查找使用阿拉丁产品的科研文献

A Type I Aggregation-Induced Emission Photosensitizer Enables Peroxide-Free Photodynamic Tooth Whitening While Preserving Enamel Integrity

Conventional hydrogen peroxide (HP) tooth whitening treatments frequently induce structural deterioration of enamel, necessitating the development of biocompatible and highly efficient alternatives. This in vitro study investigated the application of a novel functional biomaterial, the Type I aggregation-induced emission (AIE) photosensitizer CPTQ, for peroxide-free photodynamic tooth whitening. Under white-light irradiation (25 mW/cm2), CPTQ (12.5 μM) demonstrated rapid degradation of representative chromogenic molecules (crystal violet, malachite green, and rhodamine B). Extracted human teeth stained with both model pigments and complex beverage mixtures (coffee, tea, and fruit juices) were allocated into four treatment groups: negative control (NC), CPTQ, 7.5% HP, and 30% HP (n= 6 per group). Colorimetric parameters (ΔE00, Δa*, Δb*, and ΔL*) and enamel-related endpoints—including surface morphology, roughness, mineral composition (Ca/P), and microhardness—were evaluated over 6 h and analyzed using one-way ANOVA. For pigment-stained teeth, the photodynamic whitening efficiency of CPTQ was comparable to that of 30% HP (ΔE00,p> 0.05) during the 6 h treatment period. At 1.5 h, the ΔE00value in the CPTQ group (23.35 ± 2.32) was significantly greater than those in the NC group (15.70 ± 1.78,p< 0.05) and the 7.5% HP group (15.02 ± 1.63,p< 0.05). For beverage-stained teeth, the whitening efficiency (ΔE00) of CPTQ was significantly greater than that of the control group at 1.5 h (6.22 ± 2.09 vs. 1.82 ± 0.56,p< 0.01) and was significantly greater than that of 7.5% HP at 4.5 h (10.94 ± 2.82 vs. 7.56 ± 1.78,p< 0.05). Crucially, unlike the change observed after 30% HP treatments, CPTQ treatment resulted in no statistically significant differences from NC in preserved enamel surface integrity, including morphology assessed by SEM, surface roughness (RaandSa, bothp> 0.05), mineral composition (Ca and P, bothp> 0.05), and microhardness (ΔHV,p> 0.05). Mechanistic investigations using reactive oxygen species (ROS) scavengers (TBA and DABCO) suggested that hydroxyl radicals generated via the Type I photodynamic pathway are the primary drivers of pigment degradation, reducing ΔE00from 12.56 to 1.09 upon •OH inhibition. CPTQ achieved measurable in vitro whitening through a predominantly Type I ROS-mediated mechanism while causing limited changes in the evaluated enamel surface endpoints.

An activatable type I photosensitizer for NIR fluorescence imaging and photodynamic therapy of drug-resistant bacterial infections

Zhongkun Wang,Rui Zhu,Chenrui Li,Weiwei Xu,Liangyou Zhao,Guangjin Gao,Weihao An,Xiang Dong,Qingqing Miao,Qing Li

Bacterial infections pose a significant global health challenge, further exacerbated by the emergence of antibiotic-resistant strains, thereby necessitating the development of alternative therapeutic strategies. Type I photosensitizers, as an emerging phototheranostic modality, hold great promise for antibacterial treatment but are limited by poor specificity. Herein, we report a hydrogen sulfide (H 2 S)-activatable theranostic probe (CyIN) that integrates near-infrared (NIR) fluorescence imaging and type I photodynamic therapy (PDT) functionalities into a single platform for the precise treatment of drug-resistant bacterial infections. CyIN is rationally constructed by masking the hydroxyl group of iodine-substituted hemicyanine with a H 2 S-cleavable 2,4-dinitrophenyl group, which efficiently quenches NIR fluorescence and suppresses reactive oxygen species generation. Such molecular configuration allows CyIN to turn on its NIR fluorescence signal and type I photodynamic action upon interaction with bacterial-derived H 2 S, achieving distinguishable detection of drug-resistant bacterial infection, potent bacterial clearance (>99 %), and accelerated healing of bacteria-infected wounds. Furthermore, histological analyses confirm that the CyIN treatment can reduce inflammation, enhance collagen deposition, and promote tissue regeneration without systemic toxicity. Thus, this work presents a promising H 2 S-responsive phototheranostic platform for precise bacterial detection and efficient photodynamic eradication of drug-resistant bacterial infections.

Type I-E* CRISPR-Cas of Klebsiella pneumoniae upregulates bacterial virulence by targeting endogenous histidine utilization system

Jieying Li,Yuxiao Liu,Jingsi Jiang,Fang Chen,Nan Zhang,Xun Kang,Lin Liu,Yingjuan Wang,Qianfeng Xia,Chuanlong Zhu,Dai Kuang

Klebsiella pneumoniae is a globally recognized microbial pathogen with significant clinical impact. The bacterium harbors the clustered regularly interspaced short palindromic repeats (CRISPR)-Cas systems, which provide adaptive immunity against invading foreign nucleic acids. Recent studies suggest that certain CRISPR-Cas systems can regulate endogenous genes, influencing bacterial virulence. However, their role in regulating pathogenicity in K. pneumoniae remains poorly understood. This study investigates the regulatory role of the type I-E* CRISPR-Cas system in a hypervirulent K. pneumoniae strain, focusing on its impact on histidine metabolism and pathogenicity. Transcriptome analyses identified differentially expressed genes (DEGs) between the casABECD-deletion and wild-type strains, including significant upregulation of the histidine utilization (Hut) operon and downregulation of biofilm-related genes. These molecular changes resulted in enhanced histidine metabolic activity, reduced biofilm formation, attenuated virulence in A549 lung epithelial cells, and improved survival of Galleria mellonella, as validated through phenotypic and virulence assays. Our bioinformatic analysis indicated that the CRISPR-Cas system in K. pneumoniae targets the hutT sequence, which is part of the Hut operon. Furthermore, the overexpression of hutT mitigated CRISPR-Cas-mediated repression of the Hut operon, as observed in virulence assays, while simultaneous deletion of hutH and casABECD restored the reduced virulence in the ΔcasABECD strain. Additionally, deletion of casABECD significantly enhances the growth of the strain in medium with histidine as the sole carbon source, highlighting the intricate regulatory role of the CRISPR-Cas system in metabolic adaptation. Collectively, these findings uncover a novel role for the CRISPR-Cas system in regulating metabolic pathways and virulence in hypervirulent K. pneumoniae.

Double-Site Occupation Triggered Broadband and Tunable NIR-I and NIR-II Luminescence in AlNbO4:Cr3+ Phosphors

Kuangnan Lyu,Gaochao Liu,Maxim S. Molokeev,Zhiguo Xia

Near-infrared (NIR) phosphor-converted light-emitting diodes (pc-LEDs) are desired for optoelectronic and biomedical applications, while the development of target broadband NIR phosphors still remains a significant challenge. Herein, a kind of Cr 3+ -doped AlNbO 4 phosphors with a broad NIR emission ranging from 650 to 1400 nm under 450 nm excitation are reported. A giant red-shift emission peak from 866 to 1020 nm together with broadened full width at half-maximum of 320 nm is achieved simply by varying the doped Cr 3+ concentrations. Structural and spectroscopy analysis demonstrate that a concentration-dependent site-occupation of Cr 3+ emitters in different Al 3+ sites is responsible for the tunable NIR luminescence. The as-fabricated NIR pc-LED based on optimized AlNbO 4 :Cr 3+ phosphor exhibits great potential in night-vision applications. This work provides a novel design principle on the Cr 3+ -doped AlNbO 4 phosphor with tunable broadband luminescence from NIR-I to NIR-II, and these materials can be employed in NIR spectroscopy applications.

Synthesis of core-shell molecularly imprinted polymers (MIP) for spiramycin I and their application in MIP chromatography

Qi Liu,Junfen Wan,Xuejun Cao

Spiramycin I is a main component of spiramycin and a structural analogue of neospiramycin I, which is an impurity in spiramycin production. Molecular imprinting technology (MIT) has many advantages in selectivity and environmental compatibility in biomolecular separation. In this study, core-shell molecularly imprinted polymers (MIPs) were prepared for spiramycin I. Methyl methacrylate (MMA) was used to prepare the seed core, and acrylamide (AM)/methacrylic acid (MAA) was chosen to prepare the shell. The structure of polymerized MIPs was successfully characterized by transmission electron microscopy, dynamic light scattering, Fourier transform infrared spectroscopy and elemental analysis. The adsorption results showed that MIPs polymerized by different monomers exhibited very different adsorption for spiramycin I. MIPs with monomeric AM achieved a fast mass transfer, high adsorption capacity and high selectivity. Then, these MIPs were applied to separate spiramycin I from the fermentation broth in the chromatographic column, and its recovery and purity were 61% and 83%, respectively. Finally, regeneration of the MIP chromatographic column was studied to explore its recycling performance in application.

Adjusting photophysical properties of five daylight white-emitting copper (I) iodide hybrid complexes by modifying their ligands

Karima El Mir,Hao-Yu Zhu,Juan-Juan Shao,Yu-Wen Su,Paul Kwizera,Fang-Ming Wang,Li-Zhuang Chen

Five new copper iodide complexes ( 1–5 ) were prepared by the solvent evaporation method of cuprous iodide with derivatives of 2-(1 H -imidazol-1-yl) pyrimidine ( L 1 -L 5 ). All of them are daylight white emissions among 5079–6483 K and have good thermal stabilities. Their internal quantum yields (IQYs) range from 17% to 66%. By modifying the ligand's pyrimidine ring with different groups, they successfully adjust distances of Cu…Cu in Cu 2 I 2 rhomboid dimers and further influences their optical properties, which is confirmed by electronic structure calculations employing density functional theory (DFT). This research will be very helpful for understanding the structure-activity relationship of copper (I) iodide hybrid materials. And all these complexes can be used in solid-state lighting and other optoelectronic devices.

Broad-temperature-range thermoresponse of Cu(I)-based organic-inorganic hybrid metal halides with multimode dynamic luminescence

He Jiaman,Kang Liwen,Zeng Weigang,Shi Wanxin,Ling Qidan,Lin Zhenghuan

Organic-inorganic hybrid metal halides (OIMHs) based on Cu(I) ions show broad application prospects in the field of stimulus-responsive luminescent materials based on their rich structural diversity and highly adjustable electronic state. However, achieving sensitive and broad-temperature-range thermal responses for OIMHs remains a significant challenge, despite the growing interest in smart luminescence materials. In this study, 4-morpholinopiperidine (4-MP) and CuI are used to synthesize a zero-dimensional warm white-light emitting OIMH, namely MPC-W ((C 9 H 20 N 2 O) 4 (Cu 2 I 4 )(Cu 2 I 6 )(H 2 PO 2 ) 2 ), which features hybrid structures of [Cu 2 I 4 ] 2− and [Cu 2 I 6 ] 4− . Owing to the coexistence of three luminescent mechanisms-organic cluster luminescence (CL), self-trapped exciton (STE) emission of [Cu 2 I 6 ] 4− , and cluster-centered (CC) state luminescence of [Cu 2 I 4 ] 2− , MPC-W exhibits temperature and excitation wavelength-dependent dynamic luminescence. When the temperature is increased from 77 to 297 K, the luminescence color of MPC-W can be continuously tuned from blue to cyan, green, yellow-green, and white. In the range of 217–463 K, MPC-W displays an abnormal luminescence enhancement phenomenon with increasing temperature. Additionally, upon chemical stimulus, MPC-W can reversibly transform into a blue-light emitting crystal named MPC-B ((C 9 H 20 N 2 O)Cu 2 I 4 ), and a yellow-light emitting crystal named MPC-Y ((C 9 H 18 N 2 O) 7 Cu 8 I 8 ). These unique dynamic luminescent properties endow MPC-W with great application potential in temperature sensing, optical anti-counterfeiting, and password locks. The work provides a new insight for the development of novel wide temperature-responsive multifunctional intelligent luminescent materials. The alternative text for this image may have been generated using AI.

A mixed-valence biotinylated Cu(I/II) complex for tumor-targeted chemodynamic therapy accompanied by GSH depletion

Zhaoguo Hong,Xin You,Jingjing Zhong,Di Yao,He-Dong Bian,Shulin Zhao,Liangliang Zhang,Hong Liang,Fu-Ping Huang

Chemodynamic therapy (CDT), in which highly toxic hydroxyl radicals (˙OH) could be triggered by a Fenton or Fenton-like reaction to kill cancer cells, has emerged recently. Compared to traditional CDT nanomaterials, herein, an atomically-precise biotinylated Cu(I/II) complex [CuICuIICl2(VBio)]·CH3OH (VBio = deprotonated O-vanillin biotinylhydrazone), denoted VBio-CuICuII, was rationally designed and synthesized successfully. This targeted Fenton-like agent, VBio-CuICuII, is constructed from a hydroxyl radical-producible CuI ion, a CuII center as a GSH depletor for an augmented CDT effect, and a biotin moiety as a cancer-targeting unit. Owing to the obvious cell selectivity discrepancy of biotin towards normal and cancerous cells, VBio-CuICuII was able to preferentially accumulate in tumor cells. Meanwhile, the CuI metal center could be used as a Fenton-like agent to generate ˙OH. Furthermore, the CuII in VBio-CuICuII was available for successive ˙OH production via a CuI/CuII-circulation strategy under a GSH-rich tumor site, thereby improving catalytic efficiency. More importantly, in vivo results further demonstrate that VBio-CuICuII could significantly inhibit tumor growth without obvious damage toward major organs. Therefore, this multiple-identity Fenton-like agent could provide an appreciable reference value for the design of atomically precise CDT agents.

Carbon dots nanophotosensitizers with tunable reactive oxygen species generation for mitochondrion-targeted type I/II photodynamic therapy

Yunxiu Zhang,Qingyan Jia,Fuchun Nan,Jian Wang,Ke Liang,Jian Li,Xiaokuang Xue,Haohui Ren,Weimin Liu,Jiechao Ge,Pengfei Wang

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

Light-Responsive Carbon Nitride Based Atomic Cu(I) Oxidase Mimics for Dual-Mode Total Antioxidant Capacity Assay

Xiaoying Gao,Yunjia Liu,Ke Zhang,Jinlan Weng,Rongqing Chen,Xiaoyi Zhang,Zhipeng Wang,Shenghong Yang,Jian Liu

External light stimuli strategy under conventional conditions achieves a sustainable future due to its controllable spatial and temporal precision coupled with environmental friendliness. Herein, atomic Cu(I)-carbon nitride (Cu-CN) was synthesized and served as specific light-stimuli oxidase mimics for total antioxidant capacity (TAC) assay. Singlet oxygen (1O2) and hydroxyl radical (·OH) are the main intermediates, which can oxidize 3,3′,5,5′-tetramethylbenzidine (TMB) into its blue oxidant and therefore improve photothermal signal generation. Based on the intrinsic light responsiveness and photothermal conversion property, we established a colorimetric and photothermal dual-mode sensing platform. The proposed dual-mode assay presented a specific assay of ascorbic acid with LOD of 0.28 μM and 0.15 μM, respectively. This platform was further successfully applied to assess TAC of fruits and beverages. It is believed that the intelligently modulated activity and dual-mode detection function of such atomic enzyme mimics can offer a promising strategy for other analytical assays in high repeatability and reproducibility.

Painless and sensitive pepsinogen I detection: an electrochemical immunosensor based on rhombic dodecahedral Cu3Pt and MoS2 NFs

Shanshan Wei,Shiyong Li,Haolin Xiao,Feijun Zhao,Jianming Zhu,Zhencheng Chen,Liangli Cao

Gastric cancer (GC) is a common malignant tumour of the digestive tract with a high mortality rate worldwide. However, many patients delay treatment due to the avoidance of the costly and painful procedure of gastroscopy. Therefore, an early convenient screening method is essential to improve the survival rate of GC patients. To address this issue, we constructed an electrochemical immunosensor supported by rhombohedral Cu3Pt and MoS2 nanoflowers (MoS2 NFs) for rapid, painless and quantitative detection of the GC biomarker in vitro. Here, pepsinogen I was employed as a model protein biomarker to analyse the performance of the immunosensor. The rhombohedral dodecahedral Cu3Pt nanoparticles decorated with MoS2-NFs were further functionalized; this allowed the constructed sensor to possess more nano- or micro-structures, thereby improving the detection sensitivity. In specific applications, the corresponding bioactive molecules can be flexibly captured. Under optimal conditions, the immunoassay showed a wide linear range from 500 pg mL−1 to 400 ng mL−1 and a low detection limit of 167 pg mL−1 (S/N = 3). This covers the critical value of 70 ng mL−1, and the results obtained from the analysis of human serum samples were on par with those from the enzyme immunoassay, suggesting significant potential for this new method in daily diagnosis.

Facilitating the Carrier Transport Kinetics at the CsPbBr3/Carbon Interface through SbX3 (X = Cl, Br, I) Passivation

Wenwen Liu,Teng Zhang,Baohua Zhao,Chengben Liu,Youru Bai,Zhi Li,Shihui Zhu,Tailin Wang,Xinyu Sun,Heyuan Liu,Zhaobin Liu,Yanli Chen,Xiyou Li

The nonradiative carrier recombination at the perovskite/carrier selective layer (CSL) interface was accounted for the inferior power conversion efficiency (PCE) of perovskite solar cells (PSCs), especially rigid all-inorganic perovskite (CsPbI3 and CsPbBr3). In this study, targeting the poor interface, we introduce SbX3 (X = Cl, Br, I) surface passivation at the CsPbBr3/carbon interface. Smoothed compressive strain, reduced defect density, and enhanced energy-level alignment were achieved simultaneously, facilitating carrier extraction at the selective interface. With the simple aqueous solution-based two-step process, the PCE of our SbI3 passivated carbon-based CsPbBr3 PSCs has increased from 7.81% (without passivation) to 9.69%, a ∼25% enhancement. Specifically, Voc (1.657 V) of the SbI3-passivated cells was much higher than that of the control ones (1.488 V), confirming the ameliorated interface. Finally, our unencapsulated SbI3 passivated devices maintain 90% of their initial PCEs while left in the air for 30 days with a relative humidity of 60%. To conclude, we present an interfacial carrier extraction-enhanced strategy for preparing high-performance and stable CsPbBr3-based PSCs.