Molecularly Imprinting Microfiltration Membranes Able to Absorb Diethyl Phthalate from Water.

In this study, polypropylene porous membranes with an average pore size of 1.25 µm were modified by barrier discharge plasma. Next, molecularly imprinted layers with an imprint of diethyl phthalate (DEP) ware grafted of their surface. In order to optimize the composition of the modifying mixture various solvents, the ratios of functional monomers and the cross-linking monomer as well as various amounts of phthalate were verified. It was shown that the most effective membranes were obtained during polymerization in n-octane with the participation of functional monomers in the ratio 3:7 and the amount of phthalate 7 wt.%. The membranes were tested in the filtration process as well as static and dynamic sorption. In all of these processes, the imprinted membranes showed better properties than those without the imprint. The diethyl phthalate retention coefficient was 36.12% for membranes with a grafting yield of 1.916 mg/cm2. On the other hand, DEP static sorption for the imprinted membranes was 3.87 µmol/g higher than for non-imprinted membranes. Also, in the process of dynamic sorption higher values were observed for membranes with the imprint (DSMIM, 4.12 µmol/g; DSNIM, 1.18 µmol/g). The membranes were also tested under real conditions. In the process of filtration of tap water contaminated with phthalate, the presence of imprints in the membrane structure resulted in more than three times higher sorption values (3.09 µmol/g) than in the case of non-imprinted membranes (1.12 µmol/g).

Enhanced Specific Mechanism of Separation by Polymeric Membrane Modification-A Short Review.

Membrane technologies have found a significant application in separation processes in an exceeding range of industrial fields. The crucial part that is decided regarding the efficiency and effectivity of separation is the type of membrane. The membranes deal with separation problems, working under the various mechanisms of transportation of selected species. This review compares significant types of entrapped matter (ions, compounds, and particles) within membrane technology. The ion-exchange membranes, molecularly imprinted membranes, smart membranes, and adsorptive membranes are investigated. Here, we focus on the selective separation through the above types of membranes and detect their preparation methods. Firstly, the explanation of transportation and preparation of each type of membrane evaluated is provided. Next, the working and application phenomena are evaluated. Finally, the review discusses the membrane modification methods and briefly provides differences in the properties that occurred depending on the type of materials used and the modification protocol.

Specific Drug Delivery to Cancer Cells with Double-Imprinted Nanoparticles against Epidermal Growth Factor Receptor.

Epidermal growth factor receptor (EGFR), a tyrosine kinase receptor, is over-expressed in many tumors, including almost half of triple-negative breast cancers. The latter belong to a very-aggressive and drug-resistant form of malignancy. Although humanized anti-EGFR antibodies can work efficiently against these cancers both as monotherapy and in combination with genotoxic drugs, instability and high production costs are some of their known drawbacks in clinical use. In addition, the development of antibodies to target membrane proteins is a very challenging task. Accordingly, the main focus of the present work is the design of supramolecular agents for the targeting of membrane proteins in cancer cells and, hence, more-specific drug delivery. These were produced using a novel double-imprinting approach based on the solid-phase method for preparation of molecularly imprinted polymer nanoparticles (nanoMIPs), which were loaded with doxorubicin and targeted toward a linear epitope of EGFR. Additionally, upon binding, doxorubicin-loaded anti-EGFR nanoMIPs elicited cytotoxicity and apoptosis only in those cells that over-expressed EGFR. Thus, this approach can provide a plausible alternative to conventional antibodies and sets up a new paradigm for the therapeutic application of this class of materials against clinically relevant targets. Furthermore, nanoMIPs can promote the development of cell imaging tools against difficult targets such as membrane proteins.

Molecularly imprinted polymer nanoparticle-based assay (MINA): application for fumonisin B1 determination.

The enzyme-linked immunosorbent assay (ELISA) has been used as a standard tool for monitoring food and animal feed contamination from the carcinogenic fumonisin B1 (FB1). Unfortunately, ELISA is not always efficient due to the instability of the antibody and enzyme components in the immunoassay, the presence of natural enzyme inhibitors in the samples and the high levels of non-specific protein binding. Additionally, the production of antibodies for ELISA can be time-consuming and costly, due to the involvement of animals in the manufacturing process. To overcome these limiting factors, a molecularly imprinted nanoparticle based assay (MINA) has been developed, where the molecularly imprinted nanoparticles (nanoMIPs) replace the primary antibody used in a competitive ELISA. Herein, computational modelling was used to design the nanoMIPs by selecting monomers that specifically interact with FB1. The affinity of the monomers to FB1 was verified by measuring their binding in affinity chromatography experiments. The nanoMIPs were produced by solid phase synthesis and the results showed that nanoMIPs had a hydrodynamic diameter of around 249 ± 29 nm. The assay tested in model samples is highly selective and does not show cross-reactivity with other mycotoxins such as fumonisin B2 (FB2), aflatoxin B1 (AFB1), citrinin (CTT), zearalenone (ZEA), and deoxynivalenol (DON). The MINA allows the detection of FB1 in the concentration range of 10 pM-10 nM with a detection limit of 1.9 pM and a recovery of 108.13-113.76%.

Biomimetic Silica Nanoparticles Prepared by a Combination of Solid-Phase Imprinting and Ostwald Ripening.

Herein we describe the preparation of molecularly imprinted silica nanoparticles by Ostwald ripening in the presence of molecular templates immobilised on glass beads (the solid-phase). To achieve this, a seed material (12 nm diameter silica nanoparticles) was incubated in phosphate buffer in the presence of the solid-phase. Phosphate ions act as a catalyst in the ripening process which is driven by differences in surface energy between particles of different size, leading to the preferential growth of larger particles. Material deposited in the vicinity of template molecules results in the formation of sol-gel molecular imprints after around 2 hours. Selective washing and elution allows the higher affinity nanoparticles to be isolated. Unlike other strategies commonly used to prepare imprinted silica nanoparticles this approach is extremely simple in nature and can be performed under physiological conditions, making it suitable for imprinting whole proteins and other biomacromolecules in their native conformations. We have demonstrated the generic nature of this method by preparing imprinted silica nanoparticles against targets of varying molecular mass (melamine, vancomycin and trypsin). Binding to the imprinted particles was demonstrated in an immunoassay (ELISA) format in buffer and complex media (milk or blood plasma) with sub-nM detection ability.

Replacement of Antibodies in Pseudo-ELISAs: Molecularly Imprinted Nanoparticles for Vancomycin Detection.

The enzyme-linked immunosorbent assay (ELISA) is a widely employed analytical test used to quantify a given molecule. It relies on the use of specific antibodies, linked to an enzyme, to target the desired molecule. The reaction between the enzyme and its substrate gives rise to the analytical signal that can be quantified. Thanks to their robustness and low cost, molecularly imprinted polymer nanoparticles (nanoMIPs) are a viable alternative to antibodies. Herein, we describe the synthesis of nanoMIPs imprinted for vancomycin and their subsequent application in an ELISA-like format for direct replacement of antibodies.

A comparison of the performance of molecularly imprinted polymer nanoparticles for small molecule targets and antibodies in the ELISA format.

Here we show that molecularly imprinted polymer nanoparticles, prepared in aqueous media by solid phase synthesis with immobilised L-thyroxine, glucosamine, fumonisin B2 or biotin as template, can demonstrate comparable or better performance to commercially produced antibodies in enzyme-linked competitive assays. Imprinted nanoparticles-based assays showed detection limits in the pM range and polymer-coated microplates are stable to storage at room temperature for at least 1 month. No response to analyte was detected in control experiments with nanoparticles imprinted with an unrelated template (trypsin) but prepared with the same polymer composition. The ease of preparation, high affinity of solid-phase synthesised imprinted nanoparticles and the lack of requirement for cold chain logistics make them an attractive alternative to traditional antibodies for use in immunoassays.