The human Embryonic Stem Cells (hESCs) and human induced Pluripotent Stem Cells (hiPSCs) have offered numerous advantages including but not limited to model diseases, high-throughput drug screening, and regenerative purposes. However, the employment of monolayer cultures has not been sufficient to mimic the in vivo stem cells niche. Thus, three-dimensional suspension cultures have helped us to advance our knowledge and ease the development of the human organs’ counterparts, commonly referred as organoids. Currently, the challenge is the generation of homogenous and reproducible human Pluripotent Stem Cell (hPSC) aggregates, the basic cellular unit to derive organoids. To date, the Ultra-Low Attachment (ULA) 6-well plates have been routinary used for the hPSC aggregates formation, which mainly relies on the inhibition of the Rho-associated kinase (ROCK) pathway resulting in the enhancement of cell survival coming from cryopreserved stocks or when passaging. However, little is known in this regard when analyzing the aggregate formation of hPSCs with two widely used compounds: RevitaCellTM Supplement and Y27632. Importantly, due to the high demand required from the regenerative medicine, I aimed to upscale the hPSC aggregates production in the DASbox® Mini-Bioreactor System. In this thesis, I established protocols for the hPSC aggregates formation by using two different types of media in two platforms being the ULA 6-well plates and the DASbox® Mini-Bioreactor System. In addition, I demonstrated that monolayer confluence cultures before single cell inoculations are paramount for the formation of bona fide hPSC aggregates in healthy and X aneuploid hiPSCs, precisely two hESCs and five hiPSCs.

Avances en ingeniería de tejidos y en terapias celulares requerirán el desarrollo de un nuevo abanico de tecnologías. Estas incluirán sistemas de cultivo de líneas primarias en tres dimensiones (3D) con el fin de construir tejidos artificiales, sistemas de transducción eficientes y sistemas de regulación genética compatibles en humanos para ajustar intervenciones moleculares. Todo ello permitirá reprogramar las células animales con el objetivo de obtener fenotipos deseados y de optimizar la productividad celular.El objetivo de esta tesis es (i) estudiar y manipular las propiedades (electro) fisiológicas de los tejidos artificiales de miocardio mediante la regulación de BMP-2 para controlar y regenerar la funcionalidad cardiaca, (ii) estudiar, inducir y caracterizar los procesos de diferenciación y transdiferenciación de microtejidos adiposos y oseos mediante la sobre expresión de los genes BMP-2 y ΔFosB para tratar enfermedades relacionadas con el tejido oseo como la osteoporosis, y (iii) evaluar la productividad de los microtejidos artificiales para optimizar los procesos de producción con células animales. Por último, el objetivo es también automatizar la producción de microtejidos artificials para satisfacer las necesidades de la industria.Microtejidos libres de scaffold no solo presentan una alternativa a la ingeniería de tejidos para terapias celulares y regeneración de tejidos, sino también tienen un gran potencial en estudios celulares para aplicaciones en la industria bio-farmacéutica. Mientras en el área de investigación, los microtejidos artificiales presentan un modelo para el estudio de nuevos genes y proteínas implicadas en diferentes procesos celulares (diferenciación, proliferación, apoptosis, síntesis de proteínas, etc.), en el area de desarrollo, los microtejidos artificiales representan una herramienta para el análisis de dichos genes y proteínas por su acción terapéutica. Finalmente, una vez la proteína terapéutica ha sido identificada, los microtejidos artificiales podrían proveer un ambiente más beneficioso para la producción de proteínas terapéuticas. / Advances in tissue engineering and cell-based therapies will require the development of a range of specific technologies. These include systems for the cultivation of primary cells in three dimensions (3D) to form artificial tissues, efficient gene transduction technologies, and human-compatible gene regulation systems for adjustable molecular interventions all of which should enable the rational reprogramming of mammalian cells to achieve desired cell phenotypes, functionality, and to optimize cellular productivity. The aim of this thesis is to (i) study and modulate the (electro) physiological properties of artificial myocardial microtissues by BMP-2 regulation to control and to regenerate cardiac functionality, (ii) study, induce and characterize differentiation and transdifferentiation processes of adipose- and bone-microtissues by overexpression of BMP-2 and ΔFosB genes in order to treat bone-related diseases such as osteoporosis, and (iii) evaluate artificial microtissue productivity to optimize mammalian production processes. Finally, the purpose is also to automate artificial microtissue production in order to satisfy requirements for industrial scale applications.Scaffold-free artificial microtissues represent an alternative to existing tissue engineering strategies for cell-based therapies and tissue regeneration, as well as for cell-based biopharmaceutical applications. Within a research context, artificial microtissues could be used as a cell culture model to study/screen novel molecules/genes/proteins that are involved in different cellular processes (e.g. differentiation, proliferation, apoptosis, protein synthesis and secretion), while in a development context, artificial microtissues could be used as a tool to evaluate such target molecules/genes/proteins for their therapeutic action. Finally, once a therapeutic molecule/protein is identified, artificial microtissues may provide a more suitable or optimized environment for therapeutic protein production.

Master of Science in Biomedical Sciences / Department of Anatomy and Physiology / Mark L. Weiss / The traditional cell culture method after isolation from the body involves growing cells in 2 dimensions on plastic culture plate. However, the natural structure and physiology is 3 dimensions. To mimic in vivo environment, there has an increasing interest to find the way to maintain physiological properties. Here, we describe culturing human umbilical cord mesenchymal stromal cells (HUC-MSCs_in 3D setting using human platelet lysate gel. This gel is a fibrin-based structure like a blood clot. The preparation step of human platelet lysate (HPL) is by freeze- thaw cycles in order to release factors important for cells to grow and expand. Using of HPL to substitute for fetal bovine serum reduces potential cross contamination between species and xenogenicity. To maintain HPL media as a liquid, we add the anticoagulant heparin. Without adding anticoagulant, the gel will form. The aim of this study is to retrieve HUC-MSCs from HPL gel using Nattokinase, to characterize HUC-MSCs following the International Society for Cell Therapy’s MSC criteria, and to test a 3D invasion model with HPL-gel based structure. The result shows that using 1.75% Nattokinase at 60 minutes can recover the cells without reducing cell number and viability. After Nattokinase treatment, cells are able to attach to plastic and to increase in number. Moreover, they are able to differentiate into fat, bone, and cartilage no different from cells grown in 2D culture. However, to test surface markers by flow cytometry, all MSC markers are positive except CD 105. They are also positive of cell surface markers that should be negative. When seeded back to 2D culture for an additional passage, the MSCs meet ISCT criteria the same as control.

Master of Science / Department of Grain Science and Industry / X. Susan Sun / Human induced pluripotent stem cells (hiPSCs) are generated from human somatic cells using defined transcription factors. These cells possess characteristics very similar to that of human embryonic stem cells including the ability to differentiate into cell types of all three germ layers. HiPSCs show great potential in clinical researches like drug screening and regenerative medicine, that all require large amount of cells cultured under well-defined conditions. The most common culture methods used for hiPSCs are 2D culture methods using Matrigel or vitronectin coated culture plates or flasks. 2D culture methods require large surface area to produce the same amount of cells compared to 3D methods. In addition, cells cultured in 2D culture environment are far from that in vivo. In this study, we developed a robust 3D culture condition based on hiPSC-qualified PGmatrix (PGmatrix-hiPSC) hydrogel. This 3D culture system provide hiPSCs with well-defined, more in vivo-like environment that encapsulate cells in liquid rich hydrogel with appropriate oxygen supply that resembles the hypoxia condition in vivo. Two hiPSC lines grown continuously in PGmatrix-hiPSC showed higher total population expansion and higher viability, with more consistency compared to the same cell lines grown in 2D on Matrigel or Vitronectin-XF. After grown in 3D PGmatrix-hiPSC for over 25 passages, major pluripotency markers, such as Oct4, Sox2, Nanog, and SSEA4 are expressed in most hiPSCs examined by flow cytometry. RT-qPCR also confirmed adequate expression levels of major pluripotency related genes. In addition, karyotype analysis of hiPSC after 37 passages in 3D PGmatrix-hiPSC was found normal. The same hiPSC lines cultured continuously in parallel in 2D and 3D showed differences in gene expression and surface marker TRA-1-81 expression. These results indicated the 3D PGmatrix-hiPSC system is likely superior in maintaining hiPSC growth as well as pluripotency. The findings also suggest that it is very important to study cells in 3D culture environment to better understand the mechanism of pluripotency maintenance.

In the UK, 12,000 patients die from metastatic breast cancer annually. There is therefore an urgent need to identify the molecules that cause metastasis. Recent work has revealed a role for the RUNX family of transcription factors in the development of metastatic breast cancer. The RUNX proteins form active transcription factor complexes when bound by the heterodimeric partner CBFβ to regulate the expression of metastatic genes. Previous work from our laboratory has demonstrated that knockdown of CBFβ resulted in a decreased invasion capacity of the metastatic breast cancer cell line MDA-MB-231. Three-dimensional culture of MDA-MB-231 cells revealed that loss of CBFβ induces a mesenchymal to epithelial transition (MET). The aim of this project was to determine the role of the RUNX/CBFβ complex in maintaining the mesenchymal phenotype of metastatic breast cancer cells. The data presented show that the phenotype changes were accompanied by changes in EMT marker-gene expression, including Snai2, MMP9, and MMP13. Induction of CBFβ in the CBFβ-knockdown cells remarkably restored both the invasive capacity and the mesenchymal phenotype. Further analysis revealed that maintenance of the mesenchymal phenotype was dependent upon both CBFβ-partner proteins, RUNX1 and RUNX2. Taken together the data presented in this thesis demonstrate that RUNX/CBFβ complexes drive the epithelial to mesenchymal transition (EMT) in breast cancer cells. These findings are likely to be important in the development of potential therapies to inhibit the metastatic spread of breast cancer.

Multiple Alzheimer’s disease (AD) clinical trials target pathogenic amyloid-β (Aβ) species using therapeutic anti-Aβ antibodies. However, failures from recent clinical trials investigating passive anti-Aβ antibody immunization demonstrate a continued gap in our understanding of AD pathogenesis. Hence, there is an immediate need to develop new safe therapeutic approaches that can be applicable at an early stage of the disease. We developed superparamagnetic iron oxide nanoparticles (SPIONs) conjugated with anti-Aβ antibodies, which bind to Aβ peptides and aggregated Aβ species in vitro and in vivo. We hypothesized that acute and rapid removal of pathogenic Aβ species using our antibody-conjugated magnetic nanoparticles can block Aβ-driven pathogenic cascades, including Aβ-driven tau pathology in human neurons. To test this hypothesis, we applied our conjugated SPIONs in our 3D human neural cell culture model of AD, followed by rapid removal of SPION-Aβ complex by an external magnet force in real-time. We detected a 25% reduction in soluble and insoluble Aβ species including Thioflavin-S (ThioS) positive Aβ. We also showed that our targeted SPIONs could efficiently remove ThioS positive Aβ aggregates from 5XFAD AD mouse brain slices and frozen AD patient brain sections. More importantly, we found a 16% reduction in pathogenic phosphorylated-tau species after acute removal of Aβ species in our 3D human neural cell model. Our results demonstrate the therapeutic potential of SPION-assisted immunotherapy to acutely reduce both Aβ accumulation and tau pathology without chronic exposure to anti-Aβ antibodies that leads to amyloid-related imaging abnormality (ARIA) side effects. We next explored the in vivo application of conjugated SPIONs in a transgenic AD mouse model. We found that remote alternating magnetic field treatment at lower frequencies enhanced antibody delivery across the blood-brain barrier. We also observed increased microglial activation without inducing neuroinflammation using this methodology. Taken together, this work demonstrates proof of concept for applying nanomedicine and neurostimulation as a tool to remotely modulate AD pathology and improve cerebral AD drug bioavailability. / 2025-01-23T00:00:00Z

Ovarian cancer is the leading cause of death among female gynecologic cancers. Current treatments include surgical debulking, and chemotherapy. However, better interventions are needed to reduce the mortality rate of metastatic disease. Ovarian cancer cells have displayed the ability to aggregate and form 3D homogeneous and heterogeneous spheroids, which can function as micrometastases. Ovarian cancer spheroids survive independently prior to adhering to an endothelial tissue. Since aggregation has been shown to provide a survival advantage to the spheroids and increased their aggressive phenotype, this study aimed to investigate how the metabolism of ovarian cancer cells change in 3-dimensional (3D) culture. Examining metabolic pathways and identifying markers of metabolic change could provide the scientific base for new, targeted interventions for this disease. Spheroids of both homogeneous and heterogeneous composition demonstrated overall lower metabolic capacity than their adherent counterparts. Spheroids had a lower basal energetic demand than adherent cells, paralleled by lower maximal respiration capacity, glycolytic capacity, and spare respiratory capacity. We conclude that the lower energetic demand of spheroids may be a mechanism to prolong death by reserving energy and metabolic cellular processes; this may render anti-metabolic drug treatment with AICAR or metformin ineffective against disseminating ovarian cancer aggregates. / Master of Science / Ovarian cancer is currently the leading cause of death among female gynecologic cancers. While treatments exist, better interventions are needed to reduce the mortality rate in this form of cancer. Ovarian cancer cells have displayed the ability to aggregate and form 3D homogeneous and heterogeneous spheroids, which can function as micrometastases. Ovarian cancer spheroids survive independently prior to adhering to an endothelial tissue. Since aggregation has been shown to provide a survival advantage to the spheroids and increased their aggressive phenotype, this study aims to investigate how the metabolism of ovarian cancer cells change in 3- dimensional (3D) culture. Examining metabolic pathways and identifying markers of metabolic change could provide the scientific base for new, targeted interventions for this disease.

A endometriose é caracterizada pela presença de tecido endometrial fora do útero. No estudo, utilizou-se um sistema de co-cultivo 3D contendo células do estroma e endotélio endometrial. O sistema foi exposto ao soro de mulheres saudáveis ou com endometriose, que fazem ou não o uso de anticoncepcional. Posteriormente, foi avaliada a resposta do sistema no que diz respeito ao perfil de citocinas. Nossos resultados mostraram que o perfil sérico das mulheres com endometriose sem anticoncepcional apresentaram elevados níveis séricos de IL2 e IL10 com relação às saudáveis. Enquanto que as mulheres com endometriose, que fazem uso de anticoncepcional, apresentaram altos níveis de IL6 e IL8. O perfil de citocinas encontrado no homogenato das mulheres com endometriose induziu a produção exacerbada de IL2 e IL10 além de IFN-γ, TNF-α, IL6. Quando as células eram incubadas com soro de mulheres com endometriose que fazem tratamento, os níveis de IL6 e IL8 aumentaram. Os achados sugerem que o uso de co-cultivos 3D de células estromais e endoteliais endometriais é um bom modelo para novos estudos. / Endometriosis is characterized by the presence of endometrial tissue outside the uterus. In this study, we used a 3D co-culture system with stromal and endothelium endometrial cells. The system was exposed to serum of healthy women or with endometriosis do or not use contraceptive. Subsequently, he studied the response of endometrial cells with respect to the cytokine profile. Our results showed that the serum profile of women with endometriosis without contraceptive had high serum levels of IL2 and IL10 regarding healthy women. While women with endometriosis who use contraceptive, showed high levels of IL6 and IL8. The cytokine profile seen in homogenate of women with endometriosis induced high production of IL2 and IL10, in addition IFN-γ, TNF-α, IL6. When cells were incubated with serum from women with endometriosis under treatment, the levels of IL6 and IL8 increased. The findings suggest that the use of co-cultivation 3D stromal cells and endometrial endothelial is a good model for further studies.

Every year, 400,000 coronary artery bypasses (CABG) are performed in the United States. However, one third of all patients who need a CABG cannot undergo the procedure because of the lack of suitable autologous blood vessels. Both synthetic and tissue engineered vascular grafts have been used clinically for vascular grafts or other surgical applications, but no small- diameter engineered vessels have yet been successfully used for CABG. The success of vascular tissue engineering is strongly dependent on being able to control tissue contractility and extracellular matrix (ECM) production to achieve balance between tissue strength and physiological function. Smooth muscle cells (SMCs), the main contributor of contractility in blood vessels, retain phenotypic plasticity, meaning they possess the ability to switch between a contractile and synthetic phenotype. In 2D culture, a number of biochemical and mechanical cues have been shown to promote the switch to a contractile phenotype in SMCs. However, achieving a stable contractile phenotype in 3D tissue has proven difficult. The work in this dissertation describes an investigation of how passive and dynamic environmental cues influence the smooth muscle phenotype. We studied the effects of substrate modulus in conjunction with changes in cell culture media composition on SMC phenotype in 2D and 3D cultures. Culturing SMCs in a low-serum culture medium resulted in an increase in SMC contractility in 2D cell culture but not in 3D cell-derived tissue. We found that, in SMCs cultured on soft substrates, the ability to modulate SMC phenotype in response to changes in media was diminished. Passively crosslinking the ECM of our cell-derived tissues with genipin resulted in modest increases in elastic modulus, though not enough to observe changes in SMC phenotype. Additionally, we investigated how dynamic cyclic mechanical stretch, in conjunction with cell culture medium, modified SMC contractility in cell and tissue cultures. SMCs increased contractile protein expression when exposed to dynamic stretch in 2D culture, even on soft substrates, which have previously been shown to inhibit phenotypic modulation. In 3D tissue rings, after mechanical stimulation, SMCs became more aligned, the tissue became tougher, and SMCs exhibited a measurable increase in contractile protein expression. In summary, we found that increasing substrate modulus, culturing in low serum cell culture medium, and imparting cyclic mechanical stretch can promote SMC differentiation and cellular alignment, and improve tissue mechanical properties. This information can be used to more accurately recapitulate vascular tissue for use in modeling or in the creation of tissue engineered blood vessels.

Um dos desafios atuais da engenharia de tecidos é o desenvolvimento de biomateriais substitutos e/ou equivalentes que mimetizem o tecido normal. Os estudos empregando cultura celular em monocamada encontram limitações no que concerne às interações bidimensionais entre as células e experimentos utilizando animais, devido à elevada variabilidade, não conseguem predizer os resultados em humanos, comprometendo a sua relevância clínica. À vista disso, a cultura tridimensional de células (3D) utilizando um biomaterial fabricado para promover a proliferação e diferenciação celular tem sido utilizada para recriar a complexidade de um tecido normal, permitindo uma maior e complexa interação celular. Visando mimetizar o ambiente encontrado in vivo, este trabalho investiu no desenvolvimento de uma derme reconstituída (equivalente dérmico) in vitro utilizando como matriz biológica o colágeno, componente mais abundante da derme como suporte para os fibroblastos humanos, assim como na avaliação da fotobiomodulação com luz em 630 nm. Foi preparada uma esponja a partir do colágeno de serosa porcina 1,1% hidrolisado por 96 h. A caracterização do biomaterial foi realizada pela determinação da porosidade, do diâmetro dos poros, da absorção de fluidos e por ensaios de biocompatibilidade, uma vez que estes parâmetros são importantes para a proliferação e diferenciação celular na consequente formação do tecido in vitro. O biomaterial exibiu porosidade de 95,2%, com poros medianos de 44 &#956m estimados por porosimetria de injeção de mercúrio, além de canais com distância média entre as paredes de 78+/-14 &#956m estimado por MEV. Esses valores são considerados como ideais para um biosuporte de crescimento de fibroblastos. A absorção de água e meio de cultura foi de 95% e a esponja não apresentou citotoxicidade para a linhagem celular Vero. Adicionalmente, foi investigado o efeito de irradiação na cultura 3D com luz vermelha (dose 30 J/cm2), que mostrou fotobiomodulação na dose de 30 J/cm2 para cultura de células em monocamada e no início da fase de crescimento celular em cultura tridimensional. Por microscopia confocal, verificou-se que as células cultivadas na presença da esponja (cultura 3D), apresentaram diferenciação e secreção de matriz extracelular. Portanto, os resultados apresentados mostraram que a esponja de colágeno utilizada como biomaterial para suporte celular é eficiente para a produção de uma derme reconstituída (equivalente) in vitro e que a fotobiomodulação em 630 nm na dose de 30 J/cm2 de fato acelera o crescimento celular na matriz. / The development of biomaterials substitutes and/or equivalents to mimic normal tissue is a currently challenge in tissue engineering. Studies using cell monolayer culture presents limitations with respect to two-dimensional interactions between the cells, and experiments using animals cannot predict results in humans, due to the high viability, thus compromising their clinical relevance. In consequence, three-dimensional cell culture (3D) using a biomaterial designed to promote cell proliferation and differentiation has been used to recreate the complexity of a normal tissue, allowing a larger and complex cellular interaction. Aiming to mimic the in vivo environment, the present work refers to create a reconstituted dermis (dermal equivalent) in vitro using collagen, the most abundant component of the dermis, as biological matrix, as support for human fibroblasts, as well evaluate the photobiomodulation with light at 630 nm. First, a sponge was prepared from serous 1.1% porcine collagen hydrolyzed for 96 h. The biomaterial was characterized by determination of its porosity, pore diameter, the fluid absorption and the biocompatibility assays, since these parameters are important to the cell proliferation and differentiation resulting in the in vitro tissue formation. The biomaterial showed porosity of 95.2%, with a median pore of 44 &#956M estimated by mercury porosimetry injection, and channels with an average distance between the walls of 78+/-14 &#956M estimated by SEM. These values are considered as ideal for a biosupport fibroblast growth. The absorption of water and growth medium was 95%, and the sponge showed no cytotoxicity for the Vero cell line. Additionally, it was investigated the effect of irradiation in 3D culture with red light (dose 30 J/cm2), that showed photobiomodulation on the dose 30 J/cm2, for culturing cells in monolayer and in the early-stage of the cell growth in three-dimensional culture. By confocal microscopy, it was verified that the cells cultured in the presence of the sponge (3D culture), allows differentiation and extracellular matrix secretion. Therefore, the results showed that the collagen sponge used as a biomaterial for cell support and the photobiomodulation at 630 nm and dose of 30 J/cm2 are efficient for the production of a reconstructed dermis (equivalent) in vitro.