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Malignant tumor is still a leading threat to human health. Despite the rapid development of targeted therapeutic strategies, any treatment specifically acting on single target would inevitably suffer from tumor resistance, largely due to the genetic instability and variability of tumor cells. Thus, traditional therapies such as broad-spectrum chemotherapy would certainly occupy an important position in clinical cancer therapy. Nevertheless, most chemotherapeutic drugs have long been criticized for unsatisfactory therapeutic efficacy with severe off-target toxicity. Although several chemotherapeutic nanomedicines with improved therapeutic safety have been applied in clinics, the therapeutic outcomes still do not fulfill expectation. To address this challenge, enormous efforts have been devoted to developing novel nano-formulations for efficient delivery of chemotherapeutic drugs. Herein, we aim to outline the latest progression in the emerging nanomedicines of paclitaxel (PTX), with special attention to the functional nanocarriers, self-delivering prodrug-nanoassemblies and combination nanotherapeutics of PTX. Finally, the challenges and opportunities of these functional PTX nanomedicines in clinical translation are spotlighted., (Copyright © 2021. Published by Elsevier B.V.)

Purification is a necessary step before the application of nanocrystals (NCs), since the excess matter in nanoparticles solution usually causes a disadvantage to their subsequent coupling or assembling with other materials. In this work, a novel salts-based precipitation technique is originally developed for the precipitation and size-selective precipitation of aqueous NCs. Simply by addition of salts, NCs can be precipitated from the solution. After decantation of the supernatant solution, the precipitates can be dispersed in water again. By means of adjusting the addition amount of salt, size-selective precipitation of aqueous NCs can be achieved. Namely, the NCs with large size are precipitated preferentially, leaving small NCs in solution. Compared with the traditional nonsolvents-based precipitation technique, the current one is simpler and more rapid due to the avoidance of condensation and heating manipulations used in the traditional precipitation process. Moreover, the salts-based precipitation technique was generally available for the precipitation of aqueous nanoparticles, no matter if there were semiconductor NCs or metal nanoparticles. Simultaneously, the cost of the current method is also much lower than that of the traditional nonsolvents-based precipitation technique, making it applicable for mass purification of aqueous NCs.

Near-infrared (NIR) light can penetrate biological samples and even tissues without causing sample damage and avoid autofluorescence from biological samples in fluorescence detection. Thus, a luminescence resonance energy transfer (LRET)-based immunoassay that can be excited by NIR irradiation is a promising approach to the analysis of biological samples. Here we demonstrate the use of NIR-to-visible upconversion nanoparticles (UCNPs) as an energy donor, which can emit a visible light upon the NIR irradiation, and gold nanoparticles (Au NPs) as an energy acceptor, which can absorb the visible light emitted from the donor, to develop a sandwich-type LRET-based immunoassay for the detection of goat antihuman immunoglobulin G (IgG). Amino-functionalized NaYF(4):Yb, Er UCNPs and Au NPs were first prepared and then conjugated with the human IgG and rabbit antigoat IgG, respectively. The NIR-excited fluorescence emission band of human IgG-conjugated NaYF(4):Yb, Er UCNPs (lambda(max) = 542 nm) partially overlaps with the visible absorption band of the rabbit antigoat IgG-conjugated colloidal Au NPs (lambda(max) = 530 nm), satisfying the requirement of spectral overlap between donors and acceptors for LRET. A LRET system was then formed when goat antihuman IgG was added to a mixture of human IgG-modified NaYF(4):Yb, Er UCNPs (donor) and rabbit antigoat IgG-modified Au NPs (acceptor). The sandwich-type immunoreactions between the added goat antihuman IgG (primary antibody) and the two different proteins (antigen and secondary antibody on the surface of the donors and acceptors, respectively) cross-bridge the donors and acceptors and thus shorten their spacing, leading to the occurrence of LRET from UCNPs to Au NPs upon NIR irradiation. As a result, the quenching of the NIR-excited fluorescence of the UCNPs is linearly correlated to the concentration of the goat antihuman IgG (in the range of 3-67 microg x mL(-1)) present in the system, enabling the detection and quantification of the antibody. Such sandwich-type LRET-based approach can reach a very low detection limit of goat antihuman IgG (0.88 microg x mL(-1)), indicating that this method is applicable for the trace protein detection. This approach is expected to be extended to the detection of other biological molecules once the donor and acceptor nanoparticles are modified by proper molecules that can recognize the target biomolecules.

The electrochemical properties of new homogenous thionine (TH)-doped silica nanoparticles as a mediator were studied. The nanocomposites were synthesized by using sonochemical method. The sonication induced the strong combination between dye molecules and silica in the construction of the composites. By controlling reaction condition, face rougher uniform spheres could be achieved. The as-prepared nanocomposites can be used as the mediator to construct the biosensors with horseradish peroxidase coimmobilized in the gelatine matrix and cross-linked with formaldehyde. The described experimental evidences show the different ratio of ethanol to water can induce the changes in their diameters. As a consequence, the resulting biosensors exhibited amperometric response decreased with the increase of the spherical size. The resulting biosensor mediated by the 100 nm diameter of TH-doped silica nanoparticles exhibited very fast amperometric response, good stability and could be effectively used for the study of the electrocatalytic properties.

Background: Characterization of early breast cancer circulating tumor cells (CTCs) may provide valuable information on tumor metastasis. Methods: We used immunomagnetic nanospheres to capture CTCs from the peripheral blood of eight early breast cancer patients and then performed single‐cell RNA sequencing using our proposed bead‐dd‐seq method. Results: CTCs displayed obvious tumor cell characteristics, such as the activation of oxidative stress, proliferation, and promotion of metastasis. CTCs were clustered into two subtypes significantly correlated with the lymph node metastasis status of patients. CTCs in subtype 1 showed a strong metastatic ability because these CTCs have the phenotype of partial epithelial‐mesenchymal transition and enriched transcripts, indicating breast cancer responsiveness and proliferation. Furthermore, DNA damage repair pathways were significantly upregulated in subtype 1. We performed in vitro and in vivo investigations, and found that cellular oxidative stress and further DNA damage existed in CTCs. The activated DNA damage repair pathway in CTCs favors resistance to cisplatin. A checkpoint kinase 1 inhibitor sensitized CTCs to cisplatin in mouse models of breast cancer metastasis. Conclusion: The present study dissects the molecular characteristics of CTCs from early‐stage breast cancer, providing novel insight into the understanding of CTC behavior in breast cancer metastasis. [ABSTRACT FROM AUTHOR]

SiO2 encapsulated quantum dots (QDs@SiO2) have been widely adopted for fabricating high-performance phosphor-converted light-emitting diodes (QCLEDs). However, the impact of SiO2 thickness on the optical properties of QDs in QCLEDs remains largely unexplored. In this work, we studied the combined effects of light scattering, heat accumulation, and concentration quenching of QD@SiO2 on optical performance of QCLEDs. QDs@SiO2 nanoparticles with SiO2 thickness of 10–60 nm were developed to perform the experimental tests and optical and thermal simulations. Our study reveals that at low power density, QD@SiO2 with 20–30-nm SiO2 shell display optimal efficiency owning to suppressed self-absorption quenching and enhanced light scattering. However, because of heat accumulation inside QDs@SiO2 at high power density, thin SiO2 shell (10–15 nm) is more favorable to reduce thermal quenching and maintain luminous efficiency of QCLEDs. This study provides guidance for the development of appropriate QDs@SiO2 structure to meet application requirements of different QCLED devices. [ABSTRACT FROM AUTHOR]

Cathode design is indispensable for building Li-O2 batteries with long cycle life. A composite of carbon-wrapped Mo2C nanoparticles and carbon nanotubes is prepared on Ni foam by direct hydrolysis and carbonization of a gel composed of ammonium heptamolybdate tetrahydrate and hydroquinone resin. The Mo2C nanoparticles with well-controlled particle size act as a highly active oxygen reduction reactions/oxygen evolution reactions (ORR/OER) catalyst. The carbon coating can prevent the aggregation of the Mo2C nanoparticles. The even distribution of Mo2C nanoparticles results in the homogenous formation of discharge products. The skeleton of porous carbon with carbon nanotubes protrudes from the composite, resulting in extra voids when applied as a cathode for Li-O2 batteries. The batteries deliver a high discharge capacity of ≈10 400 mAh g−1 and a low average charge voltage of ≈4.0 V at 200 mA g−1. With a cutoff capacity of 1000 mAh g−1, the Li-O2 batteries exhibit excellent charge-discharge cycling stability for over 300 cycles. The average potential polarization of discharge/charge gaps is only ≈0.9 V, demonstrating the high ORR and OER activities of these Mo2C nanoparticles. The excellent cycling stability and low potential polarization provide new insights into the design of highly reversible and efficient cathode materials for Li-O2 batteries. [ABSTRACT FROM AUTHOR]

A novel binder-free electrode for lithium–oxygen batteries has been prepared by electrodepositing a Co3O4 layer onto a pretreated TiO2 fiber mesh, formed on nickel foam by an electrospinning method. The Co3O4 depositing layer is composed of Co3O4 nanoflakes, forming a uniform flower-like porous structure. The Co3O4 nanoflakes within the depositing layer provide a large amount of catalytic active sites for oxygen evolution and reduction reactions. The three-dimensional porous network of the Co3O4 depositing layer can not only facilitate the transportation of ions and electrolyte within the electrode, but also provide plenty of space to accommodate Li2O2 species formed during the discharge process. The Co3O4 spheres embedded in the TiO2 fiber mesh, formed by the treatment of a suspension of cobaltammine precipitate, function as anchors to prevent the detachment of the Co3O4 layer from the current collector, resulting in excellent structural and cycling stability. Only a slight specific capacity decay is observed at full discharge/charge after 80 cycles. This work demonstrates the important factors in the preparation of binder-free cathodes for high performance lithium–oxygen batteries. [ABSTRACT FROM AUTHOR]

In this paper, a novel fluorescence biosensing strategy based on GR-5 DNAzyme has been developed for the simple, rapid, sensitive and selective detection of lead ions (Pb2+) by using gold nanoparticles (AuNPs) as the fluorescence quencher. Data from dynamic light scattering (DLS) and zeta potential measurements demonstrated that GR-5 DNAzyme functionalized AuNPs were successfully prepared with good dispersion in aqueous solution. The carboxyfluorescein (FAM) labeled GR-5 DNAzyme was in close proximity to the AuNPs and the fluorescence signal was quenched, when the DNAzyme was modified on the surface of AuNPs. In the presence of Pb2+ ions, the GR-5 DNAzyme was activated and cleaved the substrate strand at the RNA site (rA) into two parts, which led to a short FAM-linked oligonucleotide fragment being released from the surface of the AuNPs, and the fluorescence intensity was gradually recovered. By taking advantage of the high fluorescence quenching efficiency of AuNPs, our proposed method exhibited a high sensitive detection of Pb2+ ions with a detection limit of 250 pM and a linear range from 1 nM to 100 nM. With the choice of a classic GR-5 DNAzyme instead of 8-17 DNAzyme as the catalytic unit, the selectivity of this strategy was obviously improved compared with previously reported methods. Moreover, this biosensing strategy was also used for the determination of Pb2+ in lake water samples with satisfying results. The strategy would find potential applications in environmental and biomedical fields. [ABSTRACT FROM AUTHOR]

Abstract: 2-Hydroxypropyl-β-cyclodextrin was used as a template to fabricate hollow spherical copper sulfide nanoparticle assemblies in the presence of sonication. The as-prepared spheres were uniform in shape and have well-defined shells composed of one-layered CuS nanoparticles. The interaction between the Cu ions and HP-β-CD was confirmed by the FTIR. The effects of the sonication were studied and a possible self-assembly mechanism was discussed. [Copyright &y& Elsevier]

A novel sonochemical method for preparation of mercury selenide has been developed based on the reaction of mercury acetate and sodium selenosulfate in an aqueous system at room temperature. Different complexing agents were used to control the particle size. X-ray powder diffraction (XRD), transmission electron microscopy (TEM) and X-ray photoelectron spectroscopy (XPS) were used to determine the phase, purity, size and morphology of the products. The results showed that the HgSe nanoparticles with different sizes could be obtained in the presence of complexing agents. [Copyright &y& Elsevier]

Abstract: A photochemical reaction route was developed to synthesize bismuth selenide (Bi2Se3) nanoparticles and nanorods. In an aqueous solution, bismuth nitrate (Bi(NO3)3) reacted with sodium selenosufate in the presence of reducing agent and complexing agent, and the dispersed Bi2Se3 nanoparticles were obtained with the average size of 35 nm. The nanorods were prepared via an alumina template route in the same solution. We carried out experiments to study the formation mechanism in the morphology control of the products and found that series of factors played an effective role including the irradiation time, pH value, the reducing agents and the species of complexing agents. The products were characterized by X-ray diffraction (XRD) and transmission electron microscopy (TEM). [Copyright &y& Elsevier]

Porous spherical CuI nanoparticles with an average diameter of 0.3–0.6 μm have been prepared by a simple reaction between CuO suspension, NH2OH · HCl and KI in the presence of deionized gelatin at room temperature. [Copyright &y& Elsevier]

Abstract: We report the first observation of electrogenerated chemiluminescence (ECL) from CdS spherical assemblies in both nonaqueous system and aqueous system. The CdS spherical assemblies consist of CdS nanocrystals about 5 nm in diameter. Four ECL peaks were found under cyclic voltammetric conditions. According to the annihilation mechanism and two-equivalent adsorbed surface state theory, the mechanism for ECL peaks was proposed. The morphology of the CdS spherical assemblies is proved to play an important role in maintaining the stability of partial electrogenerated species to generate the ECL light. [Copyright &y& Elsevier]

Abstract: Up-conversion nanoparticles (UCNPs), which can convert a longer wavelength radiation to a shorter wavelength radiation, have great potential use as bio-labels in biological detection. However, these NPs usually cannot be used directly unless their surface is further modified. Herein, we developed a novel and straightforward method for the synthesis of monodisperse NaYF4:Yb,Er/Polymer UCNPs. The resultant UCNPs exhibited a pure hexagonal phase, strong UC fluorescent intensity, and a uniform size of about 40nm, which were characterized by XRD, luminescence spectroscopy and TEM, respectively. FT-IR spectra revealed that these NPs were coated with a layer of hydrophilic polymers (including PVP, PEG, PAA and PEI), thus the NPs could be dispersed in water easily. More importantly, the PAA and PEI coated NPs were functionalized by –COOH and –NH2 groups, respectively, which were expected to be used for further bio-conjugation. [Copyright &y& Elsevier]