• International Journal of Stem Cells
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• v.17 no.1
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• pp.38-50
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• 2024

Induced pluripotent stem cell (iPSC) technology has revolutionized various fields, including stem cell research, disease modeling, and regenerative medicine. The evolution of iPSC-based models has transitioned from conventional two-dimensional systems to more physiologically relevant three-dimensional (3D) models such as spheroids and organoids. Nonetheless, there still remain challenges including limitations in creating complex 3D tissue geometry and structures, the emergence of necrotic core in existing 3D models, and limited scalability and reproducibility. 3D bioprinting has emerged as a revolutionary technology that can facilitate the development of complex 3D tissues and organs with high scalability and reproducibility. This innovative approach has the potential to effectively bridge the gap between conventional iPSC models and complex 3D tissues in vivo. This review focuses on current trends and advancements in the bioprinting of iPSCs. Specifically, it covers the fundamental concepts and techniques of bioprinting and bioink design, reviews recent progress in iPSC bioprinting research with a specific focus on bioprinting undifferentiated iPSCs, and concludes by discussing existing limitations and future prospects.

• International Journal of Stem Cells
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• v.17 no.2
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• pp.204-211
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• 2024

With recent advances in adeno-associated virus (AAV)-based gene therapy, efficacy and toxicity screening have become essential for developing gene therapeutic drugs for retinal diseases. Retinal organoids from human pluripotent stem cells (hPSCs) offer a more accessible and reproducible human test platform for evaluating AAV-based gene therapy. In this study, hPSCs were differentiated into retinal organoids composed of various types of retinal cells. The transduction efficiencies of AAV2 and AAV8, which are widely used in clinical trials of inherited retinal diseases, were analyzed using retinal organoids. These results suggest that retinal organoids derived from hPSCs serve as suitable screening platforms owing to their diverse retinal cell types and similarity to the human retina. In summary, we propose an optimal stepwise protocol that includes the generation of retinal organoids and analysis of AAV transduction efficacy, providing a comprehensive approach for evaluating AAV-based gene therapy for retinal diseases.

• Journal of Animal Reproduction and Biotechnology
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• v.38 no.4
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• pp.275-290
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• 2023

Background: Porcine pluripotent stem cells (pPSCs) would provide enormous potential for agriculture and biomedicine. However, authentic pPSCs have not established yet because standards for pPSCs-specific markers and culture conditions are not clear. Therefore, the present study reports comparative pluripotency characteristics in porcine induced pluripotent stem cells (piPSCs) derived from different viral transduction and reprogramming factors [Lenti-iPSCs (OSKM), Lenti-iPSCs (OSKMNL) and Sev-iPSCs (OSKM)]. Methods: Porcine fibroblasts were induced into Lenti-iPSCs (OSKM) and Lenti-iPSCs (OSKMNL) by using Lentiviral vector and Sev-iPSCs (OSKM) by using Sendaiviral vector. Expressions of endogenous or exogenous pluripotency-associated genes, surface marker and in vitro differentiation in between Lenti-piPSCs (OSKM), Lenti-iPSCs (OSKMNL) and Sev-piPSCs (OSKM) were compared. Results: Colonial morphology of Lenti-iPSCs (OSKMNL) closely resembles the naïve mouse embryonic stem cells colony for culture, whereas Sev-iPSCs (OSKM) colony is similar to the primed hESCs. Also, the activity of AP shows a distinct different in piPSCs (AP-positive (+) Lenti-iPSCs (OSKMNL) and Sev-iPSCs (OSKM), but AP-negative (-) Lenti-iPSCs (OSKM)). mRNAs expression of several marker genes (OCT-3/4, NANOG and SOX2) for pluripotency was increased in Lenti-iPSCs (OSKMNL) and Sev-iPSCs (OSKM), but Sev-iPSCs (OSKM). Interestingly, SSEA-1 of surface markers was expressed only in Sev-iPSCs (OSKM), whereas SSEA-4, Tra-1-60 and Tra-1-81 were positively expressed in Lenti-iPSCs (OSKMNL). Exogenous reprogramming factors continuously expressed in Lenti-iPSCs (OSKMNL) for passage 20, whereas Sev-iPSCs (OSKM) did not express any exogenous transcription factors. Finally, only Lenti-iPSCs (OSKMNL) express the three germ layers and primordial germ cells markers in aggregated EBs. Conclusions: These results indicate that the viral transduction system of reprograming factors into porcine differentiated cells display different pluripotency characteristics in piPSCs.

• Proceedings of the Korean Society of Embryo Transfer Conference
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• 2002.06a
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• pp.1-16
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• 2002

• 대한생식의학회:학술대회논문집
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• 2004.06a
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• pp.51-51
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• 2004

• The Korea Genome Conference
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• 2002.08a
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• pp.50.1-50.1
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• 2002

• Proceedings of the Korean Society of Developmental Biology Conference
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• 2003.02a
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• pp.3-3
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• 2003

No Abstract, See Full Text

• Proceedings of the Korean Society of Developmental Biology Conference
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• 2003.02a
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• pp.4-4
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• 2003

No Abstract, See Full Text

• Journal of Genetic Medicine
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• v.9 no.2
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• pp.67-72
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• 2012

The generation of induced pluripotent stem cells (iPSCs) derived from patients' somatic cells provides a new paradigm for studying human genetic diseases. Human iPSCs which have similar properties of human embryonic stem cells (hESCs) provide a powerful platform to recapitulate the disease-specific cell types by using various differentiation techniques. This promising technology has being realized the possibility to explore pathophysiology of many human genetic diseases at the molecular and cellular levels. Furthermore, disease-specific human iPSCs can also be used for patient-based drug screening and new drug discovery at the stage of the pre-clinical test in vitro. In this review, we summarized the concept and history of cellular reprogramming or iPSC generation and highlight recent progresses for disease modeling using patient-specific iPSCs.

• The Korean Journal of Physiology and Pharmacology
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• v.16 no.1
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• pp.1-9
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• 2012

Because the average human life span has recently increased, the number of patients who are diagnosed with neurodegenerative diseases has escalated. Recent advances in stem cell research have given us access to unlimited numbers of multi-potent or pluripotent cells for screening for new drugs for neurodegenerative diseases. Neural stem cells (NSCs) are a good model with which to screen effective drugs that increase neurogenesis. Recent technologies for human embryonic stem cells (ESCs) or induced pluripotent stem cells (iPSCs) can provide human cells that harbour specific neurodegenerative disease. This article discusses the use of NSCs, ESCs and iPSCs for neurodegenerative drug screening and toxicity evaluation. In addition, we introduce drugs or natural products that are recently identified to affect the stem cell fate to generate neurons or glia.