Encapsulation of palladium porphyrin photosensitizer in layered metal oxide nanoparticles for photodynamic therapy against skin melanoma

We designed a biodegradable nanocarrier of layered double hydroxide (LDH) for photodynamic therapy (PDT) based on the intercalation of a palladium porphyrin photosensitizer (PdTCPP) in the gallery of LDH for melanoma theragnosis. Physical and chemical characterizations have demonstrated the photosensitizer was stable in the layered structures. In addition, the synthesized nanocomposites rendered extremely efficacious therapy in the B16F10 melanoma cell line by improving the solubility of the hydrophobic PdTCPP photosensitizer. The detection of singlet oxygen generation under irradiation at the excitation wavelength of a 532 nm laser was indeed impressive. Furthermore, the in vivo results using a tumour xenograft model in mice indicated the apparent absence of body weight loss and relative organ weight variation to the liver and kidney demonstrated that the nanocomposites were biosafe with a significant reduction in tumour volume for the anti-cancer efficacy of PDT. This drug delivery system using the nanoparticle–photosensitizer hybrid has great potential in melanoma theragnosis.     

Heavy-atomic construction of photosensitizer nanoparticles for enhanced photodynamic therapy of cancer

A new type of heavy-atom-affected Pluronic (F-127) nanoparticle (FIC NP) for photodynamic therapy (PDT) is reported. FIC NPs are formulated with biocompatible constituents, and contain densely integrated iodinated aromatic molecules that form a structurally rigid core matrix and stably encapsulate photosensitizers in a monomeric form. Tiny nanoparticles (≈10 nm) are prepared by aqueous dispersion of photosensitizer-embedded aromatic nanodomains, which self-assemble by phase separation from the Pluronic melt mixture. By using spectroscopic studies and cellular experiments, the following is demonstrated: 1) enhanced singlet-oxygen generation by means of the intraparticle heavy-atom effect on the embedded photosensitizer, 2) facilitated cell uptake due to the small nanoscopic size as well as the Pluronic surface characteristics, and thereby 3) actual enhancement of PDT efficacy for a human breast-cancer cell line (MDA-MB-231), which validates a photophysically motivated nanoformulation approach toward an advanced photosensitizing nanomedicine.     

具有自组装纳米结构的AIE光敏剂用于增强光动力治疗（英文）

基于具有聚集诱导发光(AIE)性质的2,3-双(4’-(二苯基)-[1,1’-联苯]-4-基]富甲腈(BDBF)分子,制备了三种纳米结构并用于图像引导光动力学治疗(PDT).普兰尼克F127可包封BDBF形成常见的球形纳米粒子(F127@BDBF NPs),该纳米粒子可发射红色荧光,荧光量子效率(FQY)为9.8%.此外, BDBF也可在水中自组装成纳米棒(BDBF NRs).与F127@BDBF NPs相比, BDBF NRs呈现出较强的橙色荧光,具有较高的荧光量子产率(23.3%),以及基本相同的单线态氧(1O2)产生能力.利用F127对BDBF NRs进行进一步修饰可得到BDBF@F127 NRs,该纳米粒子仍然保持了棒状形貌和较好的1O2产生能力.同时,与溶解态的BDBF相比,三种纳米结构的单线态氧产生效率增强.这些纳米结构在水溶液和生理条件下具有良好的稳定性.细胞的光毒性实验表明,三种纳米结构均能有效抑制肿瘤细胞增殖.因此,通过简单的自组装方法制备高荧光量子效率和较强单线态氧产生能力的纳米结构可作为一种有效的途径来增强光动力.     

层状双氢氧化物析氧催化剂的研究进展

层状双氢氧化物具有制备简单,层间客体可调节,合成成本较低,稳定性较好等优点,因此成为析氧催化剂的研究热点,但仍存在电荷传输速率低,过电位相对较高等问题,因此需要对其改性来加快其大规模应用。首先介绍了层状双氢氧化物的结构特点,简述了其析氧反应的催化机理,然后总结了不同种类的优化改性策略来增强其催化活性。优化改性方法分别包括:与导电基材复合;合成超薄纳米片法;与石墨烯复合法;杂化改性法。重点探讨了层状双氢氧化物析氧催化剂在电解水制氢方面的应用,提出了不同改性方法的优缺点,阐明将其适当结合,有利于制备更高效的析氧催化剂,最后指出了这类催化剂仍面临的问题:回收率较低,催化剂稳定性和可实现的电流密度尚未达到工业化需求,无法实现大规模制备等难点。     

Phosphorus oxoanion-intercalated layered double hydroxides for high-performance oxygen evolution

Rational design and controlled fabrication of efficient and cost-effective electrodes for the oxygen evolution reaction (OER) are critical for addressing the unprecedented energy crisis.Nickel-iron layered double hydroxides (NiFe-LDHs) with specific interlayer anions (i.e.phosphate,phosphite,and hypophosphite) were fabricated by a co-precipitation method and investigated as oxygen evolution electrocatalysts.Intercalation of the phosphorus oxoanion enhanced the OER activity in an alkaline solution;the optimal performance (i.e.,a low onset potential of 215 mV,a small Tafel slope of 37.7 mV/dec,and stable electrochemical behavior) was achieved with the hypophosphite-intercalated NiFe-LDH catalyst,demonstrating dramatic enhancement over the traditional carbonate-intercalated NiFe-LDH in terms of activity and durability.This enhanced performance is attributed to the interaction between the intercalated phosphorous oxoanions and the edge-sharing MO6 (M =Ni,Fe) layers,which modifies the surface electronic structure of the Ni sites.This concept should be inspiring for the design of more effective LDH-based oxygen evolution electrocatalysts.     

Comparative enhancement of curcumin cytotoxic photodynamic activity by nanoliposomes and gold nanoparticles with pharmacological appraisal in HepG2 cancer cells and Erlich solid tumor model

Curcumin is a natural pigment that generates singlet oxygen upon light excitation, hence it can be used as a photosensitizer in photodynamic therapy. The extremely low water solubility and poor systemic bioavailability make curcumin a challenging molecule to be used clinically. In this study, two nanocarrier systems for curcumin were prepared and characterized; nanoliposomes and polyvinyl pyrrolidone-capped gold nanoparticles. The dark and photocytotoxicity were investigated as a function of light fluence rate (100 and 200?mW/cm²) on HepG2 cancer cells. In vivo Erlich tumor model was developed and comparison of the tumor volume, survival rate, and histopathological alterations was made for the two nanocarriers. Results showed that both curcumin nanocarriers were successfully prepared and characterized. Light irradiation was able to augment the cytotoxicity of both curcumin liposomes and gold nanoparticles, with the former being superior in cytotoxicity compared to the latter. The tumor size was almost diminished 1 month post-photodynamic treatment for both systems with regression in the number of tumor cells upon histopathological evaluation, with curcumin liposomes producing better tumor regression than gold nanoparticles with comparable survival rate. Liposomes were confirmed to be superior to gold nanoparticles as a photodynamic treatment modality for cancer.     

Organically modified silica nanoparticles with covalently incorporated photosensitizer for photodynamic therapy of cancer

We report a novel nanoformulation of a photosensitizer (PS), for photodynamic therapy (PDT) of cancer, where the PS molecules are covalently incorporated into organically modified silica (ORMOSIL) nanoparticles. We found that the covalently incorporated PS molecules retained their spectroscopic and functional properties and could robustly generate cytotoxic singlet oxygen molecules upon photoirradiation. The synthesized nanoparticles are of ultralow size ( approximately 20 nm) and are highly monodispersed and stable in aqueous suspension. The advantage offered by this covalently linked nanofabrication is that the drug is not released during systemic circulation, which is often a problem with physical encapsulation. These nanoparticles are also avidly uptaken by tumor cells in vitro and demonstrate phototoxic action, thereby highlighting their potential in diagnosis and PDT of cancer.     

具有层状碱金属盐结构的氢氧化氨基苯甲酸锌的制备及表征

以自制的β-Zn(OH)2和氨基苯甲酸为原料,水热合成了具有层状碱金属盐(LBMS)结构的氢氧化氨基苯甲酸锌化合物。通过XRD、TG-DTA、SEM和TEM分析研究了合成产物的结构、形貌和热稳定性,探讨了合成条件对水热反应产物的影响及合成产物在有机溶剂中的剥离反应。当o-NH2C6H4COOH/Zn的摩尔比为1.2,水热温度70℃下反应12h时,得到的层状物具有板块状粒子特征,层间距为1.33nm;当m-NH2C6H4COOH/Zn的摩尔比为1.8,水热温度40℃下反应24h时,得到的层状化合物具有纤维状粒子特征,层间距为1.08nm。合成的层状物在醇溶剂中可发生剥离反应,层状氢氧化邻氨基苯甲酸锌在正丁醇中的剥离量为0.12g.L-1,层状氢氧化间氨基苯甲酸锌在乙醇中的剥离量为0.18g·L-1。     

Spectral matching technology for light-emitting diode-based jaundice photodynamic therapy device

The objective of this paper is to obtain the spectrum of light-emitting diode (LED)-based jaundice photodynamic therapy device (JPTD), the bilirubin absorption spectrum in vivo was regarded as target spectrum. According to the spectral constructing theory, a simple genetic algorithm as the spectral matching algorithm was first proposed in this study. The optimal combination ratios of LEDs were obtained, and the required LEDs number was then calculated. Meanwhile, the algorithm was compared with the existing spectral matching algorithms. The results show that this algorithm runs faster with higher efficiency, the switching time consumed is 2.06?s, and the fitting spectrum is very similar to the target spectrum with 98.15% matching degree. Thus, blue LED-based JPTD can replace traditional blue fluorescent tube, the spectral matching technology that has been put forward can be applied to the light source spectral matching for jaundice photodynamic therapy and other medical phototherapy.     

Cobalt-based layered double hydroxides as oxygen evolving electrocatalysts in neutral eletrolyte

Co–M (M= Co, Ni, Fe, Mn) layered double hydroxides (LDHs) were successfully fabricated by a hexamethylenetetramine (HMT) pyrolysis method. Composite electrodes were made using a self-assembly fashion at inorganic/organic surface binder-free and were used to catalyze oxygen evolution reaction. Water oxidation can take place in neutral electrolyte operating with modest overpotential. The doping of other transitional metal cations affords mix valences and thus more intimate electronic interactions for reversible chemisorption of dioxygen molecules. The application of employing LDH materials in water oxidation process bodes well to facilitate future hydrogen utilization.     

Gold nanorod-photosensitizer conjugate with extracellular pH-driven tumor targeting ability for photothermal/photodynamic therapy

Chlorin e6-pHLIPss-AuNRs, a gold nanorod-photosensitizer conjugate containing a pH （low） insertion peptide （pHLIP） with a disulfide bond which imparts extracellular pH （pHe）-driven tumor targeting ability, has been successfully developed for bimodal photodynamic and photothermal therapy. In this bimodal therapy, chlorin e6 （Ce6）, a second-generation photosensitizer （PS）, is used for photodynamic therapy （PDT）. Gold nanorods （AuNRs） are used as a hyperthermia agent for photothermal therapy （PTT） and also as a nanocarrier and quencher of Ce6. pHLIPss is designed as a pile-driven targeting probe to enhance accumulation of Ce6 and AuNRs in cancer cells at low pH. In Ce6- pHLIPss-AuNRs, Ce6 is close to and quenched by AuNRs, causing little PDT effect. When exposed to normal physiological pH 7.4, Ce6-pHLIPs~-AuNRs loosely associate with the cell membrane. However, once exposed to acidic pH 6.2, pHLIP actively inserts into the cell membrane, and the conjugates are translocated into cells. When this occurs, Ce6 separates from the AuNRs as a result of disulfide bond cleavage caused by intracellular glutathione （GSH）, and singlet oxygen is produced for PDT upon light irradiation. In addition, as individual PTT agent, AuNRs can enhance the accumulation of PSs in the tumor by the enhanced permeation and retention （EPR） effect. Therefore, as indicated by our data, when exposed to acidic pH, Ce6-pHLIPss-AuNRs can achieve synergistic PTT/PDT bimodality for cancer treatment.     

Ageing behaviour of unary hydroxides in trivalent metal salt solutions: Formation of layered double hydroxide (LDH)-like phases

The hydroxides of Mg, Ni, Cu and Zn transform into layered double hydroxide (LDH)-like phases on ageing in solutions of Al or Cr salts. This reaction is similar to acid leaching and proceeds by a dissolution-reprecipitation mechanism offering a simple method of LDH synthesis, with implications for the accepted theories of formation of LDH minerals in the earth’s crust.     

Differential cytotoxicity of metal oxide nanoparticles

Concerns about the potential health hazards of nanomaterials are growing. To determine the potential toxicity of metal oxide nanoparticles, human SH-SY5Y neuroblastoma and H4 neuroglioma cells were exposed to Fe₂O₃, CuO and ZnO nanoparticles and their metal ion counterparts (Fe³⁺, Cu²⁺ and Zn²⁺) at a concentration range of 0.01–100 µM for 48 h, under the cell culture conditions: 95% O₂, 5% CO₂, 85% humidity, 37°C. Their ensemble cell viability was determined by MTS cell proliferation assay. A live/dead cell assay was also performed, and cellular images were acquired by a high-content fluorescence microscope and quantified by a novel computerised image analysis protocol. Our data indicated that exposure of these nanoparticles induced differential toxic effects in both SH-SY5Y and H4 cells, and the cells had dose-dependent toxic responses to the CuO nanoparticle insult. In conclusion, the toxic responses of the nanoparticles are complex, and they warrant further in vivo studies. However, it remains to be determined if these nanopartilces have synergistically enhancing or cancelling toxic effects upon both SH-SY5Y and H4 cells.     

基于NiMoCo层状双金属氢氧化物的电催化剂和超级电容器电极

本文通过调控Ni,Mo,Co三种元素的摩尔比得到一系列高效双功能电催化剂.其中,Co元素特定的氧吸附位点(Co^2+-O-Co^3+)可有效提高催化剂的活性.Mo元素在温和反应条件下具有较好的氧化还原能力.Ni是另一种高活性过渡金属.与其他材料结合可有效增强催化剂的氧化还原活性和储氧能力.所制备的NiMoCo层状双金属...     

Fabrication of superparamagnetic adsorbent based on layered double hydroxide as effective nanoadsorbent for removal of Sb (III) from water samples

In this study, the superparamagnetic adsorbent as Fe@Mg‐Al LDH was synthesised by different methods with two steps for the removal of heavy metal ions from water samples. An easy, practical, economical, and replicable method was introduced to remove water contaminants, including heavy ions from aquatic environments. Moreover, the structure of superparamagnetic adsorbent was investigated by various methods including Fourier transform infrared spectroscopy, field emission scanning electron microscopy, energy‐dispersive X‐ray spectroscopy, and vibrating sample magnetometer. For better separation, ethylenediaminetetraacetic acid ligand was used, forming a complex with antimony ions to create suitable conditions for the removal of these ions. Cadmium and antimony ions were studied by floatation in aqueous environments with this superparamagnetic adsorbent owing to effective factors such as pH, amount of superparamagnetic adsorbent, contact time, sample temperature, volume, and ligand concentration. The model of Freundlich, Langmuir, and Temkin isotherms was studied to qualitatively evaluate the adsorption of antimony ions by the superparamagnetic adsorbent. The value of loaded antimony metal ions with Fe@Mg‐Al LDH was resulted at 160.15 mg/g. The standard deviation value in this procedure was found at 7.92%. The desorption volume of antimony metal ions by the adsorbent was found to be 25 ml. The thermodynamic parameters as well as the effect of interfering ions were investigated by graphite furnace atomic absorption spectrometry.     

氨基改性过程引入去离子水对层状双氢氧化物CO_2吸附性能的影响规律研究

以共沉淀方法合成了十二烷基磺酸钠插层的Mg/Al层状双氢氧化物,并采用超声剥落方法进行氨基改性。利用元素分析、X射线衍射技术和扫描电镜表征所得样品的成分、结构以及形貌特征,利用热重分析技术表征样品在30℃、1.013×105 Pa下对CO2的吸附能力以及吸附-脱附循环再生性能。在氨基改性过程的超声剥落环节引入一定量的去离子水,重点考察了去离子水对氨基改性层状双氢氧化物的氨基负载量和CO2吸附性能的影响规律。结果表明,当改性过程中加入的去离子水量为0.1 mL/g时,样品Mg/Al 0.1N1和Mg/Al 0.1N2的CO2吸附容量均为最大,分别为1.21和1.02 mmol/g(30℃,纯CO2环境)。     

Iridium-complex-functionalized Fe3O4/SiO2 core/shell nanoparticles: a facile three-in-one system in magnetic resonance imaging, luminescence imaging, and photodynamic therapy

Highly uniform Fe3O4/SiO2 core/shell nanoparticles functionalized by phosphorescent iridium complexes (Ir) have been strategically designed and synthesized. The Fe3O4/SiO2(Ir) nanocomposite demonstrates its versatility in various applications: the magnetic core provides the capability for magnetic resonance imaging and the great enhancement of the spin-orbit coupling in the iridium complex makes it well suited for phosphorescent labeling and simultaneous singlet oxygen generation to induce apoptosis.     

M2 macrophage-targeted iron oxide nanoparticles for magnetic resonance image-guided magnetic hyperthermia therapy

Tumor-associated macrophages (TAMs) play an important role in tumor development and progression.In particular,M2 TAMs can promote tumor growth by facilitating tumor progression and malignant behav-iors.Selectively targeted elimination of M2 TAMs to inhibit tumor progression is of great significance for cancer treatment.Iron oxide nanoparticles based magnetic hyperthermia therapy (MHT) is a classical approach to destroy tumor tissue with deep penetration depth.In this study,we developed a typical M2 macrophage-targeted peptide (M2pep) functionalized superparamagnetic iron oxide nanoparticle(SPIO) for magnetic resonance imaging (MRI)-guided MHT in an orthotopic breast cancer mouse model,The obtained multifunctional SPIO-M2pep with a hydrodynamic diameter of 20 nm showed efficient targeting capability,high transverse relaxivity (149 mM-1 s-1) and satisfactory magnetic hyperthermia performance in vitro.In vivo studies demonstrated that the SPIO-M2pep based MRI can monitor the distri-bution of nanoparticles in tumor and indicate the suitable timing for MHT.The M2 macrophage-targeted MHT significantly reduced the tumor volume and the population of pro-tumoral M2 TAMs in tumor.In addition,the SPIO-M2pep based MHT can remodel the tumor immune microenvironment (TIME).The multifunctional SPIO-M2pep with M2 macrophage-targeting ability,high magnetic hyperthermia effi-ciency,MR imaging capability and effective role in remodeling the TIME hold great potential to improve clinical cancer therapy outcomes.     

Selective removal of heavy metal ions in aqueous solutions by sulfide-selector intercalated layered double hydroxide adsorbent

Remaining largely under-appreciated, a majority of metal ion sorbents are limited in their target selectivity. In this work, a 3D sulfide intercalated NiFe-layered double hydroxide (NFL-S) hierarchical sorbent has been synthesized for selective heavy metal removal. The intercalation of sulfurated groups in the interlayer of the layered double hydroxide (LDH) nanosheets endows NFL-S as a selective heavy metal ion filter; the selectivity of NFL-S for heavy metals is in the order of Pb²⁺ > Cu²⁺ ≥ Zn²⁺ > Cd²⁺> Mn²⁺, and NFL-S has high k_d values for Pb²⁺ (∼10⁶ mL/g) and Cu²⁺ (∼10⁵ mL/g). Scanning electron microscopy, X-ray photoelectron spectroscopy and powder X-ray diffraction were used to analyze the composition of the as-prepared nanoadsorbent. The selective adsorption behavior was systematically studied using batch experiments, and the performance was evaluated through kinetic and isotherm studies. Moreover, the adsorption mechanism of heavy metals by NFL-S through surface complexation was also investigated, which shows great potential for water decontamination.