Portable paper-based probe for on-site ratiometric fluorescence determination of total flavonol glycosides in plant extract using smartphone imaging.

A smartphone-assisted, paper-based ratio fluorescence probe is presented for the rapid, low-cost and on-site quantification of total flavonol glycosides in Ginkgo biloba extracts (GBE). The Al3+/Eu-MOF/paper-based probe utilizes lanthanide metal-organic framework (Ln-MOF) nanoparticles immobilized on Whatman filter paper along with Al3+ for detecting flavonols, which are the hydrolyzed products of flavonol glycosides. The color change of the paper-based fluorescence image from red to orange depends on the concentration of the target analyte in the sample solution. The smartphone equipped with a red, green, blue (RGB) color detector measured the fluorescence signal intensity on the paper substrate after adding flavonol. The analytical variables affecting the performance of the probe, including the addition sequence of the aluminum nitrate solution, its concentration, that of the Ln-MOF solution, the drying time of the paper probe, the reaction time and the sensitivity parameters of the mobile phone camera (ISO), were optimized. Under optimal conditions, the Al3+/Eu-MOF/paper-based probe has good linear response in the concentration range 7 ~ 80 µg mL- 1 and a lower detection limit of 2.07 µg mL- 1. The results obtained with the paper-based ratio fluorescence probe and smartphone combination were validated by comparing them with high-performance liquid chromatography (HPLC) measurements. This study provides a potential strategy for fabricating Al3+/Eu-MOF/paper-based probe used for total flavonol glycosides determination.

Preparation of smart magnetic fluids and application in sewage treatment: Copper adsorption, kinetic and isotherm study.

The effective removal of heavy metal ions from sewage remains a critical issue, and applying the operability of magnetic materials to large volume wastewater treatment has been a significant challenge. In this paper, metal ions adsorption induced aggregation strategy is proposed to solve this contradiction. The intelligent magnetic fluid designed in this study is a well-dispersed fluid state when treating sewage, and can efficiently adsorb heavy metal ions in wastewater with high adsorption capacity and ultra-fast adsorption kinetics. More importantly, after saturation of adsorption, the magnetic fluid will transform from a well-dispersed fluid state to an agglomeration state which is easy to precipitate and separate via external magnetic field. In a simple and effective way, the particles size of magnetic nanoparticles was precisely controlled by cellulose derivatives modification to obtain a stable magnetic fluid in water. The Freundlich model best described Cu2+ adsorption on magnetite nanoparticles, the correlation coefficients from the Cu2+ adsorption on the two magnetic fluids are 0.9554 and 0.9336, n are 1.868 and 2.117, revealing a favorable adsorption of Cu2+ onto magnetic fluids. The pseudo second-order model fitted the adsorption kinetic data better, the qe are 0.1948 and 0.1315 mmol/g and the R2 are 0.9999, indicating that the adsorption of Cu2+ onto the magnetic fluid was dominated by chemisorption. Moreover, the removal rate of Cu2+ in tap water and lake water was more than 97.1%, and the removal rate of large volume sewage was 81.7%. The synthetic magnetic fluid has high adsorption capacity, ultra-fast adsorption kinetics, reusability and easy separation, indicating its potential application for the removal of heavy metal ions from large-volume sewage.

Construction of coaxial liquid centrifugal platform for the extraction of active ingredients from natural products.

In the classical natural product extraction and separation process, it is tedious and requires large amounts of reagents and time. In this study, an efficient coaxial liquid centrifugal oil-water-oil triple-liquid-phase system with a simple structure and convenient operation was successfully constructed and used to extract flavonoids from Platycladi Cacumen. The results showed that the coaxial liquid centrifugal platform constructed in this study had good stability and 6 ml was the minimum volume of the middle phase for 1000 rpm to stabilize the system. Besides, it was easy to repeat the operation: the relative standard deviations of the extraction yields of flavonoids and sugar in six parallel operations were all less than 10%. Moreover, it was only one-tenth of the time required for this method as traditional liquid-liquid extraction while reducing the use of volatile organic reagents. Finally, the new method was more selective than the traditional method for the extraction of flavonoids. Therefore, this study provides a possibility for the coaxial liquid centrifugal platform to be used in multi-liquid phase systems to achieve the simultaneous extraction of different parts of natural products by different liquid phases. It is expected to provide a reliable reference for further expansion of small-scale experimental operations to industrial production.

Advances and applications of chiral resolution in pharmaceutical field.

The attention to chiral drugs has been raised to an unprecedented level as drug discovery and development strategies grow rapidly. However, separation of enantiomers is still a huge task, which leads to an increasing significance to equip a wider range of expertise in chiral separation science to meet the current and future challenges. In the last few decades, remarkable progress of chiral resolution has been achieved. This review summarizes and classifies chiral resolution methods in analytical scale and preparative scale systematically and comprehensively, including crystallization-based method, inclusion complexation, chromatographic separation, capillary electrophoresis, kinetic resolution, liquid-liquid extraction, membrane-based separation, and especially one bold new progress based on chiral-induced spin selectivity theory. The advances and recent applications will be presented in detail, in which the contents may bring more thinking to wide-ranging readers in various professional fields, from analytical chemistry, pharmaceutical chemistry, natural medicinal chemistry, to manufacturing of drug production.

Spontaneous Formation of Fluorescent Carbon Nanoparticles in Glutaraldehyde Solution and Their Fluorescence Mechanism.

Fluorescent carbon nanoparticles exhibit merits in terms of photochemical stability, functional modification flexibility and excellent biocompatibility. Currently, fluorescent carbon nanoparticles are often obtained by bottom-up or up-bottom strategies. So far, there has been no literature concerning spontaneous formation of fluorescent carbon nanoparticles. However, we have successfully found that fluorescent carbon nanoparticles can form spontaneously in the glutaraldehyde solution. Then further investigations were conducted on the storage time, pH and temperature, which could affect the fluorescence intensity of glutaraldehyde solution. The results indicate that the value of the fluorescence intensity will increase with the extension of the storage time. Moreover, the fluorescence mechanism of the glutaraldehyde solution was studied according to its properties and experiment results. Transmission electron microscopy was used to demonstrate nanoparticles in the glutaraldehyde solution. It's assumed that such phenomenon is probably attributed to the conjugated structure resulting from the polymerization of glutaraldehyde and the quantum confinement effect owing to the nanoparticles formed by the aggregation of polymers. Therefore, the spontaneous fluorescence produced by glutaraldehyde solution provides a simple and environmentally-friendly way to prepare fluorescent carbon nanoparticles.

Fluorescent nanomaterials combined with molecular imprinting polymer: synthesis, analytical applications, and challenges.

Fluorescent nanomaterials (FNMs) and molecular imprinted polymers (MIPs) have been widely used in analytical chemistry for determination. However, low selectivity of FNMs and low sensitivity of MIPs hinder their applications. Combining the merits of FNMs and MIPs, FNMs coated with MIPs (FNMs@MIPs) were proposed to solve those problems. Carbon dots, semiconductor quantum dots, noble metal nanoparticles, silica nanoparticles, and covalent-organic frameworks have been reported to be coated with MIPs. In order to overcome challenges for FNMs@MIPs, such as the lack of handy synthesis routes, incompatibility with aqueous solutions, heterogeneous size of particles, leakage of template molecules, the biocompatibility of FNMs@MIPs, and the inference between FNMs and MIPs, scientists proposed some solutions in recent years. We comprehensively review the newest advances of the FNMs@MIPs, and predict the direction of the future development. Graphical abstract.

Molecularly imprinted polymers for the detection of illegal drugs and additives: a review.

This review (with 154 refs.) describes the current status of using molecularly imprinted polymers in the extraction and quantitation of illicit drugs and additives. The review starts with an introduction into some synthesis methods (lump MIPs, spherical MIPs, surface imprinting) of MIPs using illicit drugs and additives as templates. The next section covers applications, with subsections on the detection of illegal additives in food, of doping in sports, and of illicit addictive drugs. A particular focus is directed towards current limitations and challenges, on the optimization of methods for preparation of MIPs, their applicability to aqueous samples, the leakage of template molecules, and the identification of the best balance between adsorption capacity and selectivity factor. At last, the need for convincing characterization methods, the lack of uniform parameters for defining selectivity, and the merits and demerits of MIPs prepared using nanomaterials are addressed. Strategies are suggested to solve existing problems, and future developments are discussed with respect to a more widespread use in relevant fields. Graphical abstract This review gives a comprehensive overview of the advances made in molecularly imprinting of polymers for use in the extraction and quantitation of illicit drugs and additives. Methods for syntheses, highlighted applications, limitations and current challenges are specifically addressed.

Molecularly imprinted polymeric stir bar: Preparation and application for the determination of naftopidil in plasma and urine samples.

In this study, molecularly imprinting technology and stir bar absorption technology were combined to develop a microextraction approach based on a molecularly imprinted polymeric stir bar. The molecularly imprinted polymer stir bar has a high performance, is specific, economical, and simple to prepare. The obtained naftopidil-imprinted polymer-coated bars could simultaneously agitate and adsorb naftopidil in the sample solution. The ratio of template/monomer/cross-linker and conditions of template removal were optimized to prepare a stir bar with highly efficient adsorption. Fourier transform infrared spectroscopy, scanning electron microscopy, selectivity, and extraction capacity experiments showed that the molecularly imprinted polymer stir bar was prepared successfully. To utilize the molecularly imprinted polymer stir bar for the determination of naftopidil in complex body fluid matrices, the extraction time, stirring speed, eluent, and elution time were optimized. The limits of detection of naftopidil in plasma and urine sample were 7.5 and 4.0 ng/mL, respectively, and the recoveries were in the range of 90-112%. The within-run precision and between-run precision were acceptable (relative standard deviation <7%). These data demonstrated that the molecularly imprinted polymeric stir bar based microextraction with high-performance liquid chromatography was a convenient, rapid, efficient, and specific method for the precise determination of trace naftopidil in clinical analysis.

Applications of magnetic surface imprinted materials for solid phase extraction of levofloxacin in serum samples.

In this work, molecularly imprinted magnetic carbon nanotubes (MCNTs@MIPs) was prepared with surface imprinting technique for extraction of levofloxacin in serum samples. The preparation of molecularly imprinted polymers (MIPs) used levofloxacin as template, methacrylic acid as functional monomer, and ethylene glycol dimethacrylate as cross-linker, and the magnetic carbon nanotubes (MCNTs) was synthesized by solvothermal method. The prepared polymers not only can be separated and collected easily by an external magnetic, but also exhibited high specific surface area and high selectivity to template molecules. Kinetic adsorption and static adsorption capacity investigations indicated that the synthesized MCNTs@MIPs had excellent recognition towards levofloxacin. Furthermore, magnetic solid phase extraction (MSPE) using the prepared MCNTs@MIPs as sorbent was then investigated, and an efficient sample cleanup was obtained with recoveries ranged from 78.7 ± 4.8 % to 83.4 ± 4.1%. In addition, several parameters, including the pH of samples, the amount of MCNTs@MIPs, the adsorption and desorption times, and the eluent, were investigated to obtain optimal extraction efficiency. Under the optimal extraction conditions, the stability of the polymer was also evaluated, and the average recovery reduced less than 7.6% after 5 cycles. MCNTs@MIPs successfully applied in the preconcentration and determination of levofloxacin in serum sample suggested that the MSPE method based on the novel polymers could be a promising alternative for selective and efficient extraction of trace amounts of pharmaceutical substances in bio-matrix samples.

Preparation of a core-shell magnetic ion-imprinted polymer via a sol-gel process for selective extraction of Cu(II) from herbal medicines.

A novel magnetic surface ion-imprinted polymer (c-MMWCNTs-SiO2-IIP) was synthesized for the first time using magnetic CNTs/Fe3O4 composites (c-MMWCNTs) as the core, 3-ammonium propyltriethoxysilane (APTES) as the functional monomer, tetraethylorthosilicate (TEOS) as the cross-linker and Cu(II) as the template. c-MMWCNTs-SiO2-IIP was evaluated for selective extraction of Cu(II) from herbal medicines via a magnetic solid phase extraction (M-SPE) procedure. One factor affecting the separation and preconcentration of the target heavy metal was pH. Under the optimized experimental conditions, the adsorption kinetics and adsorption capacity of c-MMWCNTs-SiO2-IIP toward Cu(II) were estimated. The results indicated that the adsorption mechanism corresponds to a pseudo-second order adsorption process, with a correlation coefficient (R(2)) of 0.985 and a maximum adsorption capacity of 42.2 mg g(-1). The relative selectivity factor (ß) values of Cu(II)/Zn(II) and Cu(II)/Pb(II) were 38.5 and 34.5, respectively. c-MMWCNTs-SiO2-IIP, combined with flame atomic absorption spectrometry, was successfully applied in the extraction and detection of Cu(II) in herbal medicine, with high recoveries ranging from 95.6% to 108.4%.

Less interference fluorescence analytical strategy: Bridging substance-triggered ratiometric sensor with convenient preparation and application.

High interference and narrow application range are key of bottleneck of recent fluorescence analysis methods, which limit their wide application in the sensing field. Therefore, to overcome these disadvantages, a ratiometric fluorescence sensing system utilizing berberine (BER) and silver nanoclusters protected by dihydrolipoic acid (DHLA-AgNCs) was constructed for the first time in this work, to achieve determination of BER and daunorubicin (Dau). BER aqueous solution (non-planar conformation) has no fluorescence emission. When it was mixed with DHLA-AgNCs, the conformation of BER became planar, producing fluorescence emission at 515 nm besides the fluorescence emission peak of DHLA-AgNCs at 653 nm. With the increase of BER concentration added in system, the fluorescence intensity of BER (planar conformation) at 515 nm increased obviously and the fluorescence intensity of DHLA-AgNCs decreased slightly. Therefore, the dual emission fluorescence sensing system was constructed based on a fluorescence substance and non fluorescence substance, to achieve determination of BER. Meanwhile, based on the bridging effect of BER and fluorescence resonance energy transfer effect from Dau, the altering of two peaks intensity was utilized to achieve determination of Dau. Thus, this dual emission sensing system can not only be used for fluorescence analysis of BER and its analogues, but also based on the bridging effect of BER, allowing the determination of Dau and its analogues that could not be directly measured with silver nanoclusters, expanding the application range of traditional dual emission detection systems. Meanwhile, this system has strong anti-interference ability and low toxicity to the human body and less pollution to the sample and environment. This provides a new direction and universal research strategy for the construction of new fluorescence sensing systems in the future for the analysis of target substances that cannot be directly detected with conventional fluorescence analysis methods.

Preparation of a multiple interacting magnetic fluid for rapid and sensitive simultaneous extraction of ß-nicotinamide mononucleotide metabolites in biological samples.

BACKGROUND: ß-nicotinamide mononucleotide stands out as an essential breakthrough in "anti-aging" and consistently leads the list of top-selling nutritional supplements in terms of quantity. As the metabolites of ß-nicotinamide mononucleotide, the detection of nicotinamide and N1-methylnicotinamide is of great significance for evaluating the nutritional effect of dietary supplements of ß-nicotinamide mononucleotide. However, due to the extremely low concentration of nicotinamide and N1-methylnicotinamide in vivo and the serious matrix interference in biological samples, there is an increasing demand for materials and methods of pre-treatment. RESULTS: In this study, Fe3O4@hydroxypropyl methyl cellulose@dodecylbenzenesulfonic acid magnetic fluid was synthesized for the first time, and it was used as pretreatment material to detect nicotinamide and N1- methylnicotinamide in urine samples by high performance liquid chromatography. Compared with other adsorption materials, Fe3O4@hydroxypropyl methyl cellulose@dodecylbenzenesulfonic acid nanoparticles are a kind of uniform magnetic fluid. Furthermore, they have more types and quantities of interaction sites (electrostatic interactions, hydrophobic interactions, hydrogen bonding interactions, and π-π interactions), so they own greater adsorption capacity. When the pH of the solution is 4, they can be adsorbed quickly within 10 s. The method successfully detected trace nicotinamide and N1-methylnicotinamide in urine samples in the linear range of 0.1-80 µg mL-1, the low detection limits were 0.30 ng mL-1 and 1.5 ng mL-1 respectively, and the quantification limits were 1.0 ng mL-1 and 5.0 ng mL-1, respectively. At the same time, the standard urine samples of nicotinamide and N1-methylnicotinamide showed satisfactory recovery rate 94.50-109.1 %. The results indicated that the established method can accurately and quantitatively determine trace nicotinamide and N1-methylnicotinamide in urine samples. SIGNIFICANCE: Consequently, low concentration of ß-nicotinamide mononucleotide metabolites can be detected simultaneously, and the interference can be eliminated during the detection process, which provides an efficient and convenient pretreatment method and a rapid and sensitive detection method for the analysis of ß-nicotinamide mononucleotide metabolites. What's more, it has a wide application prospect in the analysis of other similar metabolites in biological samples.

Polyethyleneimine in designed nanocomposite based magnetic halloysite nanotubes for extraction and determination of gallic acid in green tea.

An innovative and simple nanocomposite denoted as MHNTs@PEI was synthesized for gallic acid (GA) analytical sample pretreatment. Polyethyleneimine (PEI) functionalized was binded onto magnetic halloysite nanotubes (MHNTs) to inhence adsorption capacity. MHNTs@PEI was obtained only through two steps modification (amination and PEI modification). Characterizations showed that there are layers of synthetic PEI on the tubular structure of the material and magnetic spheres on its surface, both indicating successful synthesis of the nanocomposite. Furthermore, the adsorption isotherms and kinetic modeling showed that the Langmuir model and pseudo-first-order model fit the adsorption data, respectively. MHNTs@PEI achieved an adsorption capacity of 158 mg·g-1. Overall, the abundant adsorption sites significantly improved the adsorption performance of the MHNTs@PEI. Regeneration tests demonstrated that the MHNTs@PEI exhibits effective adsorption, even after undergoing five consecutive cycles. Optimization of key parameters (ratio, volume of elution, elution time and frequency) in the process of adsorption and desorption was also conducted. The limit of detection (LOD) and that of the quantification (LOQ) were 0.19 and 0.63 µg·mL-1, respectively, and the recoveries were 95.67-99.43 %. Finally, the excellent magnetism (43.5 emu·g-1) and the adsorption feature of MHNTs@PEI enabled its successful utilization in analytical sample pretreatment through the extraction of GA from green tea.

Preparation of molecularly imprinted polymers on the surface of magnetic carbon nanotubes with a pseudo template for rapid simultaneous extraction of four fluoroquinolones in egg samples.

Fluoroquinolones (FQs) have emerged as one of the most important class of antibiotics. Due to their low concentration in bio-matrix samples which contain a lot of interfering substances, the efficient solid phase extraction and accurate determination of FQs remain a challenge. In this paper, a new strategy for the isolation and enrichment of FQs from egg samples was obtained by molecularly imprinted polymers on the surface of magnetic carbon nanotubes (MCNTs@MIP), which not only can be collected and separated rapidly by an external magnetic field, but also have a high specific surface area, outstanding mechanical properties and specific recognition for FQs. MCNTs@MIP were prepared using ofloxacin as a pseudo template, methacrylic acid as a functional monomer, and ethylene glycol dimethacrylate as a cross-linker. The characteristics of the MCNTs@MIP were assessed by transmission electron microscopy (TEM), multipoint Brunauer-Emmett-Teller (BET) analysis, vibrating sample magnetometry (VSM), X-ray diffraction (XRD) and Fourier transform infrared (FT-IR) spectroscopy. The results of the adsorption experiments not only demonstrated rapid dynamic adsorption but also showed a high selectivity toward FQs. An extraction method using MCNTs@MIP coupled with high performance liquid chromatography (HPLC) was developed for the determination of four FQs in egg samples. The recovery of four FQs ranged from 95.2% ± 3.2% to 100.7% ± 3.1% and the detection limits ranged from 0.25-0.40 ng g(-1). The results demonstrate that the proposed method based on pseudo template MCNTs@MIP is a promising approach for the preconcentration, purification, and simultaneous analysis of four FQs in bio-matrix samples.

Loading behavior of gatifloxacin in urine and lake water on a novel magnetic molecularly imprinted polymer used as extraction sorbent with spectrophotometric analysis.

The loading behavior of gatifloxacin (GTFX) in human urine and lake water on a novel magnetic molecularly imprinted polymer used as extraction sorbent with UV-Visible spectrometric analysis has been studied. The magnetic polymers had been prepared using GTFX as template molecule and Fe3O4 as magnetic component. The polymer had been characterized by SEM, Fourier-transform infrared spectrometry, and appropriate magnet separator. Parameters affecting the extraction efficiency were evaluated in order to achieve optimal loading and reduce nonspecific interactions. Good linearity of the method had been obtained in the range between 0.25 and 15 µg mL(-1) by UV-Vis spectrophotometry at 286 nm with spectral analysis from 240 to 400 nm. The method detection and quantification limits of GTFX in water were 0.075 and 0.25 µg mL(-1), respectively. This study showed good selectivity and loading efficiency (α > 2) of the polymers. The loading behavior of GTFX in the samples spiked on polymers had been obtained and each other with recovery higher than 91% with RSD% between 2.5 and 3.3. No pretreatment of samples were needed and no interference of compounds in urine and lake water were observed during adsorption.

Microwave-assisted one-step green synthesis of amino-functionalized fluorescent carbon nitride dots from chitosan.

We present an economical, facile and effective microwave pyrolysis approach to synthesize highly amino-functionalized fluorescent carbon nitride dots (CNDs). The formation and the functionalization of CNDs was accomplished simultaneously through the dehydration of chitosan. It is suggested that these CNDs have good water solublility and exhibit strong fluorescence.

Adsorption behavior of pazufloxacin mesilate on amino-functionalized carbon nanotubes.

In this study, the interaction between amino-functionalized multi-walled carbon nanotubes (e-MWNTs) and antibacterial agents was investigated and the drug-loading ability of e-MWNTs was evaluated. The e-MWNTs were prepared and characterized, then were used as adsorbents for loading an antibacterial agent, pazufloxacin mesilate (PZFX). The adsorption behavior of PZFX on e-MWNTs in water was investigated. The results showed that e-MWNTs were able to form supramolecular complexes with PZFX and could be used as drug carriers with high drug-loading efficiency. Compared with pristine multi-walled carbon nanotubes (MWNTs), the adsorption efficiency of e-MWNTs was better. In kinetic studies, the pseudo-second-order model showed satisfactory fitting and good adsorption process. Langmuir model was successfully employed to describe the adsorption isotherms of PZFX on e-MWNTs and higher drug-loading ability were observed from e-MWNTs with smaller diameter. The adsorption process of e-MWNTs was sensitive to the pH and it was observed that the neutral pH gave the best adsorption. Low temperatures facilitated the adsorption process. In addition, the release process of PZFX from e-MWNTs occurred in two stages: a rapid release, then followed by a slow release, in which acidic solution favored the release process. In summary, our technique developed for the adsorption of PZFX on e-MWNTs is satisfactory.

Advances and Challenges of Fluorescent Nanomaterials for Synthesis and Biomedical Applications.

With the rapid development of nanotechnology, new types of fluorescent nanomaterials (FNMs) have been springing up in the past two decades. The nanometer scale endows FNMs with unique optical properties which play a critical role in their applications in bioimaging and fluorescence-dependent detections. However, since low selectivity as well as low photoluminescence efficiency of fluorescent nanomaterials hinders their applications in imaging and detection to some extent, scientists are still in search of synthesizing new FNMs with better properties. In this review, a variety of fluorescent nanoparticles are summarized including semiconductor quantum dots, carbon dots, carbon nanoparticles, carbon nanotubes, graphene-based nanomaterials, noble metal nanoparticles, silica nanoparticles, phosphors and organic frameworks. We highlight the recent advances of the latest developments in the synthesis of FNMs and their applications in the biomedical field in recent years. Furthermore, the main theories, methods, and limitations of the synthesis and applications of FNMs have been reviewed and discussed. In addition, challenges in synthesis and biomedical applications are systematically summarized as well. The future directions and perspectives of FNMs in clinical applications are also presented.

Recent advances in magnetic carbon nanotubes: synthesis, challenges and highlighted applications.

Magnetic carbon nanotubes (MCNTs), consisting of carbon nanotubes (CNTs) and magnetic nanoparticles (MNPs), have enormous exploration and application potentials due to their superior physical and chemical properties, such as unique magnetism and high enrichment performance. This review concentrates on the rapid advances in the synthesis and application of magnetic carbon nanotubes. Great progress has been made in the preparation of MCNTs by developing methods including chemical vapor deposition, pyrolysis procedure, sol-gel process, template-based synthesis, filling process and hydrothermal/solvothermal method. Various applications of MCNTs as a mediator of the adsorbent in magnetic solid-phase extraction, sensors, antibacterial agents, and imaging system contrast agents, and in drug delivery and catalysis are discussed. In order to overcome the drawbacks of MCNTs, such as sidewall damage, lack of convincing quantitative characterization methods, toxicity and environmental impact, and deficiency of extraction performance, researchers proposed some solutions in recent years. We systematically review the latest advances in MCNTs and discuss the direction of future development.

Sinapultide-Loaded Microbubbles Combined with Ultrasound to Attenuate Lipopolysaccharide-Induced Acute Lung Injury in Mice.

PURPOSE: Pulmonary surfactants (eg, sinapultide) are widely used for the treatment of lung injury diseases; however, they generally induce poor therapeutic efficacy in clinics. In this study, sinapultide-loaded microbubbles (MBs) were prepared and combined with ultrasound (US) treatment as a new strategy for improved treatment of lung injury diseases. METHODS: The combination treatment strategy of MBs combined with ultrasound was tested in a lipopolysaccharide (LPS)-induced mouse model of alveolar epithelial cells (AT II) and acute lung injury. Firstly, cytotoxicity, cytokines, and protein levels in LPS-mediated AT II cells were assessed. Secondly, the pathological morphology of lung tissue, the wet/dry (W/D) weight ratio, cytokines, and protein levels in LPS-mediated acute lung injury mice after treatment with the MBs were evaluated. Moreover, histology examination of the heart, liver, spleen, lung and kidney of mice treated with the MBs was performed to initially evaluate the safety of the sinapultide-loaded MBs. RESULTS: Sinapultide-loaded MBs in combination with ultrasound treatment significantly reduced the secretion of inflammatory cytokines and increased the expression of surfactant protein A (SP-A) in AT II cells. Furthermore, the pathological morphology of lung tissue, the wet/dry (W/D) weight ratio, interleukin-6 (IL-6), tumor necrosis factor-α (TNF-α) and SP-A expression level of mice treated with MBs and ultrasound were significantly improved compared to those of non-treated mice. In addition, the histology of the examined organs showed that the MBs had a good safety profile. CONCLUSION: Sinapultide-loaded MBs combined with ultrasonic treatment may be a new therapeutic option for lung injury diseases in the clinic.