Submitted by Renata Lopes (renatasil82@gmail.com) on 2016-07-04T15:23:35Z No. of bitstreams: 1 adrianaaparecidaferreira.pdf: 5164701 bytes, checksum: 1c0b93b046c9e7e8edf2355486901a90 (MD5) / Approved for entry into archive by Adriana Oliveira (adriana.oliveira@ufjf.edu.br) on 2016-07-13T16:20:14Z (GMT) No. of bitstreams: 1 adrianaaparecidaferreira.pdf: 5164701 bytes, checksum: 1c0b93b046c9e7e8edf2355486901a90 (MD5) / Made available in DSpace on 2016-07-13T16:20:14Z (GMT). No. of bitstreams: 1 adrianaaparecidaferreira.pdf: 5164701 bytes, checksum: 1c0b93b046c9e7e8edf2355486901a90 (MD5) Previous issue date: 2012-03-19 / A hemofilia é uma condição potencialmente incapacitante, cujo tratamento está associado a elevados custos financeiros. Os portadores dessa coagulopatia apresentam alta carga de morbidade devido ao desenvolvimento precoce de artropatia hemofílica. A avaliação da qualidade de vida relacionada à saúde representa as perspectivas do paciente sobre o impacto causado em sua vida pela doença e pelo tratamento. O objetivo do presente estudo foi mensurar a qualidade de vida relacionada à saúde em portadores de hemofilia e identificar fatores clínicos, demográficos e socioeconômicos associados. De caráter observacional e delineamento transversal, a pesquisa avaliou 39 portadores de hemofilia entre maio e novembro de 2011. Foram incluídos pacientes do sexo masculino, com idade maior ou igual a 18 anos e diagnóstico de hemofilia congênita, cujo tratamento de demanda estivesse vinculado ao Hemocentro de Juiz de Fora. Foram aplicados o Haem-A-QoL, questionário específico e validado para a avaliação da qualidade de vida relacionada à saúde e um questionário semiestruturado para obtenção de dados socioeconômicos e autoavaliação de saúde. Os dados clínicos, assim como registros de alterações ortopédicas estruturais e funcionais avaliadas através da Escala de Exame Físico da Federação Mundial de Hemofilia (WFH-PE) e do Escore de Independência Funcional em Hemofilia (FISH), respectivamente, foram obtidos dos prontuários médicos. Os dados foram processados em banco de dados criado por meio do software Statistical Package for the Social Sciences (SPSS), versão 15.0, sendo o nível de significância do estudo de 5%. A correlação de Spearman foi utilizada entre os escores WFH-PE, FISH e Haem-A-QoL. Na análise bivariada, foram utilizados os testes U de Mann-Whitney e Kruskal-Wallis para verificar a associação de cada variável independente com o escore de qualidade de vida relacionada à saúde. Uma análise de regressão linear múltipla foi conduzida para estimar o nível de significância para cada variável, com a utilização do método backward de eliminação de variáveis, em que as variáveis com p < 0,10 foram retidas. A média do Haem-A-QoL foi 35,55. Os domínios mais prejudicados entre portadores de hemofilia grave ou moderada foram “Esportes e lazer” e “Saúde física” e o domínio que apresentou menor comprometimento foi “Relacionamentos e sexualidade”. Entre portadores da forma leve da coagulopatia, o pior desempenho foi na dimensão “Enfrentamento”. A prevalência de artropatia foi alta (69,2%), enquanto a realização de fisioterapia foi baixa (20,5%). A média da Escala de Exame Físico foi 16,87 e a média do escore de independência funcional foi 25,64. Não houve diferença estatisticamente significativa entre a média do Haem-A-QoL dos portadores de hemofilia grave e dos portadores de hemofilia moderada (14,67 versus 17,25, p = 0,42), assim como entre a média dos escores WFH-PE (15,47 versus 16,50, p = 0,75) e FISH (16,37 versus 15,66, p = 0,82). Ambas as escalas, WFH-PE e FISH, apresentaram boa correlação com o escore de qualidade de vida relacionada à saúde dos pacientes (r = 0,634, p < 0,001 e r = - 0,623, p < 0,001, respectivamente). Acredita-se ser possível melhorar a qualidade de vida relacionada à saúde dos portadores de hemofilia a partir de investimentos na prevenção de lesões articulares e em medidas de reabilitação. / Hemophilia is a potentially disabling condition associated with high financial costs. Patients with hemophilia have a high burden of morbidity due to early development of hemophilic arthropathy. The health-related quality of life (HRQoL) assessment reflects the patient perspectives of disease and its consequences as well as of treatment. The aims of this study were to measure HRQoL values in patients with hemophilia using the Brazilian version of the Haem-A-QoL questionnaire and to identify clinical, demographic and socioeconomic factors associated with HRQoL. In this cross-section study, 39 patients were evaluated between May and November 2011. Enrollment criteria included men aged 18 years and over, level of clotting factor VIII or IX less than 30% and on-demand treatment performed at the Juiz de Fora Blood Center. All patients were asked to complete the Haem-A-QoL and to answer a self-rated health question. Socioeconomic data were obtained through a semi-structured interview. Clinical data and reports of orthopedic changes, measured by the instruments World Federation of Hemophilia – Physical Examination (WFHPE) and the Functional Independence Score in Haemophilia (FISH), were obtained from medical records. Data analysis was made using the software Statistical Package for the Social Sciences (SPSS, v.15.0), being the study significance level of 5%. Bivariate associations between the outcome and independent variables were examined by Kruskal-Wallis test or Mann-Whitney U test, and Spearman rank correlations where appropriate. Multiple linear regression analysis of significant variables was conducted. A backward stepwise method of variable elimination was used, wherein the variables with p < 0.10 were retained. Mean Haem-A-QoL scores was 35.55. The patients had more impaired scores in dimensions of “sports and leisure” and “physical health” and the dimension of “relationship and partnership” was the less impaired. Among patients with mild hemophilia, the dimension of “dealing” had the worst score. The prevalence of arthropathy was high (69.2%) although few patients had received physiotherapy treatment (20.5%). Mean WFH-PE scores was 16.87 and mean FISH was 25.64. There was no statistically significant difference between the mean Haem-A-QoL scores of patients with severe or moderate hemophilia (14.67 versus 17.25, p = 0.42), as well as the mean WFH-PE scores (15.47 versus 16.50, p = 0.75) and the mean FISH scores (16.37 versus 15.66, p = 0.82). There was a moderate positive correlation between the WFH-PE and the Haem-A-QoL scores and a moderate negative correlation between the FISH and the Haem-A-QoL scores (r = 0.634, p < 0.001 e r = - 0.623, p < 0.001, respectively). Therefore, joint injury prevention and rehabilitation measures may improve HRQoL of patients with hemophilia.

L’apparition d’une réponse immunitaire contre le Facteur VIII (FVIII) de la coagulation est une complication majeur qui survient chez 30% des hémophile A sévères. Bien que des avancées importantes aient abouti au développement de nouvelles molécules de FVIII thérapeutiques, les mécanismes conduisant à l’apparition d’une réponse immunitaire anti-FVIII restent non élucidés. Des facteurs de risques génétiques et environnementaux ont été identifiés ou suggérés, mais une compréhension complète des processus immunologiques permettant l’initiation de cette réponse au dépend de l’induction de tolérance immune chez 30% des patients restent incomprise. Ma thèse porte sur les aspects fonctionnels et structurels du FVIII et leur rôle dans l’initiation de la réponse immunitaire anti-FVIII chez le modèle murin hémophile A. Le premier rôle du FVIII est sa participation à la cascade de la coagulation, et donc la première partie de ma thèse adresse le rôle du processus de coagulation dans l’initiation de la réponse immunitaire anti-FVIII. La seconde partie de ma thèse se concentre sur l’importance des résidus du domaine C2 impliqué dans la liaison aux phospholipides dans l’endocytose et la présentation du FVIII par les cellules présentatrices de l’antigène in vitro et discute de leur relevance in vivo. / Immunogenicity of Factor VIII (FVIII) is a major hurdle that affects about 30% of severe hemophilia A patients. Though a significant advancement has been accomplished in the development of newer FVIII molecules, the factors that drive FVIII immune responses remain elusive. Many genetic and environmental risk factors have been identified or suggested but a complete understanding of the immunological basis for the antibody formation and the mechanism(s) behind tolerance induction, in the 30% of the patients that never develop anti-FVIII antibodies, are not understood. My thesis involves overlapping aspects important for initiation of an anti-FVIII immune response in a mouse model of hemophilia A. The primary role of FVIII is its participation in coagulation-associated events and thus, the first part of my thesis addresses whether coagulation events per se are implicated in the initiation of anti-FVIII immune responses. The second part of my thesis focuses on the importance of the membrane binding residues within the C2 domain of FVIII in antigen uptake and presentation by antigen presenting cells in vitro and discusses its relevance in vivo.

L’hémophilie A est une maladie hémorragique rare liée au chromosome X qui se traduit par un déficit en facteur VIII (FVIII) fonctionnel. Chez les patients atteints de la forme sévère de l’hémophilie A, l’apparition d’hémorragies incontrôlées augmente la morbidité et affecte leur qualité de vie. Le traitement de choix permettant de prévenir ou de traiter les saignements consiste en l’injection intraveineuse de FVIII thérapeutique. Cependant, chez 5 à 30% des patients, une réponse immunitaire dirigée contre le FVIII se développe. La réponse anti-FVIII est caractérisée par l’apparition d’anticorps qui inhibent l’activité pro-coagulante du FVIII. Ainsi l’apparition de ces anticorps, appelés « inhibiteurs » représente-t-elle la complication majeure du traitement des patients hémophiles A. Plusieurs facteurs de risque ont été suggérés ou proposés comme affectant le développement de la réponse anti-FVIII. Parmi eux, supporté par la théorie du « danger », la présence de médiateurs pro-inflammatoires générés par les épisodes de saignement est considérée comme adjuvant dans la réponse immunitaire anti-FVIII. Cependant, les saignements induisent de nombreux mécanismes pro mais aussi anti-inflammatoires. Ainsi, l’activation de l’endothélium vasculaire induit-elle le recrutement et l’activation des cellules effectrices appartenant aux compartiments innés et adaptatifs du système immunitaire. Au cours de ma thèse, je me suis concentré sur le rôle des saignements dans le développement de la réponse immunitaire dirigée contre le FVIII. Ainsi, ai-je découvert une association entre la présence d’un polymorphisme dans un gène induit par les saignements et la présence d’inhibiteurs du FVIII dans une cohorte de patients hémophiles A sévères. J’ai également étudié le développement de la réponse immunitaire dirigée contre le FVIII thérapeutique dans un modèle murin qui mime les saignements locaux observés chez les patients hémophiles A sévères. Finalement, j’ai caractérisé l’effet des formes réactives de l’oxygène (FRO), qui sont générées au niveau du site de saignement, sur la structure, la fonction et l’immunogénicité du FVIII. Les résultats obtenus au cours de ma thèse démontrent que les saignements ne sont pas associés à un risque plus élevé de développer des inhibiteurs dans le modèle murin largement utilisé d’hémophilie A sévère, contrairement à ce qui est communément admis. De plus, j’ai démontré une association entre un polymorphisme présent dans le promoteur du gène HMOX1 et la survenue d’inhibiteurs dans une cohorte de patients atteints d’hémophilie A sévère. En parallèle, je décris pour la première fois une altération du statut oxydatif chez les souris déficientes en FVIII et je démontre que le contrôle du statut oxydatif in vivo permet de moduler la réponse immunitaire anti-FVIII. Au contraire, l’exposition du FVIII aux FRO augmente son immunogénicité. De fait, mes résultats suggèrent que, bien que les molécules pro-inflammatoires libérées suite aux saignements puissent affecter positivement la réponse immunitaire dirigée contre le FVIII, de puissants médiateurs anti-inflammatoires sont générés in vivo et amenuisent l’effet potentiellement adjuvant des saignements. Également, ces résultats soulignent la balance complexe entre les médiateurs pro- et anti-inflammatoires qui sont générés consécutivement aux saignements ainsi que leurs effets sur la réponse immunitaire dirigée contre le FVIII thérapeutique. / Hemophilia A is a rare X-linked hemorrhagic disease consecutive to the lack of functional pro-coagulant factor VIII (FVIII). In patients with the severe form of hemophilia A, uncontrolled hemorrhages increase the morbidity and affect the quality of life. To prevent or treat bleeding episodes, therapeutic FVIII is administered intravenously. However, an anti-FVIII immune response develops in 5 to 30% of the patients. The anti-FVIII immune response is characterized by the development of anti-FVIII IgG antibodies that inhibit FVIII activity. These antibodies, referred to as “FVIII inhibitors” represent the major complication in the treatment of hemophilia A patients. Several risk factors have been suggested or proposed to predispose to the development of FVIII inhibitors. Amongst them, inspired by the “danger” theory, the presence of inflammatory mediators released upon bleeding episodes is thought to adjuvant the anti-FVIII immune response. Bleeding episodes trigger several pro and anti-inflammatory mechanisms. Thus, damage to the endothelium triggers the recruitment and activation of effector cells from the innate and adaptive compartments of the immune system. During my PhD, I investigated the role of bleedings in the development of the anti-FVIII immune response. Thus, I discovered an association between a polymorphism in the promoter region of a gene that is induced in response to bleedings, and the presence of FVIII inhibitors in a cohort of patients with severe hemophilia A. I followed the development of the immune response to therapeutic FVIII in a mouse model that mimics the localized bleedings found in patients with severe hemophilia A. Ultimately, I characterized the effects of reactive oxygen species (ROS) that are potentially released at the bleeding site in view of the structure, function and immunogenicity of the FVIII molecule. The results I obtained during my PhD demonstrate that bleedings are not associated with a higher risk for FVIII inhibitor development in the commonly used mouse model of severe FVIII deficiency. Additionally, I demonstrated an association between a polymorphism in the promoter of the HMOX1 gene and the presence of FVIII inhibitors. In parallel, I report for the first time an exacerbated oxidative status in FVIII-deficient mice as compared to control mice, and demonstrate that the control of the oxidative status in vivo reduces the anti-FVIII immune response. Conversely, the exposure of FVIII to ROS ex vivo increases the immunogenicity of the FVIII molecule. Taken together, my results suggest that, although the pro-inflammatory molecules released upon bleeding may positively affect the anti-FVIII immune response, several strong anti-inflammatory compounds are generated in vivo that dampen the potential adjuvant effect of bleedings. Ultimately, these results highlight the complex balance between the pro and anti-inflammatory mediators generated upon bleeding and their effect on the anti-FVIII immune response.

Orientadores: Marcos Augusto Francisco Borges, Regina Lúcia de Oliveira Moraes / Dissertação (mestrado) - Universidade Estadual de Campinas, Faculdade de Tecnologia / Made available in DSpace on 2018-08-22T02:03:37Z (GMT). No. of bitstreams: 1 Matsunaga_RobertaMayumi_M.pdf: 3732769 bytes, checksum: 7473b0451c343a4a40d122deb213a2eb (MD5) Previous issue date: 2013 / Resumo: De acordo com o último levantamento do Ministério da Saúde, o número de indivíduos com hemofilia cadastrados no Brasil era de 9.978 em 2010 (Ministério da Saúde, 2013), o que torna o Brasil o país com o terceiro maior número de indivíduos identificados com doença. Sendo a hemofilia uma doença que acomete o indivíduo desde o nascimento, é fundamental que a criança conheça suas limitações para ter um desenvolvimento físico saudável. Isso requer cuidados especiais a fim de evitar episódios de traumatismos que podem comprometê-la quando adulta. As crianças com hemofilia carecem de material educativo de qualidade sobre a doença e suas problemáticas. Com o intuito de informar essas crianças de forma lúdica e motivadora, o presente trabalho propõe o desenvolvimento do protótipo de um jogo educativo, denominado Hemotion, que contém informações sobre a doença. A intenção é que o jogo seja um meio lúdico de informar, esclarecer e incentivar comportamentos adequados das crianças em relação à doença que irão enfrentar por toda a vida. Trata-se de um Projeto multidisciplinar que foi desenvolvido no Laboratório de Informática, Aprendizagem e Gestão da Faculdade de Tecnologia (LIAG-FT) em conjunto com a Unidade de Hemofilia do Hemocentro, ambos da Universidade Estadual de Campinas (UNICAMP). Os desenvolvedores contam com o apoio da equipe multidisciplinar do Hemocentro, que é composta por médicos, fisioterapeutas, enfermeiros, pedagogos e psicólogos / Abstract: The Ministério da Saúde published that in Brazil there are around 9.978 people with hemophilia in the country is the third with the largest number of individuals with this disease. Hemophilia is a disease that affects the individual from birth, so it is fundamental that the child learns his limitation in order to have a healthy physical development. This requires special care to avoid episodes of trauma that may compromise the child as an adult. However, children who suffer from hemophilia do not have quality educational material on hemophilia and it's problematic. In order to inform these children in a ludic and motivating way, this project aims to develop a prototype of an educational game, called Hemotion that will have information about the disease. The intention is that the works in an entertaining way to inform enlighten and encourage appropriate behaviors of children in relation to the disease they will face throughout life. It is a multidisciplinary project that was developed in the Laboratório de Informática, Aprendizagem e Gestão da Faculdade de Tecnologia together with the a Unidade de Hemofilia do Hemocentro, both from the Universidade de Campinas. To support the project, the developers will have the assistance of the multidisciplinary team of the Hemocentro that is composed by doctors, physiotherapists, nurses, educators and psychologists / Mestrado / Tecnologia e Inovação / Mestre em Tecnologia

O fator VIII da coagulação é utilizado para o tratamento da hemofilia A e pode ser obtido a partir de concentrados do plasma humano ou na sua forma recombinante (rFVIII). Nosso laboratório tem explorado uma alternativa mais eficiente para a produção do rFVIII em células de mamíferos, utilizando um variante artificial do rFVIII humano (rFVIII-lab). O objetivo principal deste trabalho foi avaliar a imunogenicidade do rFVIII-lab utilizando camundongos modelo da hemofilia A, tendo como objetivos experimentais a purificação, caracterização de atividade funcional in vivo e caracterização de imunogenicidade do rFVIII-lab comparada a produtos de referência, um derivado de plasma e outro recombinante. Os resultados indicam que o perfil de imunogenicidade observado para o rFVIII-lab foi menos intenso e a atividade funcional observada foi similar quando comparado aos produtos de referência. A expectativa é que o presente estudo contribua para o estabelecimento de uma plataforma de produção do rFVIII no país visando o tratamento dos pacientes hemofílicos brasileiros. / Factor VIII (FVIII) replacement therapy employing either FVIII concentrates from blood plasma or recombinant FVIII is the standard of care for management of hemophilia A. Our group has been exploring a more efficient alternative for recombinant FVIII production in mammalian cells employing an engineered artificial variant of the protein (rFVIII-lab). The main objective of this study was to evaluate the immunogenicity of the rFVIII-lab using a murine model of hemophilia A and the specific experimental objectives were to purify, evaluate the in vivo functional activity and the immunogenicity of rFVIII-lab compared to plasma derived and recombinant reference products. Data revealed reduced immunogenicity of rFVIII-lab whereas functional activity was similar when compared to the reference products. The presented study is expected to contribute to the establishment of a locally production platform for the rFVIII aiming at the treatment of Brazilian hemophilic patients.

Indiana University-Purdue University Indianapolis (IUPUI) / The letters Ryan White received over the course of his diagnosis, illness, and eventual death show a spatial distribution that reflected the United States’ response to Ryan’s condition. Ryan was diagnosed with AIDS in December of 1984 at the height of the epidemic, and the panic that surrounded it. In 2000, the Children’s Museum of Indianapolis accessioned a selection of letters sent to Ryan White and his mother, from 1980 to 1993. The expanded incorporation of these letters into the museum’s “Power of Children” gallery will introduce museum visitors to the public view on Ryan and the role he played in developing the public perception and awareness of AIDS in the 1980’s. Originally, it was anticipated that the distribution and number of letters Ryan received directly related to the concentration and spread of AIDS cases around the US. This research assumed that the AIDS community would have been more supportive and empathetic of Ryan’s diagnosis, resulting in those populations sending a higher number of letters. This assumption was also informed by the fact that the highest number of AIDS cases were in areas with large populations such as New York City, Los Angeles, and Miami. Yet findings showed relatively few letters were coming from the populated coasts where AIDS was more prevalent, and many more letters than expected came from areas with lower populations across the US. Ryan was one of the first children to go public with his AIDS diagnosis, which sparked strong reactions among people throughout the United States. Ryan’s correspondence and the outpouring of support he received allows insight into the multifaceted reaction to the AIDS crisis, especially from young people. Before Ryan became associated with the AIDS epidemic, this disease was seen primarily as an urban, gay, and drug-user related issue. The goal of this research is to gain further understanding of society’s shifting response to Ryan and AIDS during the 1980’s, by placing these letters in their social and geographic context.

A tool allowing the prediction of the risk of bleeding in patients with hemophilia would be relevant for patients, stakeholders, and policymakers. We performed a systematic review of the literature searching for available risk assessment models to predict the risk of bleeding in people living with hemophilia, and to determine the key risk factors that the ideal model should include. We also systematically review the literature to determine the acceptability and accuracy of wrist-wearable devices to measure physical activity in the general population. Finally, we validated the performance of a risk assessment model for the prediction of the risk for bleeding in people living with hemophilia. We identified the following risk factors for bleeding in people living with hemophilia: plasma factor levels, history of bleeds, physical activity, antithrombotic treatment, and obesity. The FitBit Charge and FitBit Charge HR are the most accurate devices for measuring steps, and the Apple Watch is the most accurate for measuring heart rate. No device proved to be accurate in measuring energy expenditure. The predictive accuracy of the risk assessment model that we validated does not endorse its use to drive decision making on treatment strategies based on the predicted number of bleeds. This might in part be explained by the methods used in the derivation phase. The need for an accurate risk assessment model to predict the risk of bleeding in people living with hemophilia is still unmet. This should be done by including the relevant risk factors identified through our work, with data on physical activity possibly collected using an accurate wrist-wearable device, and through the application of rigorous methods in the derivation and validation phases. / Thesis / Doctor of Philosophy (PhD) / People living with hemophilia lack a coagulation factor and tend to experience spontaneous bleeds, with frequency and intensity that vary between individuals. Predicting who will experience more bleeds would allow for changing the treatment strategies and directing the best resources to the persons that can benefit more. Through this project, we identified the variables that should be considered to estimate the risk for bleeding in people living with hemophilia, namely the blood levels of the lacking coagulation factor, the bleeding history, the physical activity levels, the concomitant treatment with blood thinners, and the presence of obesity. We determined that Fitbit Charge and Charge HR are the most accurate devices for measuring steps and Apple Watch for heart rate. Lastly, we found that an existing tool for predicting the risk of bleeding is not accurate enough to be used in this setting, and a new model should be produced.

No description available.

<p>Hemophilia A and B are X-linked recessive bleeding disorders caused by the deficiency of coagulation factor VIII (FVIII) and Factor IX (FIX), respectively. Current treatment involves life-long protein replacement therapy which is invasive, expensive and inaccessible to the majority of hemophiliacs worldwide. Treatment is further compromised by the development of neutralizing antibodies. Thus, the development of an alternative treatment that is safer, cost effective and non-invasive that circumvents immune response induction is desirable.</p> <p>To this end, a chitosan-mediated gene therapy strategy delivered orally was developed to provide clinically relevant plasma expression of FVIII or FIX. Hemophilia A mice that ingested chitosan nanoparticles containing FVIII DNA transiently expressed canine FVIII reaching >100 mU one day post treatment, together with partial phenotypic correction. Residual FVIII activity was detected for several days. Repeated administration of nanoparticles restored FVIII expression for 4 weeks and reduced clotting time in treated mice. Interestingly, inhibitors and non-neutralizing antibodies were not detectable throughout the experiment.</p> <p>The immunomodulatory effects of chitosan-mediated oral gene delivery was investigated in naive hemophilia A mice and mice with pre-existing inhibitors. Administration of nanoparticles containing human FVIII DNA in naive mice suppressed systemic antibody responses and provided long-term tolerance to rhFVIII protein immunizations for at least 8 weeks. This tolerance was transferable to naive mice, suggesting development of regulatory T cells. In contrast, repeated oral nanoparticle administration was unable to suppress FVIII-specific antibody responses in hemophilia A mice with pre-existing inhibitors.</p> <p>Treatment of hemophilia B is challenged by a 25-50 fold higher therapeutic threshold. Nevertheless, hemophilia B mice fed chitosan nanoparticles containing CpG-FIXi plasmid transiently expressed therapeutically relevant human FIX >14mU/mL plasma.</p> <p>Chitosan nanoparticle formulation was optimized <em>in vitro</em> for improved transfection efficiency. Nanoparticles formulated at a chitosan:DNA charge ratio of >2:1 (N:P) provided DNA protection against proton and enzymatic degradation that mimic conditions of the stomach and intestine, respectively. The inclusion of 25 mM sodium acetate-acetic acid decreased transfection of HEK 293 cells 4-fold, while 50 mM sodium sulphate increased uptake by ~40%. Optimal transfection was achieved with chitosan chloride (CL 213) formulated at a charge ratio of 3:1 in 50 mM sodium sulphate.</p> <p>These findings suggest chitosan nanoparticles can provide clinically relevant FVIII and FIX transgene expression, which is amenable to a one-tablet-a-day dosing strategy. Taken together, chitosan-mediate gene therapy delivered orally is proposed as a potential non-invasive alternative strategy for hemophilia treatment and without inducing neutralizing and non-neutralizing antibody production.</p> / Doctor of Philosophy (PhD)

<p>The work presented in this thesis was focused on design and construction of novel cell-loaded microcapsules by incorporation of bioactive molecules (proteins or peptides) for potential application in hemophilia B treatment. The objective of this study was to improve the viability and functionality of the encapsulated cells by creating biomimetic microenvironments for cells that more closely mimic their physiological extracellular matrix (ECM) environment.</p> <p>Three cell-adhesive molecules were used in this work: fibrinogen and fibronectin, two abundant proteins present in ECM, and arginine-glycine-aspartic acid (RGD) tri-peptide, the minimal essential cell adhesion peptide sequence and the most widely studied peptide for cell adhesion. Alginate, the most commonly used biomaterial used for cell encapsulation, was combined with either of these molecules to create biomimetic microcapsules. Non-modified alginate (control) and modified alginate matrices were used to encapsulate the factor IX (FIX) secreting cells for protein delivery. In this work, FIX-engineered cord blood-derived human mesenchymal stem cells CB MSCs were used as a cell source for FIX delivery.</p> <p>Our data suggested that fibrinogen-alginate, fibronectin-alginate and RGD-alginate microcapsules improved the viability of encapsulated MSC and are applicable in cell therapy technologies. However, fibrinogen-alginate and fibronectin-alginate microcapsules more significantly enhanced the proliferation and protein secretion from the encapsulated cells and may have potential for FIX delivery for hemophilia B and other inherited or acquired protein deficiencies. RGD-alginate microcapsules can v potentially be used for other tissue engineering applications with the aim of enhanced viability and attachment of the enclosed cells. Differentiation studies showed the osteogenic (but not chondrogenic or adipogenic) differentiation capability of FIX-engineered CB MSCs and their efficient FIX secretion while encapsulated in fibrinogen-alginate and fibronectin-alginate microcapsules.</p> / Doctor of Philosophy (PhD)