Global civil society and adult education for social change : a postcolonial perspective

Adult education plays an important role in global economic development and features prominently in debates about changing requirements of post-industrial knowledge societies. This dominant technical-instrumental understanding of adult education in public discourse masks the transformative function of certain types of adult education - that is, the possibilities of adult education to improve social justice issues such as workers’ rights, human rights, civic participation in governance and socially just development. Given the increasing social stratification between and within the North and South in the global era, the potential of adult education to effect social change has been rediscovered by organisations within global civil society, namely international non-governmental organisations (INGOs). The broad objective of this research was to carry out an in-depth qualitative case study of a human rights advocacy program provided by a Northern INGO predominantly operating within the global South. The study analyses how participants see this program in terms of its potential to contribute to progressive social change in their home communities across the Asia-Pacific region. The following questions guided the study: 1. To what extent does this adult education program challenge existing systems of domination and marginalisation? 2. How did completion of the program affect participants’ views of their abilities to facilitate social action within their communities? Data sources for this research were interviews with 19 participants and staff and questionnaires from 28 participants of the program from a variety of countries in the Asia-pacific region. The gap in the literature that this study addressed is that existing empirical research sidelines the analysis of the globalisation, adult education, and social change nexus from a perspective that takes the marginalised other seriously, tending instead to mirror the material subjugation of the South in discursive practices. Social change is highly context-specific and strategies to advance it depend on the way in which people understand their reality and are affected by adverse social conditions. The present study employed a postcolonial framework that provided a holistic approach to analysing adult education for social change inclusive of material, political, and social conditions and the interplay between these from the local to the global level. The program convincingly exemplified an example of adult education for counter-hegemonic resistance against the dominant neoliberal discourse. It achieved this by enabling participants, based on Freirian pedagogical principles, to locate the problem of social change and frame their strategies to address it within mutually constitutive local and global developments and the discourses that describe them. It provided the underpinning knowledge and skills for effective advocacy and created opportunities to build networks between various stakeholders. At minimum, most advocates accord their participation in the program a supporting role in enhancing their ability to examine causes for social injustices and ways to address these. Some advocates even regarded their program participation as fundamental in understanding these issues. Almost all participants reported an increased skill-set that enabled them to become more effective advocates.

Perceiving and pursuing novelty : a grounded theory of adolescent creativity

Creativity plays an increasingly important role in our personal, social, educational, and community lives. For adolescents, creativity can enable self-expression, be a means of pushing boundaries, and assist learning, achievement, and completion of everyday tasks. Moreover, adolescents who demonstrate creativity can potentially enhance their capacity to face unknown future challenges, address mounting social and ecological issues in our global society, and improve their career opportunities and contribution to the economy. For these reasons, creativity is an essential capacity for young people in their present and future, and is highlighted as a priority in current educational policy nationally and internationally. Despite growing recognition of creativity’s importance and attention to creativity in research, the creative experience from the perspectives of the creators themselves and the creativity of adolescents are neglected fields of study. Hence, this research investigated adolescents’ self-reported experiences of creativity to improve understandings of their creative processes and manifestations, and how these can be supported or inhibited. Although some aspects of creativity have been extensively researched, there were no comprehensive, multidisciplinary theoretical frameworks of adolescent creativity to provide a foundation for this study. Therefore, a grounded theory methodology was adopted for the purpose of constructing a new theory to describe and explain adolescents’ creativity in a range of domains. The study’s constructivist-interpretivist perspective viewed the data and findings as interpretations of adolescents’ creative experiences, co-constructed by the participants and the researcher. The research was conducted in two academically selective high schools in Australia: one arts school, and one science, mathematics, and technology school. Twenty adolescent participants (10 from each school) were selected using theoretical sampling. Data were collected via focus groups, individual interviews, an online discussion forum, and email communications. Grounded theory methods informed a process of concurrent data collection and analysis; each iteration of analysis informed subsequent data collection. Findings portray creativity as it was perceived and experienced by participants, presented in a Grounded Theory of Adolescent Creativity. The Grounded Theory of Adolescent Creativity comprises a core category, Perceiving and Pursuing Novelty: Not the Norm, which linked all findings in the study. This core category explains how creativity involved adolescents perceiving stimuli and experiences differently, approaching tasks or life unconventionally, and pursuing novel ideas to create outcomes that are not the norm when compared with outcomes by peers. Elaboration of the core category is provided by the major categories of findings. That is, adolescent creativity entailed utilising a network of Sub-Processes of Creativity, using strategies for Managing Constraints and Challenges, and drawing on different Approaches to Creativity – adaptation, transfer, synthesis, and genesis – to apply the sub-processes and produce creative outcomes. Potentially, there were Effects of Creativity on Creators and Audiences, depending on the adolescent and the task. Three Types of Creativity were identified as the manifestations of the creative process: creative personal expression, creative boundary pushing, and creative task achievement. Interactions among adolescents’ dispositions and environments were influential in their creativity. Patterns and variations of these interactions revealed a framework of four Contexts for Creativity that offered different levels of support for creativity: high creative disposition–supportive environment; high creative disposition–inhibiting environment; low creative disposition–supportive environment; and low creative disposition–inhibiting environment. These contexts represent dimensional ranges of how dispositions and environments supported or inhibited creativity, and reveal that the optimal context for creativity differed depending on the adolescent, task, domain, and environment. This study makes four main contributions, which have methodological and theoretical implications for researchers, as well as practical implications for adolescents, parents, teachers, policy and curriculum developers, and other interested stakeholders who aim to foster the creativity of adolescents. First, this study contributes methodologically through its constructivist-interpretivist grounded theory methodology combining the grounded theory approaches of Corbin and Strauss (2008) and Charmaz (2006). Innovative data collection was also demonstrated through integration of data from online and face-to-face interactions with adolescents, within the grounded theory design. These methodological contributions have broad applicability to researchers examining complex constructs and processes, and with populations who integrate multimedia as a natural form of communication. Second, applicable to creativity in diverse domains, the Grounded Theory of Adolescent Creativity supports a hybrid view of creativity as both domain-general and domain-specific. A third major contribution was identification of a new form of creativity, educational creativity (ed-c), which categorises creativity for learning or achievement within the constraints of formal educational contexts. These theoretical contributions inform further research about creativity in different domains or multidisciplinary areas, and with populations engaged in formal education. However, the key contribution of this research is that it presents an original Theory and Model of Adolescent Creativity to explain the complex, multifaceted phenomenon of adolescents’ creative experiences.

Accounting at home in developing economies : Current practices and implications for the accounting professional

We determine the extent of accounting at home in developing economies in this research. We then consider the role of the accounting profession may have in promoting accounting values at home. A language of business, accounting today plays a fundamental support role within the business community to evaluate the impact past decisions, and foresees directions for future initiatives. Sound accounting practices are fundamental to ensure symmetrical information dissemination across various stakeholders. Accounting literature has sought to investigate a number of questions that attempt to improve the practice of accounting in the corporate world. Equally, we must obtain adequate understanding of how we use accounting in our everyday life, and how accounting could assist the people most affected by the effects of accounting scandals, economic conditions, and corporate collapses.

Private equity bidders : barbarians or best friends

The deal value of private equity merger and takeover activity has achieved unprecedented growth in the last couple of years, in Australia and globally. Private equity deals are not a new feature of the market; however, such deals have been subject to increased academic, professional and policy interest. This study examines the particular features of 15 major deals involving listed company "targets" and provides evidence – based on a comparison with a benchmark sample – to demonstrate the role that private equity plays in the market for corporate control. The objective of this study was to assess the friendliness of private equity bids. Based on the indicia compiled, lower bid premiums, the presence of break fees and the intention to retain senior management are compellingly different for private equity bids than for the comparative sample of bids. Using these several characteristics of "friendliness", the authors show that private equity deals are generally friendly in nature, consistent with industry rhetoric, but perhaps inconsistent with the popular belief that private equity bidders are the "barbarians at the gate".

Chinese online literature : creative consumers and evolving business models

Purpose – The internet is transforming possibilities for creative interaction, experimentation and cultural consumption in China and raising important questions about the role that “publishers” might play in an open and networked digital world. The purpose of this paper is to consider the role that copyright is playing in the growth of a publishing industry that is being “born digital”. Design/methodology/approach – The paper approaches online literature as an example of a creative industry that is generating value for a wider creative economy through its social network market functions. It builds on the social network market definition of the creative industries proposed by Potts et al. and uses this definition to interrogate the role that copyright plays in a rapidly-evolving creative economy. Findings – The rapid growth of a market for crowd-sourced content is combining with growing commercial freedom in cultural space to produce a dynamic landscape of business model experimentation. Using the social web to engage audiences, generate content, establish popularity and build reputation and then converting those assets into profit through less networked channels appears to be a driving strategy in the expansion of wider creative industries markets in China. Originality/value – At a moment when publishing industries all over the world are struggling to come to terms with digital technology, the emergence of a rapidly-growing area of publishing that is being born digital offers important clues about the future of publishing and what social network markets might mean for the role of copyright in a digital age.

Investigating the change in three dimensional deformity for idiopathic scoliosis using axially loaded MRI

Background: Adolescent idiopathic scoliosis is a complex three-dimensional deformity, involving a lateral deformity in the coronal plane and axial rotation of the vertebrae in the transverse plane. Gravitational loading plays an important biomechanical role in governing the coronal deformity, however, less is known about how they influence the axial deformity. This study investigates the change in three-dimensional deformity of a series of scoliosis patients due to compressive axial loading. Methods: Magnetic resonance imaging scans were obtained and coronal deformity (measured using the coronal Cobb angle) and axial rotations measured for a group of 18 scoliosis patients (Mean major Cobb angle was 43.4 o). Each patient was scanned in an unloaded and loaded condition while compressive loads equivalent to 50% body mass were applied using a custom developed compressive device. Findings: The mean increase in major Cobb angle due to compressive loading was 7.4 o (SD 3.5 o). The most axially rotated vertebra was observed at the apex of the structural curve and the largest average intravertebral rotations were observed toward the limits of the coronal deformity. A level-wise comparison showed no significant difference between the average loaded and unloaded vertebral axial rotations (intra-observer error = 2.56 o) or intravertebral rotations at each spinal level. Interpretation: This study suggests that the biomechanical effects of axial loading primarily influence the coronal deformity, with no significant change in vertebral axial rotation or intravertebral rotation observed between the unloaded and loaded condition. However, the magnitude of changes in vertebral rotation with compressive loading may have been too small to detect given the resolution of the current technique.

Strontium-containing mesoporous bioactive glass scaffolds with improved osteogenic/cementogenic differentiation of periodontal ligament cells for periodontal tissue engineering

To achieve the ultimate goal of periodontal tissue engineering, it is of great importance to develop bioactive scaffolds which could stimulate the osteogenic/cementogenic differentiation of periodontal ligament cells (PDLCs) for the favorable regeneration of alveolar bone, root cementum, and periodontal ligament. Strontium (Sr) and Sr-containing biomaterials have been found to induce osteoblast activity. However, there is no systematic report about the interaction between Sr or Sr-containing biomaterials and PDLCs for periodontal tissue engineering. The aims of this study were to prepare Sr-containing mesoporous bioactive glass (Sr-MBG) scaffolds and investigate whether the addition of Sr could stimulate the osteogenic/cementogenic differentiation of PDLCs in tissue engineering scaffold system. The composition, microstructure and mesopore properties (specific surface area, nano-pore volume and nano-pore distribution) of Sr-MBG scaffolds were characterized. The proliferation, alkaline phosphatase (ALP) activity and osteogenesis/cementogenesis-related gene expression (ALP, Runx2, Col I, OPN and CEMP1) of PDLCs on different kinds of Sr-MBG scaffolds were systematically investigated. The results show that Sr plays an important role in influencing the mesoporous structure of MBG scaffolds in which high contents of Sr decreased the well-ordered mesopores as well as their surface area/pore volume. Sr2+ ions could be released from Sr-MBG scaffolds in a controlled way. The incorporation of Sr into MBG scaffolds has significantly stimulated ALP activity and osteogenesis/cementogenesis-related gene expression of PDLCs. Furthermore, Sr-MBG scaffolds in simulated body fluids environment still maintained excellent apatite-mineralization ability. The study suggests that the incorporation of Sr into MBG scaffolds is a viable way to stimulate the biological response of PDLCs. Sr-MBG scaffolds are a promising bioactive material for periodontal tissue engineering application.

Numerical investigation of mechanical properties of nanowires : a review

Nanowires (NWs) have attracted intensive researches owing to the broad applications that arise from their remarkable properties. Over the last decade, immense numerical studies have been conducted for the numerical investigation of mechanical properties of NWs. Among these numerical simulations, the molecular dynamics (MD) plays a key role. Herein we present a brief review on the current state of the MD investigation of nanowires. Emphasis will be placed on the FCC metal NWs, especially the Cu NWs. MD investigations of perfect NWs’ mechanical properties under different deformation conditions including tension, compression, torsion and bending are firstly revisited. Following in succession, the studies for defected NWs including the defects of twin boundaries (TBs) and pre-existing defects are discussed. The different deformation mechanism incurred by the presentation of defects is explored and discussed. This review reveals that the numerical simulation is an important tool to investigate the properties of NWs. However, the substantial gaps between the experimental measurements and MD results suggest the urgent need of multi-scale simulation technique.

An improved model of tumour-immune system interactions

The immune system plays an important role in defending the body against tumours and other threats. Currently, mechanisms involved in immune system interactions with tumour cells are not fully understood. Here we develop a mathematical tool that can be used in aiding to address this shortfall in understanding. This paper de- scribes a hybrid cellular automata model of the interaction between a growing tumour and cells of the innate and specific immune system including the effects of chemokines that builds on previous models of tumour-immune system interactions. In particular, the model is focused on the response of immune cells to tumour cells and how the dynamics of the tumour cells change due to the immune system of the host. We present results and predictions of in silico experiments including simulations of Kaplan-Meier survival-like curves.

Privacy by design : Does it matter for social networks?

Privacy is an important component of freedom and plays a key role in protecting fundamental human rights. It is becoming increasingly difficult to ignore the fact that without appropriate levels of privacy, a person’s rights are diminished. Users want to protect their privacy - particularly in “privacy invasive” areas such as social networks. However, Social Network users seldom know how to protect their own privacy through online mechanisms. What is required is an emerging concept that provides users legitimate control over their own personal information, whilst preserving and maintaining the advantages of engaging with online services such as Social Networks. This paper reviews “Privacy by Design (PbD)” and shows how it applies to diverse privacy areas. Such an approach will move towards mitigating many of the privacy issues in online information systems and can be a potential pathway for protecting users’ personal information. The research has also posed many questions in need of further investigation for different open source distributed Social Networks. Findings from this research will lead to a novel distributed architecture that provides more transparent and accountable privacy for the users of online information systems.

Effects of enhanced somatosensory information on postural stability in older people and people with Parkinson’s disease

The somatosensory system plays an important role in balance control and age-related changes to this system have been implicated in falls. Parkinson’s disease (PD) is a chronic and progressive disease of the brain, characterized by postural instability and gait disturbance. Previous research has shown that deficiencies in somatosensory feedback may contribute to the poorer postural control demonstrated by PD individuals. However, few studies have comprehensively explored differences in somatosensory function and postural control between PD participants and healthy older individuals. The soles of the feet contain many cutaneous mechanoreceptors that provide important somatosensory information sources for postural control. Different types of insole devices have been developed to enhance this somatosensory information and improve postural stability, but these devices are often too complex and expensive to integrate into daily life. Textured insoles provide a more passive intervention that may be an inexpensive and accessible means to enhance the somatosensory input from the plantar surface of the feet. However, to date, there has been little work conducted to test the efficacy of enhanced somatosensory input induced by textured insoles in both healthy and PD populations during standing and walking. Therefore, the aims of this thesis were to determine: 1) whether textured insole surfaces can improve postural stability by enhancing somatosensory information in younger and older adults, 2) the differences between healthy older participants and PD participants for measures of physiological function and postural stability during standing and walking, 3) how changes in somatosensory information affect postural stability in both groups during standing and walking; and 4), whether textured insoles can improve postural stability in both groups during standing and walking. To address these aims, Study 1 recruited seven older individuals and ten healthy young controls to investigate the effects of two textured insole surfaces on postural stability while performing standing balance tests on a force plate. Participants were tested under three insole surface conditions: 1) barefoot; 2) standing on a hard textured insole surface; and 3), standing on a soft textured insole surface. Measurements derived from the centre of pressure displacement included the range of anterior-posterior and medial-lateral displacement, path length and the 90% confidence elliptical area (C90 area). Results of study 1 revealed a significant Group*Surface*Insole interaction for the four measures. Both textured insole surfaces reduced postural sway for the older group, especially in the eyes closed condition on the foam surface. However, participants reported that the soft textured insole surface was more comfortable and, hence, the soft textured insoles were adopted for Studies 2 and 3. For Study 2, 20 healthy older adults (controls) and 20 participants with Parkinson’s disease were recruited. Participants were evaluated using a series of physiological assessments that included touch sensitivity, vibratory perception, and pain and temperature threshold detection. Furthermore, nerve function and somatosensory evoked potentials tests were utilized to provide detailed information regarding peripheral nerve function for these participants. Standing balance and walking were assessed on different surfaces using a force plate and the 3D Vicon motion analysis system, respectively. Data derived from the force plate included the range of anterior-posterior and medial-lateral sway, while measures of stride length, stride period, cadence, double support time, stance phase, velocity and stride timing variability were reported for the walking assessment. The results of this study demonstrated that the PD group had decrements in somatosensory function compared to the healthy older control group. For electrodiagnosis, PD participants had poorer nerve function than controls, as evidenced by slower nerve conduction velocities and longer latencies in sural nerve and prolonged latency in the P37 somatosensory evoked potential. Furthermore, the PD group displayed more postural sway in both the anterior-posterior and medial-lateral directions relative to controls and these differences were increased when standing on a foam surface. With respect to the gait assessment, the PD group took shorter strides and had a reduced stride period compared with the control group. Furthermore, the PD group spent more time in the stance phase and had increased cadence and stride timing variability than the controls. Compared with walking on the firm surface, the two groups demonstrated different gait adaptations while walking on the uneven surface. Controls increased their stride length and stride period and decreased their cadence, which resulted in a consistent walking velocity on both surfaces. Conversely, while the PD patients also increased their stride period and decreased their cadence and stance period on the uneven surface, they did not increase their stride length and, hence walked slower on the uneven surface. In the PD group, there was a strong positive association between decreased somatosensory function and decreased clinical balance, as assessed by the Tinetti test. Poorer somatosensory function was also strongly positively correlated with the temporospatial gait parameters, especially shorter stride length. Study 3 evaluated the effects of manipulating the somatosensory information from the plantar surface of the feet using textured insoles in the same populations assessed in Study 2. For this study, participants performed the standing and walking balance tests under three footwear conditions: 1) barefoot; 2) with smooth insoles; and 3), with textured insoles. Standing balance and walking were evaluated using a force plate and a Vicon motion analysis system and the data were analysed in the same way outlined for Study 2. The findings showed that the smooth and textured insoles caused different effects on postural control during both the standing and walking trials. Both insoles decreased medial-lateral sway to the same level on the firm surface. The greatest benefits were observed in the PD group while wearing the textured insole. When standing under a more challenging condition on the foam surface with eyes closed, only the textured insole decreased medial-lateral sway in the PD group. With respect to the gait trials, both insoles increased walking velocity, stride length and stride time and decreased cadence, but these changes were more pronounced for the textured insoles. The effects of the textured insoles were evident under challenging conditions in the PD group and increased walking velocity and stride length, while decreasing cadence. Textured insoles were also effective in reducing the time spent in the double support and stance phases of the gait cycle and did not increase stride timing variability, as was the case for the smooth insoles for the PD group. The results of this study suggest that textured insoles, such as those evaluated in this research, may provide a low-cost means of improving postural stability in high-risk groups, such as people with PD, which may act as an important intervention to prevent falls.

UK Design as a Global Industry : International Trade and Intellectual Property

The importance of design to the UK economy is widely recognised. It is one of the key pillars of the knowledge economy, it plays an important role in the innovation process, and it is one of a number of specialisms that help to set the UK apart from global competition. But despite this importance, the nature of design-intensive industries – the businesses that practice and sell design – is remarkably hard to pin down. This uncertainty renders it hard to analyse, and makes it difficult to develop clear, consistent policies to support the designers. The Hargreaves Review recommended that more research was needed to develop a clear evidence base for improving the intellectual property system for design. This report forms part of that evidence base. It examines how UK design figures in the global economy, and considers how the intellectual property system can best support its growth.

Isolation and functional characterisation of banana phytoene synthase genes as potential cisgenes

Carotenoids occur in all photosynthetic organisms where they protect photosystems from auto-oxidation, participate in photosynthetic energy-transfer and are secondary metabolites. Of the more than 600 known plant carotenoids, few can be converted into vitamin A by humans and so these pro-vitamin A carotenoids (pVAC) are important in human nutrition. Phytoene synthase (PSY) is a key enzyme in the biosynthetic pathway of pVACs and plays a central role in regulating pVAC accumulation in the edible portion of crop plants. Bananas are a major commercial crop and serve as a staple crop for more than 30 million people. There is natural variation in fruit pVAC content across different banana cultivars, but this is not well understood. Therefore, we isolated PSY genes from banana cultivars with relatively high (cv. Asupina) and low (cv. Cavendish) pVAC content. We provide evidence that PSY in banana is encoded by two paralogs (PSY1 and PSY2), each with a similar gene structure to homologous genes in other monocots. Further, we demonstrate that PSY2 is more highly expressed in fruit pulp compared to leaf. Functional analysis of PSY1 and PSY2 in rice callus and E. coli demonstrate that both genes encode functional enzymes, and that Asupina PSYs have approximately twice the enzymatic activity of the corresponding Cavendish PSYs. These results suggest that differences in PSY enzyme activity contribute significantly to the differences in Asupina and Cavendish fruit pVAC content. Importantly, Asupina PSY genes could potentially be used to generate new cisgenic or intragenic banana cultivars with enhanced pVAC content.

Preparation, characterisation and in vivo osteogenesis of mesoporous bioactive glasses

Bone defects, especially large bone defects, remain a major challenge in orthopaedic surgery. Autologous bone transplantation is considered the most effective treatment, but insufficient donor tissue, coupled with concerns about donor site morbidity, has hindered this approach in large-scale applications. Alternative approaches include implanting biomaterials such as bioactive glass (BG), which has been widely used for bone defect healing, due to having generally good biocompatibility, and can be gradually biodegraded during the process of new bone formation. Mesoporous bioactive glass (MBG) is a newly developed bioactive glass which has been proven to have enhanced in-vitro bioactivity; however the in-vivo osteogenesis has not been studied. A critical problem in using the bone tissue engineering approach to restore large bone defects is that the nutrient supply and cell viability at the centre of the scaffold is severely hampered since the diffusion distance of nutrients and oxygen for cell survival is limited to 150-200µm. Cobalt ions has been shown to mimic hypoxia, which plays a pivotal role in coupling angiogenesis with osteogenesis in-vivo by activating hypoxia inducing factor-1α (HIF-1α) transcription factor, subsequently initiating the expression of genes associated with tissue regeneration. Therefore, one aim of this study is to investigate the in-vivo osteogenesis of MBG by comparison with BG and β-TCP, which are widely used clinically. The other aim is to explore hypoxia-mimicking biomaterials by incorporating Cobalt into MBG and β-TCP. MBG and β-TCP incorporated with 5% cobalt (5Co-MBG and 5CCP) have also been studied in-vivo to determine whether the hypoxic effect has a beneficial effect on the bone formation. The composition and microstructure of synthesised materials (BG, MBG, 5Co-MBG, 5CCP) were characterised, along with the mesopore properties of the MBG materials. Dissolution and cytotoxicity of the Co-containing materials were also investigated. Femoral samples with defects harvested at 4 and 8 weeks were scanned using micro-CT followed by processing for histology (H&E staining) to determine bone formation. Histology of MBG showed a slower rate of bone formation at 4 weeks than BG, however at 8 weeks it could be clearly seen that MBG had more bone formation. The in-vivo results show that the osteogenesis of MBG reciprocates the enhanced performance shown in-vitro compared to BG. Dissolution study showed that Co ions can be efficiently released from MBG and β-TCP in a controllable way. Low amounts of Co incorporated into the MBG and β-TCP showed no significant cytotoxicity and the Co-MBG powders maintained a mesopore structure although not as highly ordered as pure MBG. Preliminary study has shown that Co incorporated samples showed little to no bone formation, instead incurring high lymphocyte activity. Further studies need to be done on Co incorporated materials to determine the cause for high lymphocyte activity in-vivo, which appear to hinder bone formation. In conclusion, this study demonstrated the osteogenic activity of MBG and provided some valuable information of tissue reaction to Co-incorporated MBG and TCP materials.

Development of zonal cartilage constructs : effects of chondrocyte subpopulation, compressive stimulation, and culture models

Articular cartilage is a highly resilient tissue located at the ends of long bones. It has a zonal structure, which has functional significance in load-bearing. Cartilage does not spontaneously heal itself when damaged, and untreated cartilage lesions or age-related wear often lead to osteoarthritis (OA). OA is a degenerative condition that is highly prevalent, age-associated, and significantly affects patient mobility and quality of life. There is no cure for OA, and patients usually resort to replacing the biological joint with an artificial prosthesis. An alternative approach is to dynamically regenerate damaged or diseased cartilage through cartilage tissue engineering, where cells, materials, and stimuli are combined to form new cartilage. However, despite extensive research, major limitations remain that have prevented the wide-spread application of tissue-engineered cartilage. Critically, there is a dearth of information on whether autologous chondrocytes obtained from OA patients can be used to successfully generate cartilage tissues with structural hierarchy typically found in normal articular cartilage. I aim to address these limitations in this thesis by showing that chondrocyte subpopulations isolated from macroscopically normal areas of the cartilage can be used to engineer stratified cartilage tissues and that compressive loading plays an important role in zone-dependent biosynthesis of these chondrocytes. I first demonstrate that chondrocyte subpopulations from the superficial (S) and middle/deep (MD) zones of OA cartilage are responsive to compressive stimulation in vitro, and that the effect of compression on construct quality is zone-dependent. I also show that compressive stimulation can influence pericelluar matrix production, matrix metalloproteinase secretion, and cytokine expression in zonal chondrocytes in an alginate hydrogel model. Subsequently, I focus on recreating the zonal structure by forming layered constructs using the alginate-released chondrocyte (ARC) method either with or without polymeric scaffolds. Resulting zonal ARC constructs had hyaline morphology, and expressed cartilage matrix molecules such as proteoglycans and collagen type II in both scaffold-free and scaffold-based approaches. Overall, my findings demonstrate that chondrocyte subpopulations obtained from OA joints respond sensitively to compressive stimulation, and are able to form cartilaginous constructs with stratified organization similar to native cartilage using the scaffold-free and scaffold-based ARC technique. The ultimate goal in tissue engineering is to help provide improved treatment options for patients suffering from debilitating conditions such as OA. Further investigations in developing functional cartilage replacement tissues using autologous chondrocytes will bring us a step closer to improving the quality of life for millions of OA patients worldwide.