Abstract:Cell viability assays are widely used to assess the effect chemotherapeutic drugs and other agents on cell lines and have shown promise for the prediction of tumour chemosensitivity. In this study we have compared two viability assays using Daudi and CCRF-CEM cell lines over a range of 1500-100,000 cells/well of a microplate. The ATP assay was able to detect the lower limit of 1563 cells/well with luminescence values at least 100 x background readings, while the MTT assay could not detect less than 25,000 cell… Show more
“…ATP-based cell viability assays are more sensitive than other methods. 98,99 A375 cells were seeded into 96-well tissue culture plates at a density of 10 4 cells/well. 24 hours later, cells in logarithmic phase of growth were incubated with a two-fold dilution series of the test compounds, ranging in concentration from 10 mM to 4.8 mM for 36 hours at 371C.…”
Replication-competent adenoviral vectors hold the promise to be more efficient gene delivery vehicles than their replicationdeficient counterparts, but they are also associated with a higher risk for adverse effects, especially in light of the fact that there is no established effective therapy for serious, disseminated adenovirus infection. To assess whether the therapeutic options to inhibit adenoviral replication can be enhanced by expressing a suicide gene, we examined the antiadenoviral effects of 15 drugs against wild-type adenovirus type 5 (Ad5) and an Ad5-based replication-competent vector expressing herpes simplex virus-1 thymidine kinase (HSV-tk) (Ad.OW34) using a real-time polymerase chain reaction -based assay and flow cytometry. Ad5 and Ad.OW34 were highly susceptible to the fluorinated pyrimidine analogs 5-fluoro-2 0 -deoxyuridine (FUdR), 5-fluorouridine (FUR), and trifluorothymidine (TFT), with a mean 50% inhibitory concentration (IC 50 ) ranging from 0.12 to 0.32 mM. The mean IC 50 of ribavirin and cidofovir (CDV) for Ad5, the most frequently used drugs to treat adenovirus disease, was 6.87 and 3.19 mM, respectively. In contrast to Ad5, the Ad.OW34 vector was susceptible to (E)-5-(2-bromovinyl)-2 0 -deoxyuridine (BVdU, IC 50 0.09 mM), ganciclovir (GCV, IC 50 0.19 mM), and acyclovir (ACV, IC 50 32.04 mM). Additionally, we demonstrated in an animal model that Ad.OW34 vector replication can be inhibited significantly by GCV, CDV, and TFT by 35.2, 7.7, and 3.7-fold, respectively, compared to untreated animals. The observed antiadenoviral effects were primarily not through cell killing, since the in vitro 50% cytotoxic concentrations (CC 50 ) were more than 1000 times higher than the antiadenoviral IC 50 of the drugs examined, even in cells stably expressing HSV-tk. Since for HSV-tk-dependent inhibition of adenoviral vectors, stability of HSV-tk expression is crucial, we examined Ad.OW34 vector stability, by passaging the vector 10 times serially in the presence of 10 mM GCV. The HSV-tk/GCV system neither changed the susceptibility of Ad.OW34 to GCV significantly nor detectable vector rearrangements occurred, suggesting that the system might be suitable as a fail-safe mechanism to stop adenoviral vector replication.
“…ATP-based cell viability assays are more sensitive than other methods. 98,99 A375 cells were seeded into 96-well tissue culture plates at a density of 10 4 cells/well. 24 hours later, cells in logarithmic phase of growth were incubated with a two-fold dilution series of the test compounds, ranging in concentration from 10 mM to 4.8 mM for 36 hours at 371C.…”
Replication-competent adenoviral vectors hold the promise to be more efficient gene delivery vehicles than their replicationdeficient counterparts, but they are also associated with a higher risk for adverse effects, especially in light of the fact that there is no established effective therapy for serious, disseminated adenovirus infection. To assess whether the therapeutic options to inhibit adenoviral replication can be enhanced by expressing a suicide gene, we examined the antiadenoviral effects of 15 drugs against wild-type adenovirus type 5 (Ad5) and an Ad5-based replication-competent vector expressing herpes simplex virus-1 thymidine kinase (HSV-tk) (Ad.OW34) using a real-time polymerase chain reaction -based assay and flow cytometry. Ad5 and Ad.OW34 were highly susceptible to the fluorinated pyrimidine analogs 5-fluoro-2 0 -deoxyuridine (FUdR), 5-fluorouridine (FUR), and trifluorothymidine (TFT), with a mean 50% inhibitory concentration (IC 50 ) ranging from 0.12 to 0.32 mM. The mean IC 50 of ribavirin and cidofovir (CDV) for Ad5, the most frequently used drugs to treat adenovirus disease, was 6.87 and 3.19 mM, respectively. In contrast to Ad5, the Ad.OW34 vector was susceptible to (E)-5-(2-bromovinyl)-2 0 -deoxyuridine (BVdU, IC 50 0.09 mM), ganciclovir (GCV, IC 50 0.19 mM), and acyclovir (ACV, IC 50 32.04 mM). Additionally, we demonstrated in an animal model that Ad.OW34 vector replication can be inhibited significantly by GCV, CDV, and TFT by 35.2, 7.7, and 3.7-fold, respectively, compared to untreated animals. The observed antiadenoviral effects were primarily not through cell killing, since the in vitro 50% cytotoxic concentrations (CC 50 ) were more than 1000 times higher than the antiadenoviral IC 50 of the drugs examined, even in cells stably expressing HSV-tk. Since for HSV-tk-dependent inhibition of adenoviral vectors, stability of HSV-tk expression is crucial, we examined Ad.OW34 vector stability, by passaging the vector 10 times serially in the presence of 10 mM GCV. The HSV-tk/GCV system neither changed the susceptibility of Ad.OW34 to GCV significantly nor detectable vector rearrangements occurred, suggesting that the system might be suitable as a fail-safe mechanism to stop adenoviral vector replication.
“…6,[10][11][12][13] This assay has been somewhat widely studied because its reliability was demonstrated as a sensitive measure of viability in the field of cell biology. 14,15 In this study we modified previous ATP-based assays. Our ATP-based chemotherapy response assay (ATP-CRA) adopted new methods, such as the use of ultra-low attachment culture plates to inhibit the growth of normal cells and a shortened test turnaround time.…”
“…The percentage viability of the cells is evaluated by applying Equation (7) [61] and the results obtained are grouped in Figure 10. 10.1080/15685551.2018.1521563-F0010Figure 10.Cytotoxicity test of STX-10/PAA-50 hydrogel using the MTT assay at different concentrations.…”
A series of poly(acrylic acid)/poly(methyl vinyl ketone) (PAA/PMVK) blends with different compositions were prepared by the solvent casting method. The miscibility of this pair of polymers was investigated by differential scanning calorimetry(DSC), Fourier transform infra-red (FTIR) and X-Ray diffraction (XRD) techniques. An in-vitro cytotoxicity test of the drug-carrier system via MTT (3-(4,5-demethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide) assay revealed no significant cytotoxic effects at concentrations up to 100 µg· ml−1. The STX/PAA-50 drug carrier systems were also prepared by solvent casting of solutions containing the sulfamethoxazole (STX) used as drug model and PAA/PMVK blend in N.N-dimethylformamide then crosslinked with acidified ethylene glycol. The release dynamic of STX from the prepared hydrogels was investigated in which the diffusion through the polymer matrix, the enhancement of the water solubility of STX, the influence of the initial drug concentration, the pH of the medium, and the effect of the degree of swelling of the polymer matrix on the release dynamic was evaluated. According to the total gastrointestinal transit time estimated by Belzer, the estimate distribution of STX released in the different organs indicated that the performance is obtained with the drug – carrier-system containing equal ratios of polymer and 10 wt% of STX (STX-10/PAA-50).
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