Cytotoxicity of an Experimental Light-Cured Orthodontic Adhesive

2019 ◽  
Vol 294 ◽  
pp. 65-70
Author(s):  
Kanin Nimcharoensuk ◽  
Niwat Anuwongnukroh ◽  
Surachai Dechkunakorn ◽  
Vanthana Sattabanasuk ◽  
Panya Sunintaboon ◽  
...  

The objective of this study was to compare the cytotoxicity of a domestically-made light-cured orthodontic adhesive to a commercial adhesive, Transbond XT (3M Unitek, USA). An in-house orthodontic adhesive composed of a filler 60-70 weight % and a monomer ratio (BisGMA:TEGDMA) of 6:4 with 0.5% of photoinitiator was mixed. The potential cytotoxic effect of this experimental and a control adhesive was assessed by 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) assay according to ISO 10993-5: 2009(E). The L929 cell line was grown in 96-well tissue culture plates (1x105 cells/mm3). Thin cured-resin discs of each material weighing 0.4 gram were prepared and incubated for 1, 3, 5, 7, 14, and 30 days in Dulbecco’s modified Eagle medium (DMEM) at 37°C and 95% humidity with 5% CO2. The percentage of cell viability was reported by descriptive statistics. The result showed that the cell viability of the experimental adhesive was higher than Transbond XT in all measured periods. The cytotoxicity of both the adhesives gradually decreased with the progression of time. In conclusion, the in-house adhesive showed a good biocompatibility since the first day following polymerization. On the other hand, Transbond XT started with a cytotoxic potential, then, turned to be non-cytotoxic after 5 days of curing.

2018 ◽  
Vol 777 ◽  
pp. 582-586 ◽  
Author(s):  
Natthasit Pudpong ◽  
Niwat Anuwongnukroh ◽  
Surachai Dechkunakorn ◽  
Wassana Wichai ◽  
Peerapong Tua-Ngam

Objective: The aim of this study was to evaluate the cytotoxic effects of three commercial light-cured orthodontic adhesives.Materials and methods: The potential cytotoxic effects of three types of orthodontic adhesives, Grengloo, Green Glue, and Transbond XT, were tested on L929 cell culture. The cell line was grown in 96-well tissue culture plates (1x105 cells/mm3). Thin resin discs weighing 0.4, 0.6, 0.8, 0.8, and 0.8 gram of each material were prepared and aged for 1, 3, 6, 8, and 10 days, respectively, in Minimum Essential Medium (MEM) at 37°C with 5% CO2 at 100% humidity. Cell viability was assessed by the 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) assay according to ISO 10993-5: 2009 (E). The differences among the groups was statically analyzed by independent paired t-test (α = 0.05).Results: After 1 day of storage, all adhesive systems showed cytotoxic effects. However, ageing tended to considerably reduce the cytotoxicity of Green Glue. Grengloo was essentially non-cytotoxic day 3 onwards, while Green Glue and Transbond XT exhibited potential cytotoxicity at all times of the experiment. Conclusion: All tested light-cured orthodontic adhesives had cytotoxic potential during the first day. Grengloo had the highest cell viability, whereas, Green Glue had the lowest.


2019 ◽  
Vol 89 (6) ◽  
pp. 942-945 ◽  
Author(s):  
Stefano Martina ◽  
Roberto Rongo ◽  
Rosaria Bucci ◽  
Armando Viviano Razionale ◽  
Rosa Valletta ◽  
...  

ABSTRACT Objectives: To investigate the in vitro cytotoxicity of different thermoplastic materials for clear aligners on human primary gingival fibroblasts (HGFs). Materials and Methods: Four materials for clear aligners were considered in this study: Duran (Scheu-Dental GmbH, Iserlohn, Germany), Biolon (Dreve Dentamid GmbH, Unna, Germany), Zendura (Bay Materials LLC, Fremont, CA, USA), and SmartTrack (Align Technology, San Jose, CA, USA). Three out of four materials (Duran, Biolon, Zendura) were assessed as thermoformed and nonthermoformed, whereas the SmartTrack was assessed only as thermoformed. The samples were placed at 37°C in airtight test tubes containing Dulbecco's Modified Eagle's Medium (DMEM; 0.1 mg/mL) for 14 days. The cell viability of HGFs cultured with this medium was assessed by the 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) assay. Data were analyzed by means of one-way and two-way analysis of variance and post hoc tests (α = 0.05). Results: Each material exhibited a slight cytotoxic effect after 14 days. The highest cytotoxicity level on HGFs was achieved by Biolon (64.6% ± 3.3 of cell viability), followed by Zendura (74.4% ± 2.3 of cell viability), SmartTrack (78.8% ± 6.3 of cell viability), and finally Duran (84.6% ± 4 of cell viability), which was the least cytotoxic. In the comparison between nonthermoformed and thermoformed materials for Duran, Biolon, and Zendura, the thermoformed materials showed the highest level of cytotoxicity (P < .001). Conclusions: Under the experimental conditions of this study, all the materials for clear aligners presented a slight cytotoxicity. Biolon was the most cytotoxic and the thermoforming process increased the cytotoxicity of the materials.


2007 ◽  
Vol 86 (5) ◽  
pp. 441-445 ◽  
Author(s):  
M.T. Costa ◽  
M.A. Lenza ◽  
C.S. Gosch ◽  
I. Costa ◽  
F. Ribeiro-Dias

The corrosion resistance of AISI 304 stainless steel (AISI 304 SS) and manganese stainless steel (low-nickel SS) brackets in artificial saliva was investigated. The cytotoxic effects of their corrosion products on L929 cell culture were compared by two assays, crystal violet, to evaluate cell viability, and MTT (3-[4,5-dimethylthiazol-2-yl]2,5-diphenyltetrazolium bromide), for cell metabolism and proliferation. The atomic absorption spectroscopic analysis of the corrosion products demonstrated that nickel and manganese ion concentrations were higher for the AISI 304 SS-bracket immersion solution as compared with the low-nickel SS brackets. Scanning electron microscopy and energy-dispersive spectroscopy demonstrated less corrosion resistance for the AISI 304 SS brackets. Although none of the bracket extracts altered L929 cell viability or morphology, the AISI 304 SS-bracket extracts decreased cellular metabolism slightly. The results indicated that the low-nickel SS presents better in vitro biocompatibility than AISI 304 SS brackets. Abbreviations used: AISI, American Iron and Steel Institute; EDS, energy-dispersive spectroscopy; OD, optical density; ISO, International Organization for Standardization; MTT, (3-{4,5 dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide; NiSO4, nickel sulfate; SEM, standard error of the mean; WHO, World Health Organization; and TNF, tumor necrosis factor.


2019 ◽  
Vol 2019 ◽  
pp. 1-5 ◽  
Author(s):  
Vincenza Cannella ◽  
Roberta Altomare ◽  
Gabriele Chiaramonte ◽  
Santina Di Bella ◽  
Francesco Mira ◽  
...  

Objective. The aim of this study was to evaluate the cytotoxic potential of a type of endodontic pin on L929 cell line according to the UNI EN ISO 10993/2009 rule. Methods. L929 cells were used for the assays; extracts were prepared from three different-diameter endodontic pins, made of epoxy resin and fiberglass matrix and from Reference Materials (ZDEC, ZDBC, and HDP films). MTS assay was performed after 24 h, 48 h, and 72 h of exposure of L929 cells to pin and Reference Material extracts, 5% phenol solution, and control reagent. Cells cultured with different media containing extracts were monitored for up to 72 h and stained with haematoxylin/eosin. Results. Pins of different diameters had no cytotoxic effects on L929 cells at 24 h, 48 h, and 72 h (all values >70%). Cells cultured in medium containing pin extracts grew without any differences compared to the control cells. Conclusion. The endodontic pins tested showed no cytotoxic effects and did not induce changes in morphology for up to 72 h.


2020 ◽  
Vol 31 (1) ◽  
pp. 32-36
Author(s):  
Kellin Pivatto ◽  
Fabio Luis Miranda Pedro ◽  
Orlando Aguirre Guedes ◽  
Adriana Fernandes da Silva ◽  
Evandro Piva ◽  
...  

Abstract This study evaluated the cytotoxic effect and the ability to inhibit matrix metalloproteinases (MMP-2 and MMP-9) of 0.2% chitosan (CH) and 1% acetic acid (AA) compared with 17% ethylenediaminetetraacetic acid (EDTA). Cell viability assay was performed according to ISO 10993-5 with mouse fibroblasts (L929). The culture was exposed to 0.2% CH, 1% AA, and 17% EDTA. The chelating agents were evaluated immediately after contact with the cells and after 6 h, 12 h, and 24 h of incubation. Cell viability was analyzed using the 3-(4,5-dimethythiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) assay. Inhibition of the gelatinolytic activity of MMP-2 and MMP-9 was evaluated by gelatin zymography. Different concentrations of CH were evaluated: 50 mM, 5 mM, 0.5 mM, and 0.05 mM. EDTA (0.5 mM) was used as a positive control. The results demonstrated that CH and AA had an initial cytotoxic effect, which decreased after 6 h, 12 h, and 24 h, being statistically similar to EDTA (P > 0.05). Additionally, CH at concentrations of 50 mM, 5 mM, and 0.5 mM had an inhibitory effect on MMP-2 and MMP-9, similar to that of the control with EDTA. The chelating agents had no cytotoxic effects after 24 h. MMP-2 and MMP-9 were inhibited by the experimental solutions.


2020 ◽  
Vol 20 (11) ◽  
pp. 1340-1351 ◽  
Author(s):  
Ponnurengam M. Sivakumar ◽  
Matin Islami ◽  
Ali Zarrabi ◽  
Arezoo Khosravi ◽  
Shohreh Peimanfard

Background and objective: Graphene-based nanomaterials have received increasing attention due to their unique physical-chemical properties including two-dimensional planar structure, large surface area, chemical and mechanical stability, superconductivity and good biocompatibility. On the other hand, graphene-based nanomaterials have been explored as theranostics agents, the combination of therapeutics and diagnostics. In recent years, grafting hydrophilic polymer moieties have been introduced as an efficient approach to improve the properties of graphene-based nanomaterials and obtain new nanoassemblies for cancer therapy. Methods and results: This review would illustrate biodistribution, cellular uptake and toxicity of polymergraphene nanoassemblies and summarize part of successes achieved in cancer treatment using such nanoassemblies. Conclusion: The observations showed successful targeting functionality of the polymer-GO conjugations and demonstrated a reduction of the side effects of anti-cancer drugs for normal tissues.


Tumor Biology ◽  
2017 ◽  
Vol 39 (5) ◽  
pp. 101042831769756 ◽  
Author(s):  
Jia-Teng Zhong ◽  
Jian Yu ◽  
Hai-Jun Wang ◽  
Yu Shi ◽  
Tie-Suo Zhao ◽  
...  

Nowadays, although chemotherapy is an established therapy for breast cancer, the molecular mechanisms of chemotherapy resistance in breast cancer remain poorly understood. This study aims to explore the effects of endoplasmic reticulum stress on autophagy, apoptosis, and chemotherapy resistance in human breast cancer cells by regulating PI3K/AKT/mTOR signaling pathway. 3-(4,5-Dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide assay was performed to detect the cell viability of six human breast cancer cell lines (MCF-7, ZR-75-30, T47D, MDA-MB-435s, MDA-MB-453, and MDA-MB-231) treated with tunicamycin (5 µM), after which MCF-7 cells were selected for further experiment. Then, MCF-7 cells were divided into the control (without any treatment), tunicamycin (8 µ), BEZ235 (5 µ), and tunicamycin + BEZ235 groups. Cell viability of each group was testified by 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide assay. Western blotting was applied to determine the expressions of endoplasmic reticulum stress and PI3K/AKT/mTOR pathway–related proteins and autophagy- and apoptosis-related proteins. Monodansylcadaverine and Annexin V–fluorescein isothiocyanate/propidium iodide staining were used for determination of cell autophagy and apoptosis. Furthermore, MCF-7 cells were divided into the control (without any treatment), tunicamycin (5 µM), cisplatin (16 µM), cisplatin (16 µM) + BEZ235 (5 µM), tunicamycin (5 µM) + cisplatin (16 µM), and tunicamycin (5 µM) + cisplatin (16 µM) + BEZ235 groups. Cell viability and apoptosis were also evaluated by 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide assay and Annexin V–fluorescein isothiocyanate/propidium iodide staining. In MCF-7 cells treated with tunicamycin, cell viability decreased significantly, but PEAK, eIF2, and CHOP were upregulated markedly and p-PI3K, p-AKT, and p-MTOR were downregulated in dose- and time-dependent manners. In the tunicamycin + BEZ235 group, the cell viability was lower and the apoptosis rate was higher than those of the control and monotherapy groups. Compared with the cisplatin group, the tunicamycin + cisplatin group showed a relatively higher growth inhibition rate; the growth inhibition rate substantially increased in the tunicamycin + cisplatin + BEZ235 group than the tunicamycin + cisplatin group. The apoptosis rate was highest in tunicamycin + cisplatin + BEZ235 group, followed by tunicamycin + cisplatin group and then cisplatin group. Our study provide evidence that endoplasmic reticulum stress activated by tunicamycin could promote breast cancer cell autophagy and apoptosis and enhance chemosensitivity of MCF-7 cells by inhibiting the PI3K/AKT/mTOR signaling pathway.


2014 ◽  
Vol 34 (8) ◽  
pp. 848-855 ◽  
Author(s):  
I Hwang ◽  
JW Lee ◽  
JS Kim ◽  
HW Gil ◽  
HY Song ◽  
...  

Objective: Self-poisoning with (4-chloro-2-methylphenoxy) acetic acid (MCPA) is a common reason for presentation to hospitals, especially in some Asian countries. We encountered a case of a 76-year-old woman who experienced unconsciousness, shock and respiratory failure after ingesting 100 mL MCPA herbicide. We determined whether the surfactant in the formulation was the chemical responsible for the toxic symptom in this patient. Design: 3-(4,5-Dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) cell viability and lactate dehydrogenase (LDH) cytotoxicity assays were performed on human brain neuroblastoma SK-N-SH cells. The expressions of 84 genes in 9 categories that are implicated in cellular damage pathways were quantified using an RT2 Profiler™ PCR array on a human neuronal cell line challenged with polyoxyethylene tridecyl ether (PTE). Setting: Pesticide intoxication institute in university hospital. Interventions: Extracorporeal elimination with intravenous lipid emulsion. Measurements: Cell viability and gene expression. Main Results: In the MTT assay, MCPA only minimally decreased cell viability even at concentrations as high as 1 mM. Cells treated with 1-methoxy-2-propanol, dimethylamine and polypropylene glycol exhibited minimal decreases in viability, whilst the viability of cells challenged with PTE decreased dramatically; only 15.5% of cells survived after exposure to 1 µM PTE. Similarly, the results of the LDH cytotoxicity assay showed that MCPA had very low cytotoxicity, whilst cells treated with PTE showed incomparably higher LDH levels ( p < 0.0001). PTE up-regulated the expressions of genes implicated in various cell damage pathways, particularly genes involved in the inflammatory pathway. Conclusions: The surfactant PTE was likely the chemical responsible for the toxic symptom in our patient.


2021 ◽  
Vol 23 (Supplement_2) ◽  
pp. ii22-ii23
Author(s):  
G Casati ◽  
L Giunti ◽  
A Iorio ◽  
A Marturano ◽  
I Sardi

Abstract BACKGROUND Glioblastoma (GBM) is a primary human malignant brain tumor, the most common in adults. Several studies have highlighted the Hippo-pathway as a cancer signalling network. The Hippo pathway is an evolutionarily conserved signal cascade, which is involved in the control of organ growth. Dysregulations among this pathway have been found in lung, ovarian, liver and colorectal cancer. The key downstream effector of the Hippo-pathway is the Yes-associated protein (YAP); in the nucleus, its function as transcription co-activator is to interact with transcription factors, resulting in the expression of target genes involved in pro-proliferating and anti-apoptotic programs. MATERIAL AND METHODS Using western blotting analysis, we determined the nuclear expression of YAP on three GBM cell lines (U87MG, T98G and A172). To investigate which inhibitors against the Hippo-pathway were the most efficient, we performed a cytotoxic assay: we treated all the three cell lines with different inhibitors such as Verteporfin (VP), Cytochalasin D (CIT), Latrunculin A (LAT), Dobutamine (DOB) and Y27632. Afterwards, we performed a treatment using Doxorubicin (DOX) combined with the inhibitors, evaluating its cytotoxic effect on our cell lines, through cell viability experiments. More western blotting experiments were performed to investigate the oncogenic role of YAP at nucleus level. Furthermore, preliminary experiments have been conducted in order to investigate the apoptosis, senescence and autophagy modulation due to the Hippo-pathway. RESULTS We showed our cell lines express nuclear YAP. We assessed the efficiency of the main inhibitors against Hippo-pathway, proving that VP, LAT A and CIT show a strong cytostatic effect, linked to time increase; plus we saw a cytotoxic effect on T98G. The association of DOX with selected inhibitors is able to reduce cell viability and nuclear YAP expression rate in all three GBM lines. Finally, preliminary experiments were set up to assess how and if the mechanisms of apoptosis, autophagy and senescence were affected by the Hippo-pathway. The combination of DOX with inhibitors promotes resistance to apoptosis. CONCLUSION Our results show that nuclear YAP is present in all tumor lines, thus confirming that this molecular pathway is functioning in GBM lines. Nuclear YAP is more highly expressed after DOX administration. Moreover, the combined treatment (DOX with Hippo-pathway inhibitors) reduces both cell proliferation and viability, and increases the rate of apoptosis. Preliminary experiments on senescence and autophagy were used to determine the best Hippo-pathway inhibitor. These data demonstrate that the Hippo-pathway plays a crucial role in GBM proliferation and resistance to apoptosis. Inhibiting this pathway and in particular the transcription factor YAP, in association with DOX, might be an excellent therapeutic target.


Author(s):  
Pei-Tzu Li ◽  
Ying-Chu Lee ◽  
Namasivayam Elangovan ◽  
Sin-Tak Chu
Keyword(s):  

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