Seung Yeon Lee's research while affiliated with CHA University and other places

Extracellular vesicles (EVs) have been found to have the characteristics of their parent cells. Based on the characteristics of these EVs, various studies on disease treatment using mesenchymal stem cell (MSC)-derived EVs with regenerative activity have been actively conducted. The therapeutic nature of MSC-derived EVs has been shown in several studies, but in recent years, there have been many efforts to functionalize EVs to give them more potent therapeutic effects. Strategies for functionalizing EVs include endogenous and exogenous methods. In this study, human umbilical cord MSC (UCMSC)-derived EVs were selected for optimum OA treatments with expectation via bioinformatics analysis based on antibody array. And we created a novel nanovesicle system called the IGF-si-EV, which has the properties of both cartilage regeneration and long-term retention in the lesion site, attaching positively charged insulin-like growth factor-1 (IGF-1) to the surface of the UCMSC-derived Evs carrying siRNA, which inhibits MMP13. The downregulation of inflammation-related cytokine (MMP13, NF-kB, and IL-6) and the upregulation of cartilage-regeneration-related factors (Col2, Acan) were achieved with IGF-si-EV. Moreover, the ability of IGF-si-EV to remain in the lesion site for a long time has been proven through an ex vivo system. Collectively, the final constructed IGF-si-EV can be proposed as an effective OA treatment through its successful MMP13 inhibition, chondroprotective effect, and cartilage adhesion ability. We also believe that this EV-based nanoparticle-manufacturing technology can be applied as a platform technology for various diseases.

Bones are mineralized connective tissues composed of osteoclasts, osteoblasts, and osteocytes. While bone is one of the few tissues that can regenerate in adulthood, its regeneration is limited in the case of large bone defects due to an environment that is detrimental to bone formation, which can be caused by soft tissue injury and impeded vascularization, ultimately reducing the potential for significant bone creation. Consequently, recent research has focused on tissue engineering and regenerative medicine to address these complex issues. This article reviews recent major advances in the cell components used for bone regeneration studies, specific markers of bone differentiation, 3-dimensional (3D) printing techniques for the structural mimicry of bones, and the use of natural and synthetic biomaterials. Functional bone structures and bone organoids can be created using 3D printing, which allows the reconstruction of bone tissue by attaching living cells to scaffolds. These scaffolds are designed with appropriate shapes and mechanical properties to mimic the bone microenvironment. The application of 3D printing in the development of bone organoids holds promise for providing improved solutions for the development of test systems for disease modeling and drug development.

FJH-KO obtained from Antarctic krill, especially Euphausia superba, has been reported to contain high amounts of omega-3 polyunsaturated fatty acids (n-3 PUFA) and to exhibit anticancer and anti-inflammatory properties. However, its antithrombotic effects have not yet been reported. This study aimed to investigate the antithrombotic effects of FJH-KO in carrageenan-induced thrombosis mouse models and human endothelial cells. Thrombosis was induced by carrageenan injection, whereas the mice received FJH-KO pretreatment. FJH-KO attenuated carrageenan-induced thrombus formation in mouse tissue vessels and prolonged tail bleeding. The inhibitory effect of FJH-KO was associated with decreased plasma levels of thromboxane B2, P-selectin, endothelin-1, β-thromboglobulin, platelet factor 4, serotonin, TNF-α, IL-1β, and IL-6. Meanwhile, FJH-KO induced plasma levels of prostacyclin I2 and plasminogen. In vitro, FJH-KO decreased the adhesion of THP-1 monocytes to human endothelial cells stimulated by TNF-α via eNOS activation and NO production. Furthermore, FJH-KO inhibited the expression of TNF-α-induced adhesion molecules such as ICAM-1 and VCAM-1 by suppressing the NF-κB signaling pathway. Taken together, our study demonstrates that FJH-KO protects against carrageenan-induced thrombosis by regulating endothelial cell activation and has potential as an antithrombotic agent.

Extracellular vesicles (EVs) are nanosized particles that are released from cells and reflect the characteristics of the mother cell. Recently, the EVs have been used in several types of studies across many different fields. In the field of EV research, multiple cell culture and EV isolation techniques have been highlighted in importance. Various strategies, including exclusive component culture media, three-dimensional (3D) cultures, and hypoxic conditions, have been proposed for the cell culture to control function of the EVs. Ultracentrifugation, ultrafiltration, precipitation, and tangential flow filtration (TFF) have been utilized for EV isolation. Although isolated EVs have their own functionalities, several researchers are trying to functionalize EVs by applying various engineering approaches. Gene editing, exogenous, endogenous, and hybridization methods are the four well-known types of EV functionalization strategies. EV engineered through these processes has been applied in the field of regenerative medicine, including kidney diseases, osteoarthritis, rheumatoid arthritis, nervous system-related diseases, and others. In this review, it was focused on engineering approaches for EV functionalization and their applications in regenerative medicine. Graphical Abstract

Background To overcome the limitations of current alternative therapies for chronic kidney disease (CKD), tissue engineering-mediated regeneration strategies have demonstrated the possibilities for complete kidney tissue regeneration. Given the challenges associated with the reproducibility of renal basal cells, the incorporation of intermediate mesoderm (IM) cells and bioactive materials to control bioactivities of cells with supported scaffolds should be considered as a viable approach to enable the regeneration of the complex kidney structure via renal differentiation. Methods We developed PMEZ scaffolds by combining crucial bioactive components, such as ricinoleic acid-grafted Mg(OH) 2 (M), extracellular matrix (E), and alpha lipoic acid-conjugated ZnO (Z) integrated into biodegradable porous PLGA (P) platform. Additionally, we utilized differentiating extracellular vesicles (dEV) isolated during intermediate mesoderm differentiation into kidney progenitor cells, and IM cells were serially incorporated to facilitate kidney tissue regeneration through their differentiation into kidney progenitor cells in the 3/4 nephrectomy mouse model. Results The use of differentiating extracellular vesicles facilitated IM differentiation into kidney progenitor cells without additional differentiation factors. This led to improvements in various regeneration-related bioactivities including tubule and podocyte regeneration, anti-fibrosis, angiogenesis, and anti-inflammation. Finally, implanting PMEZ/dEV/IM scaffolds in mouse injury model resulted in the restoration of kidney function. Conclusions Our study has demonstrated that utilizing biodegradable PLGA-based scaffolds, which include multipotent cells capable of differentiating into various kidney progenitor cells along with supporting components, can facilitate kidney tissue regeneration in the mouse model that simulates CKD through 3/4 nephrectomy. Graphical Abstract

Melanoma, a highly malignant and aggressive form of skin cancer, poses a significant global health threat, with limited treatment options and potential side effects. In this study, we developed a temperature-responsive hydrogel for skin regeneration with a controllable drug release. The hydrogel was fabricated using an interpenetrating polymer network (IPN) of N-isopropylacrylamide (NIPAAm) and poly(vinyl alcohol) (PVA). PVA was chosen for its adhesive properties, biocompatibility, and ability to address hydrophobicity issues associated with NIPAAm. The hydrogel was loaded with doxorubicin (DOX), an anticancer drug, for the treatment of melanoma. The NIPAAm-PVA (N–P) hydrogel demonstrated temperature-responsive behavior with a lower critical solution temperature (LCST) around 34 °C. The addition of PVA led to increased porosity and faster drug release. In vitro biocompatibility tests showed nontoxicity and supported cell proliferation. The N–P hydrogel exhibited effective anticancer effects on melanoma cells due to its rapid drug release behavior. This N–P hydrogel system shows great promise for controlled drug delivery and potential applications in skin regeneration and cancer treatment. Further research, including in vivo studies, will be essential to advance this hydrogel system toward clinical translation and impactful advancements in regenerative medicine and cancer therapeutics.

Nonalcoholic fatty liver disease (NAFLD) has been linked to fat accumulation in the liver and lipid metabolism imbalance. Sesamin, a lignan commonly found in sesame seed oil, possesses antioxidant, anti-inflammatory, and anticancer properties. However, the precise mechanisms by which sesamin prevents hepatic steatosis are not well understood. This study aimed to explore the molecular mechanisms by which sesamin may improve lipid metabolism dysregulation. A in vitro hepatic steatosis model was established by exposing HepG2 cells to palmitate sodium. The results showed that sesamin effectively mitigated lipotoxicity and reduced reactive oxygen species production. Additionally, sesamin suppressed lipid accumulation by regulating key factors involved in lipogenesis and lipolysis, such as fatty acid synthase (FASN), sterol regulatory element-binding protein 1c (SREBP-1c), forkhead box protein O-1, and adipose triglyceride lipase. Molecular docking results indicated that sesamin could bind to estrogen receptor α (ERα) and reduce FASN and SREBP-1c expression via the Ca2+/calmodulin-dependent protein kinase kinase β (CaMKKβ)/ AMP-activated protein kinase (AMPK) signaling pathway. Sesamin attenuated palmitate-induced lipotoxicity and regulated hepatic lipid metabolism in HepG2 cells by activating the ERα/CaMKKβ/AMPK signaling pathway. These findings suggest that sesamin can improve lipid metabolism disorders and is a promising candidate for treating hepatic steatosis.