Molecularly imprinted polymer for recognition of 5-fluorouracil by RNA-type nucleobase pairing

Electrochemical investigation of an anticancer drug 5-Fluorouracil in the presence of Theophylline using low-cost and disposable poly(GLY) modified pencil graphite electrode

Herein this study, a facile, efficient and disposable electrochemical sensor has been prepared by electropolymerization of glycine (poly(GLY)) on the surface of pencil graphite electrode (PGE). The surface topology of the equipped poly(GLY) modified pencil graphite electrode (poly(GLY)/PGE) and bare pencil graphite electrode (BPGE) has been characterized by the scanning electron microscopy (SEM) combined with energy dispersive x-ray analysis (EDX) and charge transfer behaviour was measured by electron impedance spectroscopy (EIS) method. The voltammetric behaviour of anticancer, 5-fluorouracil (5-FU) in the presence of theophylline (THP) has been carried out in 0.1 M phosphate buffer solution (PBS) of physiological pH 7.0 using different techniques such as cyclic voltammetry (CV), linear sweep voltammetry (LSV) and differential pulse voltammetry (DPV). The proposed poly(GLY)/PGE shows augmented peak current for 5-FU at lower potential side over the BPGE due to the electrocatalytic behaviour of modifier layers wrapped on the electrode surface. The kinetic behaviour of 5-FU at modified electrode surface was studied by varying different parameters such as pH, scan rate and concentration study in 0.1 M PBS used as a supporting electrolyte. The limit of detection (LOD) for 5-FU was attained using DPV method with different concentrations (1.0-13.0 μM) and it was found to be 0.012 μM. The possible electrochemical reaction of 5-FU was proposed and it was incorporated by two electrons and two protons mechanism at modified electrode surface. The voltammetric response of poly(GLY)/PGE towards the determination of 5-FU was unaffected in the presence of some excipients in addition to the remarkable stability and reproducibility. The applicability of the proposed sensor has been performed by real sample investigation of 5-FU with a substantial percentage of recovery results in all optimized conditions.

Precision Oncology by Point-of-Care Therapeutic Drug Monitoring and Dosage Adjustment of Conventional Cytotoxic Chemotherapies: A Perspective

Therapeutic drug monitoring (TDM) of conventional cytotoxic chemotherapies is strongly supported yet poorly implemented in daily practice in hospitals. Analytical methods for the quantification of cytotoxic drugs are instead widely presented in the scientific literature, while the use of these therapeutics is expected to keep going for longer. There are two main issues hindering the implementation of TDM: turnaround time, which is incompatible with the dosage profiles of these drugs, and exposure surrogate marker, namely total area under the curve (AUC). Therefore, this perspective article aims to define the adjustment needed from current to efficient TDM practice for cytotoxics, namely point-of-care (POC) TDM. For real-time dose adjustment, which is required for chemotherapies, such POC TDM is only achievable with analytical methods that match the sensitivity and selectivity of current methods, such as chromatography, as well as model-informed precision dosing platforms to assist the oncologist with dose fine-tuning based on quantification results and targeted intervals.

Ultra-Fast Portable and Wearable Sensing Design for Continuous and Wide-Spectrum Molecular Analysis and Diagnostics

The design and characterization of spatiotemporal nano-/micro-structural arrangement that enable real-time and wide-spectrum molecular analysis is reported and demonestrated in new horizons of biomedical applications, such as wearable-spectrometry, ultra-fast and onsite biopsy-decision-making for intraoperative surgical oncology, chiral-drug identification, etc. The spatiotemporal sesning arrangement is achieved by scalable, binder-free, functionalized hybrid spin-sensitive (<↑| or <↓|) graphene-ink printed sensing layers on free-standing films made of porous, fibrous, and naturally helical cellulose networks in hierarchically stacked geometrical configuration (HSGC). The HSGC operates according to a time-space-resolved architecture that modulate the mass-transfer rate for separation, eluation and detection of each individual compound within a mixture of the like, hereby providing a mass spectrogram. The HSGC could be used for a wide range of applictions, including fast and real-time spectrogram generator of volatile organic compounds during liquid-biopsy, without the need of any immunochemistry-staining and complex power-hungry cryogenic machines; and wearable spectrometry that provide spectral signature of molecular profiles emiited from skin in the course of various dietry conditions.

Selective Impedimetric Chemosensing of Carcinogenic Heterocyclic Aromatic Amine in Pork by dsDNA-Mimicking Molecularly Imprinted Polymer Film-Coated Electrodes

Inspired by the easy intercalation of quinoxaline heterocyclic aromatic amines (HAAs) in double-stranded DNA (dsDNA), we synthesized a nucleobase-functionalized molecularly imprinted polymer (MIP) as the recognition unit of an impedimetric chemosensor for the selective determination of a 2-amino-3,7,8-trimethyl-3H-imidazo[4,5-f]quinoxaline (7,8-DiMeIQx) HAA. HAAs are generated in meat and fish processed at high temperatures. They are considered to be potent hazardous carcinogens. The MIP film was prepared by potentiodynamic electropolymerization of a pre-polymerization complex of two adenine- and one thymine-substituted bis(2,2'-bithien-5-yl)methane functional monomer molecules with one 7,8-DiMeIQx template molecule, in the presence of the 2,4,5,2',4',5'-hexa(thiophene-2-yl)-3,3'-bithiophene cross-linking monomer, in solution. The as-formed MIP chemosensor allowed for the selective impedimetric determination of 7,8-DiMeIQx in the 47 to 400 μM linear dynamic concentration range with a limit of detection of 15.5 μM. The chemosensor was successfully applied for 7,8-DiMeIQx determination in the pork meat extract as a proof of concept.

Molecularly imprinted polymers-based DNA biosensors

In multiple biological processes, molecular recognition performs an integral role in detecting bio analytes. Molecular imprinted polymers (MIPs) are tailored sensing materials that can biomimic the biologic ligands and can detect specific target molecules selectively and sensitively. The formulation of molecularly imprinted polymers is followed by the formulation of a control termed as non-imprinted polymer (NIP), which, in the absence of a template, is commonly formulated to evaluate whether distinctive imprints have been produced for the template. Given the difficulties confronting bioanalytical researchers, it is inevitable that this strategy would come out as a central route of multidisciplinary studies to create extremely promising stable artificial receptors as a replacement or accelerate biological matrices. The ease of synthesis, low cost, capability to 'tailor' recognition element for analyte molecules, and stability under harsh environments make MIPs promising candidates as a recognition tool for biosensing. Compared to biological systems, molecular imprinting techniques have several advantages, including high recognition ability, long-term durability, low cost, and robustness, allowing molecularly imprinted polymers to be employed in drug delivery, biosensor technology, and nanotechnology. Molecular imprinted polymer-based sensors still have certain shortcomings in determining biomacromolecules (nucleic acid, protein, lipids, and carbohydrates), considering the vast volume of the latest literature on biomicromolecules. These potential materials are still required to address a few weaknesses until gaining their position in recognition of biomacromolecules. This review aims to highlight the current progress in molecularly imprinted polymers (MIPs)-based sensors for the determination of deoxyribonucleic acid (DNA) or nucleobases.

Molecularly Imprinted Materials for Selective Biological Recognition

Molecular imprinting is an approach of generating imprinting cavities in polymer structures that are compatible with the target molecules. The cavities have memory for shape and chemical recognition, similar to the recognition mechanism of antigen-antibody in organisms. Their structures are also called biomimetic receptors or synthetic receptors. Owing to the excellent selectivity and unique structural predictability of molecularly imprinted materials (MIMs), practical MIMs have become a rapidly evolving research area providing key factors for understanding separation, recognition, and regenerative properties toward biological small molecules to biomacromolecules, even cell and microorganism. In this review, the characteristics, morphologies, and applicability of currently popular carrier materials for molecular imprinting, especially the fundamental role of hydrogels, porous materials, hierarchical nanoparticles, and 2D materials in the separation and recognition of biological templates are discussed. Moreover, through a series of case studies, emphasis is given on introducing imprinting strategies for biological templates with different molecular scales. In particular, the differences and connections between small molecular imprinting (bulk imprinting, "dummy" template imprinting, etc.), large molecular imprinting (surface imprinting, interfacial imprinting, etc.), and cell imprinting strategies are demonstrated in detail. Finally, future research directions are provided.

Oligonucleotide Analogs and Mimics for Sensing Macromolecular Biocompounds

Living organisms create life-sustaining macromolecular biocompounds including biopolymers. Artificial polymers can selectively recognize biocompounds and are more resistant to harsh physical, chemical, and physiological conditions than biopolymers are. Due to recognition at a molecular level, molecularly imprinted polymers (MIPs) provide powerful tools to correlate structure with biological functionality and are often used to build next-generation chemosensors. We envision an increasing emergence of nucleic acid analogs (NAAs) or biorelevant monomers built into nature-mimicking polymers. For example, if nucleobases bearing monomers arranged by a complementary template are polymerized to form NAAs, the resulting MIPs will open up novel perspectives for synthesizing NAAs. Despite their usefulness, it is still challenging to use MIPs to devise adaptive biomaterials and to implement them in point-of-care testing.

Molecular Imprinting Prevents Environmental Contamination and Body Toxicity from Anticancer Drugs: An Update

Cancer has been responsible for high morbidity and mortality globally. The treatment of cancer is possible using different kinds of therapies using anticancer drugs if it is diagnosed at the right time. Nevertheless, their appropriate administration for maximum therapeutic effect and their elimination from the patient's body causing environmental problems are two big issues which could be successfully abated using molecular imprinted polymers (MIPs) owing to their unique features. In this review, we have compiled and discussed the works on the determination and controlled release of anticancer drugs based on MIPs. We also highlighted the current challenges and remedies, and the future direction of MIPs in this area.

Programmed Transfer of Sequence Information into a Molecularly Imprinted Polymer for Hexakis(2,2'-bithien-5-yl) DNA Analogue Formation toward Single-Nucleotide-Polymorphism Detection

A new strategy of simple, inexpensive, rapid, and label-free single-nucleotide-polymorphism (SNP) detection using robust chemosensors with piezomicrogravimetric, surface plasmon resonance, or capacitive impedimetry (CI) signal transduction is reported. Using these chemosensors, selective detection of a genetically relevant oligonucleotide under FIA conditions within 2 min is accomplished. An invulnerable-to-nonspecific interaction molecularly imprinted polymer (MIP) with electrochemically synthesized probes of hexameric 2,2'-bithien-5-yl DNA analogues discriminating single purine-nucleobase mismatch at room temperature was used. With density functional theory modeling, the synthetic procedures developed, and isothermal titration calorimetry quantification, adenine (A)- or thymine (T)-substituted 2,2'-bithien-5-yl functional monomers capable of Watson-Crick nucleobase pairing with the TATAAA oligodeoxyribonucleotide template or its peptide nucleic acid (PNA) analogue were designed. Characterized by spectroscopic techniques, molecular cavities exposed the ordered nucleobases on the 2,2'-bithien-5-yl polymeric backbone of the TTTATA hexamer probe designed to hybridize the complementary TATAAA template. In that way, an artificial TATAAA-promoter sequence was formed in the MIP. The purine nucleobases of this sequence are known to be recognized by RNA polymerase to initiate the transcription in eukaryotes. The hexamer strongly hybridized TATAAA with the complex stability constant K_s^{TTTATA-TATAAA} = k_a/k_d ≈ 10⁶ M^-1, as high as that characteristic for longer-chain DNA-PNA hybrids. The CI chemosensor revealed a 5 nM limit of detection, quite appreciable as for the hexadeoxyribonucleotide. Molecular imprinting increased the chemosensor sensitivity to the TATAAA analyte by over 4 times compared to that of the nonimprinted polymer. The herein-devised detection platform enabled the generation of a library of hexamer probes for typing the majority of SNP probes as well as studying a molecular mechanism of the complex transcription machinery, physics of single polymer molecules, and stable genetic nanomaterials.

Visual detection of 2,4,6-trinitrotolune by molecularly imprinted colloidal array photonic crystal

We developed a photonic crystal (PhC) sensor for the quantification of 2,4,6-trinitrotoluene (TNT) in solution. Monodisperse (210nm in diameter) molecularly imprinted colloidal particles (MICs) for TNT were prepared by the emulsion polymerization of methyl methacrylate and acrylamide in the presence of TNT as a template. The MICs were then self-assembled into close-packed opal PhC films. The adsorption capacity of the MICs for TNT was 64mg TNT/g. The diffraction from the PhC depended on the TNT concentration in a methanol/water (3/2, v/v) potassium dihydrogen phosphate buffer solution (pH=7.0, 30mM). The limit of detection (LOD) of the sensor was 1.03μg. The color of the molecularly imprinted colloidal array (MICA) changed from green to red with an 84nm diffraction red shift when the TNT concentration increased to 20mM. The sensor response time was 3min. The PhC sensor was selective for TNT compared to similar compounds such as 2,4,6-trinitrophenol, 2,4-dinitrotoluene, 2,6-dinitrotoluene, 2-nitromesitylene, 4-nitrotoluene, 2-nitrotoluene, 1,3-dinitrobenzene, methylbenzene, 4-nitrophenol, 2-nitroaniline, 3-aminophenol and 3-nitroaniline. The sensor showed high stability with little response change after three years storage. This sensor technology might be useful for the visual determination of TNT.

Temperature and magnetism bi-responsive molecularly imprinted polymers: Preparation, adsorption mechanism and properties as drug delivery system for sustained release of 5-fluorouracil

Temperature and magnetism bi-responsive molecularly imprinted polymers (TMMIPs) based on Fe3O4-encapsulating carbon nanospheres were prepared by free radical polymerization, and applied to selective adsorption and controlled release of 5-fluorouracil (5-FU) from an aqueous solution. Characterization results show that the as-synthesized TMMIPs have an average diameter of about 150 nm with a typical core-shell structure, and the thickness of the coating layer is approximately 50 nm. TMMIPs also displayed obvious magnetic properties and thermo-sensitivity. The adsorption results show that the prepared TMMIPs exhibit good adsorption capacity (up to 96.53 mg/g at 25 °C) and recognition towards 5-FU. The studies on 5-FU loading and release in vitro suggest that the release rate increases with increasing temperature. Meanwhile, adsorption mechanisms were explored by using a computational analysis to simulate the imprinted site towards 5-FU. The interaction energy between the imprinted site and 5-FU is -112.24 kJ/mol, originating from a hydrogen bond, Van der Waals forces and a hydrophobic interaction between functional groups located on 5-FU and a NIPAM monomer. The electrostatic potential charges and population analysis results suggest that the imprinted site of 5-FU can be introduced on the surface of TMMIPs, confirming their selective adsorption behavior for 5-FU.

Molecularly imprinted polymeric micro- and nano-particles for the targeted delivery of active molecules

Molecular imprinting (MI) represents a strategy to introduce a 'molecular memory' in a polymeric system obtaining materials with specific recognition properties. MI particles can be used as drug delivery systems providing a targeted release and thus reducing the side effects. The introduction of molecular recognition properties on a polymeric drug carrier represents a challenge in the development of targeted delivery systems to increase their efficiency. This review will summarize the limited number of drug delivery MI particles described in the literature along with an overview of potential solutions for a larger exploitation of MI particles as targeted drug delivery carriers. Molecularly imprinted drug carriers can be considered interesting candidates to significantly improve the efficiency of a controlled drug treatment.

Molecularly imprinted polymers as recognition materials for electronic tongues

For over three decades now, molecularly imprinted polymers (MIPs) have successfully been used for selective chemical sensing because the shape and size of their imprinted molecular cavities perfectly matched those of the target analyte molecules. Moreover, orientation of recognizing sites of these cavities corresponded to those of the binding sites of the template molecules. In contrast, electronic tongue (e-tongue) is usually an array of low-affinity recognition units. Its selectivity is based on recognition pattern or multivariate analysis. Merging these two sensing devices led to a synergetic hybrid sensor, an MIP based e-tongue. Fabrication of these e-tongues permitted simultaneous sensing and discriminating several analytes in complex solutions of many components so that these arrays compensated for limitation in cross-reactivity of MIPs. Apparently, analytical signals generated by MIP-based e-tongues, compared to those of ordinary sensor arrays, were more reliable where a unique pattern or 'fingerprint' for each analyte was generated. Additionally, several transduction platforms (from spectroscopic to electrochemical) engaged in constructing MIP-based e-tongues, found their broad and flexible applications. The present review critically evaluates achievements in recent developments of the MIP based e-tongues for chemosensing.

Ginseng Purified Dry Extract, BST204, Improved Cancer Chemotherapy-Related Fatigue and Toxicity in Mice

Cancer related fatigue (CRF) is one of the most common side effects of cancer and its treatments. A large proportion of cancer patients experience cancer-related physical and central fatigue so new strategies are needed for treatment and improved survival of these patients. BST204 was prepared by incubating crude ginseng extract with ginsenoside-β-glucosidase. The purpose of the present study was to examine the effects of BST204, mixture of ginsenosides on 5-fluorouracil (5-FU)-induced CRF, the glycogen synthesis, and biochemical parameters in mice. The mice were randomly divided into the following groups: the naïve normal (normal), the HT-29 cell inoculated (xenograft), xenograft and 5-FU treated (control), xenograft + 5-FU + BST204-treated (100 and 200 mg/kg) (BST204), and xenograft + 5-FU + modafinil (13 mg/kg) treated group (modafinil). Running wheel activity and forced swimming test were used for evaluation of CRF. Muscle glycogen, serum inflammatory cytokines, aspartic aminotransferase (AST), alanine aminotransferase (ALT), creatinine (CRE), white blood cell (WBC), neutrophil (NEUT), red blood cell (RBC), and hemoglobin (HGB) were measured. Treatment with BST204 significantly increased the running wheel activity and forced swimming time compared to the control group. Consistent with the behavioral data, BST204 markedly increased muscle glycogen activity and concentrations of WBC, NEUT, RBC, and HGB. Also, tumor necrosis factor-α (TNF-α) and interleukin-6 (IL-6), AST, ALT, and CRE levels in the serum were significantly reduced in the BST204-treated group compared to the control group. This result suggests that BST204 may improve chemotherapy-related fatigue and adverse toxic side effects.

A Critical Review on Clinical Application of Separation Techniques for Selective Recognition of Uracil and 5-Fluorouracil

The most important objectives that are frequently found in bio-analytical chemistry involve applying tools to relevant medical/biological problems and refining these applications. Developing a reliable sample preparation step, for the medical and biological fields is another primary objective in analytical chemistry, in order to extract and isolate the analytes of interest from complex biological matrices. Since, main inborn errors of metabolism (IEM) diagnosable through uracil analysis and the therapeutic monitoring of toxic 5-fluoruracil (an important anti-cancerous drug) in dihydropyrimidine dehydrogenase deficient patients, require an ultra-sensitive, reproducible, selective, and accurate analytical techniques for their measurements. Therefore, keeping in view, the diagnostic value of uracil and 5-fluoruracil measurements, this article refines several analytical techniques involved in selective recognition and quantification of uracil and 5-fluoruracil from biological and pharmaceutical samples. The prospective study revealed that implementation of molecularly imprinted polymer as a solid-phase material for sample preparation and preconcentration of uracil and 5-fluoruracil had proven to be effective as it could obviates problems related to tedious separation techniques, owing to protein binding and drastic interferences, from the complex matrices in real samples such as blood plasma, serum samples.

Development of molecularly imprinted polymer nanoarrays of N-acryloyl-2-mercaptobenzamide on a silver electrode for ultratrace sensing of uracil and 5-fluorouracil

Graphical representation of development of mip-nanoarrays.