一种用于肿瘤治疗的高光热转换效率和高稳定性的光热剂

基于香豆素荧光团设计合成了一种光热剂(ECEI),其光热转换效率可达 85.78%。此外,冷热循环的实验结果表明,ECEI 具有良好的光稳定性。即使在线粒体膜电位受损的情况下,ECEI 也能有效靶向线粒体,在激光照射下诱导癌细胞死亡。这使 ECEI能够最大程度地破坏线粒体,从而抑制肿瘤细胞的繁殖。对小鼠肿瘤照射 1次后,小鼠肿瘤在 10 d内逐渐消失,这表明ECEI具有良好的肿瘤抑制效果。     

一种用于肿瘤治疗的高光热转换效率和高稳定性的光热剂

基于香豆素荧光团设计合成了一种光热剂(ECEI),其光热转换效率可达 85.78%。此外,冷热循环的实验结果表明,ECEI 具有良好的光稳定性。即使在线粒体膜电位受损的情况下,ECEI 也能有效靶向线粒体,在激光照射下诱导癌细胞死亡。这使 ECEI能够最大程度地破坏线粒体,从而抑制肿瘤细胞的繁殖。对小鼠肿瘤照射 1次后,小鼠肿瘤在 10 d内逐渐消失,这表明ECEI具有良好的肿瘤抑制效果。     

Polymer materials for constructing therapeutical nanoparticles in photothermal therapy

Photothermal therapy (PTT) ablates tumors by thermal effects of photothermal agents (PTAs), and attracts wide attention due to the non-invasive characteristic. The ideal PTAs are expected to have high photothermal conversion effect under NIR irradiation, as well as targeting abilities and good biocompatibility satisfying the need of application in vivo. Nanoparticles (NPs) are commonly used as anti-tumor materials, and plenty of researches on therapeutical NPs for PTT treatment have been developed. Among various building blocks for photothermal NPs, polymer materials for biomedical applications have great advantages due to their negligible toxicity, flexibility for functional modification, and ability to integrate multiple therapeutic strategies. This review focuses on the polymer materials utilized in photothermal NP designing, including their application as excellent carriers and powerful PTAs with great PTT effects. Furthermore, the synergy therapy based on polymeric nanoplatform for enhancing PTT therapeutic efficiency will be introduced.     

Fe掺杂CuS纳米颗粒的合成及其在光热/化学动力学联合治疗中的应用

以乙酰丙酮铜和硫粉为铜源和硫源,在油酸(OA)-油胺(OM)-十八烯(ODE)体系中合成了近红外吸收的硫化铜(CuS)纳米颗粒,并通过改变硫元素活化状态的方式调节其吸收峰到适合光热治疗的1064 nm附近。通过阳离子交换法进一步制备了Fe、Mn等元素掺杂的CuS纳米颗粒,并保持其吸收峰位置几乎不变。使用微乳法进行聚乙二醇(PEG)化修饰后,这些纳米颗粒在水溶液中表现出良好的分散性和稳定性。分别测试了CuS纳米颗粒在Fe³⁺掺杂前后的光热性能及羟基自由基(·OH)生成能力。结果表明,PEG修饰后Fe³⁺掺杂的CuS纳米颗粒(CuS∶Fe-PEG)在1064 nm处的质量消光系数为37.5 L·g^-1·cm-1,光热转换效率可达43.7%。虽然光热性能略低于未掺杂的CuS-PEG,但其·OH生成能力有大幅提升。细胞实验也表明,在弱酸性条件下,CuS∶Fe-PEG具有更好的肿瘤细胞抑制能力,在1064 nm激光照射下能够有效杀死肿瘤细胞,可用于光热/化学动力学联合治疗。     

Fe掺杂CuS纳米颗粒的合成及其在光热/化学动力学联合治疗中的应用

以乙酰丙酮铜和硫粉为铜源和硫源,在油酸(OA)-油胺(OM)-十八烯(ODE)体系中合成了近红外吸收的硫化铜(CuS)纳米颗粒,并通过改变硫元素活化状态的方式调节其吸收峰到适合光热治疗的1 064 nm附近。通过阳离子交换法进一步制备了Fe、Mn等元素掺杂的CuS纳米颗粒,并保持其吸收峰位置几乎不变。使用微乳法进行聚乙二醇(PEG)化修饰后,这些纳米颗粒在水溶液中表现出良好的分散性和稳定性。分别测试了CuS纳米颗粒在Fe³⁺掺杂前后的光热性能及羟基自由基(·OH)生成能力。结果表明,PEG修饰后Fe³⁺掺杂的CuS纳米颗粒(CuS∶Fe-PEG)在1 064 nm处的质量消光系数为37.5 L·g^-1·cm^-1,光热转换效率可达43.7%。虽然光热性能略低于未掺杂的CuS-PEG,但其·OH生成能力有大幅提升。细胞实验也表明,在弱酸性条件下,CuS∶Fe-PEG具有更好的肿瘤细胞抑制能力,在1 064 nm激光照射下能够有效杀死肿瘤细胞,可用于光热/化学动力学联合治疗。     

Green synthesis and antibacterial effects of aqueous colloidal solutions of silver nanoparticles using clove eugenol

Silver nanoparticles were synthesized using clove extract (CE). Scanning transmission electron microscopy (STEM) revealed the morphology of the metallic Ag nanoparticles obtained via the clove extract synthesis (Ag NPs‐CE), which had a uniform distribution and average sizes varying from 10 nm to 100 nm. Fourier transform infra‐red (FTIR) spectroscopy showed that clove eugenol acts as a capping and reducing agent being adsorbed on the surface of Ag NPs‐CE, enabling their reduction from Ag⁺ and preventing their agglomeration. Formation of the Ag⁰ structure is also confirmed in the FTIR spectrum by the presence in the Ag NPs‐CE sample of the –C=O and –C=C vibrations at wavenumbers 1600 and 2915 cm^‐1, respectively. Antibacterial and antifungal tests using three strains of bacteria and one fungi strain showed that the Ag NPs‐CE performed better compared to pure clove extract (CE) sample.     

PAA-derived gold nanorods for cellular targeting and photothermal therapy

A single-step LbL procedure to functionalize CTAB-capped GNRs via electrostatic self-assembly is reported. This approach allows for consistent biomolecule/GNR coupling using standard carboxyl-amine conjugation chemistry. The focus is on cancer-targeting biomolecule/GNR conjugates and selective photothermal destruction of cancer cells by GNR-mediated hyperthermia and NIR light. GNRs were conjugated to a single-chain antibody selective for colorectal carcinoma cells and used as probes to demonstrate photothermal therapy. Selective targeting and GNR uptake in antigen-expressing SW 1222 cells were observed using fluorescence microscopy. Selective photothermal therapy is demonstrated using SW 1222 cells, where >62% cell death was observed after cells are treated with targeted A33scFv-GNRs.     

Synthesis, surface modifications, and size-sorting of mixed nickel-zinc ferrite colloidal magnetic nanoparticles

We report on the spontaneous covalent growth of monomolecular adlayers on mixed nickel-zinc nanoferrite colloidal suspensions (ferrofluids). Synthesized nanoparticles were subjected to surface modification by means of acid chloride chemistry, leading to the formation of covalent bonds between the hydroxy groups at the nanoparticle surface and the acid chloride molecules. This procedure can be easily tailored to allow for the formation of adlayers containing both hydrophobic and hydrophilic regions stacked at predetermined distances from the magnetic core, and also providing the nanoferrites with functional carboxy groups capable of further modifications with, for example, drug molecules. Here, fluorophore aminopyrene molecules were bound to such modified nanoferrites through amide bonds. We also used the same chemistry to modify the surface with covalently bound long-chain palmitoyl moieties, and for comparison we also modified the nanoferrite surface by simple adsorption of oleic acid. Both procedures made the surface highly hydrophobic. These hydrophobic colloids were subsequently spread on an aqueous surface to form Langmuir monolayers with different characteristics. Moreover, since uniformity of size is crucial in a number of applications, we propose an efficient way of sorting the magnetic nanoparticles by size in their colloidal suspension. The suspension is centrifuged at increasing rotational speed and the fractions are collected after each run. The mean size of nanoferrite in each fraction was measured by the powder X-ray diffraction (PXRD) technique.     

The nature of colloidal platinum in aqueous solution: features of catalytic reactions

The specific features of the catalytic reduction of methylviologen by dihydrogen in water in the presence of platinum colloids synthesized by various methods are studied. The colloids prepared by the radiation-chemical reduction of PtCl₄ ^2– in the presence of polyacrylate or polyphosphate as stabilizers and colloids prepared by the reduction with dihydrogen efficiently catalyze the reaction. The citrate colloids synthesized by the reduction of PtCl₆ ^2– with citric acid are characterized by a prolonged induction period after which these colloids also gain the catalytic activity. We assume that the citrate platinum colloids are giant clusters with the close-packed metal core containing the magic number of platinum atoms (Pt₅₆₁), which are coordinated by the ligand molecules blocking the surface of the metal particle. In the presence of H₂, the ligand molecules are decomposed or removed from the surface, which is accompanied by the appearance of the catalytic activity.     

Soft template synthesis of donor–acceptor conjugated polymer nanoparticles: Structural effects,stability, and photothermal studies

Donor–acceptor conjugated polymer nanoparticles and nanofibers, based on Poly[4,4‐bis(2‐ethylhexyl)‐cyclopenta[2,1‐b;3,4‐b']dithiophene‐2,6‐diyl‐alt?2,1,3‐benzoselenadiazole‐4,7‐diyl] (PCPDTBSe), were synthesized using Pluronic F127 as a template. The nanomaterials were compared to previously reported PCPDTBSe nanoparticles, which were synthesized without the use of a template. Our goal was to improve on the aqueous stability and photothermal heating efficiency of the previously synthesized PCPDTBSe nanoparticles by decreasing their size and coating them with a biocompatible surfactant. The pluronic wrapped PCPDTBSe (PW‐PCPDTBSe) nanoparticles (40–60 nm) showed excellent aqueous stability compared to the PW‐PCPDTBSe nanofibers (d = 20–60 nm, l = 200–1000 nm) and previously synthesized PCPDTBSe nanoparticles (150 nm). Under stimulation from 800 nm near infrared light (3 W, 1 min), the PW‐PCPDTBSe nanoparticles showed greater heat generation (ΔT = 47 °C) compared to bare PCPDTBSe nanoparticles and PW‐PCPDTBSe nanofibers (ΔT = 35 °C for both). Cytotoxicity studies determined that both the PW‐PCPDTBSe nanoparticles and PW‐PCPDTBSe nanofibers displayed no significant toxicity toward either noncancerous small intestinal cells (FHs 74 Int) or colorectal cancer cells (CT26). Photothermal ablation studies confirmed that both the PW‐PCPDTBSe nanoparticles and the PW‐PCPDTBSe nanofibers can be used as localized photothermal agents to eradicate colorectal cancer cells due to their excellent ablation efficiency (>95% cell death at 15 µg/mL concentration). © 2014 Wiley Periodicals, Inc. J. Polym. Sci., Part A: Polym. Chem. 2014 , 52, 1622–1632     

Photoinduced variations in the size of nanoparticles of CdS in colloidal solutions

The possibility of decreasing the size of colloidal nanoparticles of CdS in the oxidative photocorrosion reaction in the presence of methylviologen and of increasing their size during photocatalytic reduction of sulfur in ethanol in the presence of cadmium acetate. A dependence of the quantum yield of the latter reaction on the initial size of CdS nanoparticles was observed, which was interpreted as a result of quantum size effects. __________ Translated from Teoreticheskaya i éksperimental’naya Khimiya, Vol. 43, No. 3, pp. 170–175, May–June, 2007.     

Synthesis and applications of silver nanoparticles

Over the past few decades, nanoparticles of noble metals such as silver exhibited significantly distinct physical, chemical and biological properties from their bulk counterparts. Nano-size particles of less than 100 nm in diameter are currently attracting increasing attention for the wide range of new applications in various fields of industry. Such powders can exhibit properties that differ substantially from those of bulk materials, as a result of small particle dimension, high surface area, quantum confinement and other effects. Most of the unique properties of nanoparticles require not only the particles to be of nano-sized, but also the particles be dispersed without agglomeration. Discoveries in the past decade have clearly demonstrated that the electromagnetic, optical and catalytic properties of silver nanoparticles are strongly influenced by shape, size and size distribution, which are often varied by varying the synthetic methods, reducing agents and stabilizers. Accordingly, this review presents different methods of preparation silver nanoparticles and application of these nanoparticles in different fields.     

Preparation of highly active and dispersed platinum nanoparticles on mesoporous Al-MCM-48 and their activity in the hydroisomerisation of n-octane

Platinum nanoparticles supported on Al-MCM-48 materials have been prepared. The resultant catalysts have been characterized by means of XRD, N2 physisorption experiments, scanning electron microscopy (SEM), transmission electron microscopy (TEM), temperature-programmed reduction (TPR), and diffuse reflectance infrared Fourier-transform spectroscopy (DRIFTS). The activity of these nanoparticles has been tested in relation to the hydroisomerisation of n-octane. The catalytic activities were typically 50 %, with selectivities in the isomerisation process in excess of 70 %, favouring the formation of the 3-methylheptane isomer with respect to the 2- and 4-methylheptanes.