Spatially confined CuFe2O4 nanosphere in N/O-codoped porous carbon mimetics for triple-mode sensing of antibiotics and visual detection of neurotransmitters in biofluids.

BACKGROUND: Carbon-based nanozymes have recently received enormous concern, however, there is still a huge challenge for inexpensive and large-scale synthesis of magnetic carbon-based "Two-in-One" mimics with both peroxidase (POD)-like and laccase-like activities, especially their potential applications in multi-mode sensing of antibiotics and neurotransmitters in biofluids. Although some progresses have been made in this field, the feasibility of biomass-derived carbon materials with both POD-like and laccase-like activities by polyatomic doping strategy is still unclear. In addition, multi-mode sensing platform can provide a more reliable result because of the self-validation, self-correction and mutual agreement. Nevertheless, the use of magnetic carbon-based nanozyme sensors for the multi-mode detection of antibiotics and neurotransmitters have not been investigated. RESULTS: We herein report a shrimp shell-derived N, O-codoped porous carbon confined magnetic CuFe2O4 nanosphere with outstanding laccase-like and POD-like activities for triple-mode sensing of antibiotic d-penicillamine (D-PA) and chloramphenicol (CPL), as well as colorimetric detection of neurotransmitters in biofluids. The magnetic CuFe2O4/N, O-codoped porous carbon (MCNPC) armored mimetics was successfully fabricated using a combined in-situ coordination and high-temperature crystallization method. The synthesized MCNPC composite with superior POD-like activity can be used for colorimetric/temperature/smartphone-based triple-mode detection of D-PA and CPL in goat serum. Importantly, the MCNPC nanozyme can also be used for colorimetric analysis of dopamine and epinephrine in human urine. SIGNIFICANCE: This work not only offered a novel strategy to large-scale, cheap synthesize magnetic carbon-based "Two-in-One" armored mimetics, but also established the highly sensitive and selective platforms for triple-mode monitoring D-PA and CPL, as well as colorimetric analysis of neurotransmitters in biofluids without any tanglesome sample pretreatment.

Biotemplated fabrication of N/O co-doped porous carbon confined spinel NiFe2O4 heterostructured mimetics for triple-mode sensing of antioxidants and ameliorating packaging properties.

In this work, shrimp shell-derived magnetic NiFe2O4/N, O co-doped porous carbon nanozyme with superior oxidase (OXD)-like activity was prepared and used for colorimetric/photothermal/smartphone dual-signal triple-mode detection of antioxidants in fruits and beverages. The magnetic NiFe2O4/N, O co-doped porous carbon (MNPC) material was triumphantly fabricated using a combined in-situ surface chelation and pyrolysis method. The resultant MNPC composite exhibits a superior OXD-like activity, which can effectively oxidize 3,3',5,5'-tetramethylbenzidine (TMB) for yielding colorimetric/temperature dual-signal (CTDS) in absence of H2O2. This CTDS output sensor was successfully used for the determination of ascorbic acid and tannic acid. The proposed CTDS sensor with good specificity and high sensitivity can satisfy different on-site analysis requirements. Interestingly, the MNPC as a sustainable filler was further used for improving packaging properties of polyvinyl alcohol film. In short, this work offers a large-scale and cheap method to fabricate magnetic carbon-based nanozyme for monitoring antioxidants and ameliorating packaging properties.

Recent advances in ultrasound-controlled fluorescence technology for deep tissue optical imaging.

Fluorescence imaging is a noninvasive and dynamic real-time imaging technique; however, it exhibits poor spatial resolution in centimeter-deep tissues because biological tissues are highly scattering media for optical radiation. The recently developed ultrasound-controlled fluorescence (UCF) imaging is a novel imaging technique that can overcome this bottleneck. Previous studies suggest that the effective contrast agent and sensitive imaging system are the two pivotal factors for generating high-resolution UCF images ex vivo and/or in vivo. Here, this review highlights the recent advances (2015-2020) in the design and synthesis of contrast agents and the improvement of imaging systems to realize high-resolution UCF imaging of deep tissues. The imaging performances of various UCF systems, including the signal-to-noise ratio, imaging resolution, and imaging depth, are specifically discussed. In addition, the challenges and prospects are highlighted. With continuously increasing research interest in this field and emerging multidisciplinary applications, UCF imaging with higher spatial resolution and larger imaging depth may be developed shortly, which is expected to have a far-reaching impact on disease surveillance and/or therapy.

Recent advances in ultrasound-controlled fluorescence technology for deep tissue optical imaging / 药物分析学报

Fluorescence imaging is a noninvasive and dynamic real-time imaging technique;however,it exhibits poor spatial resolution in centimeter-deep tissues because biological tissues are highly scattering media for optical radiation.The recently developed ultrasound-controlled fluorescence(UCF)imaging is a novel imaging technique that can overcome this bottleneck.Previous studies suggest that the effective contrast agent and sensitive imaging system are the two pivotal factors for generating high-resolution UCF images ex vivo and/or in vivo.Here,this review highlights the recent advances(2015-2020)in the design and synthesis of contrast agents and the improvement of imaging systems to realize high-resolution UCF imaging of deep tissues.The imaging performances of various UCF systems,including the signal-to-noise ratio,imaging resolution,and imaging depth,are specifically discussed.In addition,the challenges and prospects are highlighted.With continuously increasing research interest in this field and emerging multidisciplinary applications,UCF imaging with higher spatial resolution and larger imaging depth may be developed shortly,which is expected to have a far-reaching impact on disease surveillance and/or therapy.

Effects of Carboxyl or Amino Group Modified InP/ZnS Nanoparticles Toward Simulated Lung Surfactant Membrane.

Quantum dots (QDs) as a promising optical probe have been widely used for in vivo biomedical imaging; especially enormous efforts recently have focused on the potential toxicity of QDs to the human body. The toxicological effects of the representative InP/ZnS QDs as a cadmium-free emitter are still in the early stage and have not been fully unveiled. In this study, the DPPC/DPPG mixed monolayer was used to simulate the lung surfactant monolayer. The InP/ZnS-COOH QDs and InP/ZnS-NH2 QDs were introduced to simulate the lung surfactant membrane's environment in the presence of InP/ZnS QDs. The effects of InP/ZnS QDs on the surface behavior, elastic modulus, and stability of DPPC/DPPG mixed monolayer were explored by the surface pressure-mean molecular area isotherms and surface pressure-time curves. The images observed by Brewster angle microscope and atomic force microscope showed that the InP/ZnS QDs affected the morphology of the monolayer. The results further demonstrated that the InP/ZnS QDs coated with different surface groups can obviously adjust the mean molecular area, elastic modulus, stability, and microstructure of DPPC/DPPG mixed monolayer. Overall, this work provided useful information for in-depth understanding of the effects of the -COOH or -NH2 group coated InP/ZnS QDs on the surface of lung surfactant membrane, which will help scientists to further study the physiological toxicity of InP/ZnS QDs to lung health.

Hemin-porous g-C3N4 hybrid nanosheets as an efficient peroxidase mimic for colorimetric and visual determination of glucose.

A method is described for colorimetric determination of glucose by using hemin-porous graphitic carbon nitride (g-C3N4) hybrid nanosheets as a peroxidase mimic. The porous g-C3N4 nanosheets were prepared by a combination of one-pot self-polymerization, pyrolysis and liquid-phase exfoliation. The hemin-porous g-C3N4 hybrid nanosheets were prepared via in-situ deposition. It is shown that the hybrid composite has improved dispersibility, stability, and peroxidase-mimicking activity in the 3,3',5,5'-tetramethylbenzidine (TMB)/H2O2 system. This is deemed to be the result of the synergistic effect of hemin and porous g-C3N4 nanosheets. Based on these advantages of the nanosheets, a simple, low-cost, sensitive and selective colorimetric method was established for the determination of glucose at pH values around 7. Best performed at a wavelength of 652 nm, the assay has a linear response in the 10.0 µM to 500 µM glucose concentration range (R2 = 0.9942) and a 1.94 µM limit of detection. This method was successfully applied to the determination of glucose in (spiked) human serum samples. In our perception, the hybrid is a robust peroxidase mimic for use in POx-based assays as needed in medical diagnosis and environmental analysis. Graphical abstract Schematic presentation of the process of hemin-porous g-C3N4 hybrid nanosheets catalyzing the oxidation of peroxidase chromogenic substrate tetramethylbenzidine (TMB) in the presence of H2O2. The material was applied in colorimetric and visual determination of H2O2 and glucose.

Combined magnetic porous molecularly imprinted polymers and deep eutectic solvents for efficient and selective extraction of aristolochic acid I and II from rat urine.

Aristolochia and related plants contain nephrotoxins and mutagens in the form of aristolochic acids (AAs). However, there is still lack of a fast and specific method for monitoring AAs in biological samples. Herein, we synthesized a hybrid magnetic mesoporous carbon-molecularly imprinted polymers (MMC@MIPs) as a novel magnetic solid-phase extraction (MSPE) adsorbent for selective recognition of aristolochic acid I and II from rat urine samples. The choline chloride/glycol-based deep eutectic solvent (DES) and indomethacin were used as the eluent and dummy template molecule accordingly. The morphology, structure property and surface groups of the prepared materials were investigated in sequence, and the optimum conditions of the MMC@MIPs-MSPE procedure were also optimized well. Results showed that the proposed method had a relatively satisfactory recovery (86.7-94.3%), with low standard deviation (<4.85%) and acceptable correlation coefficients (0.991-0.996). Overall, this work not only provides an inexpensive and eco-friendly method to fabricate MMC@MIPs, but also develops a highly promising approach for the detection of aristolochic acid I and II in biological samples.

Hybrid-type carbon microcoil-chitosan composite for selective extraction of aristolochic acid I from Aristolochiaceae medicinal plants.

Aristolochic acid I is a nephrotoxic compound widely existing in many kinds of traditional Chinese medicines, especially in Aristolochiaceae medicinal plants. In this study, chitosan modified carbon microcoils were designed and prepared for the selective separation of aristolochic acid I from medicinal herbs. Successful modification of carbon microcoils was confirmed by scanning electron microscopy, Fourier-transfer infrared spectroscopy, elemental analysis, X-ray photoelectron spectroscopy, and thermogravimetric analyses. The effects of adsorption conditions were investigated and it was determined that the adsorption of aristolochic acid I was controlled by pH. Adsorption isotherms, kinetics, and selectivity tests were performed to evaluate the adsorption capacity and selectivity of the modified carbon microcoils. The chitosan modified carbon microcoils exhibited excellent binding ability (77.72 mg g-1) and satisfactory selectivity. Finally, this material was used in solid phase extraction combined with HPLC to enrich and detect aristolochic acid I from medicinal plants. The detector response for aristolochic acid I was linear from 0.5 to 150 mg L-1, and the recoveries of aristolochic acid I ranged from 73.61 to 77.73% with the relative standard deviations of less than 5%. Thus, chitosan modified carbon microcoils were ideal adsorbents for the selective extraction of aristolochic acid I from Aristolochiaceae plants.

Polydopamine/polyethyleneimine complex adhered to micrometer-sized magnetic carbon fibers for high-efficiency hemoperfusion.

Carbon-based nanomaterials have recently attracted tremendous attention in adsorption, separation and biological fields. However, such modification is not always straightforward when the surface is not chemically reactive. Given this reason, most carbon materials modification processes employ reactive linkers or coupling agents, which are complicated and time-consuming. Herein, we report on a dopamine-polyethyleneimine (PEI) coating strategy to fabricate micrometer-sized magnetic carbon fiber (MSMCF)-based extracorporeal blood-cleansing sorbent for hemoperfusion. Results showed that the dopamine/PEI-coated MSMCF had a twisted fiber shape with a size range of 80-120 µm in diameter and porous structure with a specific surface area of 146 m2 g-1. Adsorption behavior of dopamine/PEI-modified MSMCF was examined by using bilirubin as a toxin model compound. Equilibrium data were well fitted to the Langmuir isotherm model with a maximal adsorption capacity of 335.1 mg g-1 at ambient temperature. The as-obtained material had relatively high bilirubin adsorption selectivity against albumin at a normal albumin concentration. In particular, the dopamine/PEI-coated MSMCF has excellent adsorption capacity and hemocompatibility compared to the MSMCF decorated only by dopamine or PEI. Therefore, this work may pave the way for enhancing the property of the extracorporeal blood-cleansing sorbent during hemoperfusion.

Two angiotensin-converting enzyme-inhibitory peptides from almond protein and the protective action on vascular endothelial function.

This study aimed to discover and prepare novel angiotensin converting enzyme (ACE) inhibitory peptides from almond protein and further evaluate the effect on endothelial function of human umbilical vascular endothelial cells (HUVECs). Almond protein was hydrolyzed using a two-stage alcalase-protamex hydrolysis process, and the hydrolysates were subjected to a series of separations, ultrafiltration, gel filtration chromatography, and reversed-phased preparative chromatography, to obtain the active peptides. Seven ACE inhibitory fractions with the molecular weight below 1.5 kDa were isolated and prepared, and two purified ACE inhibitory peptides with the IC50 values of 67.52 ± 0.05 and 43.18 ± 0.07 µg mL(-1), were identified as Met-His-Thr-Asp-Asp and Gln-His-Thr-Asp-Asp, respectively. Then the effect of two ACE inhibitory peptides on the endothelial function of HUVECs was evaluated. Results showed that the two potent ACE inhibitory peptides significantly regulated the release of nitric oxide and endothelin in HUVECs. These results suggest that almond peptides have potential as an antihypertensive nutraceuticals or a functional food ingredient.

ß-Cyclodextrin anchoring onto pericarpium granati-derived magnetic mesoporous carbon for selective capture of lopid in human serum and pharmaceutical wastewater samples.

Functionalized magnetic carbonaceous nanomaterials, which are important materials with many practical and research applications in biomedical, pharmaceutical and biological fields, have recently attracted much attention. In this study, a magnetic mesoporous carbon coated with ß-cyclodextrin (MMC@ß-CD) was synthesized for the first time from natural pericarpium granati (PG). The as-obtained MMC@ß-CD has high surface areas (203 m(2)g(-1)), large pore volumes (0.16 cm(3)g(-1)), relatively broad mesoporous sizes (6.8 nm) and a high saturation magnetization of 26.2 emu g(-1), which is sufficient for magnetic separation by an external magnetic field. The MMC@ß-CD was used as an innovative adsorbent for magnetic solid-phase extraction of lopid via host-guest interaction prior to spectrofluorometric analysis. The proposed method was successfully applied to analyze lopid in human serum and pharmaceutical wastewater samples with recoveries in the range of 85.0-103.5% for the spiked samples. Overall, this work not only provides an inexpensive and eco-friendly method to fabricate MMC@ß-CD (or MMC) from PG, but also develops a highly selective approach for capture of lopid in biological samples and environmental substances.

Biomass-derived highly porous functional carbon fabricated by using a free-standing template for efficient removal of methylene blue.

Banana peel (BP), a biomass waste, was converted into a valuable highly porous functional carbon material (HPFCM) by a general chelate-assisted co-assembly process. The HPFCMs were fabricated by using Al(III)-based metal-organic framework-like as a free-standing template and commercial Pluronic F127 as a microstructure-directing agent. Several critical variables for fabrication including doses of Al(III) and F127, carbonization temperature had been optimized and the adsorption behavior of HPFCMs was examined by using methylene blue as dye model compound. The optimal adsorbent was validated as HPFCMs-5-1-800, and its equilibrium data were well fitted to the Langmuir isotherm model with a monolayer adsorption capacity of 385.12 mg g(-1) at ambient temperature. The surface physical properties of HPFCMs-5-1-800 were also exemplarily characterized. The findings revealed that the free-standing template is a potential route for preparation of HPFCM from waste BP.

Polyethylene glycol as a novel solvent for extraction of crude polysaccharides from Pericarpium granati.

Polyethylene glycol aqueous solution (PEGs), an environmentally friendly solvent was used, for the first time, to develop an extraction method for crude polysaccharides from pericarpium granati with ultrasonic-microwave-assisted extraction (UMAE). Compared with other extraction solvents, PEGs, especially PEG400, displayed a higher extraction yield. The extraction conditions were an ultrasonic power of 240 W, a microwave power of 365 W, a PEG400 concentration of 30% and a ratio of liquid to raw material of 20 mL/g, optimized by using Box-Behnken experimental design. Under these conditions, an extraction yield of 7.94 ± 0.3% (n=3) was obtained, which is about 25% higher than that with water as a solvent, and the polysaccharides content in pericarpium granati was 6.56 ± 0.01 mg/g expressed as glucose.

Rapid analysis of fatty acid profiles in raw nuts and seeds by microwave-ultrasonic synergistic in situ extraction-derivatisation and gas chromatography-mass spectrometry.

Based on microwave-ultrasonic synergistic in situ extraction-derivatisation (MUED), gas chromatography-mass spectrometry was proposed for rapid analysis of fatty acid profiles in raw nut and seed materials. Several critical experimental parameters for MUED, including reaction temperature, microwave power, amounts of catalyst and derivatisation reagent, have been optimised using response surface methodology. The results showed that the chromatographic peak areas of total fatty acids and the content of total unsaturated fatty acids obtained with MUED were markedly higher than those obtained by the conventional method (P<0.05 and P<0.01, respectively). The MUED method simplified the handling steps compared to the conventional procedure, shortened the sample preparation time whilst improving the extraction and derivatisation efficiency of lipids, and reduced oxidisation and decomposition of the unsaturated fatty acids. The simplicity, robustness and practicality of this method highlighted its significant potential for application in the rapid analysis of fatty acids in natural food resource samples.

Study on the PEG-based microwave-assisted extraction of flavonoid compounds from persimmon leaves.

A method for PEG-based microwave-assisted extraction (MAE) of flavonoid compounds from persimmon leaves has been successfully developed. The extraction efficiency of total flavonoid content was evaluated by the chromatographic peak areas of quercetin and kaempferol, which are two bioactive components typically found in persimmon leaves. The best combination of extraction parameters was obtained with response surface methodology. A microwave power of 525 W, liquid to solid ratio of 17:1 mL/g, and PEG aqueous solution concentration of 60% w/w were identified as the optimum parameters. Extraction dynamics analysis indicated that the quercetin, kaempferol, and total flavonoid contents were rising with increasing extraction time up to 20-25 min, from which point onwards they all decreased. Under the optimum conditions, quercetin, kaempferol, and total flavonoid contents obtained from the sample were 1.20 ± 0.05, 0.64 ± 0.11, and 16.90 ± 0.06 mg/g, respectively. Compared with ethanol-based MAE, and ethanol-based and PEG-based ultrasonic-assisted extractions, PEG-based MAE had higher efficiency for the extraction of flavonoid compounds from persimmon leaves. Overall, PEG-based MAE represents an efficient choice for the extraction of bioactive substances from traditional Chinese medicines.

Microwave-assisted one-step extraction-derivatization for rapid analysis of fatty acids profile in herbal medicine by gas chromatography-mass spectrometry.

A rapid and practical microwave-assisted one-step extraction-derivatization (MAED) method was developed for gas chromatography-mass spectrometry analysis of fatty acids profile in herbal medicine. Several critical experimental parameters for MAED, including reaction temperature, microwave power and the amount of derivatization reagent (methanol), were optimized with response surface methodology. The results showed that the chromatographic peak areas of total fatty acids and total unsaturated fatty acids content obtained with MAED were markedly higher than those obtained by the conventional Soxhlet or microwave extraction and then derivatization method. The investigation of kinetics and thermodynamics of the derivatization reaction revealed that microwave assistance could reduce activation energy and increase the Arrhenius pre-exponential factor. The MAED method simplified the sample preparation procedure, shortened the reaction time, but improved the extraction and derivatization efficiency of lipids and reduced ingredient losses, especially for the oxidization and isomerization of unsaturated fatty acids. The simplicity, speed and practicality of this method indicates great potential for high throughput analysis of fatty acids in natural medicinal samples.

Three-dimensional cell bioreactor coupled with high performance liquid chromatography-mass spectrometry for the affinity screening of bioactive components from herb medicine.

An efficient and convenient method, three-dimensional (3-D) cell bioreactor coupled with high performance liquid chromatography-mass spectrometry was developed for affinity screening and analysis of multiple bioactive components from herbal medicines. Cancer cells were cultured on a porous scaffold to form a 3-D cell bioreactor. After interacting with live and fixed cells, the HPLC fingerprinting chromatograms of herbal medicine extract were compared to evaluate the binding properties of herbal components on cells. Model anticancer drugs (paclitaxel and resveratrol) and non-anticancer drugs (ketoprofen and penicillin G) were chosen to investigate the feasibility. When cell-drug interaction time was 30 min, the binding degrees of paclitaxel and resveratrol (each 15 µg/ml) were 82.2±7.2% and 66.1±4.1%, and for ketoprofen and penicillin G (each 15 µg/ml) were less than 3%. This method was used to screen bioactive components from Polygonum cillinerve (Nakai) Ohwi (PCO) extract, and the binding degrees of two main components in PCO extract (10 µg/ml), aristolochic acid A and aristolochic acid B, were 63.0±5.1% and 18.8±0.9%, respectively. These results demonstrated that this method was highly specific, efficient and convenient for affinity screening and analysis of bioactive components interacted with cells.

Functional changes of intestinal mucosal barrier in surgically critical patients.

BACKGROUND: The gut is capable of inducing multiple organ dysfunction syndrome (MODS). In the diagnosis and treatment of critical ill patients, doctors should pay particular attention to the protection or recovery of intestinal barrier function. However, no reliable diagnostic criteria are available clinically. This study aimed to assess the changes of intestinal mucosal barrier function in surgically critical ill patients as well as their significance. METHODS: Thirty-eight surgically critical ill patients were enrolled as a study group (APACHE II>8 scores), and 15 non-critical ill patients without intestinal dysfunction were selected as a control group (APACHE II<6). General information, symptoms, physical signs, and APACHE II scores of the patients were recorded. The patients in the study group were subdivided into an intestinal dysfunction group (n=26) and a non-intestinal dysfunction group (n=12). Three ml venous blood was collected from the control group on admission and the same volume of plasma was collected from the study group both on admission and in the period of recovery. The plasma concentrations of endotoxin, diamine oxidase (DAO), D-lactate, and intestinal fatty-acid binding protein (iFABP) were detected respectively. The data collected were analyzed by the SPSS 17.0 software for Windows. RESULTS: The levels of variables were significantly higher in the study group than in the control group (P<0.01). They were higher in the intestinal dysfunction group than in the non-intestinal dysfunction group (DAO P<0.05, endotoxin, D-lactate, iFABP P<0.01). In the non-intestinal dysfunction group compared with the control group, the level of endotoxin was not significant (P>0.05), but the levels of DAO, D-lactate and iFABP were statistically significant (P<0.05). The levels of variables in acute stage were higher than those in recovery stage (P<0.01). The death group showed higher levels of variables than the survival group (endotoxin and D-lactate P<0.01, DAO and iFABP P<0.05). CONCLUSION: The plasma concentrations of endotoxin, DAO, D-lactate, and intestinal fatty-acid binding protein (iFABP) could reflect a better function of the intestinal mucosa barrier in surgically critical ill patients.