• BMB Reports
• /
• 제46권5호
• /
• pp.276-281
• /
• 2013

In this study, we aimed to compare the morphogenetic and neuronal characteristics between monolayer cells and spheroids. For this purpose, we established spheroid formation by growing SH-SY5Y cells on the hydrophobic surfaces of thermally-collapsed elastin-like polypeptide. After 4 days of culture, the relative proliferation of the cells within spheroids was approximately 92% of the values for monolayer cultures. As measured by quantitative assays for mRNA and protein expressions, the production of synaptophysin and neuronspecific enolase (NSE) as well as the contents of cell adhesion molecules (CAMs) and extracellular matrix (ECM) proteins are much higher in spheroids than in monolayer cells. Under the all-trans-retinoic acid (RA)-induced differentiation condition, spheroids extended neurites and further up-regulated the expression of synaptophysin, NSE, CAMs, and ECM proteins. Our data indicate that RA-differentiated SH-SY5Y neurospheroids are functionally matured neuronal architectures.

• 한국환경성돌연변이발암원학회지
• /
• 제17권1호
• /
• pp.7-11
• /
• 1997

Variations in adriamycin uptake and cytotoxicity were studied in tumor cells that were grown in different growth states and microenvironments. RIF-1 tumor cells were maintained in an RPMI 1640 medium, and grown in either a monolayer or multicell spheroids. For exponentially growing cells, adriamycin cytotoxicity increased with increased dosage up to 2.5 $\mu$g/ml, and this cytotoxicity was reduced when the cells were grown in a plateau phase or in an acidic microenvironment (pH 6.6). This reduced cytotoxicity was correlated with the uptake of the drug. For multicell spheroids, the cytotoxicity of the drug was reduced dramatically, and this reduction was also correlated with a reduced uptake of the drug and an acidic pH inside of the spheroids. When the drug cytotoxicity was evaluated at different locations within the spheroids, the cells in the inner regions were least affected by the drug, suggesting that both an acidic microenvironment and noncycling plateau phase cells are contributing factors in decreasing the efficacy of the drug in an organized tissue, such as multicell spheroids.

• BMB Reports
• /
• 제54권7호
• /
• pp.356-367
• /
• 2021

Cell-based therapy is a promising approach in the field of regenerative medicine. As cells are formed into spheroids, their survival, functions, and engraftment in the transplanted site are significantly improved compared to single cell transplantation. To improve the therapeutic effect of cell spheroids even further, various biomaterials (e.g., nano- or microparticles, fibers, and hydrogels) have been developed for spheroid engineering. These biomaterials not only can control the overall spheroid formation (e.g., size, shape, aggregation speed, and degree of compaction), but also can regulate cell-to-cell and cell-to-matrix interactions in spheroids. Therefore, cell spheroids in synergy with biomaterials have recently emerged for cell-based regenerative therapy. Biomaterials-assisted spheroid engineering has been extensively studied for regeneration of bone or/and cartilage defects, critical limb ischemia, and myocardial infarction. Furthermore, it has been expanded to pancreas islets and hair follicle transplantation. This paper comprehensively reviews biomaterials-assisted spheroid engineering for regenerative therapy.

• 한국생물공학회:학술대회논문집
• /
• 한국생물공학회 2003년도 생물공학의 동향(XIII)
• /
• pp.305-306
• /
• 2003

To treat fulminant hepatic failure (FHF) patients, various extracorporeal bioartificial liver (BAL) systems have been developed. Several requirements should be met for the development of BAL systems: hepatocytes should be cultured in a sufficiently high density; their metabolic functions should be of a sufficiently high level and duration; and the BAL systems module should permit scaling-up and aseptic handling. Several investigators have found that freshly isolated primary hepatocytes can be cultured into three dimensional, tightly packed, freely suspended, multicellular aggregates, or spheroids. These specialized cell structures exhibited enhanced liver specific functions and a prolonged differentiated state compared to cells maintained in a monolayer culture. Cells in spheroids appear to mimic the morphology and ultrastructure of the in vivo liver lobule. The ability of hepatocytes to organize into three-dimensional structures was hypothesized to contribute to their enhanced liver-specific activities. In this study, the ammonia removal rate and urea secretion rate of pig hepatocytes spheroids encapsulated in Ca-alginate bead were determined. A packed-bed bioreactor with encapsulated pig hepatocytes was devised as BAL support system. The efficacy of the system was evaluated in vitro.

• Journal of Microbiology and Biotechnology
• /
• 제29권2호
• /
• pp.321-329
• /
• 2019

Hair loss, also known as alopecia, is a common dermatological condition of psychosocial significance; development of therapeutic candidates for the treatment of this condition is, hence, important. Silibinin, a secondary metabolite from Silybum marianum, is an effective antioxidant that also prevents various cutaneous problems. In this study, we have investigated the effect of silibinin on hair induction using three-dimensional (3D) cultured, human dermal papilla (DP) spheroids. Silibinin was found to significantly increase viability through AKT serine/threonine kinase (AKT) activation in 3D DP spheroids. This was correlated with an increase in the diameter of the 3D DP spheroids. The activation of the wingless and INT-1 (Wnt)/${\beta}$-catenin signaling pathway, which is associated with hair growth induction in the DP, was evaluated using the T cell-specific transcription factor and lymphoid enhancer-binding factor (TCF/LEF) transcription factor reporter assay; results indicated significantly increased luciferase activity. In addition, we were able to demonstrate increased expression of the target genes, WNT5a and LEF1, using quantitative real-time PCR assay. Lastly, significantly elevated expression of signature genes associated with hair induction was demonstrated in the 3D DP spheroids treated with silibinin. These results suggest that silibinin promotes proliferation and hair induction through the AKT and Wnt/${\beta}$-catenin signaling pathways in 3D DP spheroids. Silibinin can be a potential candidate to promote hair proliferation.

• Molecules and Cells
• /
• 제44권1호
• /
• pp.50-62
• /
• 2021

Among all cancer types, lung cancer ranks highest worldwide in terms of both incidence and mortality. The crosstalk between lung cancer cells and their tumor microenvironment (TME) has begun to emerge as the "Achilles heel" of the disease and thus constitutes an attractive target for anticancer therapy. We previously revealed that crosstalk between lung cancer cells and endothelial cells (ECs) induces chemoresistance in multicellular tumor spheroids (MCTSs). In this study, we demonstrated that factors secreted in response to crosstalk between ECs and lung cancer cells play pivotal roles in the development of chemoresistance in lung cancer spheroids. We subsequently determined that the expression of hypoxia up-regulated protein 1 (HYOU1) in lung cancer spheroids was increased by factors secreted in response to crosstalk between ECs and lung cancer cells. Direct interaction between lung cancer cells and ECs also caused an elevation in the expression of HYOU1 in MCTSs. Inhibition of HYOU1 expression not only suppressed stemness and malignancy, but also facilitated apoptosis and chemosensitivity in lung cancer MCTSs. Inhibition of HYOU1 expression also significantly increased the expression of interferon signaling components in lung cancer cells. Moreover, the activation of the PI3K/AKT/mTOR pathway was involved in the HYOU1-induced aggression of lung cancer cells. Taken together, our results identify HYOU1, which is induced in response to crosstalk between ECs and lung cancer cells within the TME, as a potential therapeutic target for combating the aggressive behavior of cancer cells.

• Journal of Microbiology and Biotechnology
• /
• 제15권1호
• /
• pp.7-13
• /
• 2005

Chitosan-alginate capsules were formed by electrostatic interactions and exhibited an appropriate mechanical strength, permeability, and stability for the culture of hepatocytes. Pig hepatocytes were isolated and hepatocyte spheroids formed and immobilized in chitosan-alginate capsules. An encapsulation procedure of 3 min and spheroid formation period of 24 h were the optimum conditions for the best liver functions. Pig hepatocytes with a cell density of $6.0{\tomes}10^6$ cells/ml in the capsules were found to be most suitable for application in a bioartificial liver support system. The encapsulated pig hepatocyte spheroids exhibited stable ammonia removal and urea secretion rates in a bioreactor for 2 weeks. Accordingly, chitosan-alginate encapsulated hepatocyte spheroids in a packed-bed bioreactor would appear to have potential as a bioartificial liver.

• 한국미생물·생명공학회지
• /
• 제47권1호
• /
• pp.164-171
• /
• 2019

기존에는 방사선 요법은 효과에 비해 소화기 점막 궤양 등 부작용이 많다. 본 연구는 방사선의 작용을 모사하는 방사선 모사 미생물 유래 리보솜 스트레스 반응을 이용하여 방사선 치료의 한계를 대체할 기전적 방법을 모색하고자 한다. 암 치료의 평가를 위해서 대장암의 비균질적인 세포구성, 종양줄기세포 및 주위 미세환경 및 배양 기질 등의 상호작용을 고려할 수 있는 소화기암 스페로이드를 이용하였다. 대조군 대장암 스페로이드에 비해서 리보솜 스트레스하에서는 스페로이드 구조가 상대적으로 큰 군집을 형성하였다. 하지만 이는 구조 자체가 매우 섬긴 세포간 구성을 가진 스페로이드였으며 스페로이드 형성과정의 크기 수축은 대조군에 비해 매우 느리게 나타났다. 대조군은 강하게 뭉친 소규모 클러스트의 집합체가 최종적으로 스페로이드를 형성하여 물리적 손상을 받아도 단단한 소규모 클러스트는 유지되나 리보솜 스트레스 하에서는 물리적 손상에 의해 형태가 파손 후에는 스페로이드 형성이 거의 일어나지 않았다. 기전적으로 리보솜 스트레스 하에서 암세포의 군집하는 이동속도는 매우 느렸으며, 뭉치더라도 세포-세포간 접합부위가 상대적으로 적었다. 이 대장암 스페로이드를 이종 및 동종 이식을 통해 동물에서 증식 시 종양 조직 형성이 매우 억제되었으며, 형성이 되어도 세포-세포간 접합에 핵심단백질인 E-cadherin의 발현이 매우 감소 됨을 알 수 있었다. 결론적으로 방사선 모사 미생물 유래 리보솜 스트레스는 종양 스페로이드 세포 이동 및 접합을 저해하여 3차원 구조 형성 결함을 유발하였으며, 향후 방사선을 대체하여 약물적으로 방사선 항암효과를 구현하는 기반을 제공한다.

• 한국생물공학회:학술대회논문집
• /
• 한국생물공학회 2000년도 추계학술발표대회 및 bio-venture fair
• /
• pp.405-408
• /
• 2000

• 한국응용약물학회:학술대회논문집
• /
• 한국응용약물학회 1994년도 춘계학술대회 and 제3회 신약개발 연구발표회
• /
• pp.137-144
• /
• 1994

Spherical multicellular aggregates of adult rat hepatocytes (spheroid) which have tissue like structure, were formed and immobilized in the pores of polyurethane foam (PUF) which was used as a culture substratum. These hepatocyte/spheroids, about 100 $\mu\textrm{m}$ in diameter, have maintained higher differentiated functions than those of hepatocyte/monolayer for about 3 weeks in serum-free medium. Then, we designed a prototype module of an artificial liver support system using a PUF/spheroid packed-bed, in which hepatocyte/spheroids were immobilized at high density. The urea synthesis activity of the artificial liver was maintained at least 10 days in 100% rat blood plasma. We start examining the performance of hybrid artificial liver in an ex vivo extracorporeal experiment with an acute hepatic failure rat.