DORA
DORA (De Montfort Open Research Archive) is De Montfort University's research repository. It forms the primary public and institutional record of DMU research outputs. The breadth of research at DMU means that these outputs include articles, conference papers, books, book chapters, and other material available in a digital form. The record for each item contains descriptive information as well as, where possible, a version of the final research output. DORA also provides access to DMU PhD theses. This includes most PhD produced from 2009 onwards.
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Recent Submissions
The ‘performative’ university: Theoretical and personal reflections
(Taylor and Francis, 2024-09-09) Visser, Max; Stokes, Peter; Ashta, Ashok; Andersson, L.
For centuries, universities have proliferated and flourished around the world, playing an important role in societal knowledge production and diffusion. However, in the past four decades, this old organizational form has been subjected to neoliberal, managerialist policy doctrines such as New Public Management. Following this, universities have tended to become more ‘business-like’ in their internal management and governance, with generally perceived adverse effects on the quality of academic education, research and working conditions. These developments pose fundamental threats to academic freedom and free knowledge production and diffusion. Acknowledging various forms of academic resistance to, and coping with, these threats, the purpose of our paper is twofold. First, we adopt the concept of ‘performativity’—hitherto researched mainly in primary and second-ary schools in Anglo Saxon contexts—to account for, and critique, neoliberal university policies and practices in a variety of Global North settings. Second, through collaborative autoethnography, we add our own personal narratives to ‘talk back’ to managerialism.
Novel biopolymer spray formulation for drug delivery in precision dentistry
(Elsevier, 2024-08-08) Qutachi, Omar; Tatullo, Marco; Marrelli, Benedetta; Facente, Anastasia; Paduano, Francesco
Addressing the growing challenges of periodontal and peri-implant diseases, this study first reports a promising advancement in precision dentistry: an intricately formulated biopolymer spray designed for precise, localized drug delivery during tailored dental procedures. Poly (lactic-co glycolic acid) (PLGA), recognized for its controlled release, biodegradability, and FDA-approved biocompatibility, forms the core of this formulation. Utilizing the double emulsion method, PLGA microparticles (PLGA-MPs) were loaded with dental antibiotics: sodium amoxicillin (AMX-Na), trihydrate amoxicillin (AMX-Tri), and metronidazole (Met). This antibiotic combination was thoughtfully selected to meet the distinctive requirements of the most impacting dental treatments. The newly developed biopolymer spray underwent thorough in-vitro analysis, revealing an optimized release curve for antibiotics over time, guaranteeing sustained therapeutic efficacy, and dose-dependent efficacy, accommodating personalized treatment approaches. The positive outcomes position the novel biopolymer spray formulation the leaders in advancing localized drug delivery during dental procedures. Moreover, the precise application and the tunable formulation meets the concept of precision medicine: in detail, this formulation represents asignificant stride in dental therapeutics, significantly contributing to the predictability of dental
implantology.
In vivo analysis of hybrid hydrogels containing dual growth factor combinations, and skeletal stem cells under mechanical stimulation for bone repair
(Elsevier, 2024-08-27) Qutachi, Omar; Gothard, David; Rotherham, Michael; Smith, Emma L.; Kanczler, Janos M.; Henstock, James; Wells, Julia A.; Roberts, Carol A.; Peto, Heather; Rashidi, Hassan; Rojo, Luis; White, Lisa J.; Stevens, Molly M.; El Haj, Alicia J.; Rose, Felicity R.A.J.; Oreffo, Richard O.C.
Bone tissue engineering requires a combination of materials, cells, growth factors and mechanical cues to recapitulate bone formation. In this study we evaluated hybrid hydrogels for minimally invasive bone formation by combining biomaterials with skeletal stem cells and staged release of growth factors together with mechanotransduction. Hybrid hydrogels consisting of alginate and decellularized, demineralised bone extracellular matrix (ALG/ECM) were seeded with Stro-1+ human bone marrow stromal cells (HBMSCs). Dual combinations of growth factors within staged-release polylactic-co-glycolic acid (PLGA) microparticles were added to hydrogels to mimic, in part, the signalling events in bone regeneration: VEGF, TGF-β3, PTHrP (fast release), or BMP-2, vitamin D3 (slow release). Mechanotransduction was initiated using magnetic fields to remotely actuate superparamagnetic nanoparticles (MNP) targeted to TREK1 ion channels. Hybrid hydrogels were implanted subcutaneously within mice for 28 days, and evaluated for bone formation using micro-CT and histology. Control hydrogels lacking HBMSCs, growth factors, or MNP became mineralised, and neither growth factors, HBMSCs, nor mechanotransduction increased bone formation. However, structural differences in the newly-formed bone were influenced by growth factors. Slow release of BMP-2 induced thick bone trabeculae and PTHrP or VitD3 increased bone formation. However, fast-release of TGF-β3 and VEGF resulted in thin trabeculae. Mechanotransduction reversed the trabecular thinning and increased collagen deposition with PTHrP and VitD3. Our findings demonstrate the potential of hybrid ALG/ECM hydrogel–cell–growth factor constructs to repair bone in combination with mechanotransduction for fine-tuning bone structure. This approach may form a minimally invasive reparative strategy for bone tissue engineering applications.
Development of Artemisia annua L. as a crop for production of the antimalarial drug artemisinin
(De Montfort University, 2010-06) Burns, Corrinne
Artemisinin is the parent compound for the latest generation of anti-malarial drugs. In many cases of severe or drug-resistant malaria, the artemisinins are the only effective means of treatment for this common and life-threatening parasitic infection. However, the current supply of artemisinin is unstable, and is predicted to fall far short of demand in the coming years. As artemisinin can currently not be economically synthesised, the only source of the compound is the Chinese herb Artemisia annua L.
With the ultimate objective of stabilising the global supply of artemisinin, a Consortium of academics, agronomics and business partners was established. The Consortium, with funding from Defra and the Horticultural Development Company under the name of Project LINK 0822, was to examine the feasibility of establishing an “artemisinin supply chain” – from crop in the field to pure, active pharmaceutical ingredient – based entirely within the UK.
The work presented in this thesis formed part of this Consortium’s research – namely, the establishment and validation of rapid, accurate and economical means of quality control of both raw herbal material and purified ingredient. To that end, methods were developed allowing both field-based, triaging quantification and more accurate, high-throughput laboratory-based quantification of sample material. Improved means of artemisinin purification – in particular the removal of the inactive metabolite deoxyartemisinin, which co-elutes and co-crystallises with artemisinin - were also developed.
In addition, the potential pharmacological value of other compounds besides artemisinin was explored – namely, chrysosplenetin. This latter is a methoxylated flavonoid that accumulates with artemisinin in the plant, and has been shown, in this study, to have potential in the treatment of cancer.
Finally, the feasibility of self-medication with Artemisia annua L. - in the form of herbal teas and over-the-counter preparations of the plant – was examined, and the amount of artemisinin, deoxyartemisinin and chrysosplenetin in such preparations was examined.
During the four years in which the LINK project ran, the Consortium members worked together to ultimately develop new lines of Artemisia annua L, that not only flourished in the UK climate, but also consistently yielded high (> 2.2 % w/DW) levels of artemisinin – almost a twofold increase from that at the beginning of the project. These new lines, together with the improved analytical techniques and means of artemisinin purification, demonstrate clearly that an artemisinin supply chain can indeed be based within the UK, thus contributing to a stable, year-on-year supply of artemisinin.
Design and Modelling of Smart Power IC Components For the Automotive Industry
(De Montfort University, 2010-04) Yip, Li Juin
In this thesis, n- and p-type power semiconductor devices used for H-bridge Direct Current (DC) motor drives in automotive application are developed. It will focus on the development of power semiconductor devices which are able to support a voltage in the range of 80V-100V with the specific on-state resistance as low as possible. N- and p-type devices investigated employing the Reduced Surface Field (RESURF) and Superjunction (SJ) concept to yield high breakdown voltage with low specific on-state resistance.
For n-type devices, four different structures were analysed. They are XtreMOSTM (Trademark of AMI, for the rest of the thesis, XtreMOS is used), advanced XtreMOS, Type1 Insulated Base Transistor (IBT) and Type2 IBT. XtreMOS shows a breakdown voltage, VBD=102V and specific on-state resistance, RDSon=36.81mohm.mm2 which breaks the ‘silicon limit’ and close to SJ limit. Nevertheless, it shows a weakness which limits the VBD to a certain value. This weakness has been overcome with the advanced XtreMOS structure. With this device VBD=113V can be achieved with a small increased in RDSon. It shows RDSon=39.31mohm.mm2. Type1 and Type2 IBT devices implement the MOS-bipolar concept to obtain the bipolar current capability. Since these two devices are designed based on the core of XtreMOS process, they show the similar VBD with XtreMOS. In term of on-state performance, it is found that Type1 IBT shows a poor output current level. On the other hand, Type1 IBT exhibits an improvement in saturation current level compare to XtreMOS.
For p-type devices, the four structures investigated are reference RESURF p-type Metal-Oxide-Semiconductor (PMOS), RESURF PMOS, Modified RESURF PMOS and superjunction PMOS (SJPMOS). Among these four devices, the Modified RESURF PMOS and SJPMOS show the most promising electrical performances. The Modified RESURF PMOS shows a VBD=-91V and RDSon=207.56mohm.mm2. For the SJPMOS, VBD=-94V and RDSon=242.46mohm.mm2 are obtained.