Silver nanoparticles are widely used for many applications. In this study silver nanoparticles have been tested for their toxic effect on fibroblasts (NIH-3T3), on a human lung adenocarcinoma epithelial cell line (A-549), on PC-12-cells, a rat adrenal pheochromocytoma cell line, and on HEP-G2-cells, a human hepatocellular carcinoma cell line. The viability of the cells cultivated with different concentrations of silver was determined by the MTT assay, a photometric method to determine cell metabolism. Dose-response curves were extrapolated and IC50, total lethal concentration (TLC), and no observable adverse effect concentration (NOAEC) values were calculated for each cell line. As another approach, ECIS (electric-cell-substrate-impedance-sensing) an automated method to monitor cellular behavior in real-time was applied to observe cells cultivated with silver nanoparticles. To identify the type of cell death the membrane integrity was analyzed by measurements of the lactate dehydrogenase releases and by determination of the caspase 3/7 activity. To ensure that the cytotoxic effect of silver nanoparticles is not traced back to the presence of Ag+ions in the suspension, an Ag+salt (AgNO3) has been examined at the same concentration of Ag+present in the silver nanoparticle suspension that is assuming that the Ag particles are completely available as Ag+ions.
Three‐dimensional (3D) printing techniques are continuously evolving, thus their application fields are also growing very fast. The applications discussed here highlight the use of rapid prototyping in a dedicated biotechnology laboratory environment. The combination of improving prototypes using fused deposition modeling printers and producing useable parts with selective laser sintering printers enables a cost‐ and time‐efficient use of such techniques. Biocompatible materials for 3D printing are already available and the printed parts can directly be used in the laboratory. To demonstrate this, we tested 3D printing materials for their in vitro biocompatibility. To exemplify the versatility of the 3D printing process applied to a biotechnology laboratory, a normal well plate design was modified in silico to include different baffle geometries. This plate was subsequently 3D printed and used for cultivation. In the near future, this design and print possibility will revolutionize the industry. Advanced printers will be available for laboratories and can be used for creating individual labware or standard disposables on demand. These applications have the potential to change the way research is done and change the management of stock‐keeping, leading to more flexibility and promoting creativity of the scientists.
The uptake of nanomaterials into different cell types is a central pharmacological issue for the determination of nanotoxicity as well as for the development of drug delivery strategies. Most responses of the cells depend on their intracellular interactions with nanoparticles (NPs). Uptake behavior can be precisely investigated in vitro, with sensitive high throughput methods such as flow cytometry. In this study, we investigated two different standard cell lines, human lung carcinoma (A549) and mouse fibroblast (NIH/3T3) cells, regarding their uptake behavior of titanium dioxide NPs. Cells were incubated with different concentrations of TiO2 NPs and samples were taken at certain time points to compare the uptake kinetics of both cell lines. Samples were analyzed with the help of flow cytometry by studying changes in the side and forward scattering signal. To additionally enable a detection via fluorescence, NPs were labeled with the fluorescent dye fluorescein isothiocyanate (FITC) and propidium iodide (PI). We found that NIH/3T3 cells take up the studied NPs more efficiently than A549 cells. These findings were supported by time-lapse microscopic imaging of the cells incubated with TiO2 NPs. Our results confirm that the uptake behavior of individual cell types has to be considered before interpreting any results of nanomaterial studies.
The fabrication of individual labware is a sophisticated task that requires dedicated machines and skills. Three‐dimensional (3D) printing has the great potential to simplify this procedure drastically. In the near future, scientists will design labware digitally and then print them three dimensionally directly in the laboratory. With the available rapid prototyping printer systems, it is possible to achieve this. The materials accessible meet the needs of biotechnological laboratories that include biocompatibility and withstanding sterilization conditions. This will lead to a completely new approach of adapting the labware to the experiment or even tailor‐made it to the organism it is being used for, not adapting the experiment to a certain standard labware. Thus, it will encourage the creativity of scientists and enrich the future laboratory work. We present different examples illustrating the potential and possibilities of using 3D printing for individualizing labware. This includes a well plate with different baffle geometries, shake flask cap with built‐in luer connections, and filter holder for an in‐house developed membrane reactor system.
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