Effect of different silica coatings on the toxicity of upconversion nanoparticles on RAW 264.7 macrophage cells

• Cynthia Kembuan,
• Helena Oliveira and
• Christina Graf

Beilstein J. Nanotechnol. 2021, 12, 35–48, doi:10.3762/bjnano.12.3

• UCNP samples. However, this does not go along with a higher cytotoxicity since the thin-coated samples had a higher degree of cytotoxicity in the MTT assay in comparison to the thick-coated particles (Figure 2). The cytotoxicity of the thin-coated samples must have been caused by other effects that did

• ± 2 nm); (C) UC@thick (tSiO2 = 21 ± 3 nm). MTT assay results of silica-coated UCNPs and SiO2 nanoparticles on RAW 264.7 cells. (A) SSC histograms of RAW 264.7 cells after particle exposure for 24 h at 37 °C. UC@thin_NH2 is marked by a blue-framed peak, UC@thick_NH2 is marked by a red-framed peak, and

PEG/PEI-functionalized single-walled carbon nanotubes as delivery carriers for doxorubicin: synthesis, characterization, and in vitro evaluation

• Shuoye Yang,
• Zhenwei Wang,
• Yahong Ping,
• Yuying Miao,
• Yongmei Xiao,
• Lingbo Qu,
• Lu Zhang,
• Yuansen Hu and
• Jinshui Wang

Beilstein J. Nanotechnol. 2020, 11, 1728–1741, doi:10.3762/bjnano.11.155

• The in vitro cytotoxicity of different blank nanomaterials and DOX-loaded samples toward MCF-7 cells was assessed by using the MTT assay. In brief, cells were seeded into 96-well plates at a density of 5 × 104 cells per well and attached for 48 h. Then the culture medium was removed, and cells were

Cardiomyocyte uptake mechanism of a hydroxyapatite nanoparticle mediated gene delivery system

• Hiroaki Komuro,
• Masahiro Yamazoe,
• Kosuke Nozaki,
• Akiko Nagai and
• Tetsuo Sasano

Beilstein J. Nanotechnol. 2020, 11, 1685–1692, doi:10.3762/bjnano.11.150

• approximately 1.3 wt % [24]. Cytotoxicity assay Dose-dependent cytotoxicity of HAp/pDNA complexes on HL-1 cells was investigated in the concentration range of 0.1–10 µg/mL. The 3-(4,5-dimethylhiazol-2-yl)-2,5-diphenyl-2H-tetrazolium bromide (MTT) assay was used to assess cytotoxicity. No differences in cell

• ). (d) The FTIR spectra of the HAp nanoparticles in the range of 4000–400 cm−1. The characteristic peaks of HAp are indicated. MTT assay of HL-1 cells treated with HAp nanoparticles for 24 (white bars) and 72 h (black bars) was used to determine cytotoxicity. Non-treated cells were used as the control

Nanoparticles based on the zwitterionic pillar[5]arene and Ag⁺: synthesis, self-assembly and cytotoxicity in the human lung cancer cell line A549

• Dmitriy N. Shurpik,
• Denis A. Sevastyanov,
• Pavel V. Zelenikhin,
• Pavel L. Padnya,
• Vladimir G. Evtugyn,
• Yuriy N. Osin and
• Ivan I. Stoikov

Beilstein J. Nanotechnol. 2020, 11, 421–431, doi:10.3762/bjnano.11.33

• held at the accelerating voltage of 80 kV in scanning TEM mode using an Oxford Instruments X-Maxn 80T EDS detector. In vitro cell viability The characterization of the A549 cell viability changes under the pillar[5]arenes 3 and 4 action was performed by the MTT assay. A cell suspension of 150 μL/well

• MS-Excel. To determine the cytotoxicity of the complexes with 3/Ag+ and 4/Ag+ and to obtain a stable mixture of compounds, solutions 3 or 4 and AgNO3 in distilled water was mixed in a molar ratio of 1:10 and incubated for 30 min at 37 °C. The IC50 value using the data obtained in the MTT assay was

Design of a nanostructured mucoadhesive system containing curcumin for buccal application: from physicochemical to biological aspects

• Sabrina Barbosa de Souza Ferreira,
• Gustavo Braga,
• Évelin Lemos Oliveira,
• Jéssica Bassi da Silva,
• Hélen Cássia Rosseto,
• Lidiane Vizioli de Castro Hoshino,
• Mauro Luciano Baesso,
• Wilker Caetano,
• Craig Murdoch,
• Helen Elizabeth Colley and
• Marcos Luciano Bruschi

Beilstein J. Nanotechnol. 2019, 10, 2304–2328, doi:10.3762/bjnano.10.222

Targeted therapeutic effect against the breast cancer cell line MCF-7 with a CuFe₂O₄/silica/cisplatin nanocomposite formulation

• B. Rabindran Jermy,
• Vijaya Ravinayagam,
• Widyan A. Alamoudi,
• Dana Almohazey,
• Hatim Dafalla,
• Lina Hussain Allehaibi,
• Abdulhadi Baykal,
• Muhammet S. Toprak and
• Thirunavukkarasu Somanathan

Beilstein J. Nanotechnol. 2019, 10, 2217–2228, doi:10.3762/bjnano.10.214

• calculation was made for the other doses as indicated in Table 1. Thus, the treatment concentrations used in this experiment for CuFe2O4 were: 0.0084, 0.0168, 0.0336, and 0.168 mg/mL. The treatment concentrations for cisplatin were: 0.001125, 0.00225, 0.0045, 0.0225 mg/mL. Cell viability – MTT assay The cell

• viability was tested using 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) assay, which is based on the ability to reduce MTT to formazan crystals. The assay was performed using previously published protocols [15]. Briefly, MTT (Sigma-Aldrich) was dissolved in PBS at 5 mg/mL. The working

• cisplatin [20][21]. To overcome these limitations and to ensure specific tumor targeting, cisplatin/CuFe2O4/HYPS nanoparticles were tested. To investigate the cytotoxic efficiency of cisplatin/CuFe2O4/HYPS nanoparticles, we assessed cell viability using the MTT assay. In that assay, healthy cells will be

Incorporation of doxorubicin in different polymer nanoparticles and their anticancer activity

• Sebastian Pieper,
• Hannah Onafuye,
• Dennis Mulac,
• Jindrich Cinatl Jr.,
• Mark N. Wass,
• Martin Michaelis and
• Klaus Langer

Beilstein J. Nanotechnol. 2019, 10, 2062–2072, doi:10.3762/bjnano.10.201

• -dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) assay modified after Mosmann [59], as previously described [55]. 2 × 104 cells suspended in 100 µL cell culture medium were plated per well in 96-well plates and incubated in the presence of various concentrations of drug or drug preparations for 120 h

Synthesis and potent cytotoxic activity of a novel diosgenin derivative and its phytosomes against lung cancer cells

• Liang Xu,
• Dekang Xu,
• Ziying Li,
• Yu Gao and
• Haijun Chen

Beilstein J. Nanotechnol. 2019, 10, 1933–1942, doi:10.3762/bjnano.10.189

• 5% CO2. In vitro cell viability Cell viability was determined by MTT assay. Cells seeded in 96-well plates at 70–80% confluence were exposed to free drugs (Di, P2) and phytosomes (P, DiP, P2P) at various concentrations for 24, 48 and 72 h. At the end of the treatment period, viability was determined

• by the MTT assay [40]. Cell cycle analysis A549 and PC9 cells were plated in six-well plates at 2 × 105 cells/well. The day after plating, the cells were treated with Di or P2 for 48 h and DiP or P2P for 72 h. Then cells were trypsinized and washed with PBS. The cells were fixed with 75% pre-cooled

• IC50 values of diosgenin (Di), FZU-0021-194-P2 (P2) and their phytosomes against cancer cells by MTT assay. Characterization of different phytosomes. Supporting Information Supporting Information File 138: Additional experimental information. Acknowledgements This work received support from the

Engineered superparamagnetic iron oxide nanoparticles (SPIONs) for dual-modality imaging of intracranial glioblastoma via EGFRvIII targeting

• Xianping Liu,
• Chengjuan Du,
• Haichun Li,
• Ting Jiang,
• Zimiao Luo,
• Zhiqing Pang,
• Daoying Geng and
• Jun Zhang

Beilstein J. Nanotechnol. 2019, 10, 1860–1872, doi:10.3762/bjnano.10.181

• U87MG-EGFRvIII cells was measured by a typical MTT assay. Briefly, U87MG and U87MG-EGFRvIII cells in the logarithmic growth phase were seeded in 96-well plates with a density of 1 × 104 cells/well. After 24 h of incubation, the medium was discarded and 200 µL of fresh medium including NPs or PNPs with

Toxicity and safety study of silver and gold nanoparticles functionalized with cysteine and glutathione

• Barbara Pem,
• Igor M. Pongrac,
• Lea Ulm,
• Ivan Pavičić,
• Valerije Vrček,
• Darija Domazet Jurašin,
• Marija Ljubojević,
• Adela Krivohlavek and
• Ivana Vinković Vrček

Beilstein J. Nanotechnol. 2019, 10, 1802–1817, doi:10.3762/bjnano.10.175

• at 37 °C and 5% CO2 to allow cell attachment. The following day, AgNPs, AuNPs, AgNO3 and HAuCl4 were added to the wells in different concentrations and treated for 24 h. The MTT assay, based on the reduction of the yellow tetrazolium salt MTT (3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium

Doxorubicin-loaded human serum albumin nanoparticles overcome transporter-mediated drug resistance in drug-adapted cancer cells

• Hannah Onafuye,
• Sebastian Pieper,
• Dennis Mulac,
• Jindrich Cinatl Jr.,
• Mark N. Wass,
• Klaus Langer and
• Martin Michaelis

Beilstein J. Nanotechnol. 2019, 10, 1707–1715, doi:10.3762/bjnano.10.166

• cultured in the presence of the indicated drug concentrations. The cells were routinely tested for mycoplasma contamination and authenticated by short tandem repeat profiling. Cell viability assay Cell viability was determined by 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) assay

• . Doxorubicin sensitivity of UKF-NB-3, its doxorubicin-adapted sub-line UKF-NB-3rDOX20 and its vincristine-adapted sub-line UKF-NB-3rVCR1. A) Doxorubicin concentrations that reduce cell viability by 50% (IC50) as indicated by MTT assay after 120 h of incubation. B) Fold change in doxorubicin sensitivity

• available amino groups present on HSA. Preparations prepared without glutaraldehyde served as a control (Dox HSA (0%) NP). Values are expressed as concentrations that reduce cell viability by 50% (IC50) as determined by MTT assay after 120 h of incubation. Numerical values are presented in Supporting

Effects of gold and PCL- or PLLA-coated silica nanoparticles on brain endothelial cells and the blood–brain barrier

• Aniela Bittner,
• Angélique D. Ducray,
• Hans Rudolf Widmer,
• Michael H. Stoffel and
• Meike Mevissen

Beilstein J. Nanotechnol. 2019, 10, 941–954, doi:10.3762/bjnano.10.95

• had a significant effect on the expression levels of Akt or NF-κB or their respective phosphorylated forms indicating that the NPs do not modulate cell proliferation and inflammation. The fact that the MTT assay measures the metabolic activity of a cell might explain the lack of alterations in markers

Characterization and influence of hydroxyapatite nanopowders on living cells

• Przemyslaw Oberbek,
• Tomasz Bolek,
• Adrian Chlanda,
• Seishiro Hirano,
• Sylwia Kusnieruk,
• Julia Rogowska-Tylman,
• Ganna Nechyporenko,
• Viktor Zinchenko,
• Wojciech Swieszkowski and
• Tomasz Puzyn

Beilstein J. Nanotechnol. 2018, 9, 3079–3094, doi:10.3762/bjnano.9.286

• the cleavage of tetrazolium salt WST-8 (Dojindo Molecular Technologies, Inc, Japan) by mitochondrial dehydrogenases. The WST-8 assay is a development of the MTT assay, which is used for determining the cells metabolic activity. It is a colourimetric assay based on the extracellular reduction of

Cytotoxicity of doxorubicin-conjugated poly[N-(2-hydroxypropyl)methacrylamide]-modified γ-Fe₂O₃ nanoparticles towards human tumor cells

• Zdeněk Plichta,
• Yulia Kozak,
• Rostyslav Panchuk,
• Viktoria Sokolova,
• Matthias Epple,
• Lesya Kobylinska,
• Pavla Jendelová and
• Daniel Horák

Beilstein J. Nanotechnol. 2018, 9, 2533–2545, doi:10.3762/bjnano.9.236

• under Evolution 300 Trino microscope (Delta Optical; Mińsk Mazowiecki, Poland) after cell staining with 0.1% trypan blue. For long-term (72 h) cytotoxicity experiments, MTT assay was used. hMSC, HeLa, and MG-63 cells were plated (5 × 103) in 100 µL of medium per well in 96-well plates and allowed to

• , human K562 leukemia) demonstrated a similar sensitivity to Dox-conjugated nanoparticles; cell number decreased by 3–10% (Figure 6). Additionally, the long-term effect (72 h) of these nanoparticles was studied towards hMSCs, human MG-63, and HeLa tumor cells by MTT assay and compared to that of free Dox

• -MMAA)-Dox nanoparticles (Dox+NP) towards human cervix carcinoma cells of HeLa line and human osteosarcoma cells of MG-63 line (seeded 5∙103 per 100 µL), MTT assay. Agents were added in 200 µL of medium. Data are relative to the untreated controls and represent the mean +/− SD of three independent

Enhanced antineoplastic/therapeutic efficacy using 5-fluorouracil-loaded calcium phosphate nanoparticles

• Shanid Mohiyuddin,
• Saba Naqvi and
• Gopinath Packirisamy

Beilstein J. Nanotechnol. 2018, 9, 2499–2515, doi:10.3762/bjnano.9.233

• microscopic (AFM) images (Figure S1, Supporting Information File 1). The size of the nanoparticles was approximated as 163 ± 24.12 nm. MTT assay To determine the antineoplastic potential of 5-FU, CaP@5-FU NPs and CaP NPs, we performed an MTT assay in Duke’s type C colorectal adenocarcinoma (HCT-15) and lung

• and thus the enhanced toxicity in the tumour cells. The sustained release of 5-FU from the CaP@5-FU NPs, as described in the pH-triggered release study, was found to correlate with the findings of the MTT assay. The HCT-15 cell lines showed a saturation limit of the free drug after 10 µg/mL, whereas

• drug. This might be due to the mechanistic action of p-glycoprotein-mediated discharging [40] of the drug at the onset of the saturation concentration. To substantiate the biocompatibility of the nanoparticles, we extended the MTT assay to HEK-293 cells. The results obtained in this study indicate that

Biomimetic and biodegradable cellulose acetate scaffolds loaded with dexamethasone for bone implants

• Aikaterini-Rafailia Tsiapla,
• Varvara Karagkiozaki,
• Veroniki Bakola,
• Foteini Pappa,
• Panagiota Gkertsiou,
• Eleni Pavlidou and
• Stergios Logothetidis

Beilstein J. Nanotechnol. 2018, 9, 1986–1994, doi:10.3762/bjnano.9.189

• . Cytotoxicity studies were performed by using MTT assay, methylene-blue staining and SEM fixation and showed very good cell adhesion and proliferation, indicating the cytocompatibility of these fibrous scaffolds. Drug-release kinetics was measured for the evaluation of a controllable and sustained release of

• -Aldrich, Germany. N,N-Dimethylacetamide was obtained from Chem-Lab NV, Belgium. In MTT assay the cells used in this study were mice fibroblasts (L929) and phosphate-buffered saline (PBS), Dulbecco’s Modifies Eagle Medium (DMEM), 10% fetal bovine serum (FBS) and antibiotics were obtained from Gibco® Cell

• was measured at the absorption wavelength of the drug, using a 96-well plate reader (Luminometer Promega Glomax multi detection system). After that, the remaining samples were placed back in the incubator until the next measurement. In vitro cytotoxicity assays MTT assay direct test and methylene blue

Development of polycationic amphiphilic cyclodextrin nanoparticles for anticancer drug delivery

• Gamze Varan,
• Juan M. Benito,
• Carmen Ortiz Mellet and
• Erem Bilensoy

Beilstein J. Nanotechnol. 2017, 8, 1457–1468, doi:10.3762/bjnano.8.145

• assay. This cell line is recommended by the U.S. Pharmacopeial Convention (USP) for the cytotoxicity evaluation of polymeric systems and was therefore used. According to MTT assay, cell viability for L929 cells is given in Figure 6. It is clearly shown that all blank amphiphilic CD nanoparticle

• positive charge can improve drug loading capacity, slow down drug release and improve cellular interaction due to the negative charge of the cell membrane. Furthermore, unloaded or loaded nanoparticle cytotoxic effects were demonstrated with MTT assay in this study. In the light of the results of this

• µL), separately. After the L929 cells reached confluence, DMEM was removed from the cells and fresh medium containing blank amphiphilic CD nanoparticles was replaced and incubated for 48 h. In order to determine cell viability, 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) assay

Cationic PEGylated polycaprolactone nanoparticles carrying post-operation docetaxel for glioma treatment

• Cem Varan and
• Erem Bilensoy

Beilstein J. Nanotechnol. 2017, 8, 1446–1456, doi:10.3762/bjnano.8.144

• recurrence during the first 2 days. Cell culture studies Cytotoxicity assay for blank nanoparticles Mouse fibroblast cell lines L929 (recommended by the USP for the cytotoxicity evaluation of polymeric systems) were used to determine the cytotoxicity of blank nanoparticles with MTT assay. According to MTT

• . Then, DMEM was replaced with fresh medium containing blank nanoparticle formulations and incubated for 48 h. MTT assay was applied to determine cell viability. 20 µL of MTT solution in PBS (5 mg/mL) were added in each well and incubated for 4 h. 80 µL of MTT lysis solution containing SDS (23% w/v) and

• assay, cell viability for L929 cells is given in Figure 6 for 24 h and 48 h. When compared with the control group, the blank formulations were found to have no cytotoxic effect on L929 fibroblast cells (the differences between groups were statistically insignificant, p > 0.05), and it can be suggested

Facile fabrication of luminescent organic dots by thermolysis of citric acid in urea melt, and their use for cell staining and polyelectrolyte microcapsule labelling

• Nadezhda M. Zholobak,
• Anton L. Popov,
• Alexander B. Shcherbakov,
• Nelly R. Popova,
• Mykhailo M. Guzyk,
• Valeriy P. Antonovich,
• Alla V. Yegorova,
• Yuliya V. Scrypynets,
• Inna I. Leonenko,
• Alexander Ye. Baranchikov and
• Vladimir K. Ivanov

Beilstein J. Nanotechnol. 2016, 7, 1905–1917, doi:10.3762/bjnano.7.182

• (CV assay) and the (3-(4,5-dimethylthiazolyl-2)-2,5-diphenyltetrazolium bromide) staining technique (MTT assay) [59]. The CV assay, with some modifications [60], was used to assess the total number of adhered cells. The MTT assay, with modifications [61], was used to assess the activity of NADP-H

• also known that the MTT assay is typically used for quantifying metabolically active cells, independently of proliferation [63]. Therefore, the highest concentration of sample that caused, in the treated cells, the activation of NADP-H-dependent oxidoreductases, not more than in the intact cells, was

• adjudged to be the metabolic maximum concentration (Maxmet). Each experiment was repeated three times, with four replications. The cytotoxicity of the microcapsules decorated with O-dots The toxicity of the microcapsules was studied using two tests, the aforementioned MTT assay, and the lactate

Chitosan-based nanoparticles for improved anticancer efficacy and bioavailability of mifepristone

• Huijuan Zhang,
• Fuqiang Wu,
• Yazhen Li,
• Xiping Yang,
• Jiamei Huang,
• Tingting Lv,
• Yingying Zhang,
• Jianzhong Chen,
• Haijun Chen,
• Yu Gao,
• Guannan Liu and
• Lee Jia

Beilstein J. Nanotechnol. 2016, 7, 1861–1870, doi:10.3762/bjnano.7.178

• . MTT assay A549, Hela, RL95-2 and HepG2 cells were seeded in a 96-well plate (8000 per well) and incubated for 24 h at 37 °C with 5% CO2. Blank CNs, free MIF, or MCNs were added to the well at predetermined drug concentrations (1, 10, 50, 100, 200 μg/mL), and incubated for 48 h at 37 °C with 5% CO2

• for 48 h at 37 °C before subjecting them to MTT assay. *p < 0.05 and **p < 0.01 compared with the MIF group by the Student’s t-test. In vivo plasma concentration vs time of different MIF formulations. Male SD rats were given a single 30 mg/kg dose of MIF (in soybean oil solution) or a single dose of

Multiwalled carbon nanotube hybrids as MRI contrast agents

• Nikodem Kuźnik and
• Mateusz M. Tomczyk

Beilstein J. Nanotechnol. 2016, 7, 1086–1103, doi:10.3762/bjnano.7.102

• which component of the hybrid was responsible mainly for the cytotoxicity impact. The classical MTT assay is usually applied for this purpose. However, there have been reports of high measurement error in this method with MWCNT [40], thus Trypan Blue staining of the dead cells could be more reliable

Improved biocompatibility and efficient labeling of neural stem cells with poly(L-lysine)-coated maghemite nanoparticles

• Igor M. Pongrac,
• Marina Dobrivojević,
• Lada Brkić Ahmed,
• Michal Babič,
• Miroslav Šlouf,
• Daniel Horák and
• Srećko Gajović

Beilstein J. Nanotechnol. 2016, 7, 926–936, doi:10.3762/bjnano.7.84

• effect on NSC, treated cells were assessed with regard to viability, proliferation and cytotoxicity. The MTT assay was applied to demonstrate NSC viability and proliferation. A constant amount of starting cells for culture was used and compared after 48 h of NSC proliferation in the culture. The non

• to assess the percentage of living cells (labeled with Calcein AM) and dead cells (labeled with PI). In contrast to the MTT assay, the obtained result was standardized on number of stained cells. The mean number of living cells in all tested conditions was higher than 90%. There was no difference

Synthesis, characterization and in vitro biocompatibility study of Au/TMC/Fe₃O₄ nanocomposites as a promising, nontoxic system for biomedical applications

• Hanieh Shirazi,
• Maryam Daneshpour,
• Soheila Kashanian and
• Kobra Omidfar

Beilstein J. Nanotechnol. 2015, 6, 1677–1689, doi:10.3762/bjnano.6.170

• . Moreover, the results of the MTT assay showed no significant cytotoxicity effect when the Au/TMC/Fe3O4 nanocomposites were applied in vitro. These TMC-containing magnetic nanoparticles are well-coated by Au nanoparticles and have good biocompatibility and can thus play the role of a platform or a label in

• addition, the nontoxic nature of this nanocomposite (which was explored by a 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) assay), facilitates its application in various in vitro and in vivo settings. This work focuses on the preparation process of the novel, gold-coated, iron oxide

• viability were assessed using the MTT assay. The assay was based on the reduction of the dye MTT to formazan crystals (an insoluble, intracellular, blue product) by cellular dehydrogenases. The MTT results demonstrated that no significant decrease in cell viability occurred in presence of different

Synthesis, characterization and in vitro effects of 7 nm alloyed silver–gold nanoparticles

• Simon Ristig,
• Svitlana Chernousova,
• Wolfgang Meyer-Zaika and
• Matthias Epple

Beilstein J. Nanotechnol. 2015, 6, 1212–1220, doi:10.3762/bjnano.6.124

• , determined by atomic absorption spectroscopy. The cell viability was analyzed by the MTT assay. 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyl-2H-tetrazolium bromide (MTT; Sigma, Taufkirchen, Germany) was dissolved in PBS (5 mg mL−1) and then diluted to 1 mg mL−1 in the cell culture medium. After incubation, the

Tattoo ink nanoparticles in skin tissue and fibroblasts

• Colin A. Grant,
• Peter C. Twigg,
• Richard Baker and
• Desmond J. Tobin

Beilstein J. Nanotechnol. 2015, 6, 1183–1191, doi:10.3762/bjnano.6.120

• adult skin dermal fibroblast cells (the cells targeted in skin tattooing) with both filtered and unfiltered commercially available black ink. The MTT assay results (shown in Figure 8) indicated that at an ink dilution of 1:100 the dermal fibroblast viability was reduced significantly after a one week

• exposure. A reduction in viability was also noted from similar work on gingival fibroblasts exposed to a different tattoo ink source [37]. As the MTT assay is a colourimetry-based technique, the use of dark pigments can be problematic. It was found that the lowest dilution of tattoo ink for the MTT assay

• , the MTT assay using 1:100 diluted tattoo ink showed considerable fibroblast death. The amount of cell death with filtered tattoo ink was greater than the amount of cell death using unfiltered ink, which can be attributed to the subsequent reduction in tattoo ink particle size. Experimental Particle