The microwave dielectric response of biological solutions and electrolytes has been investigated for a number of decades though applications that utilise the response are few and far between. The dielectric features of many biological fluids are unique across the microwave spectrum and offer a wealth of possibilities for analysis techniques. This thesis documents the development of broadband and resonant microwave techniques that are suitable for applications in biological fluid analysis. Theoretical models concerning the dielectric properties and electromagnetic interaction with polar liquids such as water are examined. The means to conduct experimental observations of the dielectric spectrum of liquids are reviewed and the ability to conduct measurement on small sample volumes discussed. Broadband spectroscopy from 0.2 to 20 GHz has been performed on the simplest constituent of a biological fluid, water, and compared to literature and theoretical models. Other polar liquids such as ethanol, propanol and methanol were also examined. The impact of ions in solution on the high frequency permittivity was studied, in particular the response of alkali metal chlorides, copper sulphate and zinc sulphide. The temperature dependence of the metal chlorides was found to be highly dependent on the effective hydration radius and subsequently a means of calculating the temperature-dependent hydration radius of lithium and sodium was developed. The respective radii at room temperature were found to be 340 ±39 pm and 215± 21 pm. Relaxation processes from ion-association were examined and confirmed to be present in ions with high charge density. Comparative studies between various biological solutes in aqueous environments demonstrated that many proteins possess unique microwave dielectric spectral features based on bound water and protein-water exchange mechanisms. Two techniques for the differentiation of protein solutions are outlined based on the microwave dielectric spectrum and the relaxation processes associated with protein water. Broadband measurements were conducted from 0.5 to 40 GHz to analyse the dielectric response of whole blood and serum from human and murine donors. Based on the dielectric comparison of serum and whole blood a method for the determination of haemoglobin concentration is presented. A 9.4 GHz dielectric resonator was developed with an integrated microfluidic chip for the determination of haemoglobin concentration in samples as small as 2 microlitres. This was subsequently utilised to monitor the progression of haemoglobin levels in APCmin/+ mice with colon cancer. The results demonstrate the first microwave device with proven haematological diagnostic value with an accuracy that is equivalent to or better than existing commercial techniques (comparative standard deviation 0.85 g/dL to Sysmex system - commercial comparison >1.5 g/dL) and is non-destructive.

Tissues have limited self-healing capabilities when a defect is above its critical size. Biomaterials that can act as temporary templates (scaffolds) can facilitate regeneration of damaged tissues but need to be designed to fulfill the challenging requirements for tissue regeneration. Inorganic/organic hybrids have the potential to meet these demands. Hybrids have nanoscale interpenetrating networks (IPNs) of organic and inorganic components that give them the unique potential of tailored mechanical properties and controlled biodegradation. An important factor in designing a successful hybrid is the choice of polymer. Chitosan has been widely used in the biomedical field due to its biocompatibility, biodegradability and the ability to promote cell attachment and proliferation. In this thesis, silica/chitosan hybrid scaffolds with oriented structures were fabricated through the sol-gel method, followed by a unidirectional freeze casting process. 3-glycidoxypropyl trimethoxysilane (GPTMS) was used to obtain covalent coupling between the inorganic and organic components. Various compositions were synthesized by varying the cooling rate, the GPTMS and the inorganic content, in order to investigate their effect on the hybrid chemical structures and mechanical properties. Structural characterization and dissolution tests confirmed the covalent crosslinking of the chitosan and the silica network in hybrids. The scaffolds had a directional lamellar structure along the freezing direction and a cellular morphology perpendicular to the freezing direction, respectively. Compression testing showed that the scaffolds with 60 wt % organic were flexible and elastic perpendicular to the freezing direction whilst having ~160 kPa of compressive strength parallel to the freezing direction. The freeze cast silica/chitosan hybrid scaffolds have the potential for tissue regeneration. A key to the development and optimization of sol-gel tissue scaffolds will be an understanding of the uniformity of the critical elements and compounds in the material. Therefore another part of this thesis involves application of the time-of-flight secondary ion mass spectrometry (ToF-SIMS) technique to evaluate and compare various sol-gel silica-based scaffolds. ToF-SIMS has high surface sensitivity and the ability to construct chemical maps and depth profiles for all the elements and compounds to obtain their distribution throughout the material. However, SIMS is sensitive to topography and most of the scaffolds are highly porous, thus chemical mapping of these materials using SIMS is very challenging. This work involved the development of two experimental methodologies (Soak & Solid and Mark & Map) to overcome this issue. Sol-gel 70S30C bioactive glass foams, electrospun 70S30C bioactive glass fibers and calcium-containing silica/gelatin hybrid scaffolds were successfully analyzed, proving the feasibility of these analytical methods, which are also applicable to many other types of porous material. In addition, different silica/γ-PGA hybrid systems with calcium incorporation were studied and the ToF-SIMS data facilitated improvements in hybrid synthesis and hybrid processing routes. ToF-SIMS was shown to be a powerful analytical technique that has the potential to play a pivotal role in the biomaterial field.

We are now living in a world where the adoption of mobile computing technologies within healthcare is becoming more prevalent. Digitisation within hospitals and clinical settings have increased due to smaller, powerful and cost effective devices. The National Health Service has a target to be "completely paperless by 2018" and this Thesis presents work highlighting issues involving the lack of paperless across three key areas: (1) occupational therapists: assessment of occupants' general health and wellbeing, (2) nurses: documentation of patient's status, (3) physicians: interpretation of diagnostic tools. A study assessing the digitisation of a social care assessment chart has been undertaken. An online tool was created in an effort to reduce the amount of miscalculations when compared to the paper assessment chart. As a result, there were no miscalculations when using the online tool, compared to 40% when using the traditional paper-based assessment. In a subsequent study, an evaluation of paperless observations recordings in the form of a digital drug chart displayed on a tablet device are explored. The study established that although the digital drug chart took slightly longer for participants to use, it was the method of assessment that the user correctly noticed the patient's drug allergy to penicillin. The penultimate study involved the design, development and evaluation of an online ECG visualisation tool. Along with the traditional 12-Lead ECG, alternative formats (BSPM and ST-Vector Map) were included to allow comparisons between the most effective method of diagnosis. Work within this study showed that the BSPM was proven to be just as useful as the 12-Lead ECG in identifying myocardial infarctions. The final study aimed to evaluate whether an accurate ECG diagnosis could be made using a smartphone. A clinician was sent 15 ECGs as picture messages before providing a diagnosis for each image. Findings illustrate that all 15 ECGs were diagnosed correctly with the clinician stating that there was no key disadvantage in comparison to paper based ECGs. These studies represent each of the three key areas of healthcare discussed previously, and endeavour to bridge the gap in relation to providing sustainable digital healthcare.

The TF-1 human erythroleukemic cell line exhibits opposing physiological responses towards tumour necrosis factor-alpha (TNF-alpha) treatment, dependent upon the mitotic state of the cells. Mitotically active cells respond to TNF-alpha by rapidly undergoing apoptosis whereas TNF-alpha exposure stimulates cellular proliferation in mitotically quiescent cells. These intracellular functions of TNF-alpha are transmitted by the type I (TNFR l) and type II (TNFR 2) receptors, but the signalling mechanisms elicited by these two receptors are not fully understood. We show that the expression levels of TNFR2 vary during the TF-1 cell cycle. Furthermore, studies utilising TNF-alpha receptor subtype-specific TNF-alpha mutants implicated the TNFR2 in apoptotic signalling. These data show a bifunctional physiological role for TNF-alpha in TF-1 cells that is dependent on mitotic activity and controlled by the TNFR2. To examine the role of endogenous TNFR2 in mediating TNF-induced signalling, we used KYM-1 human rhabdomyosarcoma cells, which express high levels of the TNFR2 and TNFR l. We also used HeLa human cervical epithelial cells (which express mainly TNFR l) that had been transfected with TNFR2 cDNA and thus engineered to express higher numbers of receptors than KYM-1 cells. The role of TNFR2 activation in enhanced apoptotic cell death was confirmed in these cells expressing high levels of TNFR2. It is reported here that subtype-specific differential kinase activation and cPLA 2 activation is seen in these cell models. KYM-1 and HeLa clones displayed c-Jun N-terminal kinase (JNK) activation by wild-type TNF, TNFRl-specific mutant and TNFR2-specific mutant in combination with TNFR2-specific agonistic monoclonal antisera. Moreover, alternative expression of a TNFR2 deletion mutant lacking its cytoplasmic domain rendered the cells unable to activate .INK activity through this receptor isotype. Conversely, only activation of the TNFRl could stimulate mitogen-activated protein kinase (MAPK) or p38 MAPK activities in a time-dependent manner. In addition to kinase activation cPLA2 activity (previously thought to be mediated solely by TNFRl) was also found to increase in a receptor subtype-specific manner. The TNFRl was shown to lead to the phosphorylation and activation of CPLA2, whilst the TNFR2 was implicated in translocation of cPLAi to perinuclear regions. These findings indicate that both receptors differentially modulate extracellular signal-regulated kinases and CPLA2 and that these enzymes contribute to the TNFs cytotoxic response.

Phosphate glasses have demonstrated a high degree of suitability for use as biomaterials in a wide range of biomedical applications involving both hard and soft tissue regeneration. This study focused on the use of these glasses as substrate microcarrier materials for three-dimensional bone tissue formation. For this purpose, the successful production of phosphate glass microspheres in the ~10–200 μm size range was demonstrated using a simple, inexpensive and industrially scalable process. Microspheres made out of two different series of phosphate glass compositions were investigated: (a) iron phosphate glasses 0.5P2O5–0.4CaO–(0.1 – x)Na2O–xFe2O3 where x = 0.00, 0.01, 0.03 and 0.05 mole fraction and (b) titanium phosphate glasses 0.5P2O5–0.4CaO–(0.1 – x)Na2O–xTiO2 where x = 0.00, 0.01, 0.03, 0.05 and 0.07 mole fraction. Investigations of the microsphere physicochemical properties revealed the densification of the glass structure with increased metal oxide incorporation in the glass. Glass structural characterisation studies provided valuable information relating the physicochemical properties to glass structural arrangements at the glass phase and atomic levels. Cell culture studies involving culture of the microspheres with MG63 osteosarcoma cells and human mesenchymal stem cells indicated that microspheres made of glasses containing 3–7 mol% metal oxides, and particularly those containing 5 mol% TiO2, showed favourable characteristics in terms of cell attachment, viability, proliferation and release of proteins related to cell differentiation and metabolism under both static conditions in culture well plates and dynamic conditions in spinner flask bioreactors. Taken together, the results provide evidence of the potential of the investigated glass microspheres to function as effective microcarrier substrates for bone tissue engineering applications.

High-throughput technologies in biomedical sciences, including gene microarrays, supposed to revolutionise the post-genomic era, have barely met the great expectations they inspired to the biomedical community at first. Current efforts are still focused toward improving the technology, its reproducibility and accuracy. In the meantime, computational techniques for the analysis of the data from these technologies have achieved great progresses and show encouraging results. New approaches have been developed to extract relevant information out from these results. However, important work needs to be further conducted in order to extract even more meaningful and relevant information. These techniques offer great possibilities to explore the overall dynamic held within a living organism. The potential information contained in their output can reveal important leads at deciphering the interconnection, interaction or regulation influences that can exist between several molecules. In front of an increasing interest of the scientific community toward the exploration of these dynamics, some groups have started to develop solutions based on different technologies to extract these information related to interactions. Here we present an Artificial Neural Network-based methodology for the study of interactions in gene transcriptomic data. This will be applied and validated in a breast cancer context. This manuscript will discuss the methodological optimisation to identify biomarkers of interest from high-throughput transcriptomic technologies; and it will show how the algorithms were brought forward to identify the potential relationship that may exist between the markers identified. It will illustrate and highlight the robustness of the methods by discussing some examples of application in different breast cancer studies. The present thesis will show that despite the great difficulty to obtain gold validation to prove the robustness of the approach; it has been possible to identify some relevant features able to highlight the promises held by this preliminary development of the method. The results obtained by trying to identify the correlated component within an artificial dataset suggest some interesting ability of the approach. Additionally, when applied to the van’t Veer dataset (van’t Veer et al., 2002), the list of selected transcripts held two different isoforms for two different genes, and the method identified the strong correlation between the 2 forms. Finally, the results involving the transcripts for DTL, TK1 and CDC45L have been shown to overlap with the result of a similar work from Gevaert et al. (2006) on the van’t Veer dataset using a different method involving a Bayesian network with Markov blanket. Ultimately, this thesis will try to discuss the advantages or limitations as well as the potential application and future hopes around the methods introduced.

Regenerative Medicine is an emerging biomedical paradigm promising to radically change healthcare. For this to happen, basic science breakthroughs must be translated into the clinical setting and market. This thesis examines the evolving Regenerative Medicine Translation process from the perspective of UK-based bioentrepreneurs. While much is known about the views of scientists, clinicians and industry stakeholders, an understanding of what it is to be an RM entrepreneur and company founder and often drive the whole process has not been fully explored. Based on interviews with bioentrepreneurs and other secondary sources this thesis explores three main 'areas' of the Regenerative Medicine Translation process: Funding, Regulation, and cross-disciplinary Collaboration. A variety of conceptual tools and social science analytical motifs are employed to explore the broad range of activities and roles undertaken by bioentrepreneurs. The exploration provides an in-depth look at individual experiences (at various stages of the clinical and commercial Translation process of their research) and sheds light on factors that influence the Translation process and the evolving role of bioentrepreneurs in it. A main assumption throughout the thesis is that in the nascent field of Regenerative Medicine therapeutics (including cell-based and tissue-based), RM bioentrepreneurs are acting as crucial mediators of knowledge across the various scientific, institutional and professional domains. Their unique human capital (including scientific, clinical, regulatory and, often, business expertise) in combination with their formal status/position as founders of commercial entities aiming to commercialise new technologies, places them in a unique position between the bench, the clinic, and the industry from where they have the potential to elevate the available resources, facilitate Translation and promote innovation. Findings from this investigation address voids in the understanding of RM Translation in the UK, provide insights not available through other types of stakeholder, and by means of lessons learned, potentially can help facilitate a cadre of more successful entrepreneurs and hence more successful Translation in the future.

Macro scale magnetic separation of pure biological particles from a complex biological sample is a key technique performed in clinical and research settings. This thesis focuses on the development of a microfluidic based magnetic separator for biological applications. The work presented covers design, simulation, fabrication and testing of the magnetic separator. The magnetic separator design consists of a micron-sized channel fabricated in a biocompatible polymer, containing one inlet and three outlets. Close to the channel wall are soft permalloy elements. The external magnetic flux is provided by the permanent magnets situated on either side of the channel. Theoretical aspects of the design are discussed and special attention is paid to investigating the effects of the magnetic and fluidic forces acting within the microdevice. Fabrication of the magnetic separator was carried out in the Microsystems Engineering Centre, Heriot Watt University and at Epigem Ltd., Redcar, U.K. The manufacturing processes investigated include methods for rapid prototyping and UV-photolithography. CO2 laser ablation and powder blasting of PMMA were investigated as rapid prototyping techniques. Using UV-photolithography magnetic separators were realised in PDMS and in SU-8. Soft permalloy elements were fabricated using UV-LIGA and the correct permalloy ratio (Ni80Fe20) evaluated. Ultimately three magnetic separation systems have been successfully fabricated based on the different fabrication approaches. Magnetic separation on chip was successfully demonstrated for all three devices fabricated. Flow cytometry a highly accurate method of particle counting and analysis was used to verify the separation efficiency. Experimental testing results have shown that magnetic and non-magnetic beads can be separated with high efficiency.

This thesis describes the development of the 4-bromobenzylsulphonyl (4- Bbs) group as an enzymatically cleavable protecting group for the side chain of arginine. The protected arginine was utilised to synthesise RGD peptidcs both with and without a spacer arm and these peptides were incorporated into hydrogels. Hydrogels were made from 1,2-propandiol-3-methacrylate (glycerol methacrylate, GM MA) or butyl methacrylate (BMA) and 1,2-ethandiol dimethacrylate (ethylene glycol dimethacrylate, EGDMA) and photopolymerized as 60~m coatings. Removal of the 4-Bbs protecting group was achieved by incubation with the enzyme Glutathione-S-Transferase. Culture of human dermal fibroblasts on the materials showed significant improvements in cell adhesion and viability in serum free media on glycerol methacrylate hydrogels with nominal RGD concentrations of 1 ~mol/g or greater. A spacer arm between the peptide and the bulk was not necessary to promote cell attachment. No significant improvement in cell adhesion and viability to butyl methacrylate hydrogels was observed at any of the peptide concentrations tested. The effects of peptide concentration, GST pre-treatment of materials, cell passage number and culture with soluble RGD were investigated by examining cell morphology, adhesion, viability and F-actin organisation.

The aim of this work is to develop novel shape memory polymers (SMPs) and nanocomposites for potential biological applications. A kind of commercial SMP, shape memory polyurethane (SMPU), was used to prepare nanocomposites by incorporating nano-clay into the SMPU substrate. The mechanical behaviour, thermal property and shape memory efficiency were studied with various nanofiller loadings. Chemical synthesis methods were also employed to prepare the other designable SMP and its nanocomposites, i.e. the shape memory polystyrene co-polymer (SMPS). Multiple technologies were adopted to enhance the SMPS matrix such as modifying the chemical components, introducing various functional nanoparticles into the polymeric network and improving the dispersion of the nanoparticles. Different methods were used to characterize the overall performance of the obtained materials. Mechanical tests were performed at different dimensional scales with a varied degree of localisation. Nanoindentation was firstly applied to assess the micro-mechanical properties of shape memory polymer nanocomposites at scales down to particle size. The micro-mechanical analysis provided the fundamental information on the SMPs and their nanocomposites for bio-MEMS applications. Potential applications were also explored through manufacturing different type of device models and testing their shape recovery efficiencies. Finally, theoretical contributions were made in two areas. The first one was the theoretical analysis on the nanoparticles enhancement to the soft polymeric matrix. The other was in developing a constitutive model to describe the thermo-viscoelastic property and shape memory behaviour for SMP nanocomposites.