriers comprised of PTA, NPs have been exploited to facilitate tumor regression significantly. This review highlights the properties of PTAs, the mechanism of PTT, and the results obtained from the improved curative efficacy of PTT by utilizing NPs platforms.

An all-in-one FeOx-rGO sponge fabricated by solid-phase microwave thermal shock for water evaporation and purification

Developing high-efficiency photothermal seawater desalination devices is of significant importance in addressing the shortage of freshwater. Despite much effort made into photothermal materials, there is an urgent need to design a rapidly synthesized photothermal evaporator for the comprehensive purification of complex seawater. Therefore, we report on all-in-one FeOx-rGO photothermal sponges synthesized via solid-phase microwave thermal shock. The narrow band gap of the semiconductor material Fe3O4 greatly reduces the recombination of electron-hole pairs, enhancing non-radiative relaxation light absorption. The abundant π orbitals in rGO promote electron excitation and thermal vibration between the lattices. Control of the surface hydrophilicity and hydrophobicity promotes salt resistance while simultaneously achieving the purification of various complex polluted waters. The optimized GFM-3 sponge exhibitedan enhanced photothermal conversion rate of 97.3% and a water evaporation rate of 2.04 kg/(m2·hr), showing promising synergistic water purification properties. These findings provide a highly efficient photothermal sponge for practical applicationsof seawater desalination and purification,as well as develop a super-rapid processing methodology for evaporation devices.

Optimizing Hydrogen and Hydroxyl Adsorption over Ru/WO2.9 Metal/Metalloid Heterostructure Electrocatalysts for Highly Efficient and Stable Hydrogen Oxidation Reactions in Alkaline Media

The development of high-performance, stable and platinum-free electrocatalysts for the hydrogen oxidation reaction (HOR) in alkaline media is crucial for the commercial application of anion exchange membrane fuel cells (AEMFCs). Ruthenium, as an emerging HOR electrocatalyst with a price advantage over platinum, still needs to solve the problems of low intrinsic activity and easy oxidation. Herein, Ru nanoparticles are anchored on the oxygen-vacancy-rich metalloid WO2.9 by interfacial engineering to create abundant and efficient Ru and WO2.9 interfacial active sites for accelerated HOR in alkaline media. Ru/WO2.9 /C displays excellent catalytic activity with mass activity (8.29 A mgNM -1 ) and specific activity (1.32 mA cmNM -2 ), which are 2.5/3.3 and 21.8/8.3 times that of PtRu/C and Pt/C, respectively. Moreover, Ru/WO2.9 /C exhibits excellent CO tolerance and operational stability. Experimental and theoretical studies reveal that the improved charge transfer from Ru to WO2.9 in the metal/metalloid heterostructure significantly tune the electronic structure of Ru sites and optimize the hydrogen binding energy (HBE) of Ru. While, WO2.9 provides abundant hydroxyl adsorption sites. Therefore, the equilibrium adsorption of hydrogen and hydroxyl at the interface of Ru/WO2.9 will be realized, and the oxidation of metal Ru would be avoided, thereby achieving excellent HOR activity and durability.

Customized Microenvironments Spontaneously Facilitate Coupled Engineering of Real-Life Large-Scale Clean Water Capture and Pollution Remediation

Harnessing abundant renewable resources and pollutants on a large scale to address environmental challenges, while providing sustainable freshwater, is a significant endeavour. This study presents the design of fully functional solar vaporization devices (SVD) based on organic-inorganic hybrid nanocomposites (CCMs-x). These devices exhibit efficient photothermal properties that facilitate multitargeted interfacial reactions, enabling simultaneous catalysis of sewage and desalination. The localized interfacial heating generated by the photothermal effect of CCMs-x triggers surface-dominated catalysis and steam generation. The CCMs-x SVD achieves a solar water-vapor generation rate of 1.41 kg m-2 h-1 (90.8%), and it achieves over 95% removal of pollutants within 60 min under one-sun for practical application. The exceptional photothermal conversion rate of wastewater for environmental remediation and water capture is attributed to customized microenvironments within the system. The integrated parallel reaction system in SVD ensures it is a real-life application in multiple scenarios such as municipal/medical wastewater and brine containing high concentrations. Additionally, the SVD exhibits long-term durability, antifouling functionality toward complex ionic contaminants. This study not only demonstrates a one-stone-two-birds strategy for large-scale direct production of potable water from polluted seawater, but also opens up exciting possibilities for parallel production of energy and water resources.

Nanohole-Array Induced Metallic Molybdenum Selenide Nanozyme for Photoenhanced Tumor-Specific Therapy

Deficient catalytic sensitivity to the tumor microenvironment is a major obstacle to nanozyme-mediated tumor therapy. Electron transfer is the intrinsic essence for a nanozyme-catalyzed redox reaction. Here, we developed a nanohole-array-induced metallic molybdenum selenide (n-MoSe2) that is enriched with Se vacancies and can serve as an electronic transfer station for cycling electrons between H2O2 decomposition and glutathione (GSH) depletion. In a MoSe2 nanohole array, the metallic phase reaches up to 84.5%, which has been experimentally and theoretically demonstrated to exhibit ultrasensitive H2O2 responses and enhanced peroxidase (POD)-like activities for H2O2 thermodynamic heterolysis. More intriguingly, plenty of delocalized electrons appear due to phase- and vacancy-facilitated band structure reconstruction. Combined with the limited characteristic sizes of nanoholes, the surface plasmon resonance effect can be excited, leading to the broad absorption spectrum spanning of n-MoSe2 from the visible to near-infrared region (NIR) for photothermal conversion. Under NIR laser irradiation, metallic MoSe2 is able to induce out-of-balance redox and metabolism homeostasis in the tumor region, thus significantly improving therapeutic effects. This study that takes advantage of phase and defect engineering offers inspiring insights into the development of high-efficiency photothermal nanozymes.

Hierarchical Tantalum Oxide Composite for Efficient Solar-Driven Water Purification

Applying solar energy to generate drinking water is a clean and low-energy exhaust route to address the issue of water purification. The current challenge with solar vapor generation is constructing nano/micro-hierarchical structures that can convert solar irradiation into exploitable thermal energy with high efficiency. Although various structures and material designs have been reported in recent years, solar vapor conversion can be improved by integrating light harvesting, thermal concentration, and water diffusion. Because of the optimized solar harvesting, enhanced heat capacity, and specified diffusive path endowed by the hierarchical composite structure, amorphous tantalum oxide/carbon-based yolk-shell structures (α-Ta2O5/C YS) for highly efficient solar vapor generation under 1 sun illumination are applied in this study. As a result, the α-Ta2O5/C YS realized a water evaporation rate of 3.54 kg m-2 h-1 with a solar-thermal conversion efficiency of 91% under one sun irradiation (1 kW m-2) with excellent evaporation stability. The collected water from seawater meets the World Health Organization drinking water standard. Importantly, reactive oxygen species enabled by α-Ta2O5 could be produced for water sterilization, exhibiting a facile way for application in various scenarios to acquire drinkable water.

Micellar Nanoreactors Enabled Site-Selective Decoration of Pt Nanoparticles Functionalized Mesoporous SiO2 /WO3-x Composites for Improved CO Sensing

Site-selective and partial decoration of supported metal nanoparticles (NPs) with transition metal oxides (e.g., FeOx ) can remarkably improve its catalytic performance and maintain the functions of the carrier. However, it is challenging to selectively deposit transition metal oxides on the metal NPs embedded in the mesopores of supporting matrix through conventional deposition method. Herein, a restricted in situ site-selective modification strategy utilizing poly(ethylene oxide)-block-polystyrene (PEO-b-PS) micellar nanoreactors is proposed to overcome such an obstacle. The PEO shell of PEO-b-PS micelles interacts with the hydrolyzed tungsten salts and silica precursors, while the hydrophobic organoplatinum complex and ferrocene are confined in the hydrophobic PS core. The thermal treatment leads to mesoporous SiO2 /WO3-x framework, and meanwhile FeOx nanolayers are in situ partially deposited on the supported Pt NPs due to the strong metal-support interaction between FeOx and Pt. The selective modification of Pt NPs with FeOx makes the Pt NPs present an electron-deficient state, which promotes the mobility of CO and activates the oxidation of CO. Therefore, mesoporous SiO2 /WO3-x -FeOx /Pt based gas sensors show a high sensitivity (31 ± 2 in 50 ppm of CO), excellent selectivity, and fast response time (3.6 s to 25 ppm) to CO gas at low operating temperature (66 °C, 74% relative humidity).

Responsive Microneedles as a New Platform for Precision Immunotherapy

Microneedles are a well-known transdermal or transdermal drug delivery system. Different from intramuscular injection, intravenous injection, etc., the microneedle delivery system provides unique characteristics for immunotherapy administration. Microneedles can deliver immunotherapeutic agents to the epidermis and dermis, where immune cells are abundant, unlike conventional vaccine systems. Furthermore, microneedle devices can be designed to respond to certain endogenous or exogenous stimuli including pH, reactive oxygen species (ROS), enzyme, light, temperature, or mechanical force, thereby allowing controlled release of active compounds in the epidermis and dermis. In this way, multifunctional or stimuli-responsive microneedles for immunotherapy could enhance the efficacy of immune responses to prevent or mitigate disease progression and lessen systemic adverse effects on healthy tissues and organs. Since microneedles are a promising drug delivery system for accurate delivery and controlled drug release, this review focuses on the progress of using reactive microneedles for immunotherapy, especially for tumors. Limitations of current microneedle system are summarized, and the controllable administration and targeting of reactive microneedle systems are examined.

Tungsten-based Nanomaterials in the Biomedical Field: A Bibliometric Analysis of Research Progress and Prospects

Tungsten-based nanomaterials (TNMs) with diverse nanostructures and unique physicochemical properties have been widely applied in the biomedical field. Although various reviews have described the application of TNMs in specific biomedical fields, there are still no comprehensive studies that summarize and analyze research trends of the field as a whole. To identify and further promote the development of biomedical TNMs, a bibliometric analysis method is used to analyze all relevant literature on this topic. First, general bibliometric distributions of the dataset by year, country, institute, referenced source, and research hotspots are recognized. Next, a comprehensive review of the subjectively recognized research hotspots in various biomedical fields, including biological sensing, anticancer treatments, antibacterials, and toxicity evaluation, is provided. Finally, the prospects and challenges of TNMs are discussed to provide a new perspective for further promoting their development in biomedical research.

Superelastic 3D Assembled Clay/Graphene Aerogels for Continuous Solar Desalination and Oil/Organic Solvent Absorption

Superelastic, arbitrary-shaped, and 3D assembled clay/graphene aerogels (CGAs) are fabricated using commercial foam as sacrificial skeleton. The CGAs possess superelasticity under compressive strain of 95% and compressive stress of 0.09-0.23 MPa. The use of clay as skeletal support significantly reduces the use of graphene by 50%. The hydrophobic CGAs show high solvent absorption capacity of 186-519 times its own weight. Moreover, both the compression and combustion methods can be adopted for reusing the CGAs. In particular, it is demonstrated a design of 3D assembled hydrophilic CGA equipped with salt collection system for continuous solar desalination. Due to energy recovery and brine transport management promoted by this design, the 3D assembled CGA system exhibits an extremely high evaporation rate of 4.11 kg m-2  h-1 and excellent salt-resistant property without salt precipitation even in 20 wt% brine for continuous 36 h illumination (1 kW m-2 ), which is the best reported result from the solar desalination devices. More importantly, salts can be collected conveniently by squeezing and drying the solution out of the salt collection system. The work provides new insights into the design of 3D assembled CGAs and advances their applications in continuous solar desalination and efficient oil/organic solvent adsorption.

Mussel-inspired multifunctional hydrogel dressing with hemostasis, hypoglycemic, photothermal antibacterial properties on diabetic wounds

To meticulously establish an efficient photothermal multifunctional hydrogel dressing is a prospective strategy for the treatment of diabetic chronic wounds. Herein, glucose oxidase (GOx) was added to polydopamine/acrylamide (PDA/AM) hydrogels to reduce hyperglycemia to a normal level (3.9-6.1 mmol L^-1) and enhance compressive properties (55 kPa) and adhesive properties (32.69 kPa), which are capable of hemostasis in the wound. Then, MnO₂ nanoparticles were encapsulated into a polydopamine/acrylamide (PDA/AM) hydrogel, endowing it with excellent antibacterial properties (E. coli and S. aureus were 97.87% and 99.99%) under the irradiation of 808 nm NIR; meanwhile, the biofilm was eliminated completely. Besides, O₂ was generated (18 mg mL^-1) by the decomposition of H₂O₂ under the catalysis of MnO₂, which could accelerate the formation of angiogenesis and promote the crawling and proliferation of cells. Furthermore, the diabetic wound in vivo treated with the PDA/AM/GOx/MnO₂ hydrogel had a less inflammatory response and faster healing speed, which was completely healed in 14 days. Therefore, the multifunctional hydrogels with the capability of high compressible, hemostasis, antibacterial, hyperglycemia manipulation, and O₂ generation, demonstrate promise in diabetic chronic wound dressing.

Designing Photothermal Superhydrophobic PET Fabrics via In Situ Polymerization and 1,4-Conjugation Addition Reaction

This study demonstrates a simple and fast method to integrate superhydrophobicity, UV protection, and photothermal effect onto PET fabrics. The surface of PET fabric forms a hierarchical rough structure through in situ oxidative polymerization of the pyrrole (Py). The 1,4-conjugate addition reaction between pentaerythritol tetraacrylate, 3-aminopropyltriethoxysilane, and octadecyl acrylate not only endows the PET fabric with superhydrophobicity but also forms a cross-linked network structure which improves the stability of multifunctional coatings on the surface of the PET fabric. In addition, the wettability of the prepared PET fabric is investigated by adjusting the Py monomer and octadecyl acrylate concentration. The results reveal that the prepared PET fabrics exhibit obviously superhydrophobic behavior with a contact angle of 155.8°. The surface temperature of the superhydrophobic PPy/PET fabric can rise to 91 °C under a simulated sunlight which is much higher than the pristine PET fabric, while reaching basically the same steady-state in five heating/cooling cycles. The prepared PET fabric also possesses excellent self-cleaning, UV shielding, and solar light absorption performances. Furthermore, the superhydrophobic PET fabric exhibited excellent stability against 180 °C high temperature, strong UV radiation, different pH solutions and organic solvent erosion, 8 h washing tests, and 25 sandpaper abrasion cycles. These findings provide a path for the future development of multifunctional fabrics using fluorine-free environmentally friendly materials.

Defect engineering tuning electron structure of biphasic tungsten-based chalcogenide heterostructure improves its catalytic activity for hydrogen evolution and triiodide reduction

The design and exploration of high-efficiency and low-cost electrode catalysts are of great significance to the development of novel energy conversion technologies. In this work, metal and nonmetal heteroatoms co-doped biphasic tungsten-based chalcogenide heterostructured catalyst (Co-WS₂/P-WO_2.9) with rich defects is successfully synthesized by a vulcanization technique. The electrocatalytic performance of WS₂/WO₃ in the hydrogen evolution reaction (HER) and triiodide reduction reaction is significantly enhanced by modifying and optimizing its electronic structure through a defect engineering strategy. As an electrocatalyst for HER, the optimized Co-WS₂/P-WO_2.9 exhibits a low overpotential at 10 mA cm^-2 of 146 and 120 mV with small Tafel slopes of 86 and 74 mV dec^-1 in alkaline and acidic electrolyte, respectively. In addition, a Co-WS₂/P-WO_2.9 assembled solar cell yields a short circuit current density of 15.85 mA cm^-2, an open-circuit voltage of 0.74 V, a fill factor of 0.66, and a competitive power conversion efficiency (7.83%), which is comparable or higher than conventional Pt-based solar cell (16.02 mA cm^-2, 0.70 V, 0.63, 7.14%). The formation of a heterostructure in Co-WS₂/P-WO_2.9 leads to the presence of a built-in electric field in the interfacial region between Co-WS₂ and P-WO_2.9, which leads to an increased open-circuit voltage from 0.70 V for Pt to 0.74 V for Co-WS₂/P-WO_2.9. This work can provide a technical support for developing high-performance heterostructured catalysts, which open up a way for improving catalytic performance of heterostructured catalysts in the field of electrocatalysis.

Gradient Design of Vacancies and Their Positive Correlation with Electrochemical Anticorrosion Protection

The contribution of defects to electrochemistry is a controversial but practically applicable subject. Meanwhile, it is challenging to obtain precisely a certain nonchemometric single phase in mixed-valence compounds. The precise design of nonchemometric single-phase WO_3-x (x = 0, 0.1, 0.28, and 1) mixed-valence metal oxides (MVMOs) was achieved by the gradient intrinsic reduction method, and the correlation between oxygen vacancies and electrochemical anticorrosion protection was explored systematically. Then, the decisive role of periodic oxygen vacancies in electrochemical anticorrosion was confirmed. And the origin was the synergistic reaction of oxygen vacancy-upgraded photocathodic protection, vacancy-induced passivation, and mixed-valence reductive protection, which were brought about by the high oxygen vacancy concentration. Integrating the above three aspects, the WO_2.72 MVMO showed the best electrochemical anticorrosion performance by increasing the resistance value to 7.67 times that of the epoxy resin coating. The establishment of a positive correlation between oxygen vacancy and corrosion protection in WO_3-x (x = 0, 0.1, 0.28, and 1) materials can not only guide the design of MVMOs but also make an important contribution to the rapid precorrosion performance of the materials.

Au@MnSe2 Core-Shell Nanoagent Enabling Immediate Generation of Hydroxyl Radicals and Simultaneous Glutathione Deletion Free of Pre-Reaction for Chemodynamic-Photothermo-Photocatalytic Therapy with Significant Immune Response

As a typical tumor microenvironment-responsive therapy, chemodynamic therapy (CDT), producing hydroxyl radicals (^• OH) to eliminate tumor cells, has demonstrated great promise. Nevertheless, there are still major challenges: ^• OH generated from endogenous H₂ O₂ is usually insufficient; the CDT effect is strongly dependent on the pre-reaction with glutathione. Addressing the challenges, Au@MnSe₂ core-shell nanoagent for synergetic chemodynamic-photothermo-photocatalytic therapy combined with tetramodal imaging, including magnetic resonance imaging, computed tomography, photoacoustic, and infrared thermal imaging is reported. Distinct from the reported glutathione-depleting agents, Mn²⁺ in MnSe₂ allows immediate generation of ^• OH, independent of pre-reaction. Meanwhile, Mn³⁺ consumes glutathione by its conversion to Mn²⁺ . The Au-MnSe₂ combination promotes photothermal conversion and photocatalytic reaction, resulting in largely enhanced ^• OH generation from endogenous H₂ O₂ and significant hyperthermia. Meanwhile, immune response is effectively activated: the intratumoral expression of programmed cell death-1 and proinflammatory cytokines increase to 4-7 folds; the cytotoxic and helper T lymphocytes cells in the tumor area increase to more than 2.5-folds; an evident, temporary systemic immunostimulatory effect is demonstrated. High tumor inhibition rate (≈97.3%) and greatly prolonged survival are obtained. This highly-integrated design coordinating three different therapies with four different imaging modals provide new possibilities for high-performance theranostic nanoagents.

Hierarchical WO3-x Ultrabroadband Absorbers and Photothermal Converters Grown from Femtosecond Laser-Induced Periodic Surface Structures

Oxygen-vacancy-rich WO3-x absorbers are gaining increasing attention because of their extensive absorbance-based applications in near-infrared shielding, photocatalysis, sterilization, interfacial evaporator and electrochromic, photochromic, and photothermal fields. Thermal treatment in an oxygen-deficient atmosphere enables us to prepare WO3-x but lacks the capacity for finely manipulating the grown structures. In this work, we present that laser-induced periodic surface structure (LIPSS) obtained by femtosecond laser ablation is a good template to grow various hierarchical WO3-x ultrabroadband absorbers and photothermal converters by thermal oxidation annealing in air. Increasing annealing temperature from 600 to 1000 °C allows the manipulation of WO3-x crystal sizes from ∼70 nm to ∼4 μm, accompanied by a color transition from brown to dark blue and finally to yellow. Benefiting from annealing-induced surface cracks and phase transition into WO3-x (containing both WO3 and W18O49) at 600 °C, excellent UV-vis-NIR-MIR ultrabroadband absorbers were produced: >90% UV-NIR absorbance (0.3-2.5 μm) and 50-90% MIR absorbance (2.5-16 μm), much better than most W-based metamaterial absorbers. The higher the annealing temperature (1000 > 800 > 600 °C), the better the photothermal performances (sample temperature as the indicator) of annealed interfaces due to the increased oxidation rates and resultant thicker oxide layers (6, 150, and 507 μm), a trend which is more apparent upon the irradiation of high-density (3160 mW/cm2) and ultrabroadband (200-2500 nm) light but much less apparent for shorter-band (200-800, 420-800, 800-2500 nm, etc.) and less-intensity (1694, 1540, 1460 mW/cm2, etc.) light irradiation. This phenomenon indicates that (1) higher-performance ultrabroadband absorbers possess a higher photothermal conversion capacity; (2) thicker-WO3-x oxide layer converters are more effective in preserving photothermal heat; and (3) both the W-LIPSS and metal tungsten substrate can quickly dissipate the photothermal heat to inhibit heat accumulation in the oxide photothermal converters. It is also proved that ablation-induced high-pressure shockwaves can produce deformation layers in the subsurfaces to release annealing-induced stresses, beneficial for the formation of less-cracked non-stoichiometric WO3-x interfaces upon annealing. High-pressure shockwaves are also capable of inducing grain refinement of LIPSS, which facilitates a homogeneous growth of small non-stoichiometric metal-oxide crystals upon annealing. Our results indicate that femtosecond laser ablation is a convenient upstream template-fabrication technique compatible with the thermal oxidation annealing method to develop advanced functional oxygen-vacancy metal-oxide interfaces.

Narrow-Bandgap LaMO3 (M = Ni, Co) nanomaterials for efficient interfacial solar steam generation

Photothermal water evaporation provides a pathway towards a promising solution to global freshwater scarcity. Synergistic integration of functions in a material in diverse directions is a key strategy for designing multifunctional materials. Lanthanum-based perovskite complex oxides LaMO₃ (M = Ni and Co) have narrow band gaps with a high absorption coefficient. These functionalities have not been appropriately explored for photothermal energy conversion. Here, we synthesized nanostructured metallic LaNiO₃ and semiconducting LaCoO₃ and used them to design interfacial solar steam generators. Effective light absorption capability over the entire solar spectrum of these materials leads to a photothermal efficiency of the order of 83% for both materials. Using a cone-shaped 3D interfacial steam generator with a LaNiO₃ absorber, we achieved an evaporation rate of 2.3 kg m^-2 h^-1, corresponding to solar vapor generation efficiency of over 95%. To the best of our knowledge, this evaporation rate is higher than any oxide-based interfacial solar steam generator reported so far. Furthermore, we have also shown an effective way of using such evaporators for long-term seawater desalination.

Near-Infrared II Nanoadjuvant-Mediated Chemodynamic, Photodynamic, and Photothermal Therapy Combines Immunogenic Cell Death with PD-L1 Blockade to Enhance Antitumor Immunity

The efficacy of immune checkpoint inhibition in inducing death of cancer cells is affected by the immunosuppressive "cold" tumor microenvironment, which results in a poor response by the patient's antitumor immune system. However, the immunomodulatory effects of immunogenic cell death in response to irritation by heat energy and reactive oxygen species (ROS) can switch the tumor microenvironment from "cold" to "hot." This study has developed a nanoadjuvant for immune therapy using iron tungsten oxide (FeWOx)-based nanosheets with surface PEGylation (FeWOx-PEG). This FeWOx-PEG nanoadjuvant serves as a chemodynamic reagent via the Fenton reaction and acts as a photosensitizer for photodynamic and photothermal therapy under near-infrared II laser irradiation; however, it could also be used to augment tumor-infiltrating T-cells and provoke a systemic antitumor immune response by combining the immunogenic cell death triggered by ROS and photothermal therapy with the immune checkpoint blockade. This research demonstrates that application of the FeWOx-PEG nanoadjuvant under the guidance of magnetic resonance/computed tomography/photoacoustic imaging can eliminate the primary tumor and suppress the growth of distant tumors.

Photoluminescence-based sensing of ethanol gas with ultrafine WO3 nanorods

Ultrafine one-dimensional WO₃ nanorods (NRs) with diameters of 10-200 nm have been fabricated using a hydrothermal synthesis method. The optical performance of the WO₃ NRs strongly depends on their various defects as well as their crystal quality. Upon exposure to trace quantities of ethanol gas, the photoluminescence (PL) spectra of these nanorod samples under ultraviolet illumination showed a large variation in intensity. WO₃-NR-based ethanol gas sensing via PL spectra variation demonstrated a 100 ppm sensitivity detection limit and a wide linear detection range of 200-2000 ppm at 100°C. This outstanding optical ethanol sensing performance can be ascribed to the very large surface area to volume ratio of this material, which increases the density of active sites for ethanol adsorption and reaction with adsorbed oxygen species.

Plasmonic Oxygen Defects in MO3- x (M = W or Mo) Nanomaterials: Synthesis, Modifications, and Biomedical Applications

Nanomedicine is a promising technology with many advantages and provides exciting opportunities for cancer diagnosis and therapy. During recent years, the newly developed oxygen-deficiency transition metal oxides MO_{3- x} (M = W or Mo) have received significant attention due to the unique optical properties, such as strong localized surface plasmon resonance (LSPR) , tunable and broad near-IR absorption, high photothermal conversion efficiency, and large X-ray attenuation coefficient. This review presents an overview of recent advances in the development of MO_{3- x} nanomaterials for biomedical applications. First, the fundamentals of the LSPR effect are introduced. Then, the preparation and modification methods of MO_{3- x} nanomaterials are summarized. In addition, the biological effects of MO_{3- x} nanomaterials are highlighted and their applications in the biomedical field are outlined. This includes imaging modalities, cancer treatment, and antibacterial capability. Finally, the prospects and challenges of MO_{3- x} and MO_{3- x} -based nanomaterial for fundamental studies and clinical applications are also discussed.

NIR-II Responsive Hydrogel as an Angiogenesis Inhibition Agent for Tumor Microenvironment Reprogramming

Regulation of angiogenesis is a great challenge for effective anticancer therapy. Generally, anti-angiogenic therapies are focused on inhibition of inducers involved in pro-angiogenic communication pathways. Despite the great potential of anti-angiogenic therapy, engineering efficient angiogenesis inhibition agents (AIAs) is still a formidable challenge, since most anti-angiogenic therapies are limited due to the cancer recurrence via compensatory expression of different angiogenic mediators. Herein, we present a new strategy of near-infrared-II (NIR-II) responsive hydrogel AIAs, constructed by incorporation of nitric oxide (NO) precursor (BNN6) and 2D WO_2.9 nanosheets within hydrogel (WB@hydrogel). Because of the defect/2D engineering, the bandgap of the WO_2.9 nanosheets narrows, which extends the absorption to the NIR-II region. It offers a favorable NIR-II controlled manner for NO generation through irradiation time and light intensity. The continuous supply of NO can activate the expression of wild-type p53 protein and further reverse the transcriptional expression of pro- and anti-angiogenic factors of the tumor microenvironment (TME), subsequently alternating pro-angiogenic TME to anti-angiogenic TME. In the murine tumor model, this method achieved high tumor growth inhibition (TGI) rate and excellent anti-recurrence efficiency.

High-Entropy-Alloy Nanoparticles with Enhanced Interband Transitions for Efficient Photothermal Conversion

Photothermal materials with broadband optical absorption and high conversion efficiency are intensively pursued to date. Here, proposing by the d-d interband transitions, we report an unprecedented high-entropy alloy FeCoNiTiVCrCu nanoparticles that the energy regions below and above the Fermi level (±4 eV) have been fully filled by the 3d transition metals, which realizes an average absorbance greater than 96 % in the entire solar spectrum (wavelength of 250 to 2500 nm). Furthermore, we also calculated the photothermal conversion efficiency and the evaporation rate towards the steam generation. Due to its pronounced full light capture and ultrafast local heating, our high-entropy-alloy nanoparticle-based solar steam generator has over 98 % efficiency under one sun irradiation, meanwhile enabling a high evaporation rate of 2.26 kg m^-2  h^-1 .

The pH responsive upconversion fluorescence and photothermal conversion properties of NaYF4:Yb3+/Er3+@NaYF4@MnO2@Au

While photothermal therapy is widely applied in phototherapy, there are still challenges in developing new generation phototherapy materials with precise diagnostic functions. Here we report the construction of a pH responsive upconversion fluorescence imaging precisely guided photothermal therapy system, namely NaYF4:Yb3+/Er3+@NaYF4@MnO2@Au nanocomposites, which can effectively avoid light damage to non-target tissues. Owing to the fluorescence resonance energy transfer between the upconversion nanocrystal donor and MnO2 and Au acceptor, the upconversion fluorescence is completely quenched. However, in pH 5.3 PBS buffer, MnO2 is gradually broken down, and the upconversion fluorescence is partially recovered, which could be used for upconversion fluorescence imaging to precisely guide photothermal therapy under 980 nm excitation. Simultaneously, due to the absorption of 980 nm excitation light and the emission bands of Er3+ (2H11/2→4I15/2 and 4S3/2→4I15/2 transition), temperature increment of core@shell@MnO2@Au could reach 35.5 °C under 980 nm excitation at 0.8 W cm-2. The core@shell@MnO2@Au nanocomposites are supposed to contribute significantly in the biological applications of photoluminescence imaging and photothermal therapy.

Tailoring Photophysical Properties of Diketopyrrolopyrrole Small Molecules with Electron-Withdrawing Moieties for Efficient Solar Steam Generation

The development of photothermal materials (PTMs) for solar steam generation (SSG) has gained tremendous attention in response to the global clean water scarcity issue. However, the investigation in employing organic small-molecule PTMs for SSG applications is rarely found due to their narrow optical absorption range to harvest solar energy and insufficient photostability for long-term use. Herein, we employ a diketopyrrolopyrrole (DPP) core unit together with electron-withdrawing (EW) endcaps and siloxane side chains to introduce stronger intramolecular charge transfer (ICT) characteristics as well as the hydrophobic character. The enhanced ICT characteristics of DPP derivatives render a broad optical absorption range, less emission, and a high nonradiative decay rate for efficient solar energy harvesting and photothermal effects. Meanwhile, the hydrophobic nature of these DPP derivatives allows the facile fabrication of novel Janus photothermal membranes for effective water vaporization and solar-to-vapor conversion efficiency. By embedding DPP derivatives to the SSG device, we showed that the solar-to-vapor efficiency can reach up to 71.8% under relatively low visible light power (∼700 W m^-2), which is, on average, 2.66 times higher than that of bulk water of similar dimension. Moreover, this report demonstrates the great potential of conjugated small molecules for photothermal applications, owing to their versatility and flexibility in structural engineering and its diminishing radiative decay properties. This may inspire more innovation and advancement in SSG applications.

Vacancy-Enhanced Photothermal Killing of Bacteria Mediated by Graphene Oxide

With the emergence of antibiotic resistance, the development of efficient antimicrobial agents has become increasingly important. Graphene oxide (GO) has been used as an antibacterial agent, but how to realize and improve the antibacterial properties of GO is still required critically. Herein, we prepared two GO samples, abbreviated as GO-V11 and GO-V9. Positron annihilation spectra showed that they possessed predominantly V_CCCCCCCCCCC (V11C) and V_CCCCCCCCC (V9C) carbon vacancies, respectively. Their photothermal antibacterial properties were measured against Gram-negative Escherichia coli (E. coli) and Gram-positive Bacillus subtilis (B. subtilis) by using colony-forming unit and liquid optical density assays. GO-V9 displayed a higher photothermal antibacterial efficiency toward the two bacteria than GO-V11 because GO-V9 had a higher photothermal conversion efficiency (PTCE) (57.3%) than GO-V11 (42.5%). To reveal the difference in their PTCEs and antibacterial efficiencies, their energy band structures were tested with density functional theory calculations. The different vacancies changed the energy band structure from the indirect band gap of GO-V11 to the quasi-metallic band gap of GO-V9. The quasi-metallic band gap showed the higher PTCE, so we revealed the importance of the band gap of GO for its antibacterial mechanism. Tuning the vacancy properties is promising for improving the photothermal antibacterial efficiency.

Noble Metal Nanomaterials for NIR-Triggered Photothermal Therapy in Cancer

It is of great significance to develop anticancer therapeutic agents or technologies with high degree of specificity and patient compliance, while low toxicity. The emerging photothermal therapy (PTT) has become a new and powerful therapeutic technology due to its noninvasiveness, high specificity, low side effects to normal tissues and strong anticancer efficacy. Noble metal nanomaterials possess strong surface plasmon resonance (SPR) effect and synthetic tunability, which make them facile and effective PTT agents with superior optical and photothermal characteristics, such as high absorption cross-section, incomparable optical-thermal conversion efficiency in the near infrared (NIR) region, as well as the potential of bioimaging. By incorporating with various functional reagents such as antibodies, peptides, biocompatible polymers, chemo-drug and immune factors, noble metal nanomaterials have presented strong potential in multifunctional cancer therapy. Herein, the recent development regarding the application of noble metal nanomaterials for NIR-triggered PTT in cancer treatment is summarized. A variety of studies with good therapeutic effects against cancer from impressive photothermal efficacy of noble metal nanomaterials are concluded. Intelligent nanoplatforms through ingenious fabrication showing potential of multifunctional PTT, combined with chemo-therapy, immunotherapy, photodynamic therapy (PDT), as well as simultaneous imaging modality are also demonstrated.

Three-Dimensionally Structured Polypyrrole-Coated Setaria viridis Spike Composites for Efficient Solar Steam Generation

Solar-driven steam generation is a promising technology for the production of freshwater from seawater and polluted water. High water evaporation rates have been achieved via the interfacial heating scheme; however, they are still limited to meet the increasing need for freshwater due to the restricted evaporation area of two-dimensionally (2D) geometrical planar photothermal membranes. Herein, a three-dimensionally (3D) structured solar evaporator is prepared via coating photothermal polypyrrole (PPy) on the spike of Setaria viridis(S. viridis) for highly efficient evaporation. Due to the enlarged evaporation area and open structure for vapor dissipation, the PPy-coated S. viridis spike solar evaporator shows a high water evaporation rate of 3.72 kg m^-2 h^-1 under one sun illumination. The 3D solar evaporator also demonstrates good durability and anti-salt-clogging performance for real-life applications. Furthermore, we show that the 3D solar evaporator demonstrates effective decontamination of saline water, dye-contaminated water, and corrosive water. This work can inspire new paradigms toward developing high-performance solar steaming technologies for effective water purification to address the worldwide crisis of freshwater shortage.

Exploiting Co Defects in CoFe-Layered Double Hydroxide (CoFe-LDH) Derivatives for Highly Efficient Photothermal Cancer Therapy

Currently, two-dimensional materials are being actively pursued in catalysis and other fields due their abundance of defects, which results in enhanced performance relative to their bulk defect-free counterparts. To date, the exploitation of defects in two-dimensional materials to enhance photothermal therapies has received little attention, motivating a detailed investigation. Herein, we successfully fabricated a series of novel CoFe-based photothermal agents (CoFe-x) by heating CoFe-layered double hydroxide (CoFe-LDH) nanosheets at different temperatures (x) between 200-800 °C under a Ar atmosphere. The CoFe-x products differed in their particle size, cobalt defect concentration, and electronic structure, with the CoFe-500 product containing the highest concentration of Co²⁺ defects and most efficient photothermal performance under near-infrared (NIR, 808 nm) irradiation. Experiments and density functional theory (DFT) calculations revealed that Co²⁺ defects modify the electronic structure of CoFe-x, narrowing the band gap and thus increasing the nonradiative recombination rate, thereby improving the NIR-driven photothermal properties. In vitro and in vivo results demonstrated that CoFe-500 was an efficient agent for photothermal cancer treatment and also near-infrared (NIR) thermal imaging, magnetic resonance (MR) imaging, and photoacoustic (PA) imaging. This work provides valuable new insights about the role of defects in the rational design of nanoagents with optimized structures for improved cancer therapy.

Light: A Magical Tool for Controlled Drug Delivery

Light is a particularly appealing tool for on-demand drug delivery due to its noninvasive nature, ease of application and exquisite temporal and spatial control. Great progress has been achieved in the development of novel light-driven drug delivery strategies with both breadth and depth. Light-controlled drug delivery platforms can be generally categorized into three groups: photochemical, photothermal, and photoisomerization-mediated therapies. Various advanced materials, such as metal nanoparticles, metal sulfides and oxides, metal-organic frameworks, carbon nanomaterials, upconversion nanoparticles, semiconductor nanoparticles, stimuli-responsive micelles, polymer- and liposome-based nanoparticles have been applied for light-stimulated drug delivery. In view of the increasing interest in on-demand targeted drug delivery, we review the development of light-responsive systems with a focus on recent advances, key limitations, and future directions.

Unconventional Transport Properties of Reduced Tungsten Oxide WO2.9

The temperature and magnetic field dependence of resistivity in WO2.9 was investigated. The variation of resistivity with temperature displayed unusual features, such as a broad maximum around 230 K and a logarithmic increase of resistivity below 16 K. In the temperature range 16–230 K, we observed metallic-like behavior with a positive temperature coefficient. The combined analysis of resistivity and magnetoresistance (MR) data shows that these unusual transport properties of WO2.9 can be understood by considering the (bi)polaronic nature of charge carriers. In contrast to magnetization data, superconducting transition below Tc = 80 K was not detected in resistivity measurements, indicating that the superconductivity is localized in small regions that do not percolate. We found a strong increase in positive MR below 80 K. This effect is similar to that observed in underdoped cuprates, where the substantial increase of MR is attributed to superconducting fluctuations in small clusters. Therefore, the temperature dependence of MR indicates the presence of non-percolating superconducting clusters in WO2.9 below 80 K in agreement with magnetization data.

Facile Deflagration Synthesis of Hollow Carbon Nanospheres with Efficient Performance for Solar Water Evaporation

Solar water evaporation is a promising and environment-friendly approach to relieve global water scarcity issues. Currently, many reports show that the voids and porous structure are beneficial to the absorption of solar energy to generate water steam. Herein, carbon nanospheres with central cavity structures are rationally designed by the one-step NaN₃/fluorinated graphite deflagration method. The Na clusters derived from NaN₃ deflagration are not only provided as the hollow templates but also react with fluorinated graphite to release heat, further boosting the formation of hollow carbon nanospheres (HCSs). Benefiting from the diversity of carbon nanomaterials, rough surface, unique hollow structures, and numerous micron/submicron holes, the light absorption ability, heat localization, and water supply capacity of HCSs have been significantly enhanced. Because of these advantages, the HCS-3 exhibits an excellent water evaporation efficiency of 92.7% at 1 kW m^-2, which is much higher than that of carbon nanospheres, graphene oxide, and even most of the previous carbon materials. In addition, we demonstrated that the HCSs have a long-term stability and high efficiency of production of drinkable water and purifying various types of wastewater, including seawater, strong acid/alkaline water, and water containing dyes. To sum up, the deflagration synthetic technology as a facile and ultrafast process can be a new insight for future photothermal material design.

Facile Preparation of WO3-x Dots with Remarkably Low Toxicity and Uncompromised Activity as Co-reactants for Clinical Diagnosis by Electrochemiluminescence

The exceptional nature of WO_3-x dots has inspired widespread interest, but it is still a significant challenge to synthesize high-quality WO_3-x dots without using unstable reactants, expensive equipment, and complex synthetic processes. Herein, the synthesis of ligand-free WO_3-x dots is reported that are highly dispersible and rich in oxygen vacancies by a simple but straightforward exfoliation of bulk WS₂ and a mild follow-up chemical conversion. Surprisingly, the WO_3-x dots emerged as co-reactants for the electrochemiluminescence (ECL) of Ru(bpy)₃ ²⁺ with a comparable ECL efficiency to the well-known Ru(bpy)₃ ²⁺ /tripropylamine (TPrA) system. Moreover, compared to TPrA, whose toxicity remains a critical issue of concern, the WO_3-x dots were ca. 300-fold less toxic. The potency of WO_3-x dots was further explored in the detection of circulating tumor cells (CTCs) with the most competitive limit of detection so far.

Efficient Solar Evaporation by [Ni(Phen)3 ][V14 O34 Cl]Cl Hybrid Semiconductor Confined in Mesoporous Glass

Efficient utilization of solar energy for water evaporation is an advanced and environmentally friendly technology to address the crisis of global drinking water shortages. This study concerns an efficient solar vapor generator comprised of a light-absorbing and photothermal hybrid compound [Ni(Phen)₃ ][V₁₄ O₃₄ Cl]Cl (NiV₁₄ ) confined in mesoporous and hydrophilic glass (meso-glass). The generator is floated in water by supporting it on a domestic melamine-formaldehyde (MF) foam to ensure evaporation at the water-air interface. The porous structures and poor thermal conductivities of the meso-glass and MF foam contribute to enabling a consistent water supply, strong solar thermal localization, and less heat dissipation and convection. Associated with the strong photothermal role of NiV₁₄ , these synergistic effects lead to a water evaporation rate of 14.38 kg m^-2  h^-1 with total water evaporation efficiency of 111.4% under 6 suns and a daily solar water purification yield of 42.00 L m^-2 under 1 sun irradiation. This solar evaporation system shows great promise for high-efficiency water purification application.

A Hydrogenated Metal Oxide with Full Solar Spectrum Absorption for Highly Efficient Photothermal Water Evaporation

Searching for cost-effective photothermal material that can harvest the full solar spectrum is critically important for solar-driven water evaporation. Metal oxides are cheap materials but cannot cover the full solar spectrum. Here we prepared a hydrogenated metal oxide (H_1.68MoO₃) material, in which H-doping causes the insulator-to-metal phase transition of the originally semiconductive MoO₃. It offers a blackbody-like solar absorption of ≥95% over the entire visible-to-near-infrared solar spectrum, owing to its unusual quasi-metallic energy band, and high solar-to-heat conversion rate due to quick relaxation of excited electrons. Using a self-floating H_1.68MoO₃/airlaid paper photothermal film, we achieved a stable and high water vapor generation rate of 1.37 kg m^-2 h^-1, a superb solar-to-vapor efficiency of 84.8% under 1 sun illumination, and daily production of 12.4 L of sanitary water/m² from seawater under natural sunlight. This thus opens a new avenue of designing cost-effective photothermal materials based on metal oxides.

Metal/semiconductor interfaces in nanoscale objects: synthesis, emerging properties and applications of hybrid nanostructures

Hybrid nanostructures, composed of multi-component crystals of various shapes, sizes and compositions are much sought-after functional materials. Pairing the ability to tune each material separately and controllably combine two (or more) domains with defined spatial orientation results in new properties. In this review, we discuss the various synthetic mechanisms for the formation of hybrid nanostructures of various complexities containing at least one metal/semiconductor interface, with a focus on colloidal chemistry. Different synthetic approaches, alongside the underlying kinetic and thermodynamic principles are discussed, and future advancement prospects are evaluated. Furthermore, the proved unique properties are reviewed with emphasis on the connection between the synthetic method and the resulting physical, chemical and optical properties with applications in fields such as photocatalysis.

Quantum dot-pulsed dendritic cell vaccines plus macrophage polarization for amplified cancer immunotherapy

Dendritic cell (DC) vaccines hold great potential in cancer immunotherapy, but the suboptimal design of DC vaccines and the immunosuppressive tumor microenvironment largely impair their anti-tumor efficacy. Here, quantum dot (QD) pulsed-DC vaccines integrating with tumor-associated macrophage polarization are developed for amplified anti-tumor immunity. Semiconductor QDs are engineered with diverse functions to act as fluorescence nanoprobes, immunomodulatory adjuvants, and nanocarriers to load tumor antigens and Toll-like receptor 9 agonists. The QD-pulsed DC vaccines enable spatiotemporal tracking of lymphatic drainage and efficacy evaluation of DC immunotherapy, and trigger potent immunoactivation. Specifically, designer DC vaccine plus macrophage polarization elicits potent immune response to stimulate innate and adaptive antitumor immunity and ameliorate the immunosuppressive tumor microenvironment. As a new combination therapy, this strategy greatly boosts antigen-specific T-cell immunity and thus strongly inhibits local tumor growth and tumor metastasis in vivo. This study may provide an applicable treatment for cancer immunotherapy.

Crystal-Amorphous Core-Shell Structure Synergistically Enabling TiO2 Nanoparticles' Remarkable SERS Sensitivity for Cancer Cell Imaging

Exploring novel surface-enhanced Raman scattering (SERS) active materials with high detection sensitivity, excellent biocompatibility, low biotoxicity, and good spectral stability is urgently required for efficacious cancer cell diagnosis. Herein, black TiO₂ nanoparticles (B-TiO₂ NPs) with crystal-amorphous core-shell structure are successfully developed. Remarkable SERS activity is derived from the synergistic effect of the promising crystal-amorphous core-shell structure. Abundant excitons can be generated by high-efficiency exciton transitions in the crystal core, a feature that provides sufficient charge source. Significantly, the novel crystal-amorphous heterojunction enables the efficient exciton separation at the crystal-amorphous interface, which can effectively facilitate charge transfer from the crystal core to the amorphous shell and results in exciton enrichment at the amorphous shell. Kelvin probe force microscopy (KPFM) confirms the Fermi level of the amorphous layer shifting to a relatively low position compared to that of the crystal core, allowing efficient photoinduced charge transfer (PICT) between the amorphous shell and probe molecules. The first-principles density functional theory (DFT) calculations further indicate that the amorphous shell structure possesses a narrow band gap and a relatively high electronic density of state (DOS), which can effectively promote vibration coupling with target molecules. Moreover, MCF-7 drug-resistant (MCF-7/ADR) breast cancer cells can be quickly and accurately diagnosed based on the high-sensitivity B-TiO₂-based SERS bioprobe. To the best of our knowledge, this is the first time the crystal-amorphous core-shell heterojunction enhancement of the TiO₂-molecule PICT process, which widens the application of semiconductor-based SERS platforms in precision diagnosis and treatment of cancer, has been investigated.

Conjugated porous polymers: incredibly versatile materials with far-reaching applications

This review discusses conjugated porous polymers and focuses on relating design principles and synthetic methods to key properties and applications such as (photo)catalysis, gas storage, chemical sensing, energy storage and environmental remediation.

Supercritical CO2-assisted amorphization of WO2.72 and its high-efficiency photothermal conversion

Amorphization of WO_2.72 was successfully achieved with the assistance of supercritical carbon dioxide (SC CO₂). Amorphous SC CO₂-treated sample has strong optical absorbance and excellent photothermal conversion efficiency of 52.5% indicates they can be a promising photothermal agent.

Novel Oxygen-Deficient Zirconia (ZrO2-x) for Fluorescence/Photoacoustic Imaging-Guided Photothermal/Photodynamic Therapy for Cancer

Theranostic nanoplatforms that integrate therapy and diagnosis in a single composite have become increasingly attractive in the field of precise and efficient tumor treatment. Herein, a novel oxygen-deficient zirconia (ZrO_2-x) nanosystem based on the conjugation of thiol-polyethylene glycol-amine (SH-PEG-NH₂) and chlorin e6 (Ce6) was elaborately designed and established for efficacious photothermal/photodynamic therapy (PTT/PDT) and fluorescence/photoacoustic (FL/PA) bimodal imaging for the first time. The crystalline-disordered, PEGylated ZrO_2-x nanoparticles (ZP NPs) displayed strong optical absorption in the near-infrared (NIR) window and were featured with significant photothermal conversion capacity. The ZP NPs were further covalently conjugated with Ce6 to form ZrO_2-x@PEG/Ce6 (ZPC) NPs, which displayed a long circulatory half-life, efficient tumor accumulation, and outstanding FL/PA imaging performance. Moreover, the nanocomposites effectively generated cytotoxic intracellular reactive oxygen species (ROS) responsive to laser activation. Both cell studies and animal experiments explicitly demonstrated that ZPC NPs mediated remarkable tumor ablation with minimal systemic toxicity thanks to their tumor-specific PTT/PDT effect. Collectively, these findings may open up new avenues to broaden the application of oxygen-deficient ZrO_2-x nanostructures as high-performance photothermal agents in tumor theranostics through rational design and accurate control of their physiochemical properties.