Cytotoxicity testing

FIGURE 9.10 In vitro cytotoxicity testing of individual components of recombinant resilin curing polymer system. The light gray areas represent green fluorescence, evidence of live cells, (a) Ammonium persulphate... 

Based on these results, compounds were tested at five doses for CTA (Fig. 8). Cells were seeded at a density of 3 x 104 cells/60 mm dish, incubated for 48 h and then exposed to the tested compound at concentrations previously determined by the cytotoxicity test. Ten replicates were carried out for each treatment. 

Riddell RJ, Panacer DS, Wilde SM, et al. 1986. The importance of exposure period and cell type in in vitro cytotoxicity tests. Altern Lab Anim 14 86-92. 

Fig. 21. Molecular structures of new aromatic [M(ATSM)] analogs (a) M — Zn(II) and (b) M = Cu(II), (c) cytotoxicity tests in MCF-7 cells for the Zn(II) complex (group 2) and Cu(II) complex (group 3) and comparison with control and with cis-platin over a range of concentrations, (d) cell uptake profile monitored over 90 min, (e) confocal fluorescence imaging of Zn(II) complex in MCF-7 cells, at 100 pM cone, in DMEM, 1% DMSO (112,113).

The poor response of the synthetic polymers in the cytotoxicity tests with insulinoma cells (Table 4) provides further support for the utilization of polyanions as the inner cell suspending fluids. Given the rigid nature of the moderate molecular weight anionic polysaccharides, it seems reasonable that low molecular weight polycations can be effective in membrane formation, due to their high diffusivity. This will be elaborated upon in the discussion. 

Preliminary Cytotoxicity Testing. An essential first step is to carry out a preliminary study to evaluate the toxicity of the test material to the indicator cells, under the conditions of the main mutagenicity test. When selecting dose levels, the solubility of the test compound, the resulting pH of the media, and the osmolality of the test solutions all need to be considered. The latter two parameters have been known to induce false positive effects in in vitro mammalian tests (Brusick, 1986). The experimental procedure is carried out as follows. 

Zorn-Kruppa M, Tykhonova S, Beige G, Diehl HA, Engelke M. Comparison of human corneal cell cultures in cytotoxicity testing. ALTEX 21 129-134 (2004). 

Historically, in vitro cytotoxicity tests have not been effective in predicting human toxicity potential [11]. This has been attributable largely to insufficiency of duration of... 

As occurred with the introduction of in vitro testing for adverse pharmacokinetic properties, implementation of in vitro cytotoxicity testing in drug discovery is likely to reduce later attrition in drug development by an order of magnitude. An indispensable tool will be HCA and a cytotoxicity model similar to that described above. Attendance at the numerous annual industry conferences on HCA indicates that... 

Liebsch, H.M. and Spielmann, H. (1995) Balb/c 3T3 cytotoxicity test. Methods in Molecular Biology, 43, 177-187. 

The cytotoxicity test described in ISO 10993-5 is a good example. It is a rapid, standardised test, very sensitive and can characterise materials and significant quantities of harmful extractables and their effect on cellular growth. Because of the high sensitivity, mouse fibroblasts L929 are used as the test cells routinely. 

Various standards and procedures exist for the evaluation of the biological and immunotoxicity response of an implant [81] from the point of view of biocompatibility. Acute toxicity screening and in vivo implantation tests are fundamental in this respect. Cytotoxicity testing to detect the biological activity of the material on a mammalian cell monolayer is often the first step in assessing biocompatibility of a device. An international standard on the biological evaluation... 

Besides their utilization in the production of many compounds with therapeutic, diagnostic, and immunizing applications, animal cell cultures have undoubted utility in the performance of in vitro cytotoxicity tests. They can be used for the evaluation of potential anti-neoplastic agents and assessment of the safety of various products, such as pharmaceuticals, cosmetics, alimentary additives, pesticides, and industrial chemical products. Cell culture systems are frequently employed in the cancer chemotherapy field, in which their potential value for viability and cytotoxicity tests is largely accepted. Animal models play an important role in toxicity testing, but the pressure to adopt in vitro tests is growing since they present considerable economical advantages over in vivo tests. The use of animal models is limited to human metabolism studies, and there are... 

The monolayer culture technique is frequently employed in cytotoxicity tests with cancer lines and in studies of chemical sensitivity of different tumor types. This method offers high flexibility with respect to drug exposure and recuperation conditions, as well as to the quantification of any effect. Among all methods, cell culture in a monolayer requires a lower cell number and allows the evaluation of multiple drugs in large concentration ranges. 

Cytotoxic tests were performed using two cell lines and the MTT [3, (4,5-dimethylthiazoyl-2-yl) 2,5 (diphenyl-tetrazolium bromide] rapid colorimetric assay. Cytotoxicity test with MTT showed no enhancement of cytotoxicity by modified proteins and their peptic and tryptic peptides against COS-7 and HL-60 cells after glycation. 

Cytotoxicity tests to determine the biological reactivity of monolayer cell cultures to the... 

Cells for cytotoxicity testing are seeded in a 96-well plate (10,000 cells/well) and grown for 4 days in a final volume of 100 pL cell culture medium/well in a humidified atmosphere with 5% C02 and a temperature of 37°C. 

Benford DJ, Reavy HJ, Hubbard SA. 1988. Metabolizing systems in cell culture cytotoxicity tests. Xenobiotica 18 649-656. 

Voisin C, Aerts C, Pommery-Dutriez N, et al. 1981. Effects of gaseous pollutants on alveolar macrophages An in-vitro cytotoxicity test using cellular cultures in gas phase. In Meeting European Society for Clinical Respiratory Physiology, Gothenburg, Sweden, June 2-5, 1981. Eur J Respir Dis Suppl 62 187-188. 

This confirms that there are many fundamental similarities between fish- and mammalian cells with respect to cellular mechanisms and toxic responses. The conclusion is important from a hazard assessment point of view, because by accepting that results from mammalian cytotoxicity test as representative for fish, and in a longer range ecotoxicity, the knowledge base for assessments is increased. 

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