A5024971520- Advanced Polymer Synthesis and Characterization
- Surfactants and Colloidal Systems
- Polymer Surface Interaction Studies
- Supramolecular Self-Assembly in Materials
- Polydiacetylene-based materials and applications
- Skin Protection and Aging
- melanin and skin pigmentation
- Biochemical Analysis and Sensing Techniques
- Heavy Metal Exposure and Toxicity
- Block Copolymer Self-Assembly
- Textile materials and evaluations
- Luminescence and Fluorescent Materials
- Lipid Membrane Structure and Behavior
- Hydrogels: synthesis, properties, applications
- Tea Polyphenols and Effects
- Trace Elements in Health
- Neuroscience and Neuropharmacology Research
- Olfactory and Sensory Function Studies
- Nuclear Receptors and Signaling
- Nanoparticles: synthesis and applications
- Phytochemicals and Antioxidant Activities
- Electrostatics and Colloid Interactions
- Probiotics and Fermented Foods
- Photochromic and Fluorescence Chemistry
- Microplastics and Plastic Pollution
Unilever (United Kingdom)
2001-2016
University of Bedfordshire
2016
University of Liverpool
2008
Meharry Medical College
2001-2003
We have examined the quantity and composition of melanin in both photoprotected (volar upper arm) chronically photoexposed (dorsal forearm) skin from a range different ethnic types including African, Indian, Mexican, Chinese European. The most lightly pigmented (European, Mexican) approximately half as much epidermal darkly (African Indian) types. However, these lighter is comparatively more enriched with coloured, alkali-soluble components (up to three-fold). Regardless ethnicity, content...
Objective measurements of human skin colour were made with a tristimulus (L*a*b*) chromameter in range different ethnic types. These compared biochemical melanin content, composition and melanosome size biopsies obtained from the same sites. L*, a* b* values found to vary significantly ethnicity. In general, constitutively dark types have lower L* values, higher than light Total epidermal content appears be primary determinant (r = -0.88; P < 0.00001), whilst also has significant but more...
The mechanical properties of gels are critical to the final targeted applications. Depending on application, different may be required. Here, we show that strength and ability recover formed using a low molecular weight gelator can controlled by two independent factors (i) volume fraction co-solvent (in this case DMSO) in system (ii) temperature cycle used. These differences correlate with large scale structure network is from self-assembled fibres. This opens up potential prepare very at...
A designed peptide amphiphile C16-KKFFVLK self-assembles into nanotubes and helical ribbons in aqueous solution at room temperature. remarkable unwinding transition, leading to twisted tapes, is observed on heating. Nanotubes re-form cooling.
A combination of techniques, including high-performance liquid chromatography (HPLC), spectrophotometric measurements, and a novel method for quantifying melanosome morphology, were applied to the analysis melanin content composition in highly pigmented (Fitzpatrick type V VI) human skin. We found that total epidermal is significantly elevated photoexposed VI skin (approximately 1.6 x), while individual components suggests pheomelanin increases only slightly, whereas...
Micelles, worm-like micelles and vesicles were prepared from poly(ethylene oxide)-b-poly(caprolactone) block copolymersvia a solvent switch method, characterised by light scattering, X-ray scattering cryo-transmission electron microscopy. The volume fraction of ethylene oxide, as the hydrophilic part in these polymers, determined morphology dilute solution, with spherical micelles, precipitate being formed decreased. mechanism which systems during sequential dilution initial THF-rich...
We study both experimentally and theoretically the self-assembly of binary polycaprolactone–polyethylene oxide (PCL–PEO) block copolymers in dilute solution, where is triggered by changing solvent from common good THF to selective water, two species on their own water form vesicles spherical micelles respectively. find that inter-micellar exchange these extremely slow so resultant self-assembled structures are local but not global equilibrium (i.e., they non-ergodic). This opens up...
Block copolymers can adopt a wide range of morphologies in dilute aqueous solution. There is significant amount interest the use block copolymer vesicles for number applications. We show that series oligo(valine) and oligo(phenylalanine) peptides coupled to methacrylic group be prepared by conventional peptide coupling techniques. These successfully polymerized atom transfer radical polymerization (ATRP) hexafluoroisopropanol (HFIP) giving access poly(ethylene oxide)-b-poly(side-chain...
We present a combined experimental and theoretical study on the role of copolymer architecture in self-assembly binary PEO–PCL mixtures water–THF show that altering chain geometry composition copolymers can control form self-assembled structures lead to formation novel aggregates. First, using transmission electron microscopy turbidity measurements, we mixture sphere-forming lamella-forming increasing molecular weight lamella-former at constant ratio its hydrophilic hydrophobic components...
A series of thermally responsive branched copolymers based on N-isopropylacrylamide (NIPAAm) and poly(ethylene glycol) methacrylate (PEGMA) are synthesized using a direct, single step modified free radical polymerization strategy. The aqueous solution behaviour nanoparticle formation these studied correlated to the NIPAAm : PEGMA molar ratio chain length. All water-soluble as discrete polymer chains at low temperature. On raising temperature, inter-polymer interactions—that is, aggregation...
The luminal surface of the gastrointestinal tract is covered by a mucus gel layer that acts to protect gut epithelial cells from harsh environment. This study investigated use two human colonic adenocarcinoma cell lines, HT29-MTX-E12 and HT29, as model mimic epithelium with without layer. effect adding tea polyphenols epigallocatechin gallate (EGCG) epicatechin (EC) subsequent examination morphology viability was assessed. EGCG, at concentrations tested, very toxic HT29 cells, but less...
It has been well established that exposure to Pb during critical periods of brain development results in both cognitive and behavioral deficits. Although the mechanism by which induces developmental neurotoxicity is unknown, it may involve alterations transcription genes are essential for growth differentiation. Recent studies reveal interferes with differentiation acting on factor Sp1. Pb-induced changes activity Sp1 be consequent intermediates signal transduction pathways. This study...
The self-assembly in aqueous solution of PEG-peptide conjugates comprising a model amyloid peptide sequence FFKLVFF that contains the Aβ(16–20) KLVFF motif is investigated. X-ray diffraction reveals different packing motifs dependent on PEG chain length. This correlated to remarkable differences self-assembled nanostructures. control strand registry points subtle interplay between aromatic stacking, electrostatic and amphiphilic interactions.
Abstract A model of flavor release from encapsulated particles immersed in water has been developed that correlates well with experimental data. Flavor was determined by measuring both the quantities released particle to and air headspace. The presented here predicts a very different time if develops hydrogel at surface (swelling) compared gradual erosion. Controlled heating showed more retention when swells rapid under conditions © 2004 American Institute Chemical Engineers AIChE J, 50: 3257–3270,
We describe the one-pot synthesis of zwitterionic, pH-responsive, layered branched copolymer nanoparticles. In aqueous solution, charged layers can be switched on and off in response to solution pH changes. The colloidal stability these complex nanoparticles is superior corresponding linear triblock copolymers yet their no more demanding.
We study both experimentally and theoretically the self-assembly of binary block copolymers in dilute solution, where is triggered by changing solvent from common good THF to selective water, two species on their own water form vesicles spherical micelles respectively. find that inter-micellar exchange these very slow so self-assembled structures are local but not global equilibrium (i.e., they non-ergodic). This opens up possibility controlling micelle morphology thermodynamically...