In-situ development of self-defensive antibacterial biomaterials: phenol-g-keratin-EC based bio-composites with characteristics for biomedical applications

Recently, the development of highly inspired biomaterials with multi-functional characteristics has gained considerable attention, especially in biomedical, and other health-related areas of the modern world. It is well-known that the lack of antibacterial potential has significantly limited biomaterials for many challenging applications such as infection free wound healing and/or tissue engineering etc. In this perspective, herein, a series of novel bio-composites with natural phenols as functional entities and keratin-EC as a base material were synthesised by laccase-assisted grafting. Subsequently, the resulting composites were removed from their respective casting surfaces, critically evaluated for their antibacterial and biocompatibility features and information is also given on their soil burial degradation profile. In-situ synthesised phenol-g-keratin-EC bio-composites possess strong anti-bacterial activity against Gram-positive and Gram-negative bacterial strains i.e., B. subtilis NCTC 3610, P. aeruginosa NCTC 10662, E. coli NTCT 10418 and S. aureus NCTC 6571. More specifically, 10HBA-g-keratin-EC and 20T-g-keratin-EC composites were 100% resistant to colonisation against all of the aforementioned bacterial strains, whereas, 15CA-g-keratin-EC and 15GA-g-keratin-EC showed almost negligible colonisation up to a variable extent. Moreover, at various phenolic concentrations used, the newly synthesised composites remained cytocompatible with human keratinocyte-like HaCaT, as an obvious cell ingrowth tendency was observed and indicated by the neutral red dye uptake assay. From the degradation point of view, an increase in the degradation rate was recorded during their soil burial analyses. Our investigations could encourage greater utilisation of natural materials to develop bio-composites with novel and sophisticated characteristics for potential applications.

Eco-cities: technological showcases or public spaces?

A growing body of critical literature seeks to identify conceptual and practical problems accompanying the realisation of mainstream ‘eco-city’ initiatives around the world. However, little attention has been paid to the status of the ‘city’ itself within the broader discourse. If eco-cities are to be more than experimental ‘technological showcases’, and aim to transform urban life more generally, the question of what types of ‘cityness’ will ensue is of considerable importance. To effect a more significant sustainability transition, eco-city plans and policies may need somehow to encompass a more nuanced conceptualisation of cities as complex, unpredictable, and emergent spaces. The incompatibility of such a conceptualisation with liberal-modernist modes of planning means that radically innovative new approaches to eco-city development may need to be found. This thesis considers whether the eco-city, theorised as a multiple process of real-world experimentation, may shed some light on how ‘cityness’ might better be planned for in future. To do so, it conceptualises cityness through the lens of ‘publicness’. It makes an original contribution to knowledge by developing a new theoretical model of publicness as an ‘assemblage’ of space and behaviour, with an ‘emergent’ and ‘civic’ modality. It thereby extends recent debates over the idea of ‘urban assemblage’, and makes innovative links between theories of planning and of the public. This model informs the analysis of original empirical research, investigating the conceptualisation of the public in an international sample of official eco-city documents, and exploring the publicness of two implemented initiatives, in Portland, Oregon (US) and newly built Sejong City (South Korea). The research finds that publicness tends to be poorly articulated in mainstream eco-city plans and policies, with potentially negative implications for sustainability in the ‘urban age’. However, it also argues that state institution-led planning – even when experimental ‘governance’ approaches are adopted – may inevitably be limited in its ability to encompass the emergent public life of the city. The thesis concludes by considering the prospects for overcoming or more productively acknowledging these limits in future.

Gold, power, protest: Digital and social media and protests against large-scale mining projects in Colombia

Colombia’s Internet connectivity has increased immensely. Colombia has also ‘opened for business’, leading to an influx of extractive projects to which social movements object heavily. Studies on the role of digital media in political mobilisation in developing countries are still scarce. Using surveys, interviews, and reviews of literature, policy papers, website and social media content, this study examines the role of digital and social media in social movement organisations and asks how increased digital connectivity can help spread knowledge and mobilise mining protests. Results show that the use of new media in Colombia is hindered by socioeconomic constraints, fear of oppression, the constraints of keyboard activism and strong hierarchical power structures within social movements. Hence, effects on political mobilisation are still limited. Social media do not spontaneously produce non-hierarchical knowledge structures. Attention to both internal and external knowledge sharing is therefore conditional to optimising digital and social media use.