An ingenious technique based on the usage of fluorone-based dye; pyrosin B in prucalopride assay in different matrices through an "on-off" dye native fluorescence probe

Prucalopride (PCD), is a modern medication approved by the United States in 2018 to alleviate constipation caused by motility issues. PCD demonstrates a strong affinity and selectivity toward the 5-HT4 receptor. The study here introduces a feasible, direct, non-extractive, and affordable pathway for PCD analytical tracking. The fluorimetric study is based on the on-off effect on the emission amplitude of fluorone-based dye (pyrosin B). In a one-pot experiment, the complex between PCD and pyrosin B is formed instantly in an acidic medium. Correlation between decreased pyrosin B emission and PCD concentrations provides a linear calibration plot from 50 to 900 ng/mL. PCD-dye complex system affecting variables were meticulously tuned. The values of the estimated limit of quantitation and limit of detection for the current methodology were 47.5 and 15.7 ng/mL, respectively. Conformity of the strategy validity was achieved by a comprehensive study of the International Council for Harmonization of Technical Requirements for Pharmaceuticals for Human Use criteria. The method was convincingly applied for PCD assay in tablets and content uniformity investigation. Furthermore, PCD tracking in the spiked biological fluid was applied. Finally, the method uses distilled water as dispersing medium which rise accommodation with the green chemistry principle.

A new application of isoindole fluorophore derivative in Sitagliptin anti-diabetic medication assay: application to dosage forms and biological fluids evaluation

Dipeptidyl peptidase-4 enzyme suppressant is a unique category of oral antidiabetic medication. Sitagliptin (STG) is a perfect member of this category and is pharmaceutically marketed alone or in combination with metformin. Here, the ideal usage of an isoindole derivative was generated for STG assay in a feasible, easy-to-use, economic, and affordable way. STG as an amino group donor can form a luminescent derivative; isoindole upon interaction with o-phthalaldehyde and the existence of (2-mercaptoethanol) 0.02% v/v as a thiol group donor. Excitation (339.7 nm) and emission (434.6 nm) wavelengths were used to monitor the isoindole fluorophore yield, moreover, each experimental variable was carefully investigated and adjusted. The calibration graph was produced by plotting fluorescence intensities against STG concentrations, and controlled linearity was seen at concentrations values ranging from 50 to 1000 ng/mL. A thorough analysis of the ICH guidelines was employed to prove the technique validation. The implementation of the present technique was extended successfully into the evaluation of various types of STG dose forms and spiking samples of human plasma and urine. The developed technique was shown to be an effective, simple, and quick replacement for quality control and clinical study evaluation of STG.

Electrochemical determination of aripiprazole based on aluminium oxide nanoparticles modified carbon paste electrode

The electrochemical oxidation of aripiprazole was explored at a carbon paste electrode modified with aluminium oxide nanoparticles by cyclic voltammetry and square-wave anodic adsorptive stripping voltammetry. Experimental parameters such as carbon paste composition, scan rate, buffer pH, accumulation time, and accumulation potential were optimized in order to obtain high analytical performance. The incorporation of aluminium oxide nanoparticles into the carbon paste matrix enhanced the effective surface area of the carbon paste electrode and improved the sensitivity. On the aluminium oxide nanoparticles modified carbon paste electrode, aripiprazole exhibited an irreversible anodic peak at +1.17 V in pH 1.8 BR buffer solution. Under optimum conditions, the peak current exhibited a linear dependence with aripiprazole concentration between 0.03 and 8.0 μM with a detection limit of 0.006 μM. The analytical applicability of the voltammetric method was evaluated by quantification of ARP in human serum samples and pharmaceutical formulations.

Alternative and promising targets of biochemical analysis in sport (review of literature)

Current literature review provides an evaluation of advantages and limitations of biochemical control objects representing functional state of athletes as well as the outlook for using alternative targets regarding sports medicine. Traditionally, invasive procedures (venous blood collection, muscle biopsy) have been known as the gold standard for analyzing a wide range of biomarkers which could be employed as effective diagnostic tools to control the course of adaptation processes, monitor performance, overtraining and physical well-being of athletes, but these techniques are painful, time-consuming and place demands on storage and shipment. In this behalf finding an alternative objects for biochemical research that does not have disadvantages given above is the question of present interest. Saliva and dry blood spots (DBS) could serve as equally informative and promising targets for monitoring athletes' condition. The non-invasive nature of saliva collection allows to shorten sample collection time, reduce stress hormones levels and possible infection contamination. Moreover, collecting saliva process does not require special equipment and trained medical staff which is particularly important when athletes are at training camps. The DBS method has successfully proven itself with regard to neonatal screening and pharmacokinetics studies. Its key benefits are simplicity, small volume of bioliquid, enhanced stability of adsorbed biomarkers on the card surface, lack of special storage and transportation requirements and low costs for samples shipment to the laboratory. Taken together outlined advantages will provide the opportunity to increase the frequency of biomaterial collection to perform selective observation of training loads effects on various systems of athletes' body. The combination of DBS with immunochemical and mass-spectrometric approaches could serve as an efficient instrument to investigate the role of various biomarkers in monitoring the functional state of athletes. We searched for articles in MedLine database with the key words «dry blood spots», «saliva», «sports medicine», «sample collection», «sports biochemistry».

Seasonal Stability of SARS-CoV-2 in Biological Fluids

The transmission of SARS-CoV-2 occurs by close contact with infected persons through droplets, the inhalation of infectious aerosols, and the exposure to contaminated surfaces. Previously, we determined the virus stability on different types of surfaces under indoor and seasonal climatic conditions. SARS-CoV-2 survived the longest on surfaces under winter conditions, followed by spring/fall and summer conditions, suggesting the seasonal pattern of stability on surfaces. However, under natural conditions, the virus is secreted in various biological fluids from infected humans. In this respect, it remains unclear how long the virus survives in various types of biological fluids. This study explores SARS-CoV-2 stability in virus-spiked human biological fluids under different environmental conditions by determining the virus half-life. The virus was stable for up to 21 days in nasal mucus, sputum, saliva, tear, urine, blood, and semen; it remained infectious significantly longer under winter and spring/fall conditions than under summer conditions. In contrast, the virus was only stable up to 24 h in feces and breast milk. These findings demonstrate the potential risk of infectious biological fluids in SARS-CoV-2 transmission and have implications for its seasonality.

Serum Derived Extracellular Vesicles Mediated Delivery of Synthetic miRNAs in Human Endothelial Cells

Extracellular vesicles (EVs) have emerged in the last decades as a cell-to-cell communication mechanism. One of their mechanism of action is the direct delivery of their cargo, composed of bioactive molecules to target cells. Different methods (direct electroporation, cell transfection, chemical transfection) were developed to vehicle therapeutic molecules through EVs. However, most of these techniques presented some limitations such as EV disruption and aggregation. In the present study, we demonstrated that a direct temperature-controlled co-incubation of EVs with defined miRNAs is a stable method to deliver information to target cells without affecting EV constitutive content. We chose serum as an easy and abundant source of EVs applicable to autologous treatment after EV modification. Exogenous cel-miR-39 loaded on serum EVs (SEVs) was taken up by human endothelial cells, demonstrating an adequate miRNA loading efficacy based on the co-incubation method. Moreover, SEVs co-incubation with the angiomiRNA-126 (miR-126) enhanced their angiogenic properties in vitro and in vivo by increasing the capacity to induce capillary-like structure formation of human endothelial cells. MiR-126 loaded EVs were also shown to stimulate mouse endothelial cells to invade Matrigel plugs and create more vessels with respect to the EV naive counterpart. When SEVs were loaded with miR-19b, an anti-angiogenic miRNA, they were able to reduce Vascular endothelial growth factors (VEGF) pro-angiogenic capacity, supporting the selective biological effect mediated by the carried miRNA. Lastly, we identified Annexin A2 (ANXA2) as one of the molecules involved in the exogenous RNA binding to serum EV surface, favoring miRNA delivery to target endothelial cells for potential therapeutic application.

Venlafaxine Determination in Pharmaceutical Formulation and Serum by Ion-Selective Electrodes

BACKGROUND

The application of an ion selective technique for the determination of analyte concentrations is considered one of the most economical techniques for quality control purposes.

OBJECTIVE

To elaborate and investigate the construction and general performance characteristics of potentiometric PVC membrane sensors for venlafaxine cation (Ven+).

METHOD

The sensors are based on the use of the ion association complexes of the venlafaxine cation with phosphotungstate (PT) and silicotungstate (ST) counter anions as ion exchange sites in the plasticized PVC matrix. They are characterized by potentiometric and conductimetric measurements, performed under various conditions.

RESULTS

The electrodes showed a fast (response time around 15 s), stable (life span 45 days) and linear (r2 0.995) response for venlafaxine over the concentration range of 5x10-5 - 1x10-2 M venlafaxine hydrochloride. The solubility product of the ion pair and the formation of the precipitation reaction leading to the ion pair, were determined conductimetrically. The electrodes were found to be very selective, precise (RSD < 1%) and applicable to the potentiometric determination of venlafaxine hydrochloride in pure solutions or in pharmaceutical preparation and in biological fluid (serum), without any interference. Validation of the method shows the suitability of the proposed electrodes for use in the quality assessment of venlafaxine hydrochloride.

CONCLUSION

Using only a pH meter in combination with the selective electrodes, drug substance or drug product could be determined accurately in a few seconds. In addition, the in-house made electrodes were tested to monitor venlafaxine in serum. Acceptable results were achieved using the standard addition technique.

[Biophysical mechanisms of dehydration of nasal cavity secretion in inflammatory diseases of the upper respiratory tract]

The purpose of the study is an experimental-theoretical study of the mechanisms of structuring the secretion of the nasal cavity, in the process of its dehydration in inflammatory diseases of the upper respiratory tract. The work shows the general patterns of dehydration of natural biological fluids and their model solutions. Simulation of dehydration of the secret allowed us to identify the most informative parameters of changes in its composition in pathology and to develop criteria for diagnosing the inflammatory process of the VDP using the wedge-shaped dehydration method. The study clarified the mechanisms of dehydration of biological fluid, which expanded the possibilities of diagnosing diseases of the VDP.

A Graphene Quantum Dots-Hypochlorite Hybrid System for the Quantitative Fluorescent Determination of Total Antioxidant Capacity

Antioxidants play a major part in the prevention and impairment of oxidative stress-induced damages and diseases. Evaluating the antioxidants activity/capacity in food and biological fluid is proved to be useful for the diagnosis and treatment of these oxidative stress-induced diseases. Herein, a graphene quantum dots (GQDs)-hypochlorite system to detect the antioxidants including nonenzymatic and enzymatic antioxidants in the biological fluid is proposed. The detection principle is based on the fact that antioxidants can protect the fluorescence of GQDs from hypochlorite-caused quenching by acting as the scavengers of hypochlorite. The GQDs-hypochlorite system allows the accurate quantification of the total antioxidant capacity (TAC) of commercial drinks as well as the extracellular superoxide dismutase (SOD) secretion upon stimulation of cytokines or hyperglycemia. This system shows the excellent analytical recoveries for commercial drinks (>89.9%) and good consistency with ELISA testing for SOD secretion in cell-conditioned medium. These results demonstrate the ability and reliability of the GQD-hypochlorite system for detecting and quantifying TAC in real drinks and complex biological fluids.

Phosphoproteome Discovery in Human Biological Fluids

Phosphorylation plays a critical role in regulating protein function and thus influences a vast spectrum of cellular processes. With the advent of modern bioanalytical technologies, examination of protein phosphorylation on a global scale has become one of the major research areas. Phosphoproteins are found in biological fluids and interrogation of the phosphoproteome in biological fluids presents an exciting opportunity for discoveries that hold great potential for novel mechanistic insights into protein function in health and disease, and for translation to improved diagnostic and therapeutic approaches for the clinical setting. This review focuses on phosphoproteome discovery in selected human biological fluids: serum/plasma, urine, cerebrospinal fluid, saliva, and bronchoalveolar lavage fluid. Bioanalytical workflows pertinent to phosphoproteomics of biological fluids are discussed with emphasis on mass spectrometry-based approaches, and summaries of studies on phosphoproteome discovery in major fluids are presented.

Assays for Qualification and Quality Stratification of Clinical Biospecimens Used in Research: A Technical Report from the ISBER Biospecimen Science Working Group

This technical report presents quality control (QC) assays that can be performed in order to qualify clinical biospecimens that have been biobanked for use in research. Some QC assays are specific to a disease area. Some QC assays are specific to a particular downstream analytical platform. When such a qualification is not possible, QC assays are presented that can be performed to stratify clinical biospecimens according to their biomolecular quality.

The circulating transcriptome as a source of non-invasive cancer biomarkers: concepts and controversies of non-coding and coding RNA in body fluids

The gold standard for cancer diagnosis remains the histological examination of affected tissue, obtained either by surgical excision, or radiologically guided biopsy. Such procedures however are expensive, not without risk to the patient, and require consistent evaluation by expert pathologists. Consequently, the search for non-invasive tools for the diagnosis and management of cancer has led to great interest in the field of circulating nucleic acids in plasma and serum. An additional benefit of blood-based testing is the ability to carry out screening and repeat sampling on patients undergoing therapy, or monitoring disease progression allowing for the development of a personalized approach to cancer patient management. Despite having been discovered over 60 years ago, the clear clinical potential of circulating nucleic acids, with the notable exception of prenatal diagnostic testing, has yet to translate into the clinic. The recent discovery of non-coding (nc) RNA (in particular micro(mi)RNAs) in the blood has provided fresh impetuous for the field. In this review, we discuss the potential of the circulating transcriptome (coding and ncRNA), as novel cancer biomarkers, the controversy surrounding their origin and biology, and most importantly the hurdles that remain to be overcome if they are really to become part of future clinical practice.

Detection and Characterization of Cocaine and Related Tropane Alkaloids in Coca Leaf, Cocaine, and Biological Specimens

Cocaine, atropine and scopolamine are the three most important alkaloids in the tropane group. The detection of these alkaloids and their metabolites, at trace levels in biological matrices, is reviewed. These matrices include human and rat physiological fluids such as blood, urine, and saliva as well as human body tissue and hair. The detection, isolation, and determination of cocaine and related tropane alkaloids in cocaine-bearing leaf of South American and greenhouse-cultivated coca is discussed. The relationship between tropane alkaloids in coca leaf and their presence in illicit refined cocaine is addressed. A survey of modern methods for the detection of tropane alkaloids, including mass spectrometry, ultraviolet, infrared and Raman spectroscopy, gas and high-performance liquid chromatography and immunoassay techniques, is presented.