Mg/hydroxyapatite composites for potential bio-medical applications

This thesis was submitted for the degree of Master of Philosophy and awarded by Brunel University.Depending on an excellent combination of high mechanical property and fracture toughness, metallic biomaterials have been widely accepted for clinical application of bone fixation. However, some prominent disadvantages such as stress shielding effect due to their high elastic modulus, poisonous ions released by corrosion or mechanical wear [Puleo and Huh, 1995] definitely restrict their effective performance in-service. In addition, patients also have to bear the pain resulted from second surgery for removing implants. Although bio-degradable polymers and ceramics seem to solve the tough problem as promising substitutes, the low mechanical property and rapid corrosion rate make them fail to qualify against the bear-loading requirement in body. Therefore, we desperately look for a non-toxic suitable material for medical application which possesses appropriate mechanical properties, and favourable corrosion resistance

FUNCTIONALIZATION OF POLYCAPROLACTONE THROUGH NOVEL BLOCK COPOLYMER DESIGN FOR CELL ENGINEERING AND GENE DELIVERY

Ph.DDOCTOR OF PHILOSOPH

Cationic polymeric nanoformulation: Recent advances in material design for CRISPR/Cas9 gene therapy

Abstract(#br)CRISPR/Cas9 (clustered regularly interspaced short palindromic repeat/clustered regularly interspaced short palindromic repeat associated proteins 9) gene editing platform is a promising therapeutic tool for genetic disorders, due to its ability to manipulate the pathogenic gene in genomic level and to easily target specific gene by manipulating single-guide RNA. However, its successful delivery remains a challenge. Up to now, great efforts have been made to explore an effective strategy for CRISPR/Cas9 delivery. But among those delivery methods, physical methods are mainly operated on cultured cells thus limited to laboratorial use; viral vectors are hindered by fetal immunogenic and carcinogenic effects thus dubious in clinical application. Therefore, cationic polymeric vectors, with the ability to interact with CRISPR/Cas9 system to form a nanoformulation as a non-viral approach, are attracting increasing attentions, due to advantages such as well protection of cargos, less limitation in payload size, low immunogenicity or carcinogenicity, potential modifications for further functions, and ease in mass production. In this review, the recent discoveries on polymeric vectors utilized in delivery of CRISPR/Cas9 system will be summarized. With emphasis on advanced features of those polymeric vectors or their nanoformulations to meet the demands of different CRISPR/Cas9 delivery forms (plasmid, mRNA or protein), the detailed illustrations on their disease treatment applications, such as cancer, diabetes or antibiotic-resistant infections, will also be reviewed

The sustainable materials roadmap

Over the past 150 years, our ability to produce and transform engineered materials has been responsible for our current high standards of living, especially in developed economies. However, we must carefully think of the effects our addiction to creating and using materials at this fast rate will have on the future generations. The way we currently make and use materials detrimentally affects the planet Earth, creating many severe environmental problems. It affects the next generations by putting in danger the future of the economy, energy, and climate. We are at the point where something must drastically change, and it must change now. We must create more sustainable materials alternatives using natural raw materials and inspiration from nature while making sure not to deplete important resources, i.e. in competition with the food chain supply. We must use less materials, eliminate the use of toxic materials and create a circular materials economy where reuse and recycle are priorities. We must develop sustainable methods for materials recycling and encourage design for disassembly. We must look across the whole materials life cycle from raw resources till end of life and apply thorough life cycle assessments (LCAs) based on reliable and relevant data to quantify sustainability. We need to seriously start thinking of where our future materials will come from and how could we track them, given that we are confronted with resource scarcity and geographical constrains. This is particularly important for the development of new and sustainable energy technologies, key to our transition to net zero. Currently 'critical materials' are central components of sustainable energy systems because they are the best performing. A few examples include the permanent magnets based on rare earth metals (Dy, Nd, Pr) used in wind turbines, Li and Co in Li-ion batteries, Pt and Ir in fuel cells and electrolysers, Si in solar cells just to mention a few. These materials are classified as 'critical' by the European Union and Department of Energy. Except in sustainable energy, materials are also key components in packaging, construction, and textile industry along with many other industrial sectors. This roadmap authored by prominent researchers working across disciplines in the very important field of sustainable materials is intended to highlight the outstanding issues that must be addressed and provide an insight into the pathways towards solving them adopted by the sustainable materials community. In compiling this roadmap, we hope to aid the development of the wider sustainable materials research community, providing a guide for academia, industry, government, and funding agencies in this critically important and rapidly developing research space which is key to future sustainability.journal articl

Water soluble polyhydroxyalkanoates: Future materials for therapeutic applications

Chemical Society Reviews44102865-287

How Multidimensional Digital Empowerment Affects Technology Innovation Performance: The Moderating Effect of Adaptability to Technology Embedding

Technology innovation in high-end equipment manufacturing (HEM) enterprises technology innovation plays an important role in supporting national economies and social development, accelerating the speed of digital transformation. Digital empowerment aggravates the dynamics, complexity, and uncertainty of technology innovation in HEM enterprises. In order to improve the innovation performance mechanism of China’s HEM enterprises, the adaptability of technology embedding and digital empowerment are introduced to further explain the direct and the moderating effect. Specifically, through a literature review and practical research, the connotation and dimensional division of digital empowerment are defined. According to empowerment tools, digital empowerment is divided into resource empowerment and structural empowerment, and according to the empowerment actor relationships, digital empowerment is divided into platform empowerment and ecological empowerment. Additionally, 436 HEM enterprises are used as research objects to build a conceptual model of the different digital empowerment dimensions, adaptability to technology embedding and technology innovation performance. The research results show that resource empowerment and structural empowerment have U–shaped effects on technology innovation performance, and platform empowerment and ecological empowerment positively affect technology innovation performance. Then, adaptability to technology embedding positively moderates the U-shaped relationship between structural empowerment and technology innovation performance. Adaptability to technology embedding positively moderates the relationship between resource empowerment, platform empowerment, ecological empowerment and technology innovation performance. The research findings deepen the connotation and dimension of digital empowerment, demonstrating the nonlinear relationship between digital empowerment and technology innovation performance of HEM enterprises. Additionally, the research expands on the new applications of adaptability to technology embedding in the digital transformation of manufacturing

How Multidimensional Digital Empowerment Affects Technology Innovation Performance: The Moderating Effect of Adaptability to Technology Embedding

Technology innovation in high-end equipment manufacturing (HEM) enterprises technology innovation plays an important role in supporting national economies and social development, accelerating the speed of digital transformation. Digital empowerment aggravates the dynamics, complexity, and uncertainty of technology innovation in HEM enterprises. In order to improve the innovation performance mechanism of China’s HEM enterprises, the adaptability of technology embedding and digital empowerment are introduced to further explain the direct and the moderating effect. Specifically, through a literature review and practical research, the connotation and dimensional division of digital empowerment are defined. According to empowerment tools, digital empowerment is divided into resource empowerment and structural empowerment, and according to the empowerment actor relationships, digital empowerment is divided into platform empowerment and ecological empowerment. Additionally, 436 HEM enterprises are used as research objects to build a conceptual model of the different digital empowerment dimensions, adaptability to technology embedding and technology innovation performance. The research results show that resource empowerment and structural empowerment have U–shaped effects on technology innovation performance, and platform empowerment and ecological empowerment positively affect technology innovation performance. Then, adaptability to technology embedding positively moderates the U-shaped relationship between structural empowerment and technology innovation performance. Adaptability to technology embedding positively moderates the relationship between resource empowerment, platform empowerment, ecological empowerment and technology innovation performance. The research findings deepen the connotation and dimension of digital empowerment, demonstrating the nonlinear relationship between digital empowerment and technology innovation performance of HEM enterprises. Additionally, the research expands on the new applications of adaptability to technology embedding in the digital transformation of manufacturing

Control of Hyperbranched Structure of Polycaprolactone/Poly(ethylene glycol) Polyurethane Block Copolymers by Glycerol and Their Hydrogels for Potential Cell Delivery

A series of biodegradable amphiphilic polyurethane block copolymers with hyperbranched structure were synthesized by copolymerizing poly­(ε-caprolactone) (PCL) and poly­(ethylene glycol) (PEG) together with glycerol. The copolymers were characterized, and their composition and branch length were varied with the feeding ratio between PCL, PEG, and glycerol used. Hydrogels were formed from these copolymers by swelling of water at low polymer concentrations. The hydrogels were thixotropic, and their dynamic viscoelastic properties were dependent on the copolymer composition, branch length, and polymer concentration. Hydrolytic degradation of the hydrogels was evaluated by mass loss and changes in molecular structures. The porous morphology of the hydrogels provided good permeability for gas and nutrition. Together with the tunable rheological properties, the hydrogels were found to be suitable for 3D living cell encapsulation and delivery. The morphology of the solid copolymers was semicrystalline, while the hydrogels were totally amorphous without crystallinity, providing a mild aqueous environment for living cells. When the encapsulated cells were recovered from the hydrogels followed by subculture, they showed good cell viability and proliferation ability. The results indicate that the hyperbranched copolymers hydrogels developed in this work may be promising candidates for potential injectable cell delivery application

The Impact of Science and Technology Finance on Regional Collaborative Innovation: The Threshold Effect of Absorptive Capacity

The collaborative innovation of Beijing-Tianjin-Hebei region is faced with prominent problems such as the large gap in innovation resources and capability. In addition, science and technology (S&T) finance provides the approach to promote the flow of regional capital, technology and talents, which can facilitate the coordinated development of Beijing-Tianjin-Hebei region. Therefore, this study takes the Beijing-Tianjin-Hebei region as an example to explore the mechanism of different S&T finance on regional S&T collaborative innovation. Based on the provincial panel data of Beijing-Tianjin-Hebei region from 2009 to 2020, this paper constructs a dynamic panel threshold model with different regional absorptive capacities (technology level and economic base) as threshold variables to analyze the impact of public and market S&T finance on regional collaborative innovation. The main findings of this paper are as follows: first, the overall level of regional collaborative innovation in Beijing, Tianjin and Hebei is low, and public and market S&T finance significantly affects regional collaborative innovation in Beijing, Tianjin and Hebei. Specifically, public S&T finance plays an inhibitory role on regional collaborative innovation, and market S&T finance positively affects regional collaborative innovation. Secondly, both types of S&T finance have obvious heterogeneous threshold characteristics of absorptive capacity on regional collaborative innovation. Once the absorptive capacity of both regions breaks through the critical scale, the inhibiting effect of public S&T finance on regional collaborative innovation shows a weakening trend; with the improvement of technology level, the positive influence of market S&T finance on regional collaborative innovation keeps increasing. With the improvement of economic base, it shows a shift from negative to positive. The research findings provide theoretical and practical guidance for accelerating the pace of S&T innovation and the implementation mechanism of regional coordinated development