Synthesis of Carbon Onion and Its Application as a Porous Carrier for Amorphous Drug Delivery

Given the great potential of porous carrier-based drug delivery for stabilising the amorphous form of drugs and enhancing dissolution profiles, this work is focussed on the synthesis and application of carbon onion or onion-like carbon (OLC) as a porous carrier for oral amorphous drug delivery, using paracetamol (PA) and ibuprofen (IBU) as model drugs. Annealing of nanodiamonds at 1100 °C produced OLC with a diamond core that exhibited low cytotoxicity on Caco-2 cells. Solution adsorption followed by centrifugation was used for drug loading and results indicated that the initial concentration of drug in the loading solution needs to be kept below 11.5% PA and 20.7% IBU to achieve complete amorphous loading. Also, no chemical interactions between the drug and OLC could be detected, indicating the safety of loading into OLC without changing the chemical nature of the drug. Drug release was complete in the presence of sodium dodecyl sulphate (SDS) and was faster compared to the pure crystalline drug, indicating the potential of OLC as an amorphous drug carrier

Properties, mechanism and applications of diamond as an antibacterial material

Antibiotic resistance in bacteria is a current threat causing an increasing number of infections of difficult clinical management. While the overuse and misuse of antibiotics are investigated to reduce them, the need for alternatives to approaches is rising. Carbon-based materials shown recent moderate to high antibacterial properties and diamond, thanks to its superior mechanical, tribological, electrical, chemical and biological quality is a choice material to investigate for safe antibacterial films, coatings and particles. Here, the antibacterial properties of diamond films, nanodiamonds, DLC films and a comprehensive list of the composites developed from them are discussed along with a summary of the bacterial strains used and the most efficient composition and/or concentration discovered. In a later stage, the mechanisms of action and the parameters that are believed to influence them are discussed and finally, an overview of the biomedical and food industry applications is given

Characterisation and antibacterial properties of modified bentonites in animal litter application

Summarization: Characterisation of 2 bentonites samples with XRD, XRF, FTIR, TG Modification through cation exchange and porous water saturation Antibacterial properties assessments with MBC and MIC measurement

Antibacterial Properties And Characterisation Of Diamond And Graphite Thin Films And Coatings For Biomedical Applications

The rise of bacteria resistant to a wide spectrum of antibiotics has been a concern for researchers in the last decades. Several strategies to replace antibiotics were investigated such as silver or copper-based materials to name only the most promising antibacterial agents. However, bacteria evolve fast. Structural and genetic resistance abilities appeared before copper and silver drawbacks of being toxic to mammalian cells were overcome with research. Thus, it is critical to find alternatives with higher intrinsic biocompatibility and less chance for bacteria to develop resistance mechanisms against them. Carbon-based, and especially diamond-based materials are very promising regarding these properties. Their antibacterial abilities as surface-modified materials, drug carriers, and biocompatible materials were already demonstrated at different scales. However, the mechanisms of action of antibacterial diamonds are not understood yet. Hence, this PhD focused on understanding the influence of the carbon hybrids proportion in the diamond structure on their antibacterial properties. The results obtained with two model bacteria strains showed that the sp2/sp3 hybridised carbon ratio affected the antibacterial properties of diamond films. The higher the sp3 proportion, the better the antibacterial properties against both bacteria. The role of the spatial localisation of the electrons involved in sp3 hybridisation was discussed to explain these results. Surface structure of diamond films showed promising abilities to kill Gram-negative bacteria in the literature but failed against Gram-positive bacteria. This work demonstrated that adapting the size of the surface structures to the Gram-positive bacteria by tailoring the roughness also increased the surface free energy of the diamond films and displayed antibacterial properties against both Gram-positive and Gram-negative bacteria. Finally, the film deposition technique is also of prominent importance, and it modified several surface characteristics of the graphite films, explaining why CVD graphite coatings showed substantial antibacterial properties while PVD graphite coatings did not.</p

Antibacterial properties of polycrystalline diamond films

Electronic and mechanical properties, and their biocompatibility, make diamond-based materials promising biomedical applications. The cost required to produce high quality single crystalline diamond films is still a hurdle to prevent them from commercial applications, but the emergence of polycrystalline diamond (PCD) films grown by chemical vapour deposition (CVD) method has provided an affordable strategy. PCD films grown on silicon wafer have been used throughout and were fully characterised by SEM, XPS, Raman spectroscopy and FTIR. The samples contain nearly pure carbon, with impurities originated from the CVD growth and the silicon etching process. Raman spectroscopy revealed it contained tetrahedral amorphous carbon with small tensile stress. The sp2 carbon content, comprised between 16.1 and 18.8%, is attributed to the diamond grain boundaries and iron-catalysed graphitisation. Antibacterial properties of PCD films were performed with two model bacteria, i.e. Escherichia coli (Gram-negative) and Staphylococcus aureus (Gram-positive) using direct contact and shaking flask methods. The samples showed strong bacteriostatic properties against S. aureus and E. coli with the direct contact method and no influence on planktonic bacterial growth. These results suggest that the bacteriostatic mechanism of PCD films is linked to their surface functional groups (carbon radicals and –NH2 and –COOH groups) and that no diffusible molecules or components were involved

Smoothing of single crystal diamond by high-speed three-dimensional dynamic friction polishing: Optimization and surface bonds evolution mechanism

The high-speed three-dimensional movement dynamic friction polishing (3DM-DFP) has been recognized as an efficient approach for ultra-smoothing single crystal diamond (SCD) surface. Continuing from the previous works focusing on the subsurface cleavage of diamond after 3DM-DFP, process optimization and surface reaction evolution mechanism as a fundamental building block is investigated, for the first time, for comprehensively understanding this fast-smoothing manner. By systematically adjusting the controlling factor, stronger load (0.3 MPa) and appropriate duration (0.5 h) as well as moderate sliding speed (in the range of 30 to 45 m s−1) is found to be able to obtain the smooth surface of SCD without uncontacted traces or break-surface cleavage. Subtle residual clues on SCD surface as a function of progressive DFP procedure indicate that Fe catalytic oxidation mainly produce Fe2O3 and partial intermediate oxides Fe1-yO. Meanwhile, the activated oxygen inserts sp3 Csingle bondC bonds could form Csingle bondO or Cdouble bondO and C-O-V (vacancy) at existing reactive surface sites. The (100) favorable Cdouble bondO bonds can be rebuilt if (100) surface is reformed, although the Csingle bondO bonds associated with non-(100) rough surface would replace them during DFP procedure. The formed Csingle bondOsingle bondC and concomitant C-O-V as well as the oxidized graphite give rise to the increase of Csingle bondO proportion, and finally the covered defective graphitic phase has an approximate Csingle bondO/Cdouble bondO ratio of 1.25. All these are endowed potential value for future upgrading of DFP technique for diamond surface smoothing.</div

Images Of Research 2018

Images Of Research 2018 Winners: Martha Papadopoulou – ‘One picture – two worlds’ - Judges' Prize Winner Mandi Jamalian Hamedani – ‘In search for inner peace’ - Katherine May People's Choice Winner Olga Yegorova – ‘ “Ni Una Menos, ni una muerta más!” fighting for the lives of Bolivian women’ - Judges' Prize Runner-up Kate Gooch and Georgine Barkham-Perry – ‘Finding Hope in a Hopeless Place’ - People's Choice Runner-up Images Of Research 2018 successful submissions: Abbey Ellis – ‘Something’s Missing’ Emily Castells – ‘Fast-Paced Study in Respiratory Research’ Andrew Blain – ‘Inside the Dish’ Aude Cumont – ‘Army of Mushrooms, by Disinfection Mushrooms’ Ben Parsons – ‘Holey Prayers’ Thomas Newman – ‘Big Sky, Big Future’ Diyana Kasimon – ‘Unity in Diversity’ Jan Vandeburie – ‘Reading Between the Lines’ Philip Evans – ‘Andromeda’s revenge’ John Goodwin – ‘Return to Winston Parva: Sex and Violence at the ‘Regal’’ Yogini Chudasama – ‘Secrets to Living Longer’ Eleni Ganiti – ‘Contemporary Art?’ Emily Richardson – ‘Cellular Fireworks’ Seth O'Neill – ‘Achille's Heat’ Padraig Donnelly – ‘Peering into Jupiter's Atmosphere from Earth’ Colin Hyde – ‘In the midst of life we are in death’ Georgina Lockton – ‘Researching Vehicle Automation in 1960s Britain’ Jan Oliver Ringert and José Miguel Rojas – ‘DriverLeics’ Amy Van Allen – ‘Life in the Andes’ Eva Krockow – ‘Line Up and Take Note’ Yewande Okuleye – ‘Hemp Seeds in Safe Hands’Rod Moore - 'Vaping'</p