Effect of functional monomers and porogens on morphology, structure and recognition properties of 2-(4-methoxyphenyl)ethylamine imprinted polymers

Theoretical and experimental proof for selective response of imprinted sorbent - analysis of hordenine in human urine

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 ± 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 K_d (2.75 and 370 μmol L^-1) and two values of B_max (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 (ΔE_B1 = -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 ± 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.

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.

A separation of tyramine on a 2-(4-methoxyphenyl)ethylamine imprinted polymer: an answer from theoretical and experimental studies

A 2-(4-methoxyphenyl)ethylamine imprinted polymer (MIP) was successfully applied for the selective separation of tyramine. A computational analysis was used to predict the affinity of the polymer matrix towards tyramine and a preliminary experimental evaluation was made for the target analyte. Then the experimental analysis of polymer towards tyramine was continued. The binding sites were characterized with employment of the Langmuir and Freudlich models. After the optimization of solid phase extraction towards tyramine, the most appropriate systems for the extraction steps were chosen: methanol-water 85:15 v/v for the loading and the washing as well as 0.04 M aq. ammonium acetate-methanol 30:70 v/v for the elution steps. The biogenic compounds as tryptamine, serotonin, octopamine, synephrine, and l-tyrosine were used for the selectivity study on the basis of binding capacities of the analytes on the imprinted and the non-imprinted polymers. The theoretical approach to obtained results allowed to explain the adsorption selectivity of the tested polymer. Finally, the complex matrix of bovine serum albumin was used to show the usefulness of imprinted material for bioanalysis. The obtained recoveries showed the superiority of MIP over the commercial sorbent C18. Total recoveries of tyramine from spiked bovine serum albumin sample were determined as: 95±2%, 14±3%, and 1.9±0.4% for the imprinted, non-imprinted, and commercial C18 sorbents, respectively.

Uniform core–shell molecularly imprinted polymers: a correlation study between shell thickness and binding capacity

A model of core–shell MIPs was constructed to evaluate the correlation between shell thickness and binding capacity.

Synthesis and characterization of 4-(2-aminoethyl)aniline imprinted polymer as a highly effective sorbent of dopamine

The aim of the study was to develop an efficient sorbent for the separation of dopamine. 4-(2-Aminoethyl)aniline was chosen as a pseudo-template to produce the imprinted polymers from seven different functional monomers in the presence of ethylene glycol dimethacrylate as a cross-linker. The binding capacity showed that the highest binding specificity towards dopamine was achieved when methacrylic acid was used as the monomer in methanol solution to form a polymer matrix. The imprinting factor value was equal to 22.96. Other biogenic amines were bound much more weakly. A simple theoretical model was used to give an insight into the imprinting process and the selectivity of polymer matrix. Two artificial urine samples were used as the complex matrices to show the usefulness of the new sorbent for bioanalysis.