Publications by authors named "Sangbum Park"

Unlabelled: Neural crest cells (NCCs) are a multipotent embryonic cell population of ectodermal origin that extensively migrate during early development and contribute to the formation of multiple tissues. Cardiac NCCs play a critical role in heart development by orchestrating outflow tract septation, valve formation, aortic arch artery patterning, parasympathetic innervation, and maturation of the cardiac conduction system. Abnormal migration, proliferation, or differentiation of cardiac NCCs can lead to severe congenital cardiovascular malformations.

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Interactions between the developing heart and the embryonic immune system are essential for proper cardiac development and maintaining homeostasis, with disruptions linked to various diseases. While human pluripotent stem cell (hPSC)-derived organoids are valuable models for studying human organ function, they often lack critical tissue-resident immune cells. Here, we introduce an advanced human heart assembloid model, termed hHMA (human heart-macrophage assembloid), which fully integrates autologous cardiac tissue- resident macrophages (MPs) with pre-existing human heart organoids (hHOs).

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Circulating monocytes infiltrate and coordinate immune responses in tissues surrounding implanted biomaterials and in other inflamed tissues. Here we show that immunometabolic cues in the biomaterial microenvironment govern the trafficking of immune cells, including neutrophils and monocytes, in a manner dependent on the chemokine receptor 2 (CCR2) and the C-X3-C motif chemokine receptor 1 (CX3CR1). This affects the composition and activation states of macrophage and dendritic cell populations, ultimately orchestrating the relative composition of pro-inflammatory, transitory and anti-inflammatory CCR2, CX3CR1 and CCR2 CX3CR1 immune cell populations.

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The hair follicle is a dynamic mini-organ that has specialized cycles and architectures with diverse cell types to form hairs. Previous studies for several decades have investigated morphogenesis and signaling pathways during embryonic development and adult hair cycles in both mouse and human skin. In particular, hair follicle stem cells and mesenchymal niches received major attention as key players, and their roles and interactions were heavily revealed.

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Congenital heart defects are the most prevalent human birth defects, and their incidence is exacerbated by maternal health conditions, such as diabetes during the first trimester (pregestational diabetes). Our understanding of the pathology of these disorders is hindered by a lack of human models and the inaccessibility of embryonic tissue. Using an advanced human heart organoid system, we simulated embryonic heart development under pregestational diabetes-like conditions.

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The multiple layers of the skin cover and protect our entire body. Among the skin layers, the epidermis is in direct contact with the outer environment and serves as the first line of defense. The epidermis functions as a physical and immunological barrier.

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Pluripotent stem cell-derived organoids can recapitulate significant features of organ development in vitro. We hypothesized that creating human heart organoids by mimicking aspects of in utero gestation (e.g.

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Wound healing has been extensively studied through the lens of inflammatory disorders and cancer, but limited attention has been given to hematophagy and arthropod-borne diseases. Hematophagous ectoparasites, including ticks, subvert the wound healing response to maintain prolonged attachment and facilitate blood-feeding. Here, we unveil a strategy by which extracellular vesicles (EVs) ensure blood-feeding and arthropod survival in three medically relevant tick species.

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Stem cell differentiation requires dramatic changes in gene expression and global remodeling of chromatin architecture. How and when chromatin remodels relative to the transcriptional, behavioral, and morphological changes during differentiation remain unclear, particularly in an intact tissue context. Here, we develop a quantitative pipeline which leverages fluorescently-tagged histones and longitudinal imaging to track large-scale chromatin compaction changes within individual cells in a live mouse.

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Hair follicles are mini organs that repeat the growth and regression cycle continuously. These dynamic changes are driven by the regulation of stem cells via their multiple niche components. To build the complex structure of hair follicles and surrounding niches, sophisticated morphogenesis is required during embryonic development.

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Wound repair is essential to restore tissue function through the rebuilding of pre-existing structures. The repair process involves the re-formation of tissue, which was originally generated by embryonic development, with as similar a structure as possible. Therefore, these two processes share many similarities in terms of creating tissue architecture.

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Adipose tissue-derived mesenchymal stem cells (AD-MSCs) release extracellular vesicles such as exosomes, apoptotic bodies, and microparticles. In particular, exosomes are formed inside cells via multivesicular bodies (MVBs), thus their protein, DNA, and RNA content are similar to those of the parent cells. Exosome research is rapidly expanding, with an increase in the number of related publications observed in recent years; therefore, the function and application of MSC-derived exosomes could emerge as cell-free therapeutics.

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Organs consist of multiple cell types that ensure proper architecture and function. How different cell types coexist and interact to maintain their homeostasis in vivo remains elusive. The skin epidermis comprises mostly epithelial cells, but also harbours Langerhans cells (LCs) and dendritic epidermal T cells (DETCs).

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Adult stem cells are rare, undifferentiated cells found in all tissues of the body. Although normally kept in a quiescent, nondividing state, these cells can proliferate and differentiate to replace naturally dying cells within their tissue and to repair its wounds in response to injury. Due to their proliferative nature and ability to regenerate tissue, adult stem cells have the potential to treat a variety of degenerative diseases as well as aging.

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Background/aim: The kidney excretes waste materials and regulates important metabolic functions, and renal disorders constitute a significant medical problem and can result in fatalities. In the present study, mesenchymal stem cells derived from canine umbilical cord blood (cUCB-MSCs) were isolated and evaluated for their ability to improve renal function in a canine model of acute kidney injury (AKI).

Materials And Methods: The canine AKI model was developed by i.

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Cells in healthy tissues acquire mutations with surprising frequency. Many of these mutations are associated with abnormal cellular behaviours such as differentiation defects and hyperproliferation, yet fail to produce macroscopically detectable phenotypes. It is currently unclear how the tissue remains phenotypically normal, despite the presence of these mutant cells.

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Cellulose, which is one of the most-abundant and -renewable natural resources, has been extensively explored as an alternative substance for electrode materials such as activated carbons. Here, we demonstrate a new class of coffee-mediated green activation of cellulose as a new environmentally benign chemical-activation strategy and its potential use for all-paper flexible supercapacitors. A piece of paper towel is soaked in espresso coffee (acting as a natural activating agent) and then pyrolyzed to yield paper-derived activated carbons (denoted as "EK-ACs").

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Tissue repair is fundamental to our survival as tissues are challenged by recurrent damage. During mammalian skin repair, cells respond by migrating and proliferating to close the wound. However, the coordination of cellular repair behaviours and their effects on homeostatic functions in a live mammal remains unclear.

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Stem cells are essential for both tissue maintenance and injury repair, but many aspects of stem cell biology remain incompletely understood. Recent advances in live imaging technology have allowed the direct visualization and tracking of a wide variety of tissue-resident stem cells in their native environments over time. Results from these studies have helped to resolve long-standing debates about stem cell regulation and function while also revealing previously unanticipated phenomena that raise new questions for future work.

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Retinal pigment epithelium (RPE) is a major component of the eye. This highly specialized cell type facilitates maintenance of the visual system. Because RPE loss induces an irreversible visual impairment, RPE generation techniques have recently been investigated as a potential therapeutic approach to RPE degeneration.

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Adult tissues replace lost cells via pools of stem cells. However, the mechanisms of cell self-renewal, commitment, and functional integration into the tissue remain unsolved. Using imaging techniques in live mice, we captured the lifetime of individual cells in the ear and paw epidermis.

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Hair follicles are mammalian skin organs that periodically and stereotypically regenerate from a small pool of stem cells. Hence, hair follicles are a widely studied model for stem cell biology and regeneration. This protocol describes the use of two-photon laser-scanning microscopy (TPLSM) to study hair regeneration within a living, uninjured mouse.

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The retinal pigment epithelium (RPE) is a highly specialized cell type located between the choroid and neural retina of the eye. RPE degeneration causes irreversible visual impairment, extending to blindness. Cell therapy has recently emerged as a potential therapeutic approach for retinal degeneration.

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The rapidly approaching smart/wearable energy era necessitates advanced rechargeable power sources with reliable electrochemical properties and versatile form factors. Here, as a unique and promising energy storage system to address this issue, we demonstrate a new class of heterolayered, one-dimensional (1D) nanobuilding block mat (h-nanomat) battery based on unitized separator/electrode assembly (SEA) architecture. The unitized SEAs consist of wood cellulose nanofibril (CNF) separator membranes and metallic current collector-/polymeric binder-free electrodes comprising solely single-walled carbon nanotube (SWNT)-netted electrode active materials (LiFePO4 (cathode) and Li4Ti5O12 (anode) powders are chosen as model systems to explore the proof of concept for h-nanomat batteries).

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