• Journal of Periodontal and Implant Science
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• v.40 no.3
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• pp.111-118
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• 2010

Purpose: The aim of this study was to investigate whether vitrification in the cryopreservation of periodontal ligament (PDL) cells could be useful for tooth banking. Methods: In step 1, primary cultured human PDL cells were cryopreserved in 100% conventional cryopreservation media and 100% vitrification media (ESF40 media) in different temperatures for 2 weeks. In step 2, a series of modified vitrification formulae named T1 (75% vitrification media + 25% F-media), T2 (50% vitrification media + 50% F-media) and T3 (25% vitrification media + 75% F-media) were used to store PDL cells for 2 weeks and 4 weeks in liquid nitrogen. MTT assay was performed to examine the viability of PDL cells. Results: Maximum cell viability was achieved in cells stored in 100% conventional cryopreservation media at $-196^{\circ}C$ (positive control group) in step 1. Compared to the positive control group, viability of the cells stored in 100% vitrification media was very low as 10% in all test conditions. In step 2, as the percentage of vitrification media decreased, the cell viability increased in cells stored for 2 weeks. In 4-week storage of cells in step 2, higher cell viability was observed in the T2 group than the other vitrification formulae while the positive control group had the highest viability. There was no statistically significant difference in the cell viability of 2-week and 4-week stored cells in the T2 group. Conclusions: These observations indicate 100% vitrification media is not successful in PDL cell cryopreservation. Conventional cryopreservation media is currently the most appropriate media type for this purpose while T2 media would be interesting to test for long-term storage of PDL cells.

• The Journal of the Korean dental association
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• v.55 no.9
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• pp.592-603
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• 2017

Purpose: The effects of various concentrations of ascorbic acid on stem cell spheroids derived from intraoral areas are not known yet. Thus, the purpose of this study is to evaluate the effects of different concentrations of ascorbic acid on the morphology and cellular viability of stem cell spheroids derived from the gingival tissues. Materials and Methods: Stem cells were plated onto silicon elastomer-based concave microwells and grown in the presence of ascorbic acid at concentrations ranging from 0.003% to 0.3%. The morphology of the cells was viewed under an inverted microscope at day 1, 2, 3 and 5. Qualitative live/dead assay and quantitative cellular viability using Cell Counting Kit-8 were performed on day 2 and day 5. Results: Gingiva-derived stem cells formed spheroids irrespective of ascorbic acid concentration in silicon elastomer-based concave microwells. Increase in the diameter of spheroid were seen with higher concentrations of ascorbic acid. Higher cellular viability was seen in higher concentrations of ascorbic acid. Conclusion: Within the experimental setting, the application of ascorbic acid on stem-cell spheroids produced an increase in the size and higher viability with higher dosage. It can be suggested ascorbic acid be applied with stem cell spheroids for tissue engineering purposes.

• Biomedical Science Letters
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• v.25 no.1
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• pp.66-74
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• 2019

Hyperlipidemia is defined as conditions of the accumulation of lipids such as free fatty acids (FFA), triglyceride (TG), cholesterol and/or phospholipid in the bloodstream. Hyperlipidemia can cause lipid accumulation in non-adipose tissue, which is lipid-cytotoxic effects in many tissues and mediates cell dysfunction, inflammation or programmed cell death (PCD). TG is considered to be a major cause of atherosclerosis through inflammatory necrosis of vascular endothelial cells. Recently, TG have also been shown to exhibit lipid-cytotoxicity and induce PCD. Therefore, we investigated the effect of TG on the cytotoxic effect of various cell types. When exposed to TG, the cell viability of U937 monocytes and Jurkat T lymphocytes, as well as the cell viability of MCF-7, a non-immune cell, decreased in time- and dose-dependent manner. In U937 cells and Jurkat cells, caspase-9, an intrinsic apoptotic caspase, and caspase-8, an extrinsic apoptotic caspase, were increased by exposure to TG. However, in TG-treated MCF-7 cells, caspase-8 activity increased only without caspase-9 activity. In addition, the reduction of cell viability by TG was recovered when all three cell lines were treated with pan-caspase inhibitor. These results suggest that activation of apoptotic caspases by TG causes lipotoxic effect and decreases cell viability.

• Proceedings of the Korean Society of Applied Pharmacology
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• 1996.04a
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• pp.259-261
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• 1996

• Journal of Apiculture
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• v.33 no.4
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• pp.277-282
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• 2018

Ethanol extracted propolis (EEP) was mixed with honey (honeypolis) to dissolve well in water and in vitro skin irritation test was conducted. In vitro method is designed to predict and classify the skin irritation potential of a chemical by assessment of its effect on $EpiDerm^{TM}$, a reconstituted three-dimensional human epidermis model. Cytotoxicity is expressed as the reduction of mitochondrial dehydrogenase activity measured by formazan production from MTT after a 60 min exposure period. In this study under the given conditions honeypolis showed no irritant effects. Honeypolis meets acceptance criteria if: mean absolute OD 570 nm of the three negative control tissues is ${\geq}0.8$ and ${\leq}2.8$, mean relative tissue viability of the three positive control tissues is ${\leq}20%$, standard deviation of relative tissue viability obtained from each three concurrently tested tissues is ${\leq}18%$. Honeypolis is therefore classified as "non-irritant" in accordance with UN GHS "No Category".

• Biomolecules & Therapeutics
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• v.18 no.1
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• pp.56-64
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• 2010

Pentoxifylline (PTX) has been used for the local reduction of fat tissue in the clinical setting. However, its safety and efficacy have not been proven. The aim of this study was to evaluate the effects of PTX on cell lines established from fat tissue. Newly cultured human preadipocytes and adipocytes from subcutaneous abdominal fat in addition to purchased human lung fibroblasts and keratinocytes were treated with PTX at different concentrations. Cell viability was determined using the Cell counting kit (CCK)-8 assay and lipolysis was evaluated using an Elisa kit. DNA fragmentation, Western blot analysis, Hoechst and Propidium Iodide (PI) staining and fluorescence activated cell scanning analysis were performed to confirm apoptosis. The viability of adipocytes, preadipocytes, keratinocytes and fibroblasts was markedly decreased at concentrations of PTX above 20 mM. Apoptosis was induced at concentrations of PTX over 40 mM in all cell lines. Lipolysis was increased by 60% at concentrations of PTX of 20 mM compared to the control. In conclusion, the results of this study showed that 20 mM of PTX induced lipolysis. At concentrations over 20 mM, PTX reduced the viability of all cells studied including: adipocytes, preadipocytes, fibroblasts and keratinocytes, in a non-specific manner.

• The Journal of Korean Academy of Prosthodontics
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• v.41 no.2
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• pp.111-127
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• 2003

Statement of problem : Resin cements were used widely on all ceramic crowns, but the influence of resin cements on biocells was not understood clearly. Purpose : This study was investigated to evaluate the biocompatibility of resin cements for all-ceramic crowns. Material and Method : The resin cements used in this study were Panavia F (Kuraray Co., Ltd. Japan), Variolink II (Vivadent Ets., Schann / Liechtenstein), and Bistite II (Bistite dual cure resin cement-clear Tokuyama Soda Co. Japan). The viability of normal human oral keratocytes, gingival fibroblast, and gingival fibroblast immortalized by Human Papilloma virus 16 was measured in vitro for evaluation of cytotoxicity on resin cements, and the response of pulp tissue was analyzed and evaluated with light microscope after application of cements at cutting edge of incisors. Results : The normal human oral keratocytes was the most sensitive to toxicity of resin cement, and toxicity of cements was higher in Bistite II than in Variolink II. The cell viability of immortalized gingival fibroblast did not affected by type of cement and cultivation period, but there was a tendency that cytotoxicity in Bistite II was higher than in Variolink II. The cell viability of gingival fibroblast was similar to that of immortalized gingival fibroblast regardless of cement type, but Bistite II showed more toxic than others after 5 days cultivation. The responses of pulp tissue according to cement type were similar after 2 days cultivation, but revealed high toxicity in Bistite II after 10 days cultivation. Conclusion : Variolink II was more biocompatible than any other resin cements used in this study.

• Journal of Microbiology and Biotechnology
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• v.32 no.6
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• pp.740-748
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• 2022

As circ_UBE2D2 has been confirmed to have targeted binding sites with multiple miRNAs involved in septic acute kidney injury (SAKI), efforts in this study are directed to unveiling the specific role and relevant mechanism of circ_UBE2D2 in SAKI. HK-2 cells were treated with lipopolysaccharide (LPS) to construct SAKI model in vitro. After sh-circ_UBE2D2 was transfected into cells, the transfection efficiency was detected by qRT-PCR, cell viability and apoptosis were determined by MTT assay and flow cytometry, and expressions of Bcl-2, Bax and Cleaved-caspase 3 were quantified by western blot. Target genes associated with circ_UBE2D2 were predicted using bioinformatics analysis. After the establishment of SAKI rat model, HE staining and TUNEL staining were exploited to observe the effect of circ_UBE2D2 on tissue damage and cell apoptosis. The expression of circ_UBE2D2 was overtly elevated in LPS-induced HK-2 cells. Sh-circ_UBE2D2 can offset the inhibition of cell viability and the promotion of cell apoptosis induced by LPS. Circ_UBE2D2 and miR-370-3p as well as miR-370-3p and NR4A3 have targeted binding sites. MiR-370-3p inhibitor reversed the promoting effect of circ_UB2D2 silencing on viability of LPS-treated cells, but shNR4A3 neutralized the above inhibitory effect of miR-370-3p inhibitor. MiR-370-3p inhibitor weakened the down-regulation of NR4A3, Bax and Cleaved caspase-3 and the up-regulation of Bcl-2 induced by circ_UB2D2 silencing, but these trends were reversed by shNR4A3. In addition, sh-circ_UBE2D2 could alleviate the damage of rat kidney tissue. Circ_UBE2D2 mitigates the progression of SAKI in rats by targeting miR-370-3p/NR4A3 axis.

• Medical Lasers
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• v.10 no.2
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• pp.76-81
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• 2021

Biological tissues and organs are composed of different arrays of cells, biochemical cues, and extracellular matrices arranged in a complex microarchitecture. Laser-Assisted Bioprinting (LAB) is an emerging and promising technology that is reproducible with high accuracy that can be used for fabricating complex bioengineered scaffolds that mimic tissues and organs. The LAB process allows researchers to print intricate structural scaffolds using cells and different biomaterials essential for facilitating cell-scaffold interaction and to induce tissue and organ regeneration which cannot be achieved in a traditional scaffold fabrication. This process can fabricate artificial cell niches or architecture without affecting cellular viability and material integrity. This review tackles the basic principles and key aspects of Laser-Assisted Bioprinting. Recent advances, limitations, and future perspectives are also discussed.

• Journal of the Korean Crystal Growth and Crystal Technology
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• v.33 no.3
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• pp.104-109
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• 2023

Electrospinning was performed using an eco-friendly solvent composed of acetic acid, ethyl acetate and distilled water to investigate the effect of gelatin concentration on mechanical properties and cytotoxicity of absorbable poly(D,L-lactic acid) (PDLLA)/gelatin blend membrane. The tensile stress, strain at break, and WUC of the PDLLA/gelatin (97/3) scaffold at 26 wt% concentration were determined to be 3.9 ± 0.7 MPa, 37 ± 1.3 %, and 273 ± 33 %, respectively. FT-IR results revealed that PDLLA and gelatin were bound only by van der Waals interactions. The cell viability of PDLLA/gelatin membranes containing 0 %, 1 %, 2 %, 3 %, and 4 % gelatin were more than 100 %, which makes all membranes highly suitable as a barrier membrane for absorbable periodontal tissue regeneration due to their marketed physical properties and biocompatibility.