Attenuation of quorum sensing using computationally designed polymers

It is generally accepted that the majority of Gram-negative and Gram-positive bacteria communicate via production and sensing of small signal molecules, autoinducers. The ability of bacteria to sense their population density is termed quorum sensing (QS). Quorum sensing controls certain phenotypic traits, particularly virulence factors and biofilm formation. In this project a new solution for the attenuation of quorum sensing which involves selective sequestering of the signal molecules using rationally designed synthetic polymers was explored.EThOS - Electronic Theses Online ServiceGBUnited Kingdo

Modulation of EGFR activity by molecularly imprinted polymer nanoparticles targeting intracellular epitopes

In recent years, molecularly imprinted polymer nanoparticles (nanoMIPs) have proven to be an attractive alternative to antibodies in diagnostic and therapeutic applications. However, several key questions remain: how suitable are intracellular epitopes as targets for nanoMIP binding? And to what extent can protein function be modulated via targeting specific epitopes? To investigate this, three extracellular and three intracellular epitopes of epidermal growth factor receptor (EGFR) were used as templates for the synthesis of nanoMIPs which were then used to treat cancer cells with different expression levels of EGFR. It was observed that nanoMIPs imprinted with epitopes from the intracellular kinase domain and the extracellular ligand binding domain of EGFR caused cells to form large foci of EGFR sequestered away from the cell surface, caused a reduction in autophosphorylation, and demonstrated effects on cell viability. Collectively, this suggests that intracellular domain-targeting nanoMIPs can be a potential new tool for cancer therapy

Does size matter? Study of performance of pseudo-ELISAs based on molecularly imprinted polymer nanoparticles prepared for analytes of different sizes

The aim of this work is to evaluate whether the size of the analyte used as template for the synthesis of molecularly imprinted polymer nanoparticles (nanoMIPs) can affect their performance in pseudo-enzyme linked immunosorbent assays (pseudo-ELISAs). Successful demonstration of a nanoMIPs-based pseudo-ELISA for vancomycin (1449.3 g mol) was demonstrated earlier. In the present investigation, the following analytes were selected: horseradish peroxidase (HRP, 44 kDa), cytochrome C (Cyt C, 12 kDa) biotin (244.31 g mol) and melamine (126.12 g mol). NanoMIPs with a similar composition for all analytes were synthesised by persulfate-initiated polymerisation in water. In addition, core-shell nanoMIPs coated with polyethylene glycol (PEG) and imprinted for melamine were produced in organics and tested. The polymerisation of the nanoparticles was done using a solid-phase approach with the correspondent template immobilised on glass beads. The performance of the nanoMIPs used as replacement for antibodies in direct pseudo-ELISA (for the enzymes) and competitive pseudo-ELISA for the smaller analytes was investigated. For the competitive mode we rely on competition for the binding to the nanoparticles between free analyte and corresponding analyte-HRP conjugate. The results revealed that the best performances were obtained for nanoMIPs synthesised in aqueous media for the larger analytes. In addition, this approach was successful for biotin but completely failed for the smallest template melamine. This problem was solved using nanoMIP prepared by UV polymerisation in an organic media with a PEG shell. This study demonstrates that the preparation of nanoMIP by solid-phase approach can produce material with high affinity and potential to replace antibodies in ELISA tests for both large and small analytes. This makes this technology versatile and applicable to practically any target analyte and diagnostic field

A Nanosensor for TNT Detection Based on Molecularly Imprinted Polymers and Surface Enhanced Raman Scattering

We report on a new sensor strategy that integrates molecularly imprinted polymers (MIPs) with surface enhanced Raman scattering (SERS). The sensor was developed to detect the explosive, 2,4,6-trinitrotoluene (TNT). Micron thick films of sol gel-derived xerogels were deposited on a SERS-active surface as the sensing layer. Xerogels were molecularly imprinted for TNT using non-covalent interactions with the polymer matrix. Binding of the TNT within the polymer matrix results in unique SERS bands, which allow for detection and identification of the molecule in the MIP. This MIP-SERS sensor exhibits an apparent dissociation constant of (2.3 ± 0.3) × 10−5 M for TNT and a 3 μM detection limit. The response to TNT is reversible and the sensor is stable for at least 6 months. Key challenges, including developing a MIP formulation that is stable and integrated with the SERS substrate, and ensuring the MIP does not mask the spectral features of the target analyte through SERS polymer background, were successfully met. The results also suggest the MIP-SERS protocol can be extended to other target analytes of interest

The Influence of Transport Load on Quality of Repair Works of Non-Rigid Pavements with Application by a Jet-Injection Method

Increased traffic intensity and increased axial Load from vehicles on road surfaces contribute to the formation of defects in the form of potholes and cracks. To improve the service Life and traffic safety timely care of the coating is required. Untimely work Leads to a decrease in the service Life of the pavement. The use of a jet-injection method of repair of road surfaces aLLows to perform work quickLy with minimaL cost in reLation to other methods of repair. The articLe considers the process of eLimination of defects on non-rigid road surfaces with the use of bitumen-mineraL mixtures by a jet-injection method. The resuLts of experimentaL studies carried out in the course of repair work on the second technicaL category road with high traffic intensity and increased axiaLLoad from vehicLes are presented. It was found out that the formation of the structure of the bitumen-mineraL mixture in the pothoLe of the road surface occurs over a reLativeLy Long period of time. Under the influence of contact stresses under the tire of the car, there are deformations of the material, the excess of whichLeads to its decompression. It is experimentaLLy proved that in order to increase the serviceLife of the repaired road surface, additionaL compaction of the bitumen-mineraL mixture is necessary. It was found that the excessLoad on the Layer of bitumen-mineraL mixture in the pothoLe coating at the stage of formation of its structure above the tensiLe strength contributes to the formation of pLastic deformations and reduce the required compaction coefficient. To improve the quaLity of repair work, it is necessary to Limit the axiaLLoad of vehicLes on the surface of the pothoLe for 20-30 days during the formation of the structure of the Laid materiaL in the pothoLe of the road surface

Гидроксид и оксид германия(IV): метод синтеза и физико-химические свойства

Our work is focused on a development of physical-chemical backgrounds and methods of controlled synthesis of germanium hydroxide GeO(OH)2, which is a precursor for the synthesis of functional materials based on germanium oxide. The method of controlled synthesis of germanium hydroxide by heterophase interaction ammonia solution with germanium tetraiodide was elaborated. It yields hydroxide with relatively low water content (~ 14 wt. %), which can be easily filtrated. The average germanium dioxide content is as higher as 86 wt.%. Physical-chemical properties of germanium hydroxide and products of thermal decomposition have been investigated by using of chemical and thermal analysis, gravimetric analysis, XRDA, IR-spectroscopy.Предложен вариант метода получения гидроксида германия(IV), сочетающий достоинства гетерофазного метода синтеза и использование в качестве предшественника иодида германия GeI4. Представлены результаты изучения физико-химических свойств гидроксида германия GeO(OH)2 - исходного соединения для синтеза функциональных материалов на основе диоксида германия

Electrochemically synthesized polymers in molecular imprinting for chemical sensing

This critical review describes a class of polymers prepared by electrochemical polymerization that employs the concept of molecular imprinting for chemical sensing. The principal focus is on both conducting and nonconducting polymers prepared by electropolymerization of electroactive functional monomers, such as pristine and derivatized pyrrole, aminophenylboronic acid, thiophene, porphyrin, aniline, phenylenediamine, phenol, and thiophenol. A critical evaluation of the literature on electrosynthesized molecularly imprinted polymers (MIPs) applied as recognition elements of chemical sensors is presented. The aim of this review is to highlight recent achievements in analytical applications of these MIPs, including present strategies of determination of different analytes as well as identification and solutions for problems encountered

Disposable sensors in diagnostics, food and environmental monitoring

Disposable sensors are low‐cost and easy‐to‐use sensing devices intended for short‐term or rapid single‐point measurements. The growing demand for fast, accessible, and reliable information in a vastly connected world makes disposable sensors increasingly important. The areas of application for such devices are numerous, ranging from pharmaceutical, agricultural, environmental, forensic, and food sciences to wearables and clinical diagnostics, especially in resource‐limited settings. The capabilities of disposable sensors can extend beyond measuring traditional physical quantities (for example, temperature or pressure); they can provide critical chemical and biological information (chemo‐ and biosensors) that can be digitized and made available to users and centralized/decentralized facilities for data storage, remotely. These features could pave the way for new classes of low‐cost systems for health, food, and environmental monitoring that can democratize sensing across the globe. Here, a brief insight into the materials and basics of sensors (methods of transduction, molecular recognition, and amplification) is provided followed by a comprehensive and critical overview of the disposable sensors currently used for medical diagnostics, food, and environmental analysis. Finally, views on how the field of disposable sensing devices will continue its evolution are discussed, including the future trends, challenges, and opportunities