NIR‐II Driven Plasmon‐Enhanced Catalysis for a Timely Supply of Oxygen to Overcome Hypoxia‐Induced Radiotherapy Tolerance

Hypoxia, as a characteristic feature of solid tumor, can significantly adversely affect the outcomes of cancer radiotherapy (RT), photodynamic therapy, or chemotherapy. In this study, a strategy is developed to overcome tumor hypoxia‐induced radiotherapy tolerance. Specifically, a novel two‐dimensional Pd@Au bimetallic core–shell nanostructure (TPAN) was employed for the sustainable and robust production of O₂ in long‐term via the catalysis of endogenous H₂O₂. Notably, the catalytic activity of TPAN could be enhanced via surface plasmon resonance (SPR) effect triggered by NIR‐II laser irradiation, to enhance the O₂ production and thereby relieve tumor hypoxia. Thus, TPAN could enhance radiotherapy outcomes by three aspects: 1) NIR‐II laser triggered SPR enhanced the catalysis of TPAN to produce O₂ for relieving tumor hypoxia; 2) high‐Z element effect arising from Au and Pd to capture X‐ray energy within the tumor; and 3) TPAN affording X‐ray, photoacoustic, and NIR‐II laser derived photothermal imaging, for precisely guiding cancer therapy, so as to reduce the side effects from irradiation.     

Multifunctional Nano‐Bioprobes Based on Rattle‐Structured Upconverting Luminescent Nanoparticles

Lanthanide‐doped upconversion nanoparticles (UCNPs) have shown great promise in versatile bioapplications. For the first time, organosilica‐shelled β‐NaLuF₄:Gd/Yb/Er nanoprobes with a rattle structure have been designed for dual‐modal imaging and photodynamic therapy (PDT). Benefiting from the unique rattle structure and aromatic framework, these nanoprobes are endowed with a high loading capacity and the disaggregation effect of photosensitizers. After loading of β‐carboxyphthalocyanine zinc or rose Bengal into the nanoprobes, we achieved higher energy transfer efficiency from UCNPs to photosensitizers as compared to those with conventional core–shell structure or with pure‐silica shell, which facilitates a large production of singlet oxygen and thus an enhanced PDT efficacy. We demonstrated the use of these nanoprobes in proof‐of‐concept X‐ray computed tomography (CT) and UC imaging, thus revealing the great potential of this multifunctional material as an excellent nanoplatform for cancer theranostics.     

Nanoscale Metal–Organic Layers for Deeply Penetrating X‐ray‐Induced Photodynamic Therapy

We report the rational design of metal–organic layers (MOLs) that are built from [Hf₆O₄(OH)₄(HCO₂)₆] secondary building units (SBUs) and Ir[bpy(ppy)₂]⁺‐ or [Ru(bpy)₃]²⁺‐derived tricarboxylate ligands (Hf‐BPY‐Ir or Hf‐BPY‐Ru; bpy=2,2′‐bipyridine, ppy=2‐phenylpyridine) and their applications in X‐ray‐induced photodynamic therapy (X‐PDT) of colon cancer. Heavy Hf atoms in the SBUs efficiently absorb X‐rays and transfer energy to Ir[bpy(ppy)₂]⁺ or [Ru(bpy)₃]²⁺ moieties to induce PDT by generating reactive oxygen species (ROS). The ability of X‐rays to penetrate deeply into tissue and efficient ROS diffusion through ultrathin 2D MOLs (ca. 1.2 nm) enable highly effective X‐PDT to afford superb anticancer efficacy.     

Flexible Viologen‐Based Porous Framework Showing X‐ray Induced Photochromism with Single‐Crystal‐to‐Single‐Crystal Transformation

A viologen‐based Borromean entangled porous framework was found to be sensitive to both Cu_Kα and Mo_Kα X‐ray sources, showing rapid photochromic response and recovery within one minute. The X‐ray‐induced photochromic process is accompanied by a reversible single‐crystal‐to‐single‐crystal (SC‐SC) structural transformation, an unprecedented phenomenon for X‐ray sensitive materials. The complex can be further processed into portable thin films for detecting the dose of the X‐ray exposure. Moreover, the photochromism can occur over a broad temperature range of 100–333 K, both in the form of single crystals and thin films, making it a potential candidate for practical indoor and outdoor applications.     

Photodynamic Therapy of Oligoethylene Glycol‐Dendronized Reduction‐Sensitive Porphyrins

Graphene oxide (GO ) and its functionalized derivatives have attracted increasing attention in medical treatment. Herein, a reduction sensitive PEI‐GO ‐SS ‐TPP was synthesized for photodynamic therapy. More than 80% porphyrin release was observed in the presence of 10 mmol•L⁻¹ DTT in one day. The confocal laser scanning microscopy confirmed that the cell uptake efficiency of PEI‐GO‐SS‐TPP was remarkably enhanced as compared to free porphyrin which was significantly dependent on incubation time. For photodynamic therapy, GSH‐OEt could effectively increase the photodynamic therapy efficiency of PEI‐GO ‐SS ‐TPP . Compared with free porphyrin, the toxicity from PEI‐GO ‐SS ‐TPP is much higher with a low IC₅₀ (2.1 µg/mL ) value. All results indicate that the PEI‐GO ‐SS ‐TPP PSs are promising for photodynamic therapy.     

Synthesis of a Ruthenium(II) Compound based on 5‐(2‐Pyrimidyl)‐1H‐tetrazole for Photodynamic Therapy

Ru^II compounds have been universally investigated due to their unique physical and chemical properties. In this paper, a new Ru^II compound based on 2,2′‐bipy and Hpmtz [2,2′‐bipy = 2,2′‐bipyridine, Hpmtz = 5‐(2‐pyrimidyl)‐1H‐tetrazole], namely [Ru(2,2′‐bipy)₂(pmtz)][PF₆] · 0.5H₂O was prepared and characterized by elemental analysis, IR and single‐crystal X‐ray diffraction. [Ru(2,2′‐bipy)₂(pmtz)][PF₆] · 0.5H₂O shows a mononuclear structure and forms a three‐dimensional network by non‐classic hydrogen bonds. The ability of generation of ROS (reactive oxygen species) makes it has a low phototoxicity IC₅₀ (half‐maximal inhibitory concentration) after Xenon lamp irradiation on Hela cells in vitro. The results demonstrate that [Ru(2,2′‐bipy)₂(pmtz)][PF₆] · 0.5H₂O with high light toxicity and low dark toxicity may be a potential candidate for photodynamic therapy.     

BSA‐IrO2: Catalase‐like Nanoparticles with High Photothermal Conversion Efficiency and a High X‐ray Absorption Coefficient for Anti‐inflammation and Antitumor Theranostics

Intrinsically integrating precise diagnosis, effective therapy, and self‐anti‐inflammatory action into a single nanoparticle is attractive for tumor treatment and future clinical application, but still remains a great challenge. In this study, bovine serum albumin–iridium oxide nanoparticles (BSA‐IrO₂ NPs) with extraordinary photothermal conversion efficiency, good photocatalytic activity, and a high X‐ray absorption coefficient were prepared through one‐step biomineralization. The nanoparticles allow tumor phototherapy and simultaneous photoacoustic/thermal imaging and computed tomography. More importantly, BSA‐IrO₂ NPs can also act as a catalase to protect normal cells against H₂O₂‐induced reactive oxygen pressure and inflammation while significantly enhancing photoacoustic imaging through microbubble‐based inertial cavitation. These remarkable features may open up the exploration iridium‐based nanomaterials in theranostics.     

(E)‐2‐[(4‐Chlorophenyl)iminomethyl]‐5‐methoxyphenol and (E)‐2‐[(2‐chlorophenyl)iminomethyl]‐5‐methoxyphenol: X‐ray and DFT‐calculated structures

The crystal structures of the title 4‐chlorophenyl, (I), and 2‐chlorophenyl, (II), compounds, both C₁₄H₁₂ClNO₂, have been determined using X‐ray diffraction techniques and the molecular structures have also been optimized at the B3LYP/6‐31 G(d,p) level using density functional theory (DFT). The X‐ray study shows that the title compounds both have strong intramolecular O—H...N hydrogen bonds and that the crystal networks are primarily determined by weak C—H...π and van der Waals interactions. The strong intramolecular O—H...N hydrogen bond is evidence of the preference for the phenol–imine tautomeric form in the solid state. The IR spectra of the compounds were recorded experimentally and also calculated for comparison. The results from both the experiment and theoretical calculations are compared in this study.     

Aggregation‐Induced Emission Gold Clustoluminogens for Enhanced Low‐Dose X‐ray‐Induced Photodynamic Therapy

The use of gold nanoparticles as radiosensitizers is an effective way to boost the killing efficacy of radiotherapy while drastically limiting the received dose and reducing the possible damage to normal tissues. Herein, we designed aggregation‐induced emission gold clustoluminogens (AIE‐Au) to achieve efficient low‐dose X‐ray‐induced photodynamic therapy (X‐PDT) with negligible side effects. The aggregates of glutathione‐protected gold clusters (GCs) assembled through a cationic polymer enhanced the X‐ray‐excited luminescence by 5.2‐fold. Under low‐dose X‐ray irradiation, AIE‐Au strongly absorbed X‐rays and efficiently generated hydroxyl radicals, which enhanced the radiotherapy effect. Additionally, X‐ray‐induced luminescence excited the conjugated photosensitizers, resulting in a PDT effect. The in vitro and in vivo experiments demonstrated that AIE‐Au effectively triggered the generation of reactive oxygen species with an order‐of‐magnitude reduction in the X‐ray dose, enabling highly effective cancer treatment.     

Synthesis of Imatinib‐loaded chitosan‐modified magnetic nanoparticles as an anti‐cancer agent for pH responsive targeted drug delivery

Targeted drug delivery is a promising approach to overcome the limitations of classical chemotherapy. In this respect, Imatinib‐loaded chitosan‐modified magnetic nanoparticles were prepared as a pH sensitive system for targeted delivery of drug to tumor sites by applying a magnetic field. The proposed magnetic nanoparticles were prepared through modification of magnetic Fe₃O₄ nanoparticles with chitosan and Imatinib. The structural, morphological and physicochemical properties of the synthesized nanoparticles were determined by different analytical techniques including energy‐dispersive X‐ray spectroscopy (EDS), field emission scanning electron microscopy (FESEM), Fourier‐transform infrared (FTIR) spectroscopy, high resolution transmission electron microscopy (HR‐TEM), vibrating sample magnetometry (VSM), X‐ray diffraction (XRD) and X‐ray photoelectron spectroscopy (XPS). UV/visible spectrophotometry was used to measure the Imatinib contents. Thermal stability of the prepared particles was investigated and their efficiency of drug loading and release profile were evaluated. The results demonstrated that Fe₃O₄@CS acts as a pH responsive nanocarrier in releasing the loaded Imatinib molecules. Furthermore, the Fe₃O₄@CS/Imatinib nanoparticles displayed cytotoxic effect against MCF‐7 breast cancer cells. Results of this study can provide new insights in the development of pH responsive targeted drug delivery systems to overcome the side effects of conventional chemotherapy.     

Hollow and Yolk‐Shell Iron Oxide Nanostructures on Few‐Layer Graphene in Li‐Ion Batteries

We report a simple and template‐free strategy for the synthesis of hollow and yolk‐shell iron oxide (FeO_x) nanostructures sandwiched between few‐layer graphene (FLG) sheets. The morphology and microstructure of this material are characterized in detail by X‐ray diffraction, X‐ray absorption near‐edge structure, X‐ray photoelectron spectroscopy, Raman spectroscopy, scanning and transmission electron microscopy. Its properties are evaluated as negative electrode material for Li‐ion batteries and compared with those of solid FeO_x/FLG and two commercial iron oxides. In all cases, the content of carbon in the electrode has a great influence on the performance. The use of pristine FLG improves the capacity retention and further enhancement is achieved with the hollow structure. For a low carbon loading of 18 wt. %, the presence of metallic iron in the hollow and yolk‐shell FeO_x/FLG composite significantly enhances the capacity retention, albeit with a relatively lower initial reversible capacity, retaining above 97 % after 120 cycles at 1000 mA g^?1 in the voltage range of 0.1–3.0 V.     

On the Solvent‐free Structure of a Jäger‐type Cobalt(II) N2O2‐Chelate Complex

A combined synchrotron X‐ray and density functional theory (DFT) study on the structure of a Jäger‐type N₂O₂ chelate complex was carried out. The ethoxy‐substituted bis(3‐oxo‐enaminato)cobalt(II) complex ( 1 ) was an original sample from the laboratory of the late Professor Ernst‐G. Jäger (University of Jena, Germany). Single‐crystal X‐ray analysis revealed essentially flat molecules of 1 , which are unsolvated and coordinatively unsaturated. The DFT calculations on the isolated molecule predict a planar structure for the non‐hydrogen atoms, which is a local minimum on the energy surface. The crystal packing is achieved through off‐set stacking (staircase arrangement), resulting in a herringbone pattern in the space group P2₁2₁2₁. The structure of 1 is compared to known structures of related bis(3‐oxo‐enaminato)cobalt(II) complexes ( 2 – 4 ). Original bulk material of 1 was investigated by scanning electron microscopy (SEM), powder X‐ray diffraction (PXRD), melting point determination, and infrared (IR) spectroscopy.     

trans‐3‐Ethyl‐cis‐2,6,6‐trimethyl‐4‐oxocyclohexanecarboxylic acid: an intermediate in the synthesis of a highly potent estrogen

The title compound, C₁₂H₂₀O₃, (IV), the ethyl ester of which is an intermediate in the synthesis of a compound reported to be highly estrogenic, has been prepared. After the initial steps reported for the synthesis of this ester intermediate were followed, it was converted into the crystalline acid, (IV), for X‐ray analysis. It was verified that (IV) was racemic when prepared. X‐ray analysis showed that anti‐hydrogenation of the double bond had occurred in the synthesis, making the orientation of the carboxyl group cis to the 2‐methyl group and trans to the 3‐ethyl group. NMR spectroscopy showed that the stereochemistry of (IV) was identical with that of its ester precursor. While the earlier report did not note the stereochemistry of this ester, it pointed out that the estrogenic product derived from it possessed the opposite carboxyl‐2‐methyl orientation, i.e.trans, although no X‐ray analysis was performed. In the light of these results and the importance of correlating biological activity with compound structure, the unequivocal characterization of the highly estrogenic compound is warranted.     

Poly(L‐Glutamic Acid)‐Drug Conjugates for Chemo‐ and Photodynamic Combination Therapy

Despite the polymeric vascular disrupting agent (poly(_L‐glutamic acid)‐graft‐methoxy poly(ethylene glycol)/combretastatin A4) nanoparticles can efficiently inhibit cancer growth, their further application is still a challenge owing to the tumor recurrence and metastasis after treatment. In this study, two poly(_L‐glutamic acid)‐drug conjugates for chemo‐and photodynamic combination therapy are fabricated. PLG‐g‐mPEG‐CA4 nanoparticles are prepared by combretastatin A4 (CA4) and poly(_L‐glutamic acid)‐graft‐methoxy poly(ethylene glycol) (PLG‐g‐mPEG) using the Yamaguchi esterification reaction. PLG‐g‐mPEG‐TPP (TPP: 5, 10, 15, 20‐tetraphenylporphyrin) nanoparticles are constructed using PLG‐g‐mPEG and amine porphyrin through condensation reaction between carboxyl group of PLG‐g‐mPEG and amino group of porphyrin. The results showed that PLG‐g‐mPEG‐CA4 nanoparticles have good antitumor ability. PLG‐g‐mPEG‐TPP nanoparticles can produce singlet oxygen under the laser irradiation. Moreover, the combined therapy of PLG‐g‐mPEG‐CA4 and PLG‐g‐mPEG‐TPP nanoparticles has higher antitumor effect than the single chemotherapy or the single photodynamic therapy in vitro. The combination of CA4 nondrug and photodynamic therapy provides a new insight for enhancing the tumor therapeutic effect with vascular disrupting agents and other therapy.     

Exploring Lead‐Free Hybrid Double Perovskite Crystals of (BA)2CsAgBiBr7 with Large Mobility‐Lifetime Product toward X‐Ray Detection

Halide double perovskites have recently bloomed as the green candidates for optoelectronic applications, such as X‐ray detection. Despite great efforts, the exploration of promising organic–inorganic hybrid double perovskites toward X‐ray detection remains unsuccessful. Now, single crystals of the lead‐free hybrid double perovskite, (BA)₂CsAgBiBr₇ (BA⁺ is n‐butylammonium), featuring the unique 2D multilayered quantum‐confined motif, enable quite large μτ (mobility‐lifetime) product up to 1.21×10^?3 cm² V^?1. This figure‐of‐merit realized in 2D hybrid double perovskites is unprecedented and comparable with that of CH₃NH₃PbI₃ wafers. (BA)₂CsAgBiBr₇ crystals also exhibit other intriguing attributes for X‐ray detection, including high bulk resistivity, low density of defects and traps, and large X‐ray attenuation coefficient. Consequently, a vertical‐structure crystal device under X‐ray source yields a superior sensitivity of 4.2 μC Gy_air^?1 cm^?2.     

Bismuth‐Containing SBA‐15 Mesoporous Silica Catalysts for Solvent‐Free Liquid‐Phase Oxidation of Cyclohexane by Molecular Oxygen

Bismuth (Bi)‐containing SBA‐15 mesoporous silica catalysts, Bi/SBA‐15, with different Bi loadings were synthesized by a direct hydrothermal method. The materials were characterized in detail by various techniques. Powder‐X‐ray‐diffraction (PXRD), N₂‐adsorption/desorption, and transmission‐electron‐microscopic (TEM) analyses revealed that the well‐ordered hexagonal structure of SBA‐15 is maintained after Bi incorporation. Diffuse‐reflectance UV/VIS, Raman, and X‐ray photoelectron spectroscopy (XPS) showed that the incorporated Bi‐atoms are highly dispersed, most of them entering the internal surface of SBA‐15. The new, very stable catalysts were found to be highly efficient for the oxidation of cyclohexane in a solvent‐free system, molecular oxygen (O₂) being used as oxidant.     

Magnetized inorganic–bioorganic nanohybrid [nano Fe3O4‐SiO2@Glu‐Cu (II)]: A novel nanostructure for the efficient solvent‐free synthesis of thiazolidin‐2‐imines

In this research, a solvent‐free four‐component one‐pot reaction of phenyl isothiocyanate, phenylacetylene, various kinds of aldehydes, and amines was interpreted to obtain the desired five‐membered heterocycles named thiazolidin‐2‐imines. The promotor of this transformation is a novel magnetite‐based multilayered inorganic–bioorganic nanohybrid prepared via embedding glutamic acid on the magnetized silica followed by anchoring Cu (II) [nano Fe₃O₄‐SiO₂@Glu‐Cu (II)]. The newly synthesized nanostructure is characterized through Fourier‐transform infrared (FT‐IR), field‐emission scanning electron microscopy (FESEM), energy dispersive X‐ray analysis (EDAX), transmission electron microscopy (TEM), X‐ray fluorescence (XRF), thermogravimetric analysis or derivative thermogravimetric (TGA/DTG), vibrating sample magnetometer (VSM), X‐ray photoelectron spectroscopy (XPS), and Brunauer–Emmett–Teller (BET) techniques. This protocol is a straightforward one‐step procedure to obtain thiazolidin‐2‐imines without requirement to propargylamines or imines as substrates. In addition, easy work‐up procedure, high yields of products, absence of organic solvents in the reaction media, recovery and reusability of nano Fe₃O₄‐SiO₂@Glu‐Cu ( II) to promote the reaction at least for three runs without activity lost, simple separation of the catalyst from reaction mixture via an external magnet, and regioselectivity of the method are some highlighted aspects of the approach.     

A‐site Cation Engineering for Highly Efficient MAPbI3 Single‐Crystal X‐ray Detector

Metal halide perovskites have emerged as a new generation of X‐ray detector materials. However, large‐sized MAPbI₃ single crystals (SCs) still exhibit lower performance than MAPbBr₃ SCs in X‐ray detection. DFT (density functional theory) simulations suggest the problem could be overcome by alloying large‐sized cations at the A site. The alloyed process could notably decrease the electron–phonon coupling strength and increase the material defect formation energy. Accordingly, centimeter‐sized alloyed DMAMAPbI₃ (DMA=dimethylammonium) and GAMAPbI₃ (GA=guanidinium) SCs are obtained. Electrical characterizations confirm the GAMAPbI₃ SCs display improved charge collection efficiency. It also exhibits a remarkable reduction of dark current, an important figure of merit for X‐ray detectors. With a judiciously designed device architecture, the overall detector performance confirms GAMAPbI₃ SCs as one of the most sensitive perovskite X‐ray detectors to date.     

100 Picosecond Diffraction Catches Structural Transients of Laser‐Pulse Triggered Switching in a Spin‐Crossover Crystal

We study by 100 picosecond X‐ray diffraction the photo‐switching dynamics of single crystal of the orthorhombic polymorph of the spin‐crossover complex [(TPA)Fe(TCC)]PF₆, in which TPA=tris(2‐pyridyl methyl)amine, TCC^2?=3,4,5,6‐Cl₄‐Catecholate^2?. In the frame of the emerging field of dynamical structural science, this is made possible by using optical pump/X‐ray probe techniques, which allow following in real time structural reorganization at intra‐ and intermolecular levels associated with the change of spin state in the crystal. We use here the time structure of the synchrotron radiation generating 100 picosecond X‐ray pulses, coupled to 100 fs laser excitation. This study has revealed a rich variety of structural reorganizations, associated with the different steps of the dynamical process. Three consecutive regimes are evidenced in the time domain: 1) local molecular photo‐switching with structural reorganization at constant volume, 2) volume relaxation with inhomogeneous distribution of local temperatures, 3) homogenization of the crystal in the transient state 100 µs after laser excitation. These findings are fundamentally different from those of conventional diffraction studies of long‐lived photoinduced high spin states. The time‐resolution used here with picosecond X‐ray diffraction probes different physical quantities on their intrinsic time‐scale, shedding new light on the successive processes driving macroscopic switching in a functionalized material. These results pave the way for structural studies away from equilibrium and represent a first step toward femtosecond crystallography.     

Manipulating Layered P2@P3 Integrated Spinel Structure Evolution for High‐Performance Sodium‐Ion Batteries

Structural evolution of the cathode during cycling plays a vital role in the electrochemical performance of sodium‐ion batteries. A strategy based on engineering the crystal structure coupled with chemical substitution led to the design of the layered P2@P3 integrated spinel oxide cathode Na_0.5Ni_0.1Co_0.15Mn_0.65Mg_0.1O₂, which shows excellent sodium‐ion half/full battery performance. Combined analyses involving scanning transmission electron microscopy with atomic resolution as well as in situ synchrotron‐based X‐ray absorption spectra and in situ synchrotron‐based X‐ray diffraction patterns led to visualization of the inherent layered P2@P3 integrated spinel structure, charge compensation mechanism, structural evolution, and phase transition. This study provides an in‐depth understanding of the structure‐performance relationship in this structure and opens up a novel field based on manipulating structural evolution for the design of high‐performance battery cathodes.