Recent progress in aptamer-based microfluidics for the detection of circulating tumor cells and extracellular vesicles

Liquid biopsy is a technology that exhibits potential to detect cancer early,monitor therapies,and predict cancer prognosis due to its unique characteristics,including noninvasive sampling and real-time analysis.Circulating tumor cells(CTCs)and extracellular vesicles(EVs)are two important components of circulating targets,carrying substantial disease-related molecular information and playing a key role in liquid biopsy.Aptamers are single-stranded oligonucleotides with superior affinity and specificity,and they can bind to targets by folding into unique tertiary structures.Aptamer-based microfluidic platforms offer new ways to enhance the purity and capture efficiency of CTCs and EVs by combining the advantages of microfluidic chips as isolation platforms and aptamers as recognition tools.In this review,we first briefly introduce some new strategies for aptamer discovery based on traditional and aptamer-based microfluidic approaches.Then,we subsequently summarize the progress of aptamer-based microfluidics for CTC and EV detection.Finally,we offer an outlook on the future directional challenges of aptamer-based microfluidics for circulating targets in clinical applications.

Current developments of bioanalytical sample preparation techniques in pharmaceuticals

Sample preparation is considered as the bottleneck step in bioanalysis because each biological matrix has its own unique challenges and complexity.Competent sample preparation to extract the desired analytes and remove redundant components is a crucial step in each bioanalytical approach.The matrix effect is a key hurdle in bioanalytical sample preparation,which has gained extensive consideration.Novel sample preparation techniques have advantages over classical techniques in terms of accuracy,automation,ease of sample preparation,storage,and shipment and have become increasingly popular over the past decade.Our objective is to provide a broad outline of current developments in various bioanalytical sample preparation techniques in chromatographic and spectroscopic examinations.In addition,how these techniques have gained considerable attention over the past decade in bioanalytical research is mentioned with preferred examples.Modern trends in bioanalytical sample preparation techniques,including sorbent-based microextraction techniques,are primarily emphasized.

Microfluidic reactor with immobilized enzyme-from construction to applications:A review

Microfluidic,as the systems for using microchannel(micron-or sub-micron scale)to process or manipulate microflow,is being widely applied in enzyme biotechnology and biocatalysis.Microfluidic immobilized enzyme reactor(MIER)is a tool with great value for the study of catalytic property and optimal reaction parameter in a flourishing and highly producing manner.In view of its advantages in efficiency,economy,and addressable recognition especially,MIER occupies an important position in the investigation of life science,including molecular biology,bioanalysis and biosensing,biocatalysis etc.Immobilization of enzymes can generally improve their stability,and upon most occasions,the immobilized enzyme is endowed with recyclability.In this review,the enzyme immobilization techniques applied in MIER will be discussed,followed by summarizing the novel developments in the field of MIER for biocatalysis,bioconversion and bioanalysis.The preponderances and deficiencies of the current state-of-the-art preparation ways of MIER are peculiarly discussed.In addition,the prospects of its future study are outlined.

Current status and future directions of high-throughput ADME screening in drug discovery

During the last decade high-throughput in vitro absorption,distribution,metabolism and excretion(HTADME)screening has become an essential part of any drug discovery effort of synthetic molecules.The conduct of HT-ADME screening has been"industrialized"due to the extensive development of software and automation tools in cell culture,assay incubation,sample analysis and data analysis.The HT-ADME assay portfolio continues to expand in emerging areas such as drug-transporter interactions,early soft spot identification,and ADME screening of peptide drug candidates.Additionally,thanks to the very large and high-quality HT-ADME data sets available in many biopharma companies,in silico prediction of ADME properties using machine learning has also gained much momentum in recent years.In this review,we discuss the current state-of-the-art practices in HT-ADME screening including assay portfolio,assay automation,sample analysis,data processing,and prediction model building.In addition,we also offer perspectives in future development of this exciting field.

Liquid chromatographic methods for determination of the new antiepileptic drugs stiripentol, retigabine, rufinamide and perampanel: A comprehensive and critical review

The new antiepileptic drugs perampanel,retigabine,rufinamide and stiripentol have been recently approved for different epilepsy types.Being them an innovation in the antiepileptics armamentarium,a lot of investigations regarding their pharmacological properties are yet to be performed.Besides,considering their broad anticonvulsant activities,an extension of their therapeutic indications may be worthy of investigation,especially regarding other seizure types as well as other central nervous system disorders.Although different liquid chromatographic(LC)methods coupled with ultraviolet,fluorescence,mass or tandem-mass spectrometry detection have already been developed for the determination of perampanel,retigabine,rufinamide and stiripentol,new and more cost-effective methods are yet required.Therefore,this review summarizes the main analytical aspects regarding the liquid chromatographic methods developed for the analysis of perampanel,retigabine(and its main active metabolite),rufinamide and stiripentol in biological samples and pharmaceutical dosage forms.Furthermore,the physicochemical and stability properties of the target compounds will also be addressed.Thus,this review gathers,for the first time,important background information on LC methods that have been developed and applied for the determination of perampanel,retigabine,rufinamide and stiripentol,which should be considered as a starting point if new(bio)analytical techniques are aimed to be implemented for these drugs.

Synthesis and Spectral Properties of Novel Water-soluble Near-infrared Fluorescent Indocyanines

Two fluorescent pentamethine and a squarylium indocyanines containing at least one p-carboxybenzyl group on N atoms in the heterocyclic rings were synthesized. They had good water solubility and photostability. Their maximum absorption and maximum emission were 600-700 nm in water. When it was anchored onto nanostructured TiO2 electrode, compared with in water, the squaraine showed double absorption peaks (one blue shifted and another red shifted) and absorption intensity of the red shift peak increased with the increase of the time of irradiation. The intensity of the blue one decreased simultaneously. We proposed that the presence of two electronic charge forms of squaraine anchored on the TiO2 film might be the reason.

The auxin concentration in sixteen Chinese marine algae

The author determined the occurrence of indole-3-acetic acid in sixteen Chinese marine algae collected from the east coast of China with fluorescence spectrophotometry (FS) and wheat coleop- tile bioanalysis methods (WCB). The concentration of indole-3-acetic acid (IAA) presented was from 1.1–46.9 ng/g Fw (fresh weight) with FS and 5.3–110.2 ng/g Fw with WCB. The results by the two meth- ods were in the orders of 10-3–103 ng/g Fw reported previously from multiple references.

Novel Heptamethine 3H-Indocyanines and their Spectral Properties

Novel heptamethine 3H-indocyanine dyes are synthesized and embedded into a matrix of silica gel derived from tetraethoxysilicane. The photophysical properties of these near infrared dyes in various solvents and in SiO2 sol gel were investigated. The results show that the dyes containing cyclohexenylene bridge and N-(p-carboxy)benzyl groups have better photostability and longer absorption wavelength than those containing linear heptamethine bridge and/or N-(5- carboxy)pentanyl groups. The absorption maxima of these dyes are in reverse proportion to the polarity of the solvents. The microenvironment of the dyes in SiO2 sol-gel characters medium polarity (between methanol and DMF) according to the absorption maxima.

Syntheses and properties of photostable near-infrared cyanines and their cyclodextrin conjugates

Three fluorescent indocyanines containing p-carboxybenzyl groups on N atoms in the heterocyclic tings were synthesized under supersonic. The maxima wavelength of the absorption and emission of the dyes were 550-800 nm in water. Compared with those in aqueous solutions, the fluorescence intensity of the dyes in the α/β-cyclodextrin, Al^3＋, Zn^2＋, Sn^2＋ or the α/β-cyclodextrin in the aqueous solutions of the cations became stronger. The crystal Shapes of the dyes and their cyclodextrin inclusions were mostly acicular or polygon. The NHS-carboxyl squarylium indocyanine was prepared and used to conjugate with taurine or benzylamine, the results indicated that the dyes could couple covalently to biomass containing free NH2 group. Structure and some thermal parameters of the molecule of the trimethine cyanine were obtained by DFT method of Gaussian O3.

Three-dimensional aspects of formulation excipients in drug discovery:a critical assessment on orphan excipients,matrix effects and drug interactions

Formulation/pharmaceutical excipients play a major role in formulating drug candidates,with the objectives of ease of administration,targeted delivery and complete availability.Many excipients used in pharmaceutical formulations are orphanized in preclinical drug discovery.These orphan excipients could enhance formulatability of highly lipophilic compounds.Additionally,they are safe in preclinical species when used below the LD50 values.However,when the excipients are used in formulating compounds with diverse physico-chemical properties,they pose challenges by modulating study results through their bioanalytical matrix effects.Excipients invariably present in study samples and not in the calibration curve standards cause over-/under-estimation of exposures.Thus,the mechanism by which excipients cause matrix effects and strategies to nullify these effects needs to be revisited.Furthermore,formulation excipients cause drug interactions by moderating the pathways of drug metabolizing enzymes and drug transport proteins.Although it is not possible to get rid of excipient driven interactions,it is always advised to be aware of these interactions and apply the knowledge to draw meaningful conclusions from study results.In this review,we will comprehensively discuss a)orphan excipients that have wider applications in preclinical formulations,b)bioanalytical matrix effects and possible approaches to mitigating these effects,and c)excipient driven drug interactions and strategies to alleviate the impacts of drug interactions.

Journal of Pharmaceutical Analysis

Journal of Pharmaceutical Analysis welcomes submissions of fulllength reviews, original research papers and short communication.The act of submitting a manuscript to the Journal carries with it the right to publish that paper.Journal of Pharmaceutical Analysis is published to attract and disseminate innovative and expert findings in the fields:(1) Analysis of traditional Chinese medicine (medicinal materials,patent medicine, prescription, injection)(2) Pharmaceutical analysis of complex system(3) Quality control and methods of biotech drug(4) Action mechanism and metabolisms(5)Quantitative and qualitative analysis in the drug screening process(6) Tracer analysis in molecular pharmacology(7) Quantitative analysis in biopharmaceutics (8) Clinical laboratory and

The application of immunoassay in bioanalysis

Immunoassay technology is an analytical method with high sensitivity and specificity; it provides a technique to assay materials which cannot be measured by other methods, or are difficult to detect. It plays a very important role in biological sample pre-treatment, therapeutic drug monitoring and drug determination, and is one of the important means for in vivo drug analyses. This paper reviews immunoassays commonly used in bioanalysis, including immunoextraction and immunodepletion for pretreatment of biological samples, conventional immunoassay methods and new immunoassay technologies for determination of target drugs.

Aptamer-based Membrane Protein Analysis and Molecular Diagnostics

Membrane proteins are vital components of the cell membrane and play crucial roles in various cellular activities.Analysis of membrane proteins is of paramount importance for studying molecular events inside cells and organisms and holds promising prospects for early disease diagnosis and treatment assessment.Benefiting from obvious merits including high affinity,high specificity and ease of modification,aptamers have been regarded as ideal molecular recognition elements in membrane protein analysis and molecular diagnostics strategies.This review summarised recent advances in membrane protein-specific aptamer screening,aptamer-based static and dynamic membrane protein analysis,and aptamer-based molecular diagnostic techniques.Prospects and challenges were also discussed.

Bioanalysis and Pharmacokinetics of Eight Active Components from Huanglian Jiedu Decoction in Rat Plasma by LC-ESI-MS/MS Method

Objective To develop a sensitive and rapid liquid chromatography-electrospray ionization-tandem mass spectrometry （LC-ESI-MS/MS） method for the simultaneous determination of wogonin, coptisine, berberine, palmatine, jatrorrhizine, phellodendrine, magnoflorine, and wogonoside in rat plasma and to evaluate the pharmacokinetic characteristics of Huanglian Jiedu Decoction （HJD）. Methods LC separation was performed on an Acquity HSS T3 column （100 mm × 2.1 mm, 1.8 μm） using gradient elution with the mobile phase consisting of acetonitrile and 0.1% formic acid water. The detection was accomplished by using positive electrospray ionization in multiple-reaction monitoring mode. Plasma samples were pretreated by protein precipitation. Results The method showed a good linearity over a wide concentration range （r^2 〉 0.99）. The lower limits of quantification were 0.20 ng/mL for coptisine and phellodendrine, 0.48 ng/mL for berberine, 0.10 ng/mL for jatrorrhizine, 0.32 ng/mL for magnoflorine, 0.30 ng/mL for palmatine, and 4.80 ng/mL for wogonin and wogonoside, respectively. The intra- and inter-day precision of the analytes was less than 12.11%, while the accuracy was between -14.46% and 4.86%. The mean recovery of all the analytes ranged from 93.10% to 110.91%. Conclusion This validated method offers thee advantages of high sensitivity. It is successfully applied to evaluating the pharmacokinetic properties of HJD.

DNA Technology-assisted Signal Amplification Strategies in Electrochemiluminescence Bioanalysis

Sensitive and accurate detection of biological analytes,such as proteins,genes,small molecules,ions,cells,etc.,has been a significant project in life science.Signal amplification is one of the most effective approaches to improve the sensitivity of bioanalysis.Taking advantage of specific base pairing,programmable operation,and predictable assembly,DNA is flexible and suitable to perform the signal amplification procedure.In recent years,signal amplification strategies by means of DNA technology have been widely integrated into the construction of electrochemiluminescence(ECL)biosensors,achieving desirable analytical performance in clinical diagnosis,biomedical research,and drug development.To the best of our knowledge,these DNA signal amplification technologies mainly include classical polymerase chain reaction,and various amplification approaches conducted under mild conditions,such as rolling circle amplification(RCA)or hyperbranched RCA,cleaving enzyme-assisted amplification,DNAzyme-involved amplification,toehold-mediated DNA strand displacement amplification without enzyme participation,and so on.This review overviews the recent advancements of DNA signal amplification strategies for bioanalysis in the ECL realm,sketching the creative trajectory from strategies design to ultrasensitive ECL platform construction and resulting applications.

Attenuated Total Reflection Surface-Enhanced Infrared Absorption Spectroscopy: a Powerful Technique for Bioanalysis

Attenuated total reflection surface-enhanced infrared absorption spectroscopy(ATR-SEIRAS)has recently been proven to be a powerful tool for bioanalysis.It enables in situ and in real-time observation of dynamic processes occurring on specific interface,revealing rich structural and functional information of biomolecules at sub monolayer level.The aim of this general review was to give an overview of the cutting edge applications of ATRSEIRAS.We start with description of the basic configuration of the standard ATR-SEIRAS platform.The enhanced mechanisms and methods to fabricate enhanced substrates are then presented.We discuss the recent developments,challenges and applications of ATR-SEIRAS in bioanalysis,mainly focusing on DNA analysis,protein behavior and cell properties.Finally,further development of the ATRSEIRAS technique with enhanced sensitivity,improved time and spatial resolutions will be prospected.

Bioanalysis in single cells: current advances and challenges

Cells, basic units of living structures and functions, build up a complicated small world, and their order and complexity resemble a small universe. The detailed understanding and elucidation of the matter transport and energy conversion mechanisms within a single cell will expand our knowledge about the origin and evolution of life, the disease mechanisms and much more. In past decades, single-cell analysis has been rapidly and significantly improved and various methodologies have been developed to reveal the complexity of mass, energy, and information within single cells. In this review, we focused on the methods developed in recent years for single-cell analysis, including electrochemical method, optical method, and mass spectrometry method. We reviewed the recent advances and representative studies in this research field, and also discussed the strengths and limitations of each method. Finally, we presented the existing technical challenges and further directions for single-cell analysis.

High-Performance Photocathodic Bioanalysis Based on Core-Shell Structured Cu_(2)O@TiO_(2) Nanowire Arrays with Air–Liquid–Solid Joint Interfaces

Developing photoelectrochemical(PEC)bioassays based on the principle of a photocathodic measurement of enzymatic product H_(2)O_(2) is highly attractive because it can naturally avoid interfering signals arising from reductive species inherent to biofluids.However,fluctuant oxygen levels in the analyte solution can compromise the accuracy of photocathodic bioanalysis and restrict its application because oxygen reduction potential is similar to H_(2)O_(2).Herein,we addressed this restriction by constructing a triphase biophotocathode with air–liquid–solid joint interfaces by immobilizing an oxidase enzyme film on the tip part of superhydrophobic p-type semiconductor nanowire arrays.Such a triphase biophotocathode has a reaction zone with steady and air phasedependent oxygen concentration which stabilizes and increases the oxidase kinetics,and enables the photocathodic measurement principle in reliable PEC bioassay development with high selectivity,good accuracy,and a wide linear detection range.Moreover,the biophotocathode shows good stability during repeated testing under light illumination.This reliable PEC bioassay system has broad potential in the fields of disease diagnosis,medical research,and environmental monitoring.

Metabolomics Combined with Network Pharmacology Uncovers Effective Targets of Tao-Hong-Si-Wu Decoction for Its Protection from Sepsis-Associated Acute Lung Injury

Sepsis-induced acute lung injury(ALI)is a leading cause of death among septic complications.Tao-Hong-Si-Wu decoction(TSD),a classical recipe from traditional Chinese medicine used for treating ischemic stroke,has been recently reported to alleviate inflammation and inflammation-stimulated injuries related to the pathology of ALI.Here,we first observed the therapeutic effect of TSD on sepsis-induced ALI.Based on integrated metabolomics and network pharmacology analysis(NPA)techniques,we aim to understand the mechanism of TSD alleviating ALI.TSD’s effects were observed in rats modeled by cecal ligation and puncture(CLP)and rat macrophages stimulated by lipopolysaccharide(LPS).Metabolomics analyses were applied to determine the ingredients in the medicine and key metabolites correlated to the NPA for the prediction of TSD targets.Gene and protein expressions of the key predicted targets were evaluated in the lung tissue and macrophages of septic model rat by quantitative polymerase chain reaction(PCR)and enzyme-linked immunosorbent assays,respectively.TSD improved survival rate and protected against lung injury in CLP rats.Eleven endogenous metabolites were related to TSD’s actions.TSD significantly suppressed IL-6 and TNF-αsecretions and their gene expressions both in the lung tissue of the model rats and in LPS-stimulated macrophages.TSD also restored decreased lung protein expression of VEGFA in septic model rats.Targeted proteins and their affecting metabolites were finally validated in an external test set of rats.This study shows that metabolomics coupled with NPA is a promising approach to explore potential targets of medicine with complex compositions.

Lanthanide NIR luminescence for telecommunications, bioanalyses and solar energy conversion

Present-day advanced technologies heavily rely on the exciting magnetic and spectroscopic properties of lanthanide ions. In particular, their ability to generate well-characterized and intense near-infrared (NIR) luminescence is exploited in any modern fiber-optic telecommunication network. In this feature article, we first summarize the whereabouts underlying the design of highly luminescent NIR molecular edifices and materials. We then focus on describing the main trends in three applications related to this spectral range: telecommunications, biosciences, and solar energy conversion. In telecommunications, efforts concentrate presently on getting easily processable polymer-based waveguide amplifiers. Upconversion nanophosphors emitting in the visible after NIR excitation are now ubiquitous in many bioanalyses while their application to bio-imaging is still in its early stages; however, highly sensitive NIR-NIR systems start to be at hand for both in vitro and in vivo imaging, as well as dual probes combining magnetic resonance and optical imaging. Finally, both silicon-based and dye-sensitized solar cells benefit from the downconversion and upconversion capabilities of lanthanide ions to harvest UV and NIR solar light and to boost the overall quantum efficiency of these next-generation devices.