Abstract |
Zinc Oxide nanoparticles (ZnO NPs) are one of the most widely used nanomaterials as industrial products in optical and electrical field, food packing and also in biomedical research. However, when they come in contact with cells under specific concentrations and above a certain period of time, they could become toxic, causing cell death. This study investigates the short-time toxicological profiles of ZnO NPs in NIH 3T3 mouse fibroblasts, in different concentrations and various time points in order to determine the minimal ZnO concentration in the cells, along with the minimum time so as to stay alive.
In this study, a very well-known polymer Polydimethylsiloxane (PDMS) plays the role of the scaffold. Such a scaffold is an artificial environment where cells can grow, differentiate and proliferate. PDMS is commonly used because of its low prices, and easy fabrication route, and it is usually replicated from a master mold, it is non- toxic, biocompatible and possess optical transparency. It plays a critical role in this study because a Non-Linear Optical Microscopy (NLOM), is going to be used in order to depict the existence of ZnO NPs along with cells, their interactions and finally their toxicity. For this reason, except biocompatibility which is necessary for cells to grow up, transparency is also an important requirement. Hence, a selection process took place. At first, the polymer Polylactic acid (PLA) (fabrication through 3D printing) is tested but without meeting all the necessary requirements. Thus, PDMS was selected as the ideal substrate in this study. Furthermore, the toxicity of ZnO NPs to cells investigated through various cytotoxicity assays such as; Live/Dead assay and, MTT assay. Also, more optical images are taken to visualize these results for Optical and Confocal microscopy.
Last but not least, it should not be forgotten that this procedure has the potential to be performed on a living organism. For this reason, attempting to simulate the natural physiological environment of cells to have a better mimicking profile (e.g., of blood flow), microfluidic chips were used. Through this way, the fluid was creating shear forces and dynamic mechanical stresses that cells would normally be exposed if there was on a living organism rather than on a static well plate.
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