Cytotoxicity test, for

Evaluation of biocompatibility resulted chieflyfrom clinical experience (Boutin, 1972 Hulbert, Morrison and Klawitter, 1972 Griss etal., 1973 Griss, 1984 Mit-telmeier, Heisel and Schmitt, 1987) supported by in vitro cytotoxicity testing (for example Catelas etal., 1998 Nkamgueu etal., 2000, and many other contributors). 

Although the initially reported tissue compatibility tests for subcutaneous implants of poly(BPA-iminocarbonate) were encouraging (41,42), it is doubtful whether this polymer will pass more stringent biocompatibility tests. In correspondence with the properties of most synthetic phenols, BPA is a known irritant and most recent results indicate that BPA is cytotoxic toward chick embryo fibroblasts in vitro (43). Thus, initial results indicate that poly(BPA-iminocarbonate) is a polymer with highly promising material properties, whose ultimate applicability as a biomaterial is questionable due to the possible toxicity of its monomeric building blocks. 

Tissue Culture Assay. Kogure et al. (48) report a novel tissue culture assay for detecting several types of sodium channel blockers. The mouse neuroblastoma cell line ATCC CCL 131 is grown in RPMI 1640 supplemented with 13.5% fetal bovine serum and 100 pg/ml gentamycin, in an atmosphere of 5% C0 95% air at 37 C. Ninety-six well plates are seeded with 1 x 10 cells in 200 pi of medium containing 1 mM ouabain and 0.075 mM veratridine. Veratridine and ouabain cause neuroblastoma cells to round-up and die. In the presence of sodium channel blockers (e.g., TTXs or STXs), the lethal action of veratridine is obviated and cells retain normal morphology and viability. An important feature of this assay is that a positive test for sodium channel blockers results in normal cell viability. Since bacterial extracts can contain cytotoxic components, this assay offers an advantage over tests that use cell death as an endpoint. The minimum detectable level of TTX is approximately 3 nM, or approximately 1/1000 mouse unit. 

Some of the [Au(N,0)Cl2] derivatives, namely 58a, 59a and 59b, which have been tested for cytotoxic activity against various human tumor cell lines, have shown significant effects [144]. Compound 57 is a potential alternative to dimethylgold (III) P diketonates and can be used as a starting material for gold coatings by the CVD method [140]. Recent studies have shown that the long-term stability of these... 

Many gold compounds have been tested for their potential antitumor activity by examining their cytotoxicity against cell lines in culture. This avoids barriers that arise in vivo due to uncertain absorption, restricted distribution, and variable metabolism of drugs. 

Scheme 6 Structure of coralyne derivatives and a substituent in 8-position tested for cytotoxicity and topoisomerase 1 and II poisons...

Biological evaluation of medical devices—Part 5 Tests for cytotoxicity in vitro methods. ISO 10993-5 1992(E). International Standards Organization, 1992. 

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. 

Furthermore, these compounds were found to possess growth-regulating activity [130,131]. The same compounds were tested for their cytotoxic and cytomutagenic effects. As a result, only weak mutagenic and mytostatic properties of the compounds have been detected [132],... 

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. 

Moustafa and Ahmed reported the synthesis of isoxazoles [92,93]. These compounds are related to pyrazoles except that an oxygen replaces the amine nitrogen. Scheme 49 shows the synthesis of 182 from the corresponding chal-cone 183 by reaction with hydroxylamine. Although these compounds were not tested for cytotoxicity as tubulin binders, they were found to possess antibacterial and anti-fungal activity. 

Recent studies, including the use of Microtox and ToxAlert test kits [55,56], were carried out for the determination of the toxicity of some non-ionic surfactants and other compounds (aromatic hydrocarbons, endocrine disruptors) before implementation on raw and treated wastewater, followed by the identification and quantification of polar organic cytotoxic substances for samples with more than 20% inhibition. Furthermore, the study of their contribution to the total toxicity was obtained using sequential solid-phase extraction (SSPE) before liquid chromatography-mass spectrometry (LC-MS) detection. This combined procedure allows one to focus only on samples containing toxic substances. 

Thus, cytotoxicity assays are unlikely to provide an adequate predictor of in vivo irritation in every case. There is no doubt that some type of compounds (such as surfactants) will give (and have given) acceptable correlations with in vivo data. However, for the diversity of compounds common in the pharmaceutical industry, cytotoxicity assays alone are inadequate predictors of ocular irritation, though they may have a place in a battery of tests. For instance, if one is interested in a very quick assessment that will be corroborated later, cytotoxicity assays may be indicated. But each laboratory needs to make its own evaluation of the utility and value of these methods. 

Thomson, M.A., Hearn, L.A., Smith, K.T., Teal, J.J. and Dickens, M.S. (1989b). Evaluation of the neutral red cytotoxicity assay as a predictive test for the ocular irritancy potential of cosmetic products. In Alternative Methods in Toxicology, Vol. 7 (Goldberg, A.M., Ed.). Mary Ann Liebert, New York, pp. 297-305. 

The tests for in vitro biocompatibility were performed on normal cells (Vero) and tumor cells (glioblastoma). No cytotoxicity was detected in cells (normal or tumor) cultured with red and white onion extracts at low concentrations (between 0% and 1%), the cell viability being aronnd 90%. At higher concentration, the viability decrease slowly at 80% (Fig. 41.4a). On the other hand, garlic extracts indnce toxicity both on normal and tnmor cells at very low concentrations (Fig. 41.4b). 

Finally, a good number of peptides and depsipeptides of marine origin have also been reported for their antimalarial activity. Unfortunately, this activity has often been accompanied by some strong cytotoxicity. For this reason they have mainly been tested for their anticancer activity, and many have even advanced in clinical trials. ... 

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