Regenerative NanoOctopus Based on Multivalent-Aptamer-Functionalized Magnetic Microparticles for Effective Cell Capture in Whole Blood.

Isolation of specific rare cell subtypes from whole blood is critical in cellular analysis and important in basic and clinical research. Traditional immunomagnetic cell capture suffers from suboptimal sensitivity, specificity, and time- and cost-effectiveness. Mimicking the features of octopuses, a device termed a "NanoOctopus" was developed for cancer cell isolation in whole blood. The device consists of long multimerized aptamer DNA strands, or tentacle DNA, immobilized on magnetic microparticle surfaces. Their ultrahigh sensitivity and specificity are attributed to multivalent binding of the tentacle DNA to cell receptors without steric hindrance. The simple, quick, and noninvasive capture and release of the target cells allows for extensive downstream cellular and molecular analysis, and the time- and cost-effectiveness of fabrication and regeneration of the devices makes them attractive for industrial manufacture.

Plant Leaf Functional Adaptions along Urban-Rural Gradients of Jinhua City.

Environmental changes induced by urbanization may significantly alter plant survival strategies, thereby introducing uncertainties in their ability to withstand extreme heat. This study, centered on Jinhua City, distinguished urban, suburban, and rural areas to represent the various intensities of urbanization. It examined the leaf function properties of evergreen and deciduous trees common in these regions, focusing on leaf and branch characteristics. Employing an analysis of variance (ANOVA), principal component analysis (PCA), and path analysis (PA) of the plant functional traits and the climatic factors of each region, this study assessed the impact of urbanization on plant survival strategies. By tracking changes in plant functional traits from June to August, it explored the capacity of plants to acclimate to urban-warming-related heat stress across different urbanization gradients. The findings revealed that leaf thickness (LT) and stomatal size (SS) initially decreased and then increased, whereas specific leaf area (SLA) and leaf tissue density (LTD) first rose and then declined, from rural to urban regions. From June to August, branch wood density (WD), chlorophyll (Chl) content, LTD, and leaf dry matter content (LDMC) increased, whereas SLA and leaf water content (LWC) diminished, in all regions. PCA suggested that there was no significant change in the resource allocation strategy of plants (p > 0.05), with drought tolerance significantly reduced in the suburbs on the gradient of urbanization (p < 0.05). During the summer, with high temperature, plants were predominantly biased towards slow-return, conservative strategies, particularly among evergreen species. Compared to precipitation, PA revealed a significant urban warming effect. During summer, temperature was the main factor influencing resource investment strategy and drought resistance, with a notably stronger impact on the former. The high temperature in summer promoted a conservative survival strategy in plants, and the urbanization effect increased their tolerance to high temperatures.

Microfluidic chip interfacing microdialysis and mass spectrometry for in vivo monitoring of nanomedicine pharmacokinetics in real time.

Although liposomes have demonstrated significant clinical success as drug delivery vehicles, pharmacokinetic (PK) profiling of liposomal nanomedicines remains difficult due to technical challenges accurately measuring low concentrations of free drug in complex biological matrices. Microdialysis (MD) is well established as a powerful in vivo sampling tool for PK studies, but non-volatile salts present in the microdialysate are incompatible with mass spectrometry (MS) analysis without tedious sample pre-treatment. To address this issue, a µSPE-based microfluidic chip was fabricated to interface MD with MS. By incorporating PEG 20,000 as an effective anti-foulant, the µSPE-based microfluidic chip demonstrated excellent efficiencies in drug extraction and de-salting of the microdialysate, providing a promising approach to real-time monitoring of nanomedicine PK profiles.

MOF-74/polystyrene-derived Ni-doped hierarchical porous carbon for structure-oriented extraction of polycyclic aromatic hydrocarbons and their metabolites from human biofluids.

Polycyclic aromatic hydrocarbons (PAHs), as a major source that significantly increase the risk of developing lung cancer, severely jeopardize public health in modern society. The analysis of PAHs and their metabolites (hydroxylated PAHs, OH-PAHs) is important for biomonitoring and exposure assessment. However, due to the difference in their physico-chemical properties and matrix interference, realizing high-performance extraction of both PAHs and OH-PAHs is still a challenge. Herein, a nickel-doped hierarchical porous carbon (Ni/HPC) is synthesized by carbonizing the polystyrene (PS) infiltrated metal-organic frameworks (MOF-74(Ni)). The obtained Ni/HPC exhibits hierarchical pores and evenly distributed Ni atoms, providing efficient diffusion pathways and adsorption sites. The custom Ni/HPC-coated solid-phase microextraction (SPME) fiber shows superior enrichment capabilities for PAHs and their metabolites under various interfering conditions, verifying its practicability in real sample analysis. The proposed method provides a new strategy to synthesize carbon-based adsorbents that achieves matrix-resistant enrichment of PAHs and OH-PAHs, which simplifies the related sample preparation process for environmental analysis and clinical diagnosis.

Sampling-rate calibration for rapid and nonlethal monitoring of organic contaminants in fish muscle by solid-phase microextraction.

Solid-phase microextraction (SPME) is a promising technique for determining organic contaminants within biotic systems. Existing in vivo SPME-kinetic calibration (SPME-KC) approaches are unwieldy due to the necessity of predetermining a distribution coefficient for the analyte of interest in the tissue and the preloading of a calibrating compound to the fiber. In this study, a rapid and convenient SPME alternative calibration method for in vivo analysis, termed SPME-sampling rate (SPME-SR) calibration, was developed and validated under both laboratory and field conditions to eliminate such presampling requirements. Briefly, the SPME probe is inserted into tissue, in this study fish dorsal-epaxial muscle, for 20 min allowing the concentrations of target analytes in the fish muscle to be determined by the extracted amount of analyte and the predetermined sampling rates. Atrazine, carbamazepine, and fluoxetine were detected nonlethally in the low ppb levels within fish muscle, with both laboratory and field-derived results obtained by in vivo SPME-KC comparable (within a factor of 1.27) to those obtained by lethal sampling followed by tissue liquid extraction. The technique described in this study represents an important advance which broadens the application of SPME in vivo sampling technology.

Synergistic Multimodal Cancer Therapy Using Glucose Oxidase@CuS Nanocomposites.

Multimodal nanotherapeutic cancer treatments are widely studied but are often limited by their costly and complex syntheses that are not easily scaled up. Herein, a simple formulation of glucose-oxidase-coated CuS nanoparticles was demonstrated to be highly effective for melanoma treatment, acting through a synergistic combination of glucose starvation, photothermal therapy, and synergistic advanced chemodynamic therapy enabled by near-infrared irradiation coupled with Fenton-like reactions that were enhanced by endogenous chloride.

Facile fabrication of composited solid phase microextraction thin membranes for sensitive detections of trace hydroxylated polycyclic aromatic hydrocarbons in human urine.

Solid phase microextraction (SPME) has potential to be used for the high-performance enrichments of hydroxylated polycyclic aromatic hydrocarbons (OH-PAHs), which are important biomarkers of PAH exposure. By choosing suitable adsorbent, it is conducive to fabricate new-type of SPME device for improved extraction efficiencies towards OH-PAHs. In this study, a novel method of surface solvent evaporation has been proposed to fabricate SPME thin membrane, integrating the advantages of polydimethylsiloxane (PDMS) and different porous adsorbents. The powdery metal organic framework (Uio66-NH2), porous polymer (powdery polymer aerogel, PPA) and ordered mesoporous carbon (OMC) have been chosen as typical adsorbents and fabricated as thin membranes successfully, indicating the universality of the proposed method for membrane fabrication. Comparing the extraction efficiencies of three prepared membranes towards OH-PAHs, the OMC-PDMS membrane has demonstrated best enrichment efficiencies. The OMC-PDMS membrane was used for the enrichments of trace OH-PAHs in human urine of both smokers and nonsmokers, combining with liquid chromatographic tandem mass spectrometry (LC-MS/MS). The detection limits were in the range of 0.15-0.39 ng L-1, and satisfactory recoveries were found to be 82.1%-115%. It can be seen that the universal strategy to fabricate SPME membrane is helpful to achieve broad-spectrum or selective enrichments of target analytes from complex matrix by simple modulation of membrane components.

Quantitation of polymeric-microneedle-delivered HA15 in tissues using liquid chromatography-tandem mass spectrometry.

A rapid and sensitive liquid chromatography-tandem mass spectrometric method was developed and validated for the determination of HA15, an emerging anticancer compound targeting GSPA5/BIP delivered by dissolvable polymeric microneedles. The linear range of quantification for HA15 was 2.5-1000 ng/ml in plasma and tissue homogenate and the limit of detection and lower limit of quantification are 1 and 2.5 ng/ml, respectively. The inter- and intra-day accuracy and precision were within the acceptable range. HA15 was extracted from mouse plasma and organs using protein precipitation and using dabrafenib as an internal standard and the drug was stable under relevant analytical conditions. The method was used to analyze drug loading, dissolution in vitro, and release ex vivo from dissolvable polymeric microneedles and used to compare these materials to subcutaneous injection for the tissue distribution in tumor bearing nude mice.

Multifunctional Graphene-Oxide-Reinforced Dissolvable Polymeric Microneedles for Transdermal Drug Delivery.

Dissolvable polymeric microneedles (DPMNs) are promising transdermal drug delivery systems with minimal invasiveness and improved patient compliance. Incorporation of a small amount of graphene oxide (GO) in the biocompatible polymers for microneedle fabrication results in important new DPMN properties, that is, dramatically enhanced mechanic strength (10-17 times at 500 mg/mL GO), improved moisture resistance, self-sterilization, antibacterial and anti-inflammatory properties (demonstrated in vitro), and near-infrared light-activated controlled drug release (demonstrated in vitro and in vivo), which were exploited for the transdermal delivery of the chemotherapeutic, HA15, to melanoma-bearing mouse models. These new properties improve their efficacy of transdermal drug delivery and ease of use, enhance their capability of controlled drug release, enlarge the scope of the polymers that can be used for DPMN fabrication, prevent microbial contamination during storage and transportation, and reduce infection risk in clinical applications.

A simple and cost-effective approach to fabricate tunable length polymeric microneedle patches for controllable transdermal drug delivery.

Polymeric microneedles (MNs) are attractive transdermal drug delivery systems because of their efficient drug delivery and minimal invasiveness. Master template fabrication is the most time-consuming and costly step in producing polymeric MNs using a micromoulding approach. Herein, this issue is addressed by modifying tattoo needle cartridges by adjusting the volume of a PDMS spacer, thus streamlining polymeric MN fabrication and significantly reducing its manufacturing cost. Using the fabricated master template, dissolvable polymeric MN systems containing poly(vinyl pyrrolidone) (PVP) and poly(vinyl alcohol) (PVA) were developed. This MN system exhibits several advantages, including controllable MN length, uniform distribution of each needle, and controllable drug release profiles. Overall, polymeric MN fabrication using this method is inexpensive, simple, and yields controllable and effective transdermal drug delivery.

One-calibrant kinetic calibration for on-site water sampling with solid-phase microextraction.

The existing solid-phase microextraction (SPME) kinetic calibration technique, using the desorption of the preloaded standards to calibrate the extraction of the analytes, requires that the physicochemical properties of the standard should be similar to those of the analyte, which limited the application of the technique. In this study, a new method, termed the one-calibrant kinetic calibration technique, which can use the desorption of a single standard to calibrate all extracted analytes, was proposed. The theoretical considerations were validated by passive water sampling in laboratory and rapid water sampling in the field. To mimic the variety of the environment, such as temperature, turbulence, and the concentration of the analytes, the flow-through system for the generation of standard aqueous polycyclic aromatic hydrocarbons (PAHs) solution was modified. The experimental results of the passive samplings in the flow-through system illustrated that the effect of the environmental variables was successfully compensated with the kinetic calibration technique, and all extracted analytes can be calibrated through the desorption of a single calibrant. On-site water sampling with rotated SPME fibers also illustrated the feasibility of the new technique for rapid on-site sampling of hydrophobic organic pollutants in water. This technique will accelerate the application of the kinetic calibration method and also will be useful for other microextraction techniques.

Polymeric microneedles for controlled transdermal drug delivery.

Polymeric microneedle (MN) systems are interesting transdermal drug delivery systems because of their controlled drug delivery, tunable properties, and ease of patient self-administration. They are biocompatible and can easily and painlessly penetrate the stratum corneum, delivering their contents into the dermis where they can be adsorbed into systemic circulation. Polymeric MNs can facilitate appropriate therapeutic dosing by controlling the release kinetics of pre-loaded drugs, targeting specific tissues, or responding to changing physiological conditions. This can be accomplished by modifying the degradation and swelling profiles of the host polymer and the diffusion profiles of the encapsulated drugs. In this review various mechanisms of controlled drug delivery using polymeric MNs, including new strategies, applications, and their future outlook are summarized and evaluated.

Non-invasive isolation of rare circulating tumor cells with a DNA mimic of double-sided tape using multimeric aptamers.

Circulating tumor cells (CTCs) are indicative for cancer diagnosis and prognosis. However, conventional immuno-magnetic cell capture technologies using antibody- and aptamer-functionalized magnetic particles generate increased intracellular oxidative stress through endocytosis. Herein, we efficiently, selectively, and non-invasively isolate CTCs from whole blood by mimicking double-sided tape using DNA.

Determination of trace water contents of organic solvents by gas chromatography-mass spectrometry-selected ion monitoring.

This paper describes the development of a novel gas chromatography-mass spectrometry-selected ion monitoring (GC/MS-SIM) method for the determination of trace water contents of organic solvents, using the characteristic m/z 18, m/z 17, and m/z 16 ions of H2O as the qualitative ion and the m/z 18 ion as the quantifier ion. The accuracy and precision of this method were validated. An excellent linear correlation was obtained for trace water contents between 0 and 0.5217 wt%, with a correlation coefficient (R2) of 0.9999, in addition to spike recoveries of 82.6-112.6%, and relative standard deviations (n = 6) of 0.4-7.2%. The limit of detection (S/N = 3) and limit of quantitation (S/N = 10) for the trace water contents of organic solvents were 0.0005% wt% and 0.0016% wt%, respectively.The analytical results confirmed that this method was useful for determining the trace water contents of organic solvents, because it has a low detection limit and wide linear range. It requires only small amounts of the samples and enables sample batch analysis. It is very environmentally friendly and saves reagents.

Evaluation of the availability of bound analyte for passive sampling in the presence of mobile binding matrix.

Elucidating the availability of the bound analytes for the mass transfer through the diffusion boundary layers (DBLs) adjacent to passive samplers is important for understanding the passive sampling kinetics in complex samples, in which the lability factor of the bound analyte in the DBL is an important parameter. In this study, the mathematical expression of lability factor was deduced by assuming a pseudo-steady state during passive sampling, and the equation indicated that the lability factor was equal to the ratio of normalized concentration gradients between the bound and free analytes. Through the introduction of the mathematical expression of lability factor, the modified effective average diffusion coefficient was proven to be more suitable for describing the passive sampling kinetics in the presence of mobile binding matrixes. Thereafter, the lability factors of the bound polycyclic aromatic hydrocarbons (PAHs) with sodium dodecylsulphate (SDS) micelles as the binding matrixes were figured out according to the improved theory. The lability factors were observed to decrease with larger binding ratios and smaller micelle sizes, and were successfully used to predict the mass transfer efficiencies of PAHs through DBLs. This study would promote the understanding of the availability of bound analytes for passive sampling based on the theoretical improvements and experimental assessments.

Application of microemulsion thin layer chromatography for the fingerprinting of licorice (Glycyrrhiza spp.).

Microemulsion thin layer chromatography (ME-TLC) has been developed for the fingerprinting of aqueous extract of licorice (Glycyrrhiza spp.). The separation conditions and operational processes of the method have been optimized, and its chromatographic characteristics compared with conventional TLC. The ME-TLC system is easier to operate, and with higher resolution and better reproducibility than the conventional TLC. The separation mechanism and retention behavior of ME-TLC are found to differ significantly from conventional TLC. The technique has been applied to the analysis of different licorice species including G. uralensis, G. glabra and G. inflata; and to monitor the dynamic accumulation of active ingredients in licorice plant harvested at different times during its growing cycle in a Good Agriculture Practice (GAP) research farm. Results show that without post-chromatographic derivatization, the ME-TLC fingerprinting images of different species appear as clear, well resolved bands and with strong intensities to reveal distinctively different compositional features of the samples. The technique has also been applied successfully to monitor the dynamic accumulation of active components in licorice plant as a function of growing time in an experimental licorice farm. The study demonstrates the potential of ME-TLC technique as a rapid fingerprinting tool for the authentication and quality assessment of licorice as well as other herbs.

Isolation and identification of flavonoids in licorice and a study of their inhibitory effects on tyrosinase.

Five different flavonoids were isolated from licorice after multistep chromatographic fractionation. The aim was to identify and characterize active components in licorice responsible for antibrowning activities and to seek new tyrosinase inhibitors for applications as antibrowning and depigmenting agents in the food and cosmetic industries. The isolated flavonoids were identified as liquiritin, licuraside, isoliquiritin, liquiritigenin (from Glycyrrhiza uralensis Fisch.), and licochalcone A (from Glycyrrhiza inflate Bat.) by UV, MS, (1)H NMR, and (13)C NMR analyses. The inhibitory potencies and capacities of these flavonoids toward monophenolase activity of mushroom tyrosinase were investigated. The IC(50) values of licuraside, isoliquiritin, and licochalcone A for monophenolase activity were 0.072, 0.038, and 0.0258 mM, respectively. A study of the mechanisms of monophenolase inhibition by these flavonoids indicated that they are all competitive inhibitors. Different from the above flavonoids, no inhibitory activity was observed for liquiritin, whereas liquiritigenin activated the monophenolase activity as a cofactor. The inhibitory effect of licuraside, isoliquiritin, and licochalcone A on diphenolase activity with l-DOPA as the substrate was much lower than those with l-tyrosine. Results suggest that licuraside, isoliquiritin, and licochalcone A have the high potential to be further developed into effective antibrowning and depigmenting agents.

Calibration of pre-equilibrium HF-LPME and its application to the rapid determination of free analytes in biological fluids.

This study establishes a novel calibration method for pre-equilibrium hollow-fiber liquid-phase microextraction (PE-HF-LPME), where the time constant of the extraction of the analyte from sample matrix to the extraction phase (organic solvent) is obtained from a simple concentration curve. Comparing to the traditional kinetic calibration method, where the time constant was obtained from the extraction time profile, the new calibration approach shows improved accuracy and precision. More importantly, deuterated standards are not required in the new method, thus significantly improving its cost-effectiveness and extending its applicability to a wide range of analytes lack of deuterated analogs serving as internal standards. In addition, mass spectrometry is not necessary for the quantification of analytes with the new calibration method, which may further extend the applicability of PE-HF-LPME to some laboratories without mass spectrometers. This study has been substantiated with both theoretical and experimental evidences. Further, the feasibility of the method for real biological samples was demonstrated by measuring the free concentration of flunitrazepam in urine and plasma samples and its drug-protein binding ratio in plasma. The results showed that the method had a short analysis time and was easily implemented with high accuracy and good reproducibility.

The mass transfer dynamics of hollow fiber liquid-phase microextraction and its application for rapid analysis of biological samples.

Hollow fiber liquid-phase microextraction (HF-LPME) has been demonstrated to potentially become a mainstream sample preparation technique for complex samples. Nevertheless, the need for a relatively long extraction time is considered to be the major disadvantage of this method. Lengthy extractions may cause the loss of the extraction phase and may change the contents of biological samples via the action of enzymes. Therefore, control calibrations for particular biological systems must be made. In this study, a theoretical model of the mass transfer dynamics of two-phase HF-LPME was proposed, and the kinetic calibration (KC) of this method for plasma and urine samples was validated. The theoretical results were validated by examining the kinetics of the extraction and back-extraction processes of HF-LPME. The KC-HF-LPME method was successfully used to correct for matrix effects in plasma and urine samples during flunitrazepam analysis. The free amount of flunitrazepam was extracted from plasma for 10 min and analyzed by gas chromatography/mass spectrometry. The amount of pre-added standard and the standard remaining in the extraction phase after extraction were used for the quantification of flunitrazepam in plasma and urine samples. The new method not only significantly shortens the extraction time but also provides a new opportunity to determine the free concentration of analyte in biological systems.

Tissue-specific in vivo bioconcentration of pharmaceuticals in rainbow trout (Oncorhynchus mykiss) using space-resolved solid-phase microextraction.

The space-resolved solid-phase microextraction (SR-SPME) technique was employed to study the tissue-specific bioconcentration of pharmaceuticals in live fish. The segmented design of the SPME fibers allowed for the simultaneous determination of pharmaceutical residues in fish dorsal-epaxial muscle and adipose tissue with a single SPME fiber. The miniaturized fiber endowed the technique with high spatial resolution allowing for quantification of analytes within adjacent, relatively small tissues of immature rainbow trout. The pre-equilibrium sampling and kinetic calibration approach yielded efficient and accurate quantitation of pharmaceuticals in fish tissue. The ability of the SPME method to repeatedly sample the same fish circumvents problems arising from interanimal variation, thus improving the precision of generated bioconcentration kinetic profiles. In vivo monitoring with SR-SPME was validated with in vitro liquid extraction of tissue samples using methanol. Of the nine compounds evaluated, five (atrazine, gemfibrozil, carbamazepine, ibuprofen, and fluoxetine) bioconcentrated in adipose and muscle tissue over the eight exposure days. Although the accumulation of analytes in both tissues was positively correlated, each compound partitioned with differing affinities as modified by their hydrophobicity and unique molecular structure. Water samples analyzed using the SPME technique yielded results similar to those determined by solid-phase extraction (SPE); however, SPME was more rapid and operationally much simpler. This study illustrates the application conditions for in situ SR-SPME while demonstrating the potential of these miniaturized SPME fibers for simultaneous in vivo repeated sampling of multiple tissues.