Publications by authors named "Andrew Michelmore"

Endometriosis is a common yet under-recognised chronic inflammatory disease, affecting 176 million women, trans and gender diverse people globally. The National Endometriosis Clinical and Scientific Trials (NECST) Registry is a new clinical registry, collecting and tracking diagnostic and treatment data, and patient-reported outcomes on people with endometriosis. The registry is a research priority action item from the 2018 National Action Plan for Endometriosis and aims to provide, large-scale, national and longitudinal population-based data on endometriosis.

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If plasma polymer thin films are to be synthesised from sustainable and natural precursors of chemically heterogeneous composition, it is important to understand the extent to which this composition influences the mechanism of polymerisation. To this end, a well-studied monoterpene alcohol, terpinen-4-ol, has been targeted for a comparative study with the naturally occurring mix of terpenes (viz. oil) from which it is commonly distilled.

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Article Synopsis
  • * This study examines a modified surface dressing to improve the cryopreservation process for multipotent adult progenitor cells (MAPC) by optimizing attachment times and enhancing cell recovery.
  • * By functionalizing the surface with hyaluronic acid, the research found a way to delay cell spreading, allowing for better cryopreservation outcomes and increased recovery of adhered cells.
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A novel 2D nanomaterial, TiCT MXene, added conductivity and reinforcement to a common elastomer, nitrile butadiene rubber (NBR). X-ray diffraction revealed the intercalation of lithium ions and elastomer chains into the MXene interlayer spacing, which enabled exfoliation in the elastomer. The reaction between MXene and NBR was proved by a stepwise Fourier transform infrared spectroscopy.

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Deposition chemistry from plasma is highly dependent on both the chemistry of the ions arriving at surfaces and the ion energy. Typically, when measuring the energy distribution of ions arriving at surfaces from plasma, it is assumed that the distributions are the same for all ionic species. Using ethyl acetate as a representative organic precursor molecule, we have measured the ion chemistry and ion energy as a function of pressure and power.

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Lipopolysaccharides (LPS) are the major component of the outer membrane of all Gram-negative bacteria and some cyanobacteria and are released during growth and cell death. LPS pose a potential health risk in water, causing acute respiratory illnesses, inhalation fever, and gastrointestinal disorders. The need for rapid and accurate detection of LPS has become a major priority to facilitate more timely and efficacious intervention and, hence, avoid unsafe water distribution.

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Historically, there have been two opposing views regarding deposition mechanisms in plasma polymerisation, radical growth and direct ion deposition, with neither being able to fully explain the chemistry of the resultant coating. Deposition rate and film chemistry are dependent on the chemistry of the plasma phase and thus the activation mechanisms of species in the plasma are critical to understanding the relative contributions of various chemical and physical routes to plasma polymer formation. In this study, we investigate the roles that hydrogen plays in activating and deactivating reactive plasma species.

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The emergence of nanostructured materials has opened new horizons in the development of next generation biosensors. Being able to control the design of the electrode interface at the nanoscale combined with the intrinsic characteristics of the nanomaterials engenders novel biosensing platforms with improved capabilities. The purpose of this review is to provide a comprehensive and critical overview of the latest trends in emerging nanostructured electrochemical biosensors.

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This review aims to provide a broad introduction to the use of cell sheets and the role of materials in the delivery of cell sheets to patients within a clinical setting. Traditionally, cells sheets have been, and currently are, fabricated using established and accepted cell culture methods within standard formats (e.g.

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Human Mesenchymal Stem cells (hMSCs) are becoming a major focus in biomedical fields. Application of in vitro expanded hMSCs to treat numerous ailments has led to a commercial emphasis on improving hMSC growth ex vivo. Production of substrate independent, novel thin films is one potential tool for production of commercial viable hMSC expansion.

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A practical fabrication technique is presented to tackle the trade-off between the water flux and salt rejection of thin film composite (TFC) reverse osmosis (RO) membranes through controlled creation of a thinner active selective polyamide (PA) layer. The new thin film nano-composite (TFNC) RO membranes were synthesized with multifunctional poly tannic acid-functionalized graphene oxide nanosheets (pTA-f-GO) embedded in its PA thin active layer, which is produced through interfacial polymerization. The incorporation of pTA-f-GOL into the fabricated TFNC membranes resulted in a thinner PA layer with lower roughness and higher hydrophilicity compared to pristine membrane.

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Chemically functionalized surfaces may be produced via plasma polymerization, however a high degree of functional group retention is often difficult to achieve. Here, the plasma polymerization of three structurally related ester precursors, ethyl isobutyrate (EIB), methyl isobutyrate (MIB) and ethyl trimethylacetate (ETMA) is compared at low and high pressure. In moving from a low pressure to higher pressure regime, significant changes in the plasma chemistry and resulting plasma polymer deposit were observed with much higher retention of chemical functionality at the higher pressure observed.

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Culture surfaces that substantially reduce the degree of cell manipulation in the delivery of cell sheets to patients are described. These surfaces support the attachment, culture, and delivery of multipotent adult progenitor cells (MAPC). It was essential that the processes of attachment/detachment to the surface did not affect cell phenotype nor the function of the cultured cells.

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Furfuryl methacrylate (FMA) is a promising precursor for producing polymers for biomedical and cell therapy applications. Herein, FMA plasma polymer coatings were prepared with different powers, deposition times, and flow rates. The plasma polymer coatings were characterized using atomic force microscopy (AFM), scanning electron microscopy (SEM), x-ray photoelectron spectroscopy (XPS), and time-of-flight secondary ion mass spectrometry (ToF-SIMS).

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We report a systematic study of the plasma polymerization of ethyl α-bromoisobutyrate (EBIB) to produce thin film coatings capable of serving as ATRP initiation surfaces, for which they must contain α-bromoisobutyryl functional groups. In the deposition of polymeric coatings by plasma polymerization there generally occurs considerable fragmentation of precursor ("monomer") molecules in the plasma; and the retention of larger structural elements is challenging, particularly when they are inherently chemically labile. Empirical principles such as low plasma power and low pressure are usually utilized.

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Graphene oxide (GO) nanosheets have antibacterial properties that have been exploited as a biocidal agent used on desalination membrane surfaces in recent research. Nonetheless, improved strategies for efficient and stable attachment of GO nanosheets onto the membrane surface are still required for this idea to be commercially viable. To address this challenge, we adopted a novel, single-step surface modification approach using tannic acid cross-linked with polyethylene imine as a versatile platform to immobilize GO nanosheets to the surface of polyamide thin film composite forward osmosis (FO) membranes.

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A proof of concept for the label-free detection of bacteriophage MS2, a model indicator of microbiological contamination, is validated in this work as a porous silicon (pSi) membrane-based electrochemical biosensor. PSi membranes were used to afford nanochannel architectures. The sensing mechanism was based on the nanochannel blockage caused by MS2 binding to immobilized capture antibodies.

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Surface engineering of functionalised polymer films is a rapidly expanding field of research with cross disciplinary implications and numerous applications. One method of generating functionalised polymer films is radio frequency induced plasma polymerisation which provides a substrate independent coating. However, there is currently limited understanding surrounding chemical interactions in the plasma phase and physical interactions at the plasma-surface interface, and their effect on functional group retention in the thin film.

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While plasma polymerization is used extensively to fabricate functionalized surfaces, the processes leading to plasma polymer growth are not yet completely understood. Thus, reproducing processes in different reactors has remained problematic, which hinders industrial uptake and research progress. Here we examine the crucial role pressure plays in the physical and chemical processes in the plasma phase, in interactions at surfaces in contact with the plasma phase, and how this affects the chemistry of the resulting plasma polymer films using ethanol as the gas precursor.

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Graphene oxide (GO) nanosheets were attached to the polyamide selective layer of thin film composite (TFC) forward osmosis (FO) membranes through a poly L-Lysine (PLL) intermediary using either layer-by-layer or hybrid (H) grafting strategies. Fourier transform infrared spectroscopy, zeta potential, and thermogravimetric analysis confirmed the successful attachment of GO/PLL, the surface modification enhancing both the hydrophilicity and smoothness of the membrane's surface demonstrated by water contact angle, atomic force microscopy, and transmission electron microscopy. The biofouling resistance of the FO membranes determined using an adenosine triphosphate bioluminescence test showed a 99% reduction in surviving bacteria for GO/PLL-H modified membranes compared to pristine membrane.

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Advanced membranes that combine mechanical robustness with fast permeation are crucial to many applications such as water purification, ions selectivity, and gas separation. Graphene sheets offer a promising opportunity to fabricate thin, high-flux, and pressure-endurable membranes because of their unique 2D morphology, oxidizable surface, and electrical conductivity. We herein report a highly effective yet simple approach to the fabrication of graphene membranes featuring controllable oxidation degrees and thus tunable structures and properties.

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Graphene platelets (GnPs) are a class of novel 2D nanomaterials owing to their very small thickness (∼3 nm), high mechanical strength and electric conductivity (1460 S cm(-1)), and good compatibility with most polymers as well as cost-effectiveness. In this paper we present a low-cost processing technique for producing modified GnPs and an investigation of the electrical and mechanical properties of the resulting composites. After dispersing GnPs in solvent N-methyl-2-pyrrolidone, a long-chain surfactant (Jeffamine D 2000, denoted J2000) was added to covalently modify GnPs, yielding J2000-GnPs.

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External parameters (RF power and precursor flow rate) are typically quoted to define plasma polymerization experiments. Utilizing a parallel-plate electrode reactor with variable geometry, it is shown that these parameters cannot be transferred to reactors with different geometries in order to reproduce plasma polymer films using four precursors. Measurements of ion flux and power coupling efficiency confirm that intrinsic plasma properties vary greatly with reactor geometry at constant applied RF power.

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Materials mechanical properties are known to be an important regulator of cellular processes such as proliferation, differentiation and migration, and have seen increasing attention in recent years. At present, there are only few approaches where the mechanical properties of thin films can be controllably varied across an entire surface. In this work, we present a technique for controlled generation of gradients of surface elastic moduli involving a weak polyelectrolyte multilayer (PEM) system of approximately 100 nm thickness and time dependent immersion in a solution of 1-ethyl-3-(3-dimethylaminopropyl) carbodiimide (EDC) as a crosslinking agent.

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Rather than using graphene oxide, which is limited by a high defect concentration and cost due to oxidation and reduction, we adopted cost-effective, 3.56 nm thick graphene platelets (GnPs) of high structural integrity to melt compound with an elastomer-ethylene-propylene-diene monomer rubber (EPDM)-using an industrial facility. An elastomer is an amorphous, chemically crosslinked polymer generally having rather low modulus and fracture strength but high fracture strain in comparison with other materials; and upon removal of loading, it is able to return to its original geometry, immediately and completely.

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