BIOENGINEERING APPROACHES FOR IMPROVED DIFFERENTIATION OF CULTURED RETINAL TISSUES FROM PLURIPOTENT STEM CELLS

BIOENGINEERING APPROACHES FOR IMPROVED DIFFERENTIATION OF CULTURED RETINAL TISSUES FROM PLURIPOTENT STEM CELLS

Author: Michael Phelan

Publisher:

Published: 2021

Total Pages: 237

ISBN-13:

DOWNLOAD EBOOK

Sight is the most powerful of all human senses. For the vast majority of people on Earth, the loss of that sense would be unimaginable. Without assistive technology, it would separate them from their ability to work, their ability to travel, and their ability to interact with their loved ones. And yet, this extraordinary process, carefully refined by billions of years of evolution, is threatened for millions of people all over the world from a wide array of diseases of the retina. Many of these diseases arise from malnutrition and infection and are being rapidly eradicated. However, many dozens more result from convoluted permutations of genetics, age, and diet that threaten blindness for millions more with little hope of treatment, even with the best of modern medicine. As our life expectancies extend and our population ages, these diseases will only become more prevalent. In humanity's ever-present pursuit of medicine and knowledge to improve our quality of life, cutting-edge treatments offer promise that one day soon, even these diseases may be eradicated. One key technology capable of treating these devastating illnesses, on the precipice of being translated to real-world clinical treatments, is pluripotent stem cell-derived therapies. Patient-specific pluripotent stem cells, meaning pluripotent stem cells sourced directly from the patient, have a wealth of applications ranging from drug identification to disease modeling to implantation and regeneration. This research has been developed and advanced remarkably in the approximately two decades since the early isolation of pluripotent stem cells. Naturally, this advancement has predominantly been focused on cell and molecular biology. However, this focus has left significant research questions to be answered from engineering perspectives across a wide latitude of sub-disciplines. This dissertation explores three independent avenues of engineering principles as they relate to improving 2D and 3D retinal tissues derived from pluripotent stem cells in materials, devices, and computation. The first aim explores how plant protein-based nanofibrous scaffolds can marry the advantages and minimize the disadvantages of synthetic and animal-derived scaffolds for the culture of 2D retinal pigment epithelium (RPE) constructs. The second aim describes the development and testing of a novel, perfusing rotating wall vessel (RWV) bioreactor to support culture of 3D retinal organoids. Finally, the third aim performs a meta-analysis of published RNA-Seq datasets to determine the precise mechanisms by which bioreactors support organoid growth and extrapolate how these conclusions can support future experiments.


Retinal Degenerative Diseases

Retinal Degenerative Diseases

Author: Matthew M. LaVail

Publisher: Springer Science & Business Media

Published: 2011-12-21

Total Pages: 867

ISBN-13: 1461406315

DOWNLOAD EBOOK

This book will contain the proceedings of the XIV International Symposium on Retinal Degeneration (RD2010), held July 13-17, 2010, in Mont-Tremblant, Quebec, Canada. The volume will present representative state-of-the-art research in almost all areas of retinal degenerations, ranging from cytopathologic, physiologic, diagnostic and clinical aspects; animal models; mechanisms of cell death; candidate genes, cloning, mapping and other aspects of molecular genetics; and developing potential therapeutic measures such as gene therapy and neuroprotective agents for potential pharmaceutical therapy.


Retinal Differentiation of Pluripotent Stem Cells

Retinal Differentiation of Pluripotent Stem Cells

Author: Debarchana Sarkar

Publisher:

Published: 2017-01-26

Total Pages:

ISBN-13: 9781360998589

DOWNLOAD EBOOK

This dissertation, "Retinal Differentiation of Pluripotent Stem Cells" by Debarchana, Sarkar, was obtained from The University of Hong Kong (Pokfulam, Hong Kong) and is being sold pursuant to Creative Commons: Attribution 3.0 Hong Kong License. The content of this dissertation has not been altered in any way. We have altered the formatting in order to facilitate the ease of printing and reading of the dissertation. All rights not granted by the above license are retained by the author. Abstract: The retina is an internal photosensitive neural tunic which absorbs light and prevents it from reflecting back. The light receptors and neurons of the retina are initial processor of visual information. Various anomalies of the retina such as retinitis pigmentosa, cone-rod dystrophy to retinal degenerative diseases cause severe loss of vision since they affect photoreceptors directly or indirectly. Conventional therapies have never been fully successful in restoring vision in such diseases. However current research in stem cell therapies has shown remarkable potential. In this project, induced pluripotent stem cells from mouse were coxed into photoreceptor fate in presence and absence of Dorsomorphin using specific media in a stepwise differentiation process. Dorsomorphin is an inhibitor of Bone Morphogenic Protein (BMP) whose suppression may influence neural differentiation. Studies were done using conventional inverted microscopy and fluorescent microscopy on mouse induced pluripotent stem cells (miPS cells). Immunolabelling techniques involving Pax6, Crx, RPE65, Rhodopsin and Opsin were used to evaluate the advantage of these as markers for stem cells differentiation. Reverse Transcriptase PCR was done to confirm the gene expression on the differentiated cells. Human iPS derived Mesenchymal stem cells were cultured and the effect of different concentrations of Retinoic Acid such as 0mM, 0.1mM and 0.5mM on cell proliferation was tested in both presence and absence of Dorsomorphin. The results revealed both control and Dorsomorphin treated miPS cells successfully differentiated into photoreceptors-like cells as detected by positive staining of Rhodopsin and Opsin. The cells were however negative for Pax6, and very weak staining for RPE and Crx. The presence or absence of Dorsomorphin did not make any difference on miPS differentiation. The same observation was made on differentiating human iPS-MSC where Dorsomorphin did not reveal much effect. However highest cell count of proliferating cells was observed in the subgroups containing 0.1mM Retinoic Acid on Day7 groups as control had an average of 590 317.23 and treatment 1206 .33 114.99 cells, with statistical significance of PIn conclusion, the study reveals that iPS can be another potential stem cell source for therapies of retinal diseases involving photoreceptors where the question of ethical issue is not a problem unlike embryonic stem cells. Also it reveals the concentration of Retinoic Acid most suited for human iPS-MSC cell proliferation. Dorsomorphin did not seem to have much effect on either type of stem cells in terms of promoting photoreceptor differentiation. DOI: 10.5353/th_b5071270 Subjects: Retina - Differentiation Stem cells


Human Embryonic Stem Cells

Human Embryonic Stem Cells

Author: Jon Odorico

Publisher: Garland Science

Published: 2004-02-01

Total Pages: 391

ISBN-13: 0203487346

DOWNLOAD EBOOK

Since the first successful isolation and cultivation of human embryonic stem cells at the University of Wisconsin, Madison in 1998, there has been high levels of both interest and controversy in this area of research. This book provides a concise overview of an exciting field, covering the characteristics of both human embryonic stem cells and pluripotent stem cells from other human cell lineages. The following chapters describe state-of-the-art differentiation and characterization of specific ectoderm, mesoderm and endoderm-derived lineages from human embryonic stem cells, emphasizing how these can be used to study human developmental mechanisms. A further chapter discusses genetic manipulation of human ES cells. The concluding section covers therapeutic applications of human ES cells, as well as addressing the ethical and legal issues that this research have raised.


Towards an in Vitro Model for Age-related Macular Degeneration

Towards an in Vitro Model for Age-related Macular Degeneration

Author: Lena Mesch

Publisher:

Published: 2021

Total Pages: 0

ISBN-13:

DOWNLOAD EBOOK

The human retina is a complex tissue within the human eye and essential for the sense of sight. Retinal diseases, such as age-related macular degeneration (AMD) or retinitis pigmentosa (RP) affect or destroy the sense of vision and impair the quality of life of patients drastically. As currently for many retinal diseases there are only few, or no treatment options available and animal models recapitulate the pathology of those diseases poorly. Therefore, adequate in vitro models of the human retina and the supporting retinal pigment epithelium (RPE) are urgently required. In AMD, pathological changes do not exclusively involve cells of the neural retina, but initial disease manifestation takes place within the retinal pigment epithelium (RPE) and its near surroundings. Therefore, various protocols for the differentiation of RPE cells from human pluripotent stem cells (hPSCs) have been developed in recent years, showing the generation of mature and functional RPE cells. In this thesis, two distinct approaches for the differentiation of hiPSC-RPE have been applied and were subsequently investigated for several essential characteristics of RPE cells. These essential RPE hallmarks included molecular characteristics, pigmentation, and morphology. Overall analysis demonstrated that both approaches equivalently generated RPE cells of good quality. Nevertheless, RPE cells which are cultured on plastic surfaces in 2D pose several disadvantages, as those conditions promote e.g. transdifferentiation or detachment from the culture plate. Consequently, long-term cultivation over several month to years remains difficult. In this thesis, those drawbacks were aimed to overcome by implementing a novel three-dimensional RPE organoid (RPEorg) approach. RPE organoids were differentiated simultaneously with retinal organoids and cultured for more than 300 days. A basic characterization of early (day 80-100), intermediate (day 191) and aged (day 280-360) RPEorg was performed by immunostainings and qRT-PCR analysis. RPEorg expressed several common RPE markers, some of them strongly increasing with age. Deeper analyses of RPEorg showed ultrastructural signs of mature RPE cells, such as apical microvilli and tight junctions, as well as melanosomes. Functionality of RPE cells comprised in RPEorg was demonstrated by phagocytosis of bovine photoreceptor outer segments (POS). Overall, maturation of RPE cells with age could be observed. As a next step, RPE organoids were investigated for age-related changes in the context for AMD. Therefore, RPEorg were stained for drusen-associated proteins, such as APOE and TIMP3, lipids and hydroxyapatite. Those data were supported by qRT-PCR analysis and showed presence and partly upregulation of several disease relevant markers with aging. Additionally, transmission electron microscopy revealed ultrastructural signs of drusen formation in aged RPEorg. To summarize, RPEorg are a suitable model for mature RPE and allows for investigations of age-associated changes related to AMD. Long-term cultivation of RPEorg enables studies of early stages of disease manifestation and drusen formation, which renders it suitable for pathomechanistic as well as drug developmental studies.


Stem Cell Regulators

Stem Cell Regulators

Author:

Publisher: Academic Press

Published: 2011-11-23

Total Pages: 523

ISBN-13: 0123860164

DOWNLOAD EBOOK

First published in 1943, Vitamins and Hormones is the longest-running serial published by Academic Press. The Editorial Board now reflects expertise in the field of hormone action, vitamin action, X-ray crystal structure, physiology and enzyme mechanisms. Under the capable and qualified editorial leadership of Dr. Gerald Litwack, Vitamins and Hormones continues to publish cutting-edge reviews of interest to endocrinologists, biochemists, nutritionists, pharmacologists, cell biologists and molecular biologists. Others interested in the structure and function of biologically active molecules like hormones and vitamins will, as always, turn to this series for comprehensive reviews by leading contributors to this and related disciplines. This volume focuses on stem cell regulators. Longest running series published by Academic Press Contributions by leading international authorities


Stem Cells and the Future of Regenerative Medicine

Stem Cells and the Future of Regenerative Medicine

Author: Institute of Medicine

Publisher: National Academies Press

Published: 2002-01-25

Total Pages: 112

ISBN-13: 0309170427

DOWNLOAD EBOOK

Recent scientific breakthroughs, celebrity patient advocates, and conflicting religious beliefs have come together to bring the state of stem cell researchâ€"specifically embryonic stem cell researchâ€"into the political crosshairs. President Bush's watershed policy statement allows federal funding for embryonic stem cell research but only on a limited number of stem cell lines. Millions of Americans could be affected by the continuing political debate among policymakers and the public. Stem Cells and the Future of Regenerative Medicine provides a deeper exploration of the biological, ethical, and funding questions prompted by the therapeutic potential of undifferentiated human cells. In terms accessible to lay readers, the book summarizes what we know about adult and embryonic stem cells and discusses how to go about the transition from mouse studies to research that has therapeutic implications for people. Perhaps most important, Stem Cells and the Future of Regenerative Medicine also provides an overview of the moral and ethical problems that arise from the use of embryonic stem cells. This timely book compares the impact of public and private research funding and discusses approaches to appropriate research oversight. Based on the insights of leading scientists, ethicists, and other authorities, the book offers authoritative recommendations regarding the use of existing stem cell lines versus new lines in research, the important role of the federal government in this field of research, and other fundamental issues.


Retinal Organoids Over the Decade

Retinal Organoids Over the Decade

Author: Zi-Bing Jin

Publisher:

Published: 2019

Total Pages: 0

ISBN-13:

DOWNLOAD EBOOK

Retinal organoids (ROs) are 3D tissue structures derived from embryonic stem cells (ESCs) or induced pluripotent stem cells (iPSCs) in vitro, which characterize the structure and function of retina to a certain extent. Since 2011, mouse and human retinal organoids have been available, opening up new avenues for retinal development, disease and regeneration research. Over the decade, great progress has been made in the development of retinal organoids, which is reflected in the improvement of differentiation efficiency and development degree. At the same time, retinal organoids also show broad application prospects, which are widely used in the construction of disease models. On this basis, the mechanism of disease, drug screening and retinal regeneration therapy have been explored. Although retinal organoids have a bright future, the deficiency of their structure and function, the limitations of differentiation and culture, and the difference compared with embryonic retina still remain to be solved.


Bioprinting in Regenerative Medicine

Bioprinting in Regenerative Medicine

Author: Kursad Turksen

Publisher: Springer

Published: 2015-09-02

Total Pages: 148

ISBN-13: 3319213865

DOWNLOAD EBOOK

This volume presents the current state of laser-assisted bioprinting, a cutting edge tissue engineering technology. Nineteen chapters discuss the most recent developments in using this technology for engineering different types of tissue. Beginning with an overview, the discussion covers bioprinting in cell viability and pattern viability, tissue microfabrication to study cell proliferation, microenvironment for controlling stem cell fate, cell differentiation, zigzag cellular tubes, cartilage tissue engineering, osteogenesis, vessel substitutes, skin tissue and much more. Because bioprinting is on its way to becoming a dominant technology in tissue-engineering, Bioprinting in Regenerative Medicine is essential reading for those researching or working in regenerative medicine, tissue engineering or translational research. Those studying or working with stem cells who are interested in the development of the field will also find the information invaluable.