Rationally designed molecularly imprinted polymer membranes as antibody and enzyme mimics in analytical biotechnology

The paper is a self-review of works on development of new approaches to formation of mimics of receptor and catalytic sites of biological macromolecules in the structure of highly cross-linked polymer membranes and thin films. The general strategy for formation of the binding sites in molecularly imprinted polymer (MIP) membranes and thin films was described. A selective recognition of a number of food toxins, endocrine disruptors and metabolites is based on the results of computational modeling data for the prediction and optimization of their structure. A strategy proposed for the design of the artificial binding sites in MIP membranes was supported by the research performed by the authors on development of a number of the MIP membrane-based affinity and catalytic biosensors for selective and sensitive measurement (detection limits 0.3–100 nM) of the target analytes. Novel versatile approaches aimed at improving sensitivity of the developed biosensor systems were discussed

Development of a homogenous assay based on fluorescent imprinted nanoparticles for analysis of nitroaromatic compounds

Herein we describe the development of a homogeneous assay for the detection of 4-nitroaniline (4-NA) and 2,4-dinitroaniline (2,4-diNA). This assay relies on fluorescent molecularly imprinted nanoparticles (nanoMIPs) which, upon interaction with the target analytes, generate a reduction in fluorescence emission intensity (quenching). This is due to a responsive fluorescent monomer (N-2-propenyl-(5-dimethylamino)-1-naphthalene sulphonamide) employed in the manufacture of the nanoMIPs which, by virtue of the imprinting process, is capable of selective interaction with the target analyte, thus giving rise to a quenching effect. Selectivity experiments showed excellent recognition properties toward the target molecule. Under optimal conditions, the fluorescence intensity of these nanoMIPs decreased as the concentration of the imprinted analyte increased from 10 nM to 2.71 μM. A linear relation between the negative logarithm of 4-NA or 2,4-diNA concentrations and the fluorescence intensity for both nanosystems was found (R2 = 0.991 and R2 = 0.9895), with excellent sensitivity (limit of detection (LOD) = 7 and 6 nM, respectively). Furthermore, both nanosystems have been successfully applied for detection of 4-NA or 2,4-diNA in tap water, with recoveries between 90% to 100.6% and 92% to 100.3%, respectively. Thanks to the versatility of the imprinting process, this nanosystem holds the potential for further development of several optical sensors for many other compounds. [Figure not available: see fulltext.].</p

MIRATE: MIps RATional dEsign Science Gateway.

Molecularly imprinted polymers (MIPs) are high affinity robust synthetic receptors, which can be optimally synthesized and manufactured more economically than their biological equivalents (i.e. antibody). In MIPs production, rational design based on molecular modeling is a commonly employed technique. This mostly aids in (i) virtual screening of functional monomers (FMs), (ii) optimization of monomer-template ratio, and (iii) selectivity analysis. We present MIRATE, an integrated science gateway for the intelligent design of MIPs. By combining and adapting multiple state-of-the-art bioinformatics tools into automated and innovative pipelines, MIRATE guides the user through the entire process of MIPs' design. The platform allows the user to fully customize each stage involved in the MIPs' design, with the main goal to support the synthesis in the wet-laboratory. AVAILABILITY: MIRATE is freely accessible with no login requirement at http://mirate.di.univr.it/. All major browsers are supported

Sensor based on molecularly imprinted polymer membranes and smartphone for detection of Fusarium contamination in cereals

The combination of the generic mobile technology and inherent stability, versatility and cost-effectiveness of the synthetic receptors allows producing optical sensors for potentially any analyte of interest, and, therefore, to qualify as a platform technology for a fast routine analysis of a large number of contaminated samples. To support this statement, we present here a novel miniature sensor based on a combination of molecularly imprinted polymer (MIP) membranes and a smartphone, which could be used for the point-of-care detection of an important food contaminant, oestrogen-like toxin zearalenone associated with Fusarium contamination of cereals. The detection is based on registration of natural fluorescence of zearalenone using a digital smartphone camera after it binds to the sensor recognition element. The recorded image is further processed using a mobile application. It shows here a first example of the zearalenone-specific MIP membranes synthesised in situ using “dummy template”-based approach with cyclododecyl 2, 4-dihydroxybenzoate as the template and 1-allylpiperazine as a functional monomer. The novel smartphone sensor system based on optimized MIP membranes provides zearalenone detection in cereal samples within the range of 1–10 µg mL−1 demonstrating a detection limit of 1 µg mL−1 in a direct sensing mode. In order to reach the level of sensitivity required for practical application, a competitive sensing mode is also developed. It is based on application of a highly-fluorescent structural analogue of zearalenone (2-[(pyrene-l-carbonyl) amino]ethyl 2,4-dihydroxybenzoate) which is capable to compete with the target mycotoxin for the binding to zearalenone-selective sites in the membrane’s structure. The competitive mode increases 100 times the sensor’s sensitivity and allows detecting zearalenone at 10 ng mL−1. The linear dynamic range in this case comprised 10–100 ng mL−1. The sensor system is tested and found effective for zearalenone detection in maize, wheat and rye flour samples both spiked and naturally contaminated. The developed MIP membrane-based smartphone sensor system is an example of a novel, inexpensive tool for food quality analysis, which is portable and can be used for the “field” measurements and easily translated into the practice

Detecting and targeting senescent cells using molecularly imprinted nanoparticles

The progressive accumulation of senescent cells in tissues in response to damage importantly contributes to pathophysiological conditions such as fibrosis, diabetes, cancer, Alzheimer's and ageing. Consistent with this, eliminating senescent cells prolongs the lifespan and healthspan in animals and ameliorates certain diseases. Detecting and clearing senescent cells from human tissues could therefore have a significant diagnostic and prognostic impact. However, identifying senescent cells in vivo has proven to be complex. To address this, we characterized and validated a panel of novel membrane markers of senescence. Here, we show the application of molecularly imprinted nanoparticles (nanoMIPs) against an extracellular epitope of one of these markers, B2M, to detect senescent cells in vitro and in vivo. We show that nanoMIPs do not elicit toxic responses in the cells or in mice and successfully recognize old animals, which have a higher proportion of senescent cells in their organs. Importantly, nanoMIPs loaded with drugs can specifically kill senescent cells. Our results provide a proof-of-principle assessment of specific and safe nanotechnology-based approaches for senescent cell detection and clearance with potential clinical relevance