Selective adenosine-5'-monophosphate uptake by water-compatible molecularly imprinted polymer

Novel adsorptive materials by adenosine 5'-triphosphate imprinted-polymer over the surface of polystyrene nanospheres for selective separation of adenosine 5'-triphosphate biomarker from urine

In this study, we have developed a method to assess adenosine 5'-triphosphate by adsorptive extraction using surface adenosine 5'-triphosphate-imprinted polymer over polystyrene nanoparticles (412 ± 16 nm) for selective recognition/separation from urine. Molecularly imprinted polymer was synthesized by emulsion copolymerization reaction using adenosine 5'-triphosphate as a template, functional monomers (methacrylic acid, N-isopropyl acrylamide, and dimethylamino ethylmethacrylate) and a crosslinker, methylenebisacrylamide. The binding capacities of imprinted and non-imprinted polymers were measured using high-performance liquid chromatography with UV detection with a detection limit of 1.6 ± 0.02 µM of adenosine 5'-triphosphate in the urine. High binding affinity (Q_MIP , 42.65 µmol/g), and high selectivity and specificity to adenosine 5'-triphosphate compared to other competitive nucleotides including adenosine 5'-diphosphate, adenosine 5'-monophosphate, and analogs such as adenosine, adenine, uridine, uric acid, and creatinine were observed. The imprinting efficiency of imprinted polymer is 2.11 for urine (Q_MIP , 100.3 µmol/g) and 2.51 for synthetic urine (Q_MIP , 48.5 µmol/g). The extraction protocol was successfully applied to the direct extraction of adenosine 5'-triphosphate from spiked human urine indicating that this synthesized molecularly imprinted polymer allowed adenosine 5'-triphosphate to be preconcentrated while simultaneously interfering compounds were removed from the matrix. These submicron imprinted polymers over nano polystyrene spheres have a potential in the pharmaceutical industries and clinical analysis applications.

Synthesis of imprinted hydrogel microbeads by inverse Pickering emulsion to controlled release of adenosine 5'‑monophosphate

Herein, we propose the synthesis of a microspherical imprinted hydrogel meant for the controlled release of a nucleotide, adenosine 5'-monophosphate (5'-AMP). Indeed, molecularly imprinted polymers-based (MIPs) materials possess remarkable selective molecular recognition ability that mimicks biological systems. MIPs have been used in numerous applications and hold great promise for the vectorization and/or controlled release of therapeutics and cosmetics. But, the conception of imprinted hydrogels-based drug delivery systems that are able to release polar bioactive compounds is explored weakly. Herein, the synthesis of imprinted hydrogel microbeads by inverse Pickering emulsion is detailed. Microspheres showed a large 5'-AMP loading capacity, around 300 mg·g^-1, and a high binding capacity comparatively to the non-imprinted counterpart. The MIP had a thermo-responsive release behavior providing sustained release of adenosine 5'-monophosphate in an aqueous buffer simulating both human skin pH and temperature.

Boronate affinity materials for separation and molecular recognition: structure, properties and applications

Boronate affinity materials, as unique sorbents, have emerged as important media for the selective separation and molecular recognition of cis-diol-containing compounds. With the introduction of boronic acid functionality, boronate affinity materials exhibit several significant advantages, including broad-spectrum selectivity, reversible covalent binding, pH-controlled capture/release, fast association/desorption kinetics, and good compatibility with mass spectrometry. Because cis-diol-containing biomolecules, including nucleosides, saccharides, glycans, glycoproteins and so on, are the important targets in current research frontiers such as metabolomics, glycomics and proteomics, boronate affinity materials have gained rapid development and found increasing applications in the last decade. In this review, we critically survey recent advances in boronate affinity materials. We focus on fundamental considerations as well as important progress and new boronate affinity materials reported in the last decade. We particularly discuss on the effects of the structure of boronate ligands and supporting materials on the properties of boronate affinity materials, such as binding pH, affinity, selectivity, binding capacity, tolerance for interference and so on. A variety of promising applications, including affinity separation, proteomics, metabolomics, disease diagnostics and aptamer selection, are introduced with main emphasis on how boronate affinity materials can solve the issues in the applications and what merits boronate affinity materials can provide.

Dual-template docking oriented molecular imprinting: a facile strategy for highly efficient imprinting within mesoporous materials

Molecular imprinting within mesoporous materials is a challenging task. Herein, we present a new strategy, called dual-template docking oriented molecular imprinting (DTD-OMI), for facile and highly efficient imprinting within mesoporous materials.

Molecular imprinting science and technology: a survey of the literature for the years 2004-2011

Herein, we present a survey of the literature covering the development of molecular imprinting science and technology over the years 2004-2011. In total, 3779 references to the original papers, reviews, edited volumes and monographs from this period are included, along with recently identified uncited materials from prior to 2004, which were omitted in the first instalment of this series covering the years 1930-2003. In the presentation of the assembled references, a section presenting reviews and monographs covering the area is followed by sections describing fundamental aspects of molecular imprinting including the development of novel polymer formats. Thereafter, literature describing efforts to apply these polymeric materials to a range of application areas is presented. Current trends and areas of rapid development are discussed.

Fullerene derived molecularly imprinted polymer for chemosensing of adenosine-5'-triphosphate (ATP)

For molecular imprinting of oxidatively electroactive analytes by electropolymerization, we used herein reductively electroactive functional monomers. As a proof of concept, we applied C60 fullerene adducts as such for the first time. For that, we derivatized C60 to bear either an uracil or an amide, or a carboxy addend for recognition of the adenosine-5'-triphosphate (ATP) oxidizable analyte with the ATP-templated molecularly imprinted polymer (MIP-ATP). Accordingly, the ATP complex with all of the functional monomers formed in solution was potentiodynamically electropolymerized to deposit an MIP-ATP film either on an Au electrode of the quartz crystal resonator or on a Pt disk electrode for the piezoelectric microgravimetry (PM) or capacitive impedimetry (CI) determination of ATP, respectively, under the flow-injection analysis (FIA) conditions. The apparent imprinting factor for ATP was ∼4.0. After extraction of the ATP template, analytical performance of the resulting chemosensors, including detectability, sensitivity, and selectivity, was characterized. The limit of detection was 0.3 and 0.03mM ATP for the PM and CI chemosensor, respectively. The MIP-ATP film discriminated structural analogues of ATP quite well. The Langmuir, Freundlich, and Langmuir-Freundlich isotherms were fitted to the experimental data of the ATP sorption and sorption stability constants appeared to be nearly independent of the adopted sorption model.

Molecular Imprinting of Tri-O-Acetyladenosine for the Synthetic Imitation of an ATP-Binding Cleft in Protein Kinases

A number of diseases, including cancer, diabetes, and inflammation, are linked to deregulation of cell signaling pathways controlled by protein kinases. Inhibition of the kinases involved can interrupt aberrant signaling and have a specific therapeutic effect. Protein kinases are recognized as validated therapeutic targets for the treatment of a number of diseases and there are considerable efforts to discover new kinase inhibitors suitable for drug development. The main goal of this study was to fabricate the synthetic imitations of the adenosine triphosphate (ATP) binding cleft in protein kinases and thus produce polymers suitable for screening and isolation of new protein kinase ATP-mimetic inhibitors from different sources. Such polymers were created by the imprinting of tri-O-acetyladenosine in acrylic polymer matrix with the use of methacrylic acid (MAA) or 3-vinylbenzoic acid (VBA) as a functional monomer and ethylene glycol dimethacrylate as a cross-linking agent. The imprints prepared with the use of VBA demonstrate substantially better binding efficiency than that with MAA and particularly high affinity to the initial template (K_d as low as 1.2 μM), sufficient concentration of binding sites N (up to 32 μmol g^-1 ), and pronounced specificity (imprinting factor up to 11). Under flow conditions, the fabricated polymers also demonstrate high capacity and template affinity. The produced imprints reproduce spatially noncovalent interactions present in the ATP binding site of protein kinases and can be anticipated as approximate synthetic imitations of the binding cleft.

Depletion of albumin and immunoglobulin G from human serum using epitope-imprinted polymers as artificial antibodies

Serum is a readily available source for noninvasive studies in clinical research, but it contains abundant proteins such as albumin and immunoglobulin G that can hinder the presence of low-abundant proteins as well as decrease sample loading capacity of analytical methods. Therefore, depletion of these two proteins is required to observe low-abundance serum proteins. Molecularly imprinted polymers are template-induced artificial antibodies with the ability to recognize and selectively bind the target molecule. In this study, artificial albumin and immunoglobulin G antibodies were developed by using two epitopes of human serum albumin and immunoglobulin G as templates. Acrylic acid, acrylamide, and N-acryl tyramine were the corresponding monomers; N,N'-ethylene bisacrylamide served as a cross-linker, and cellulosic fibers were used as a supporting matrix. The adsorption capacity of these artificial antibodies was 15.2 mg, 10 mg, and 15 μL per gram for human serum albumin, immunoglobulin G, and human serum, respectively. The dissociation constant (Kd ) of these artificial antibodies toward the human serum albumin and immunoglobulin G was 1 μM and 0.6 μM, respectively. The biomimetic properties of these artificial antibodies, coupled with their economical and rapid production, high specificity and their reusability, make them attractive for protein separation and analysis.

Design and synthesis of α-carboxy phosphononucleosides

Rhodium catalyzed O-H insertion reactions employing α-diazophosphonate 20 with appropriately protected thymidine, uridine, cytosine, adenosine and guanosine derivatives leads to novel 5'-phosphononucleoside derivatives. Deprotection led to a novel series of phosphono derivatives bearing a carboxylic acid moiety adjacent to the phosphonate group with potential antiviral and/or anticancer activity. The phosphononucleosides bearing an α-carboxylic acid group are envisaged as potential diphosphate mimics. Conversion to mono- and diphosphorylated phosphononucleosides has been effected for evaluation as nucleoside triphosphate mimics. Most of the novel phosphononucleosides proved to be inactive against a variety of DNA and RNA viruses. Only the phosphono AZT derivatives 56-59 showed weak activity against HIV-1 and HIV-2.

Molecular imprinting of AMP by an ionic-noncovalent dual approach

In order to mimic recognition properties of adenylate kinase, molecularly imprinted polymers (MIPs) were prepared for adenosine 5'-monophosphate (AMP), a substrate of the enzyme. Different functional monomers interacting with the phosphate moiety were tested, and the MIP giving the best specific binding of AMP was composed with one equivalent of 2-(dimethylamino)ethyl methacrylate and ten equivalents of acrylamide compared to AMP. Packed into solid phase cartridge, this polymer showed similar characteristics than the enzyme, since it was specific for AMP toward other nucleotides.

Examination of imprinting process with molsidomine as a template

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.