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1.
Int J Mol Sci ; 25(9)2024 Apr 23.
Article in English | MEDLINE | ID: mdl-38731823

ABSTRACT

This study presents the initial attempt at introducing a magnetic molecularly imprinted polymer (MIP) designed specifically for lamotrigine with the purpose of functioning as a drug carrier. First, the composition of the magnetic polymer underwent optimization based on bulk polymer adsorption studies and theoretical analyses. The magnetic MIP was synthesized from itaconic acid and ethylene glycol dimethacrylate exhibiting a drug loading capacity of 3.4 ± 0.9 µg g-1. Structural characterization was performed using powder X-ray diffraction analysis, vibrating sample magnetometry, and Fourier transform infrared spectroscopy. The resulting MIP demonstrated controlled drug released characteristics without a burst effect in the phospahe buffer saline at pH 5 and 8. These findings hold promise for the potential nasal administration of lamotrigine in future applications.


Subject(s)
Drug Carriers , Lamotrigine , Molecularly Imprinted Polymers , Lamotrigine/chemistry , Drug Carriers/chemistry , Molecularly Imprinted Polymers/chemistry , Molecularly Imprinted Polymers/chemical synthesis , Molecular Imprinting/methods , Spectroscopy, Fourier Transform Infrared , Drug Liberation , X-Ray Diffraction , Adsorption , Hydrogen-Ion Concentration
2.
Int J Mol Sci ; 22(17)2021 Sep 03.
Article in English | MEDLINE | ID: mdl-34502468

ABSTRACT

In this paper, magnetic molecularly imprinted nano-conjugates were synthesized to serve as selective sorbents in a model study of tyramine determination in craft beer samples. The molecularly imprinted sorbent was characterized in terms of morphology, structure, and composition. The magnetic dispersive solid phase extraction protocol was developed and combined with liquid chromatography coupled with mass spectrometry to determine tyramine. Ten samples of craft beers were analyzed using a validated method, revealing tyramine concentrations in the range between 0.303 and 126.5 mg L-1. Tyramine limits of detection and quantification were 0.033 mg L-1 and 0.075 mg L-1, respectively. Therefore, the fabricated molecularly imprinted magnetic nano-conjugates with a fast magnetic responsivity and desirable adsorption performance could be an effective tool for monitoring tyramine levels in beverages.


Subject(s)
Beer/analysis , Magnetic Phenomena , Molecular Imprinting , Nanoconjugates/chemistry , Tyramine/analysis
3.
Int J Mol Sci ; 22(7)2021 Apr 01.
Article in English | MEDLINE | ID: mdl-33915912

ABSTRACT

The aim of this study was to develop magnetic molecularly imprinted nano-conjugate sorbent for effective dispersive solid phase extraction of antazoline (ANT) and its metabolite, hydroxyantazoline (ANT-OH) in analytical method employing liquid chromatography coupled with mass spectrometry method. The core-shell material was characterized in terms of adsorption properties, morphology and structure. The heterogeneous population of adsorption sites towards ANT-OH was characterized by two Kd and two Bmax values: Kd (1) = 0.319 µg L-1 and Bmax (1) = 0.240 µg g-1, and Kd (2) = 34.6 µg L-1 and Bmax (2) = 5.82 µg g-1. The elemental composition of magnetic sorbent was as follows: 17.55, 37.33, 9.14, 34.94 wt% for Si, C, Fe and O, respectively. The extraction protocol was optimized, and the obtained results were explained using theoretical analysis. Finally, the analytical method was validated prior to application to pharmacokinetic study in which the ANT was administrated intravenously to three healthy volunteers. The results prove that the novel sorbent could be useful in extraction of ANT and ANT-OH from human plasma and that the analytical strategy could be a versatile tool to explain a potential and pharmacological activity of ANT and ANT-OH.


Subject(s)
Antazoline/blood , Molecularly Imprinted Polymers/chemistry , Nanoconjugates/chemistry , Adsorption , Adult , Antazoline/pharmacokinetics , Healthy Volunteers , Humans , Male , Solid Phase Extraction
4.
J Sep Sci ; 42(7): 1412-1422, 2019 Apr.
Article in English | MEDLINE | ID: mdl-30681270

ABSTRACT

The objective of this article was to design the selective molecularly imprinted sorbent dedicated to the solid-phase extraction of S-pramipexole from the complex matrix such as human urine. For that purpose, S-2,6-diamino-4,5,6,7-tetrahydrobenzothiazole was used as the template acting as the structural analog of S-pramipexole and five various monomers were employed in the presence of ethylene glycol dimethacrylate to produce molecularly imprinted polymers. The binding capabilities of resulted polymers revealed that the highest imprinting effect was noted for polymer prepared from the itaconic acid. The comprehensive analysis of morphology and the characterization of binding sites showed not only negligible differences in the extension of surfaces of imprinted and nonimprinted polymers but also higher heterogeneity of binding sites in the imprinted material. Comprehensive optimization of the molecularly imprinted solid-phase extraction allowed to select the most appropriate solvents for loading, washing, and elution steps. Subsequent optimization of mass of sorbent and volumes of solvents allowed to achieve satisfactory total recoveries of S-pramipexole from the model multicomponent real sample of human urine that equals to 91.8 ± 3.2% for imprinted sorbent with comparison to only 37.1 ± 1.1% for Oasis MCX.


Subject(s)
Molecular Imprinting , Polymers/chemistry , Pramipexole/isolation & purification , Solid Phase Extraction , Adsorption , Humans , Particle Size , Polymers/chemical synthesis , Pramipexole/chemistry , Pramipexole/urine , Stereoisomerism , Surface Properties
5.
J Sep Sci ; 40(8): 1824-1833, 2017 Apr.
Article in English | MEDLINE | ID: mdl-28195396

ABSTRACT

This study presents a validated strategy for the determination of tryptamine in the presence of its competitors, which involves the molecularly imprinted solid-phase extraction combined with high-performance liquid chromatography coupled with fluorimetric detection. Tryptamine-imprinted microscale sorbent was produced from 4-vinylbenzoic acid and ethylene glycol dimethacrylate in methanol by precipitation polymerization, and its imprinting factor was equal to 15.4 in static experiments or 18.6 in dynamic binding experiments. The method for tryptamine determination in the presence of serotonin and l-tryptophan was validated using a complex matrix of bovine serum albumin yielding the recoveries of tryptamine that ranged between 98.7 and 107.0%. Very low limits of detection and limits of quantification for tryptamine (19.9 and 60.3 nmol/L, respectively) allow the quantification of tryptamine in human cerebrospinal fluid in the presence of tryptophan and serotonin.


Subject(s)
Molecular Imprinting , Tryptamines/cerebrospinal fluid , Chromatography, High Pressure Liquid , Humans , Polymers , Serotonin , Solid Phase Extraction , Tryptophan
6.
J Sep Sci ; 39(5): 895-903, 2016 Mar.
Article in English | MEDLINE | ID: mdl-26732188

ABSTRACT

An efficient molecularly imprinted solid-phase extraction protocol was developed for the separation of dopamine (DA) from human urine. After successful validation of the analytical method using high-performance liquid chromatography coupled with fluorescence detection, a new strategy for the selective determination of DA in the presence of norepinephrine and epinephrine in human urine was presented. In the proposed protocol, the LODs and quantification for DA were 166 ± 36 and 500 ± 110 nmol/L, respectively, and the total recoveries of DA in the range of 1-15 µmol/L varied between 98.3 and 101.1%. DA was detected in the real urine samples at the level of 47-167 µg/L (0.250-0.895 µmol/L). The superiority of the novel analytical strategy was shown by comparison with the results obtained for a commercially available imprinted sorbent.


Subject(s)
Dopamine/isolation & purification , Dopamine/urine , Polymers/chemistry , Solid Phase Extraction/methods , Chromatography, High Pressure Liquid , Humans , Molecular Imprinting , Polymers/chemical synthesis , Solid Phase Extraction/instrumentation
7.
Int J Biol Macromol ; 264(Pt 2): 130645, 2024 Apr.
Article in English | MEDLINE | ID: mdl-38460633

ABSTRACT

Hyaluronic acid (HA), a biodegradable, biocompatible and non-immunogenic therapeutic polymer is a key component of the cartilage extracellular matrix (ECM) and has been widely used to manage two major types of arthritis, osteoarthritis (OA) and rheumatoid arthritis (RA). OA joints are characterized by lower concentrations of depolymerized (low molecular weight) HA, resulting in reduced physiological viscoelasticity, while in RA, the associated immune cells are over-expressed with various cell surface receptors such as CD44. Due to HA's inherent viscoelastic property and its ability to target CD44, there has been a surge of interest in developing HA-based systems to deliver various bioactives (drugs and biologics) and manage arthritis. Considering therapeutic benefits of HA in arthritis management and potential advantages of novel delivery systems, bioactive delivery through HA-based systems is beginning to display improved outcomes over bioactive only treatment. The benefits include enhanced bioactive uptake due to receptor-mediated targeting, prolonged retention of bioactives in the synovium, reduced expressions of proinflammatory mediators, enhanced cartilage regeneration, reduced drug toxicity due to sustained release, and improved and cost-effective treatment. This review provides an underlying rationale to prepare and use HA-based bioactive delivery systems for arthritis applications. With special emphasis given to preclinical/clinical results, this article reviews various bioactive-loaded HA-based particulate carriers (organic and inorganic), gels, scaffolds and polymer-drug conjugates that have been reported to treat and manage OA and RA. Furthermore, the review identifies several key challenges and provides valuable suggestions to address them. Various developments, strategies and suggestions described in this review may guide the formulation scientists to optimize HA-based bioactive delivery systems as an effective approach to manage and treat arthritis effectively.


Subject(s)
Arthritis, Rheumatoid , Osteoarthritis , Humans , Hyaluronic Acid/therapeutic use , Hyaluronic Acid/metabolism , Osteoarthritis/drug therapy , Osteoarthritis/metabolism , Arthritis, Rheumatoid/metabolism , Pharmaceutical Preparations , Polymers/therapeutic use
8.
Acta Pol Pharm ; 70(4): 601-9, 2013.
Article in English | MEDLINE | ID: mdl-23923384

ABSTRACT

In recent years, the investigations of new drug delivery systems have been directed on the development of some "intelligent" drug delivery devices that are able to directly respond to the patient's individual needs. New drug delivery systems should maximize the efficiency of administrated therapeutic agents and improve the patient's quality of life. Introduction of the new drug delivery devices is an important scientific goal, which could be achieved by combining new technologies and intelligent biomaterials. Molecular imprinting technology has a high potential for the preparation of optimized drug delivery forms. Here, molecularly imprinted polymers (MIPs) are promising new materials for such purposes, but their application in this field is nowadays at a developing stage. In this review, the principles of molecular imprinting and the recognition-release mechanisms of polymeric matrices are discussed. The potential application of molecularly imprinted materials as the future drug delivery systems with various administering routes (transdermal, ocular or oral) are presented, and some future prospects for the imprinted polymers are outlined.


Subject(s)
Drug Carriers , Molecular Imprinting , Polymers/chemistry , Technology, Pharmaceutical/methods , Chemistry, Pharmaceutical , Delayed-Action Preparations , Drug Administration Routes , Molecular Structure , Structure-Activity Relationship
9.
Nanomaterials (Basel) ; 13(2)2023 Jan 06.
Article in English | MEDLINE | ID: mdl-36677999

ABSTRACT

Molecular imprinting technology is a well-known strategy to synthesize materials with a predetermined specificity. For fifty years, the "classical" approach assumed the creation of "memory sites" in the organic polymer matrix by a template molecule that interacts with the functional monomer prior to the polymerization and template removal. However, the phenomenon of a material's "memory" provided by the "footprint" of the chemical entity was first observed on silica-based materials nearly a century ago. Through the years, molecular imprinting technology has attracted the attention of many scientists. Different forms of molecularly imprinted materials, even on the nanoscale, were elaborated, predominantly using organic polymers to induce the "memory". This field has expanded quickly in recent years, providing versatile tools for the separation or detection of numerous chemical compounds or even macromolecules. In this review, we would like to emphasize the role of the molecular imprinting process in the formation of highly specific siloxane-based nanomaterials. The distinct chemistry of siloxanes provides an opportunity for the facile functionalization of the surfaces of nanomaterials, enabling us to introduce additional properties and providing a way for vast applications such as detectors or separators. It also allows for catalyzing chemical reactions providing microreactors to facilitate organic synthesis. Finally, it determines the properties of siloxanes such as biocompatibility, which opens the way to applications in drug delivery and nanomedicine. Thus, a brief outlook on the chemistry of siloxanes prior to the discussion of the current state of the art of siloxane-based imprinted nanomaterials will be provided. Those aspects will be presented in the context of practical applications in various areas of chemistry and medicine. Finally, a brief outlook of future perspectives for the field will be pointed out.

10.
Pharmaceutics ; 15(6)2023 Jun 03.
Article in English | MEDLINE | ID: mdl-37376096

ABSTRACT

Simultaneous diagnostics and targeted therapy provide a theranostic approach, an instrument of personalized medicine-one of the most-promising trends in current medicine. Except for the appropriate drug used during the treatment, a strong focus is put on the development of effective drug carriers. Among the various materials applied in the production of drug carriers, molecularly imprinted polymers (MIPs) are one of the candidates with great potential for use in theranostics. MIP properties such as chemical and thermal stability, together with capability to integrate with other materials are important in the case of diagnostics and therapy. Moreover, the MIP specificity, which is important for targeted drug delivery and bioimaging of particular cells, is a result of the preparation process, conducted in the presence of the template molecule, which often is the same as the target compound. This review focused on the application of MIPs in theranostics. As a an introduction, the current trends in theranostics are described prior to the characterization of the concept of molecular imprinting technology. Next, a detailed discussion of the construction strategies of MIPs for diagnostics and therapy according to targeting and theranostic approaches is provided. Finally, frontiers and future prospects are presented, stating the direction for further development of this class of materials.

11.
Polymers (Basel) ; 15(14)2023 Jul 24.
Article in English | MEDLINE | ID: mdl-37514538

ABSTRACT

The aim of this study was to create molecularly imprinted polymers (MIPs) that are specific towards 4-borono-L-phenylalanine (BPA) to serve as boron compound carriers. The honeycomb-like MIPs were characterized in the matter of adsorption properties, morphology, structure, and cytotoxicity towards A549 and V79-4 cell lines. The honeycomb-like MIP composed from methacrylic acid and ethylene glycol dimethacrylate was characterized by a binding capacity of 330.4 ± 4.6 ng g-1 and an imprinting factor of 2.04, and its ordered, porous morphology was confirmed with scanning electron microscopy. The theoretical analysis revealed that the coexistence of different anionic forms of the analyte in basic solution might lower the binding capacity of the MIP towards BPA. The release profiles from the model phosphate buffer saline showed that only 0 to 4.81% of BPA was released from the MIP within the time frame of two hours, furthermore, the obtained material was considered non-cytotoxic towards tested cell lines. The results prove that MIPs can be considered as effective BPA delivery systems for biomedical applications and should be investigated in further studies.

12.
J Sep Sci ; 35(8): 1050-7, 2012 Apr.
Article in English | MEDLINE | ID: mdl-22589167

ABSTRACT

A 2-(3,4-dimethoxyphenyl)ethylamine imprinted polymer (MIP(pt) ) was prepared via the precipitation polymerization together with a nonimprinted polymer (NIP). The morphology of particles was investigated by scanning electron microscopy and the specific surface areas were estimated by methylene blue adsorption (60.5 ± 3.5 and 36.9 ± 1.2 m(2)/g for MIP(pt) and NIP, respectively). The binding experiments were performed to determine the binding capacity of MIP(pt)/NIP particles toward dopamine. Next, the effects of solvents on loading, washing, and eluting steps were examined on solid-phase extraction (SPE). Methanol-water 85:15 v/v (loading step), methanol (washing step), and 0.04 M aqueous ammonium acetate-methanol 30:70 v/v (eluting step) were selected as the most effective systems. Described SPE protocol was successfully applied for separation of dopamine on 2-(3,4-dimethoxyphenyl)ethylamine imprinted particles. Finally, the molecularly imprinted polymer was used for determination of dopamine in spiked banana extract. The total recovery of dopamine from MIP(pt) was equal to 88.5 ± 4.6%, but from NIP was only 12.8 ± 2.3%. The developed material and method were demonstrated to be applicable for the separation of dopamine from bananas. The commercial sorbent C18 was not suitable to such application.


Subject(s)
Dopamine/isolation & purification , Musa/chemistry , Polymers/chemistry , Solid Phase Extraction/methods , Adsorption , Dopamine/analysis , Food Contamination/analysis , Molecular Imprinting , Polymers/chemical synthesis , Solid Phase Extraction/instrumentation
13.
Polymers (Basel) ; 14(13)2022 Jul 04.
Article in English | MEDLINE | ID: mdl-35808783

ABSTRACT

The paper describes the formation of six aromatic N-(2-arylethyl)-2-methylprop-2-enamides with various substituents in benzene ring, viz., 4-F, 4-Cl, 2,4-Cl2, 4-Br, 4-OMe, and 3,4-(OMe)2 from 2-arylethylamines and methacryloyl chloride in ethylene dichloride with high yields (46-94%). The structure of the compounds was confirmed by 1H NMR, 13C NMR, IR, and HR-MS. Those compounds were obtained to serve as functionalized templates for the fabrication of molecularly imprinted polymers followed by the hydrolysis of an amide linkage. In an exemplary experiment, the imprinted polymer was produced from N-(2-(4-bromophenyl)ethyl)-2-methylprop-2-enamide and divinylbenzene, acting as cross-linker. The hydrolysis of 2-(4-bromophenyl)ethyl residue proceeded and the characterization of material including SEM, EDS, 13C CP MAS NMR, and BET on various steps of preparation was carried out. The adsorption studies proved that there was a high affinity towards the target biomolecules tyramine and L-norepinephrine, with imprinting factors equal to 2.47 and 2.50, respectively, when compared to non-imprinted polymer synthesized from methacrylic acid and divinylbenzene only.

14.
Molecules ; 16(5): 3826-44, 2011 May 05.
Article in English | MEDLINE | ID: mdl-21546882

ABSTRACT

A bulk polymerization method was used to easily and efficiently prepare homoveratric acid (3,4-dimethoxyphenylacetic acid)-imprinted polymers from eight basic monomers: 2-vinylpyridine, 4-vinylpyridine, 1-vinylimidazole, N-allylaniline, N-allylpiperazine, allylurea, allylthiourea, and allylamine, in the presence of homoveratric acid as a template in N,N-dimethylformamide as a porogen. The imprinted polymer prepared from allylamine had the highest affinity to the template, showing an imprinting factor of 3.43, and allylamine polymers MIP8/NIP8 were selected for further studies. Their binding properties were analyzed using the Scatchard method. The results showed that the imprinted polymers have two classes of heterogeneous binding sites characterized by two pairs of K(d), B(max) values: K(d)(1) = 0.060 µmol/mL, B(max)(1) = 0.093 µmol/mg for the higher affinity binding sites, and K(d)(2) = 0.455 µmol/mL, B(max)(2) = 0.248 µmol/mg for the lower affinity binding sites. Non-imprinted polymer has only one class of binding site, with K(d) = 0.417 µmol/mL and B(max) = 0.184 µmol/mg. A computational analysis of the energies of the prepolymerization complexes was in agreement with the experimental results. It showed that the selective binding interactions arose from cooperative three point interactions between the carboxylic acid and the two methoxy groups in the template and amino groups in the polymer cavities. Those results were confirmed by the recognition studies performed with the set of structurally related compounds. Allylamine polymer MIP8 had no affinity towards biogenic amines. The obtained imprinted polymer could be used for selective separation of homoveratric acid.


Subject(s)
Molecular Imprinting/methods , Polymers/chemistry , Vanillic Acid/analogs & derivatives , Allylamine/chemistry , Imidazoles/chemistry , Models, Molecular , Piperazine , Piperazines/chemistry , Pyridines/chemistry , Thiourea/analogs & derivatives , Thiourea/chemistry , Urea/analogs & derivatives , Urea/chemistry , Vanillic Acid/chemistry , Vanillic Acid/isolation & purification
15.
Polim Med ; 41(1): 3-15, 2011.
Article in Polish | MEDLINE | ID: mdl-21744655

ABSTRACT

The review focuses on progress of molecularly imprinted polymers for medical diagnostics and clinical analysis. This class of new and selective polymeric materials could find future applications in monitoring of diabetes and tumors, in diagnostics of kidney and heart diseases, arteriosclerosis or in blood analysis.


Subject(s)
Biosensing Techniques , Materials Testing , Molecular Diagnostic Techniques/methods , Molecular Imprinting/methods , Polymers/analysis , Polymers/chemistry , Arteriosclerosis/diagnosis , Diabetes Mellitus/diagnosis , Heart Diseases/diagnosis , Hematologic Tests/methods , Humans , Kidney Diseases/diagnosis , Monitoring, Physiologic/methods , Neoplasms/diagnosis
16.
Materials (Basel) ; 14(8)2021 Apr 08.
Article in English | MEDLINE | ID: mdl-33917896

ABSTRACT

In the last 10 years, we have witnessed an extensive development of instrumental techniques in analytical methods for determination of various molecules and ions at very low concentrations. Nevertheless, the presence of interfering components of complex samples hampered the applicability of new analytical strategies. Thus, additional sample pre-treatment steps were proposed to overcome the problem. Solid sorbents were used for clean-up samples but insufficient selectivity of commercial materials limited their utility. Here, the application of molecularly imprinted polymers (MIPs) or ion-imprinted polymers (IIPs) in the separation processes have recently attracted attention due to their many advantages, such as high selectivity, robustness, and low costs of the fabrication process. Bulk or monoliths, microspheres and core-shell materials, magnetically susceptible and stir-bar imprinted materials are applicable to different modes of solid-phase extraction to determine target analytes and ions in a very complex environment such as blood, urine, soil, or food. The capability to perform a specific separation of enantiomers is a substantial advantage in clinical analysis. The ion-imprinted sorbents gained interest in trace analysis of pollutants in environmental samples. In this review, the current synthetic approaches for the preparation of MIPs and IIPs are comprehensively discussed together with a detailed characterization of respective materials. Furthermore, the use of sorbents in environmental, food, and biomedical analyses will be emphasized to point out current limits and highlight the future prospects for further development in the field.

17.
J Agric Food Chem ; 68(49): 14502-14512, 2020 Dec 09.
Article in English | MEDLINE | ID: mdl-33227193

ABSTRACT

In this paper, we developed and validated a new analytical method to determine the pharmacokinetic profile of hordenine in plasma samples of human volunteers after oral administration of hordenine-rich dietary supplements. For this purpose, a magnetic molecularly imprinted sorbent was fabricated and characterized. The application of a magnetic susceptible material facilitates pretreatment step while working with a highly complex sample, reducing time and costs. An optimized, fast, and reliable separation step was combined with liquid chromatography tandem mass spectrometry, providing an analytical method for analysis of hordenine in human plasma after dietary supplement intake. The method was validated (lower limit of quantification of 0.05 µg/L), enabling the pharmacokinetic profile of hordenine to be determined. The highest concentration of hordenine was noted after 65 ± 14 min, reaching the value of 16.4 ± 7.8 µg/L. The average t1/2 was 54 ± 19 min. The apparent volume of distribution was 6000 ± 2600 L (66 ± 24 L/kg when adjusted for weight).


Subject(s)
Chromatography, High Pressure Liquid/methods , Nanoconjugates/chemistry , Tandem Mass Spectrometry/methods , Tyramine/analogs & derivatives , Administration, Oral , Humans , Limit of Detection , Magnetics , Plasma/chemistry , Preliminary Data , Tyramine/administration & dosage , Tyramine/blood , Tyramine/pharmacokinetics
18.
J Chromatogr A ; 1613: 460677, 2020 Feb 22.
Article in English | MEDLINE | ID: mdl-31727352

ABSTRACT

The objective of this paper was to extend comprehensive theoretical and experimental investigations at the molecular level to identify factors responsible for the high selectivity of imprinted sorbents. This knowledge was utilized in a new analytical strategy devoted to the analysis of hordenine in human urine after beer consumption. Among the various polymeric compositions tested, the most effective material was built up from methacrylic acid and ethylene glycol dimethacrylate (MIP1), showing a satisfactory binding capacity (4.44 ±â€¯0.15 µmol g-1) and high specificity towards hordenine (AF = 5.90). The comprehensive analyses of porosity data and surface measurements revealed differences between imprinted polymers. The characterization of binding sites of MIP1 revealed a heterogeneous population with two values of Kd (2.75 and 370 µmol L-1) and two values of Bmax (1.82 and 99 µmol g-1) for higher and lower affinity respectively. The extensive theoretical analyses of interactions between various analytes and the MIP model cavity showed the highest binding energy for hordenine (ΔEB1 = -175.17 kcal mol-1). The method was validated for selectivity, lowest limit of quantification, calibration curve performance, precision, accuracy, matrix effect, carry-over and stability in urine. Extracts were prepared according to guidelines of the European Medicines Agency. The validation criteria were fulfilled, and the method was satisfactorily applied to urine samples collected prior to, and 2 h after, consumption of 2 L of beer, revealing the presence of hordenine at the mean level of 129 ±â€¯27 ng mL-1. Additionally, ability of the sorbent to purify the urine sample was assessed using flow injection analysis tandem mass spectrometry, for comparison with other extraction techniques.


Subject(s)
Tyramine/analogs & derivatives , Urinalysis/methods , Beer , Humans , Methacrylates/chemistry , Polymers/chemistry , Tyramine/analysis , Tyramine/isolation & purification
19.
Molecules ; 14(6): 2212-25, 2009 Jun 17.
Article in English | MEDLINE | ID: mdl-19553893

ABSTRACT

Eight different functional monomers were used with ethylene glycol dimethacrylate as a cross-linker and molsidomine as a template to obtain molecularly imprinted polymers (MIPs). Non-covalent interactions between molsidomine and each functional monomer in DMSO prior to thermal bulk polymerization were utilized. On the basis of calculated imprinting factors, MIP prepared with N,N'-diallyltartaramide was chosen for further investigations. Examination of interactions in the prepolymerization complex between molsidomine and N,N'-diallyltartaramide was performed using the Job method. The absorbance of isomolar solutions reaching a maximum for the molar ratio of template to monomer equal to 1:4. Scatchard analysis was used for estimation of the dissociation constants and the maximum amounts of binding sites. The polymer based on N,N'-diallyltartaramide has two classes of heterogeneous binding sites characterized by two values of K(d) and two B(max): K(d)(1) = 1.17 mM(-1) and B(max)(1) = 0.8 mumol/mg for the higher affinity binding sites, and K(d)(2) = 200 microM(-1) and B(max)(2) = 2.05 mumol/mg for the lower affinity binding sites. Furthermore, effects of pH and organic solvent on binding properties of MIP and NIP were investigated, together with release of molsidomine from both MIP and NIP.


Subject(s)
Molecular Imprinting/methods , Molsidomine/chemistry , Polymers/chemistry , Cross-Linking Reagents/chemistry , Methacrylates/chemistry , Molecular Structure
20.
J Chromatogr A ; 1587: 61-72, 2019 Feb 22.
Article in English | MEDLINE | ID: mdl-30579638

ABSTRACT

In this paper, we proposed an innovative hydrophilic interaction dispersive solid-phase extraction (HI-d-SPE) protocol suitable for the isolation of the potential cyanide intoxication marker, 2-aminothiazoline-4-carboxylic acid (ATCA), from such complicated matrix as post-mortem blood. To create an optimal HI-d-SPE protocol, two sorbents were used: a molecularly imprinted polymer (MIP) and commercially available Oasis-MCX®. The latter sorbent was identified as more recovery-efficient with higher clean-up abilities in a carefully optimized process. Computational analysis was employed to provide insight into the adsorption mechanism of the two selected sorbents. The theoretical results were in agreement with the experiment regarding the efficiency of the sorbent. HI-d-SPE was successfully applied to the analysis of ATCA in 20 post-mortem blood samples using LC-MS/MS. The analytical performance of the method was finally compared to prior existing methods, in turn revealing its superiority.


Subject(s)
Biomarkers/blood , Diagnostic Techniques and Procedures , Solid Phase Extraction/methods , Thiazoles/blood , Thiazoles/isolation & purification , Adsorption , Chromatography, Liquid , Humans , Hydrophobic and Hydrophilic Interactions , Polymers , Reproducibility of Results , Tandem Mass Spectrometry
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