Search

Minimizing the interaction of nanomedicines with the mononuclear phagocytic system (MPS) is a critical challenge for their clinical translation. Conjugating polyethylene glycol (PEG) to nanomedicines is regarded as an effective approach to reducing the sequestration of nanomedicines by the MPS. However, recent concerns about the immunogenicity of PEG highlight the demand of alternative low‐fouling polymers as innovative coating materials for nanoparticles. Herein, a highly hydrophilic sulfoxide‐containing polymer—poly(2‐(methylsulfinyl)ethyl acrylate) (PMSEA)—is used for the surface coating of iron oxide nanoparticles (IONPs). It is found that the PMSEA polymer coated IONPs have a more hydrophilic surface than their PEGylated counterparts, and demonstrate remarkably reduced macrophage cellular uptake and much less association with human plasma proteins. In vivo study of biodistribution and pharmacokinetics further reveals a much‐extended blood circulation (≈2.5 times longer in terms of elimination half‐life t1/2) and reduced accumulation (approximately two times less) in the organs such as the liver and spleen for IONPs coated by PMSEA than those by PEG. It is envisaged that the highly hydrophilic sulfoxide‐containing polymers have huge potential to be employed as an advantageous alternative to PEG for the surface functionalization of a variety of nanoparticles for long circulation and improved delivery. [ABSTRACT FROM AUTHOR]

[Display omitted] Central nervous system (CNS) disorders affect as many as 1.5 billion people globally. The limited delivery of most imaging and therapeutic agents into the brain is a major challenge for treatment of CNS disorders. With the advent of nanotechnologies, controlled delivery of drugs with nanoparticles holds great promise in CNS disorders for overcoming the blood–brain barrier (BBB) and improving delivery efficacy. In recent years, magnetic iron oxide nanoparticles (MIONPs) have stood out as a promising theranostic nanoplatform for brain imaging and drug delivery as they possess unique physical properties and biodegradable characteristics. In this review, we summarize the recent advances in MIONP-based platforms as imaging and drug delivery agents for brain diseases. We firstly introduce the methods of synthesis and surface functionalization of MIONPs with emphasis on the inclusion of biocompatible polymers that allow for the addition of tailored physicochemical properties. We then discuss the recent advances in in vivo imaging and drug delivery applications using MIONPs. Finally, we present a perspective on the remaining challenges and possible future directions for MIONP-based brain delivery systems. [ABSTRACT FROM AUTHOR]

Despite its great promise in non-invasive treatment of cancers, magnetic resonance-guided focused ultrasound surgery (MRgFUS) is currently limited by the insensitivity of magnetic resonance imaging (MRI) for visualization of small tumors, low efficiency of in vivo ultrasonic energy deposition, and damage to surrounding tissues. We hereby report the development of an active targeting nano-sized theranostic superparamagnetic iron oxide (SPIO) platform for significantly increasing the imaging sensitivity and energy deposition efficiency using a clinical MRgFUS system. The surfaces of these PEGylated SPIO nanoparticles (NPs) were decorated with anti-EGFR (epidermal growth factor receptor) monoclonal antibodies (mAb) for targeted delivery to lung cancer with EGFR overexpression. The potential of these targeted nano-theranostic agents for MRI and MRgFUS ablation was evaluated in vitro and in vivo in a rat xenograft model of human lung cancer (H460). Compared with nontargeting PEGylated SPIO NPs, the anti-EGFR mAb targeted PEGylated SPIO NPs demonstrated better targeting capability to H460 tumor cells and greatly improved the MRI contrast at the tumor site. Meanwhile, this study showed that the targeting NPs, as synergistic agents, could significantly enhance the efficiency for in vivo ultrasonic energy deposition in MRgFUS. Moreover, we demonstrated that a series of MR methods including T2-weighted image (T2WI), T1-weighted image (T1WI), diffusion-weighted imaging (DWI) and contrast-enhanced T1WI imaging, could be utilized to noninvasively and conveniently monitor the therapeutic efficacy in rat models by MRgFUS. [ABSTRACT FROM AUTHOR]

Metal–organic frameworks (MOFs) comprising metal ions or clusters coordinated to organic ligands have become a class of emerging materials in the field of biomedical research due to their bespoke compositions, highly porous nanostructures, large surface areas, good biocompatibility, etc. So far, many MOFs have been developed for imaging and therapy purposes. The unique porous nanostructures render it possible to adsorb and store various substances, especially for gaseous molecules, which is rather challenging for other types of delivery vectors. In this review, we mainly focus on the recent development of MOFs for controlled release of three gaseous transmitters, namely, nitric oxide (NO), carbon monoxide (CO), and hydrogen sulfide (H2S). Although these gaseous molecules have been known as air pollutants for a long time, much evidence has been uncovered regarding their important physiological functions as signaling molecules. These signaling molecules could be either physically absorbed onto or covalently linked to MOFs, allowing for the release of loaded signaling molecules in a spontaneous or controlled manner. We highlight the designing concept by selective examples and display their potential applications in many fields such as cancer therapy, wound healing, and anti-inflammation. We hope more effort could be devoted to this emerging fields to develop signaling molecule-releasing MOFs with practical applications. [ABSTRACT FROM AUTHOR]

Light‐assisted 3D printing technology, which uses a light source to solidify a photopolymerizable prepolymer solution, has shown great potential in the development of antibacterial hydrogels with high‐resolution, specific features and functionalities. 3D‐printed hydrogels with customized structures and antibacterial functions are widely used in tissue engineering, regenerative medicine, wound healing, and implants to advance the modeling and treatment of diseases. In the current review, an overview of light‐assisted 3D printing technologies is first provided for the development of antibacterial hydrogels. Novel strategies involving the integration of inorganic nanomaterials, antibiotics, and functional polymers into 3D‐printed hydrogels for the enhancement of antibacterial effects are then discussed. Finally, the perspective of advanced design using artificial intelligence and machine learning is proposed, providing a comprehensive yet succinct examination of 3D‐printed hydrogels for antibacterial purposes. [ABSTRACT FROM AUTHOR]

Patients with brain cancers including medulloblastoma lack treatments that are effective long‐term and without side effects. In this study, a multifunctional fluoropolymer‐engineered iron oxide nanoparticle gene‐therapeutic platform is presented to overcome these challenges. The fluoropolymers are designed and synthesized to incorporate various properties including robust anchoring moieties for efficient surface coating, cationic components to facilitate short interference RNA (siRNA) binding, and a fluorinated tail to ensure stability in serum. The blood‐brain barrier (BBB) tailored system demonstrates enhanced BBB penetration, facilitates delivery of functionally active siRNA to medulloblastoma cells, and delivers a significant, almost complete block in protein expression within an in vitro extracellular acidic environment (pH 6.7) – as favored by most cancer cells. In vivo, it effectively crosses an intact BBB, provides contrast for magnetic resonance imaging (MRI), and delivers siRNA capable of slowing tumor growth without causing signs of toxicity – meaning it possesses a safe theranostic function. The pioneering methodology applied shows significant promise in the advancement of brain and tumor microenvironment‐focused MRI‐siRNA theranostics for the better treatment and diagnosis of medulloblastoma. [ABSTRACT FROM AUTHOR]

Functional liquid metal nanoparticles (NPs), produced from eutectic alloys of gallium, promise new horizons in the fields of sensors, microfluidics, flexible electronics, catalysis, and biomedicine. Here, the development of a vapor cavity generating ultrasonic platform for nebulizing liquid metal within aqueous media for the one‐step production of stable and functional liquid metal NPs is shown. The size distribution of the NPs is fully characterized and it is demonstrated that various macro and small molecules can also be grafted onto these liquid metal NPs during the liquid‐based nebulization process. The cytotoxicity of the NPs grafted with different molecules is further explored. Moreover, it is shown that it is possible to control the thickness of the oxide layer on the produced NPs using electrochemistry that can be embedded within the platform. It is envisaged that this platform can be adapted as a cost‐effective and versatile device for the rapid production of functional liquid metal NPs for future liquid metal‐based optical, electronic, catalytic, and biomedical applications. An ultrasonic platform for nebulizing liquid metal within aqueous media is developed to achieve one‐step production of stable and functional liquid metal nanoparticles grafted with different molecules. This platform is able to control the thickness of the oxide layer on the produced nanoparticles using embedded electrochemical components. The demonstrated technique may enable future liquid metal‐based electronic, catalytic, and biomedical applications. [ABSTRACT FROM AUTHOR]

Nanoengineering the composition and morphology of functional nanoparticles endows them to perform multiple tasks and functions. An intriguing strategy for creating multifunctional nanomaterials involves the construction of core–shell nanostructures, which have enabled promising applications in biomedicine, energy, sensing, and catalysis. Here, a straightforward nanoengineering approach is presented utilizing liquid metal nanoparticles and galvanic replacement to create diverse core–shell nanostructures. Controlled nanostructures including liquid metal core‐gold nanoparticle shell (LM@Au), gold nanoparticle core‐gallium oxide shell (Au@Ga oxide), and hollow Ga oxide nanoparticles are successfully fabricated. Remarkably, these investigations reveal that LM@Au exhibits exceptional photothermal performance, achieving an impressive conversion efficiency of 65.9%, which is five times that of gold nanoparticles. By leveraging the high photothermal conversion efficiency and excellent biocompatibility of LM@Au, its promising application in hyperthermia cancer therapy is demonstrated. This simple yet powerful nanoengineering strategy opens new avenues for the controlled synthesis of complex core–shell nanostructures, advancing various fields beyond biomedicine. [ABSTRACT FROM AUTHOR]

Droplet‐based microfluidics represents a disruptive technology in the field of chemistry and biology through the generation and manipulation of sub‐microlitre droplets. To avoid droplet coalescence, fluoropolymer‐based surfactants are commonly used to reduce the interfacial tension between two immiscible phases to stabilize droplet interfaces. However, the conventional preparation of fluorosurfactants involves multiple steps of conjugation reactions between fluorinated and hydrophilic segments to form multiple‐block copolymers. In addition, synthesis of customized surfactants with tailored properties is challenging due to the complex synthesis process. Here, we report a highly efficient synthetic method that utilizes living radical polymerization (LRP) to produce fluorosurfactants with tailored functionalities. Compared to the commercialized surfactant, our surfactants outperform in thermal cycling for polymerase chain reaction (PCR) testing, and exhibit exceptional biocompatibility for cell and yeast culturing in a double‐emulsion system. This breakthrough synthetic approach has the potential to revolutionize the field of droplet‐based microfluidics by enabling the development of novel designs that generate droplets with superior stability and functionality for a wide range of applications. [ABSTRACT FROM AUTHOR]

Droplet‐based microfluidics represents a disruptive technology in the field of chemistry and biology through the generation and manipulation of sub‐microlitre droplets. To avoid droplet coalescence, fluoropolymer‐based surfactants are commonly used to reduce the interfacial tension between two immiscible phases to stabilize droplet interfaces. However, the conventional preparation of fluorosurfactants involves multiple steps of conjugation reactions between fluorinated and hydrophilic segments to form multiple‐block copolymers. In addition, synthesis of customized surfactants with tailored properties is challenging due to the complex synthesis process. Here, we report a highly efficient synthetic method that utilizes living radical polymerization (LRP) to produce fluorosurfactants with tailored functionalities. Compared to the commercialized surfactant, our surfactants outperform in thermal cycling for polymerase chain reaction (PCR) testing, and exhibit exceptional biocompatibility for cell and yeast culturing in a double‐emulsion system. This breakthrough synthetic approach has the potential to revolutionize the field of droplet‐based microfluidics by enabling the development of novel designs that generate droplets with superior stability and functionality for a wide range of applications. [ABSTRACT FROM AUTHOR]

The blood-brain barrier (BBB) protects the brain from toxic substances within the bloodstream and keeps the brain's homeostasis stable. On the other hand, it also represents the main obstacle in the treatment of many CNS diseases. Among different techniques, nanoparticles have emerged as promising tools to enhance brain drug delivery of therapeutic molecules. For successful drug delivery, nanoparticles may either modulate BBB integrity or exploit transport systems present on the endothelium. In this review, we present two different nanoparticles to enhance brain drug delivery. Poly(butyl cyanoacrylate) nanoparticles were shown to induce a reversible disruption of the BBB in vitro which may be exploited by simultaneous injection of the drug in question. By coating the poly(butyl cyanoacrylate) nanoparticles with, e.g., ApoE, it is also possible to circumvent the BBB via the LDL-receptor. Another example of the use of receptor-mediated endocytosis to enhance brain uptake of nanoparticles are poly(ethylene glycol)-coated Fe3O4 nanoparticles which are covalently attached to lactoferrin. These nanoparticles have been shown to facilitate the transport via the lactoferrin receptor, and so could then be used for magnetic resonance imaging. [ABSTRACT FROM AUTHOR]

Electrospraying technique has attracted much attention in food science because of its importance for biological macromolecule encapsulation of food bioactive substances. The purpose of this review is to overview the electrospraying technique and its recent application advances for biological macromolecule encapsulation of food bioactive substances. First, the history, principles, setup, and products of the electrospraying technique are briefly introduced. Second, the application of electrosprayed nano-, micro-, and millimeter-sized particles with solid, porous, core-shell, and multi-core structures for biological macromolecule encapsulation of nutrients is reviewed. Thirdly, the application of electrosprayed micro- and millimeter-sized particles for biological macromolecule encapsulation of probiotics is analyzed. Finally, the application of electrospraying technique for biological macromolecule encapsulation of food bioactive substances is summarized and an outlook is provided. This review will provide guide instruction to the research and development of electrosprayed particles for biological macromolecule encapsulation of food bioactive substances in novel food development. It will be useful for those who are interested to enter this field. [ABSTRACT FROM AUTHOR]

As an alternative choice to CdSe nanocrystals synthesized in organic phase, CdTe nanocrystals synthesized in aqueous solution, have attracted increasing research interests in recent years. This feature article summarizes the aqueous solution-based syntheses, some optoelectronic applications, and bioapplications of CdTe nanocrystals, with emphasis on the recent progresses in related fields. [ABSTRACT FROM AUTHOR]

Abstract: A stable and sensitive toxin residues immunosensor based on the relaxation of magnetic nanoparticles was developed. The method was performed in one reaction and offered sensitive, fast detection of target toxin residues in water. The target analyte, microcystin-LR (MC-LR) in Tai lake water, competed with the antigens on the surface of the magnetic nanoparticles and then influenced the formation of aggregates of the magnetic nanoparticles. Accordingly, the magnetic relaxation time of the magnetic nanoparticles was changed under the effect of the target analyte. The calibration curve was deduced at different concentrations of the target analyte. The limit of detection (LOD) of MC-LR was 0.6ngg−1 and the detection range was 1–18ngg−1. Another important feature of the developed method was the easy operation: only two steps were needed (1) to mix the magnetic nanoparticle solution with the sample solution and (2) read the results through the instrument. Therefore, the developed method may be a useful tool for toxin residues sensing and may find widespread applications. [Copyright &y& Elsevier]

• Iron oxide nanoparticles can induce reversible phase transitions in lipid systems. • Transitions are induced by alternating magnetic field. • Particle size and hydrophobicity influence reversibility. • Phase transitions can be used to control drug release. Nanostructured lipid-based liquid crystalline (LLC) systems can display different drug release rates and also be stimuli-responsive, rendering them the potential to serve as 'on-demand' drug delivery systems. In this study, a magnetically-responsive cubic phase nanocomposite was engineered by doping iron oxide nanoparticles (IONPs) into a phytantriol (PHYT)-based lipid that exhibits transformation in nanostructure under external alternating magnetic field (AMF). The effects of IONP surface hydrophilicity/hydrophobicity, size and concentration were determined in dispersed systems, and the effect of hydration state of the system was also assessed. Time-resolved small angle X-ray scattering (SAXS) was used to probe the impact of these variables on the transformation of nanostructure with and without the application of AMF. The inclusion of both hydrophobic and hydrophilic IONPs reduced the temperature of the phase transition from the inverted bicontinuous cubic (V 2) phase to inverted hexagonal (H 2) phase and imparted magnetic-responsiveness to the systems. The size of the IONPs played an important role in governing the phase reversibility of the dispersed systems, while the concentration of the IONPs had more impact on the phase behaviour of the bulk systems. These successfully demonstrated a completely reversible magneto-responsive phase transition in the nanostructured LLC systems through optimising the selection of IONPs. [ABSTRACT FROM AUTHOR]

Carbon monoxide (CO) has emerged as a potential therapeutic agent for the treatment of many diseases. However, the therapeutic outcome is highly dependent on the dosages and administration sites. Hence, there is mounting interest in the development of CO‐releasing materials to accomplish site‐specific and dose‐controlled delivery of CO. Herein, a micellar nanoparticle platform for the photo‐mediated release of CO by using amphiphilic triblock copolymers bearing CO‐releasing moieties of 3‐hydroxylflavone (3‐HF) derivatives within the middle blocks is developed. These micelles are relatively stable without CO leakage but undergo visible light‐mediated CO release and simultaneous main chain scission. Moreover, these micellar nanoparticles are cytocompatible regardless of light irradiation, which shows unique anti‐inflammatory performance only after light irradiation as a result of photo‐triggered CO release. This work may represent the first example of main‐chain degradable micellar nanocarriers with controlled CO‐releasing performance for potential anti‐inflammatory applications. [ABSTRACT FROM AUTHOR]

Stimuli-responsive nano-assemblies are emerging as promising drug delivery systems (DDSs) with spatial and temporal tenability, which can undergo structural transition for controlled drug release upon excitation by either exogenous or endogenous stimuli. Particularly, exogenous stimuli-responsive nano-assemblies based remotely controlled DDSs, have received much attention due to their accuracy and reliability realized by tunable exogenous triggers such as light, magnetic field, or temperature. In this review, we will briefly introduce the current state-of-the-art technologies of nano-assembly synthesis and summarize the recent advances in remotely controlled nano-assembly-based DDSs activated by different exogenous stimuli or endogenous/exogenous dual-stimuli. Furthermore, the pioneering progress in bio-cleanable stimuli-responsive nano-assemblies that holds great relevance to clinical translation will be described. Finally, we will conclude with our perspectives on current issues and future development of this field. The objective of this review is to outline current advances of nano-assemblies as remotely controlled DDSs, in hopes of accelerating the future development of intelligent nanomedicines. The current state-of-the-art technologies for nano-assemblies construction, and their applications in remotely controlled nano-assembly-based DDSs. Unlabelled Image • Stimuli-responsive nano-assemblies are promising drug delivery systems for controlled drug release. • Nano-assemblies responsive to exogenous stimuli are employed for remotely controlled drug delivery. • The properties of the nano-assembly-based drug delivery systems are dependent on stimuli-triggered structural transition. • Bio-cleanable stimuli-responsive nano-assemblies hold great potential for clinical translation. [ABSTRACT FROM AUTHOR]

Nanoparticle tracers with small sizes and large magnetization are critical for biomedical imaging and especially for magnetic particle imaging (MPI). Small size is important for accessing future intracellular and neurological in vivo applications Here, we show <15 nm nanoparticles made of zero valent iron cores, iron oxide shells and coated with a strongly binding brush co-polymer are effective MPI tracers. The small nanoparticle cores create a hydrodynamic diameter that is half of the state-of-the-art iron oxide tracers while the strongly magnetic zero valent iron maintains similar MPI signal magnitude and resolution. [ABSTRACT FROM AUTHOR]

Abstract Many types of collagens from different sources have been used in food, pharmaceutics, biomedicine, tissue engineering, etc. Their physicochemical properties have been widely investigated to understand their behaviors and functions. However, the polymorphism and stability of collagen nanostructures have not been systematically studied. In the current manuscript, polymorphism and stability of nanostructures of three types of collagens from bovine flexor tendon, rat tail, and tilapia skin are characterized by sodium dodecyl sulfate-polyacrylamide gel electrophoresis (SDS-PAGE), atomic force microscopy (AFM), and attenuated total reflectance Fourier transform infrared (ATR-FTIR) spectrometry. SDS-PAGE results show loading volumes have no influence on the protein bands of three types of collagens except the intensity, whereas collagen concentrations have obvious effects. AFM results show all the three types of collagens have multiple nanostructures, which are concentration-dependent. AFM results also show collagen nanostructures change with incubation time at 37 °C. According to the ATR-FTIR results, the nanostructures changes are associated with the change of protein secondary structures. These results demonstrate three types of collagens have different nanostructures, stability, protein secondary structures, and SDS-PAGE behaviors. This work also indicates that the nanostructures and secondary structures of collagens can be controlled by adjusting concentration and incubation time for the three types of collagens, which provide simple ways to design and prepared desired nanostructures of collagen-based foods. It will be also beneficial to fundamental understanding of the collagen nanoscale structure formation in different collagen-based foods. Graphical abstract Image 1 Highlights • Collagens from bovine flexor tendon, rat tail, and tilapia skin were analyzed. • Collagen concentrations affected their SDS-PAGE behaviors. • Collagens had multiple nanostructures that were concentration-dependent. • Collagens nanostructures changed with incubation time. • Secondary protein structures changed with incubation time. [ABSTRACT FROM AUTHOR]

Collagen plays a pivotal role in human physiological functions and extracted collagen has multiple potential applications. Tilapia skin can be applied to extract collagen for maximizing the profit of tilapia processing. Electrospinning/electrospraying is novel micro- and nano-techniques to fabricate microfibers and microspheres in a simple and easy way. In this work, we extract collagens from tilapia skin by three types of extraction methods: acetic acid method, hot water method, and sodium hydroxide method. Then, these extracted collagens are characterized by sodium dodecyl sulfate-polyacrylamide gel electrophoresis and Fourier transform infrared spectrometry. These extracted collagens have different molecular weights and different protein secondary structures. Finally, these extracted collagens are applied to fabricate electrosprayed microspheres, electrospun microfibers, and mixed microspheres/microfibers with multiple potential applications by adjusting the collagen concentrations. Higher polymer molecular weight only needs lower concentration to produce microfibers. The microfiber diameter increases with the increase of collagen concentration. This work proves that extraction methods have obvious effect on the preparation of electrospun/electrosprayed microstructures of tilapia skin collagen and provide a way to maximize resource utilization of tilapia processing waste. Image 1 [ABSTRACT FROM AUTHOR]

• Brain pathologies are considered one of the greatest contributors of death and disability worldwide. • The major challenge to effective treatment is finding therapeutics that cross the blood–brain barrier and target aberrant cellular processes, while having minimum effect on essential cellular processes, and healthy cells. • CRISPR technology has emerged as a biomedical tour de force with the potential to revolutionise the treatment of both neurological and cancer related brain pathologies. • The aim of this review is to take stock of the progress made in CRISPR technology in relation to treating brain pathologies. Brain pathologies are considered one of the greatest contributors of death and disability worldwide. Neurodegenerative Alzheimer's disease is the second leading cause of death in adults, whilst brain cancers including glioblastoma multiforme in adults, and pediatric-type high-grade gliomas in children remain largely untreatable. A further compounding issue for patients with brain pathologies is that of long-term neuropsychiatric sequela - as a symptom or arising from high dose therapeutic intervention. The major challenge to effective, low dose treatment is finding therapeutics that successfully cross the blood–brain barrier and target aberrant cellular processes, while having minimum effect on essential cellular processes, and healthy bystander cells. Following over 30 years of research, CRISPR technology has emerged as a biomedical tour de force with the potential to revolutionise the treatment of both neurological and cancer related brain pathologies. The aim of this review is to take stock of the progress made in CRISPR technology in relation to treating brain pathologies. Specifically, we will describe studies which look beyond design, synthesis, and theoretical application; and focus instead on in vivo studies with translation potential. Along with discussing the latest breakthrough techniques being applied within the CRISPR field, we aim to provide a prospective on the knowledge gaps that exist and challenges that still lay ahead for CRISPR technology prior to successful application in the brain disease treatment field. [ABSTRACT FROM AUTHOR]

Rupture of vulnerable atherosclerotic plaque is the major pathological cause of luminal thrombosis in acute coronary syndromes. Since foamy macrophages have been identified as a prominent component in vulnerable atherosclerotic lesions and osteopontin (OPN) is reported to be highly expressed in foamy macrophages, OPN could be a potential target for vulnerable atherosclerotic plaque imaging. The current study designed an OPN-specific MRI/optical dual-modality probe to detect vulnerable plaques. Fluorescence imaging revealed that 24 h after injection of the Cy5.5-OPN-DMSA-MNPs (COD-MNPs), the atherosclerotic plaques in carotid artery exhibited significant higher signals in high fat diet (HFD) fed mice in comparison to the group injected with Cy5.5-IgG-DMSA-MNPs (CID-MNPs) or normal diet fed group injected with COD-MNPs (1.87 ± 0.19 × 10 10 vs. 0.74 ± 0.04 × 10 10 , 0.73 ± 0.03 × 10 10 p/sec/cm 2 /sr, P < 0.05). Meanwhile, MRI displayed stronger T 2 contrast enhancement 24 h post-injection at the area of atherosclerotic plaques in the carotid of HFD fed group injected with COD-MNPs than group injected with CID-MNPs or normal diet fed group injected with COD-MNPs (post/pre signal ratio: 0.64 ± 0.04 vs . 0.95 ± 0.02, 0.98 ± 0.01, P < 0.05 ). As a dual-modality molecular probe, the resulting COD-MNPs conjugates exhibit promising potentials for noninvasive detection of vulnerable atherosclerotic plaque in vivo . [ABSTRACT FROM AUTHOR]

Abstract: It was demonstrated that oligonucleotides, independent of their base sequence and length, could effectively induce the cellular uptake of mercapto acid-capped CdTe QDs after the oligonucleotides were covalently attached on the surface of the QDs. Following these experimental observations, a conjugate composed of covalently linked anti-survivin antisense oligonucleotides (ASON) and CdTe QDs was designed and synthesized. Then, the survivin mRNA down-regulation and the apoptosis of HeLa cells induced by ASON were studied. Systematic experimental results revealed that CdTe-ASON could effectively induce the apoptosis of HeLa cells, while CdTe QDs offered the possibility to visualize the specific intracellular localization of the CdTe-ASON probes strongly associated with their biological functions. [ABSTRACT FROM AUTHOR]

Novel poly(N-vinyl-2-pyrrolidone) (PVP)-coated nickel ferrite nanocrystals were prepared by simultaneously pyrolyzing nickel(II) acetylacetonate (Ni(acac)2) and iron(III) acetylacetonate (Fe(acac)3) in N-vinyl-2-pyrrolidone (NVP). The PVP coating was formed in situ through polymerization of NVP. The crystalline structure of the resultant nickel ferrite was analyzed by high-resolution transmission electron microscopy, electron diffraction patterns, and powder X-ray diffraction. In addition, the valence state of Ni and the metal contents of Ni and Fe in different valence states were analyzed by X-ray photoelectron spectroscopy (XPS), atomic absorption and the phenanthroline method. The surface coating layer of PVP and its binding states were characterized by Fourier transform infrared spectroscopy in combination with XPS. Colloidal stability experiments revealed that the nanocrystals could be dispersed well in both phosphate-buffered saline and Dulbecco's Modified Eagle Medium. [ABSTRACT FROM AUTHOR]

Abstract: Biotinylated denatured bovine serum albumin (Bt-dBSA)-coated cadmium telluride (CdTe) quantum dot (QD) conjugates were prepared and used to develop the multiplexed fluoroimmunoassay for the simultaneous determination of five chemical residues. An immune complex was formed using avidin as the bridge to link the Bt-dBSA-QDs with the antibodies. Primarily, individual quantitative determinations of five representative chemical residues were carried out based on the different emission properties of the QDs. Five antibodies were then conjugated with the corresponding QDs to establish the indirect competition fluorescent-linked immunosorbent assay (ic-FLISA) for the simultaneous detection of five chemicals in one well of a microplate. The linear range for dexamethason (DEX) was from 0.33μg/kg to 10μg/kg, 0.28μg/kg to 10μg/kg for gentamicin (GM), 0.16μg/kg to 25μg/kg for clonazepam (CZP), 0.17μg/kg to 10μg/kg for medroxyprogesterone acetate (MPA) and 0.32μg/kg to 25μg/kg for ceftiofur (CEF), respectively. The limit of detection (LOD) for the simultaneous determination of DEX, GM, CZP, MPA and CEF were as low as 0.13μg/kg, 0.16μg/kg, 0.07μg/kg, 0.06μg/kg and 0.14μg/kg, respectively. This detection method was used to analyze samples of pork muscle and the recoveries ranged from 61.3% to 80.3% for DEX and from 74.0% to 87.2% for MPA. Further more, good correlation between the novel ic-FLISA and traditional ELISA was demonstrated during the determination of DEX and MPA residues in real samples. The QD-based protocol described here is less time consuming than the classical method and it may be sufficiently flexible to be used in other systems for the simultaneous multicolor detection of the drugs. [Copyright &y& Elsevier]

Abstract: An ultrasensitive and rapid sequential injection analysis (SIA) based on real-time PCR (SIA-rt-PCR) assay was developed by using different nanoparticles for the detection of small molecule chemicals residues. Gold (Au) nanoparticle, conjugated with goat anti-rabbit IgG and duplex strand DNA (dsDNA), was used as a substitute for chemiluminescent probes in an SIA system. By indirect competitive immunoreactions in the SIA system, the gold nanoparticles were attached to antigens which were immobilized by superparamagnetic nanoparticles (SMNPs). The dsDNA on the gold nanoparticles was dehybridized and then the single-stranded DNA (ssDNA) was collected and quantified with rt-PCR, which showed a rather low linearity range from 2.5attomolL−1 (aM) to 250 femtomolL−1 (fM) and the LOD was 1.4aM. This method, which is rapid, automated and capable of high-throughput, was used to detect methyl-3-quinoxaline-2-carboxylic acid (MQCA) residues in real samples. The analytical results had a coefficient of variation of less than 15% and the recovery was 89–108%. [Copyright &y& Elsevier]

Abstract: The present paper described a rapid and ultrasensitive detection method using a microfluidic chip for analyzing 7-aminoclonazepam (7-ACZP) residues in human urine. A microfluidic chip-based immunoassay with laser-induced fluorescence (LIF) detection based on the water-soluble denatured bovine serum albumin (dBSA)-coated CdTe quantum dots (QDs) was prepared for the ultrasensitive detection of 7-ACZP. The whole procedure including the chip and the control software was designed and constructed in our own laboratory. The detection of 7-ACZP could be completed within 5min. The results demonstrated that under the optima conditions, 7-ACZP residues could be detected with a precision of 5% relative standard deviation (RSD), and the linear range and the limit of detection (LOD) for 7-ACZP were 1.1–60.1 and 0.021ngmL−1, respectively. This method was compared with ELISA and showed a good correlation. This microfluidic chip with LIF detection was applied to the determination of 7-ACZP residues in positive human urine samples, and the results were confirmed by high-performance liquid chromatography and tandem mass spectrometry (LC/MS/MS). This ultrasensitive detection technique was proved to be practical for clinical use. [Copyright &y& Elsevier]

[Display omitted] In addition to being notorious air pollutants, nitric oxide (NO), carbon monoxide (CO), and hydrogen sulfide (H 2 S) have also been known as endogenous gaseous signaling molecules (GSMs). These GSMs play critical roles in maintaining the homeostasis of living organisms. Importantly, the occurrence and development of many diseases such as inflammation and cancer are highly associated with the concentration changes of GSMs. As such, GSMs could also be used as new therapeutic agents, showing great potential in the treatment of many formidable diseases. Although clinically it is possible to directly inhale GSMs, the precise control of the dose and concentration for local delivery of GSMs remains a substantial challenge. The development of gaseous signaling molecule-releasing molecules provides a great tool for the safe and convenient delivery of GSMs. In this review article, we primarily focus on the recent development of macromolecular nanocarriers for the local delivery of various GSMs. Learning from the chemistry of small molecule-based donors, the integration of these gaseous signaling molecule-releasing molecules into polymeric matrices through physical encapsulation, post-modification, or direct polymerization approach renders it possible to fabricate numerous macromolecular nanocarriers with optimized pharmacokinetics and pharmacodynamics, revealing improved therapeutic performance than the small molecule analogs. The development of GSMs represents a new means for many disease treatments with unique therapeutic outcomes. [ABSTRACT FROM AUTHOR]