Behavior of neuro-2a cells on femtosecond laser structured silicon substrates

Thesis Type: Postgraduate

Institution Of The Thesis: Middle East Technical University, Graduate School of Natural and Applied Sciences, Micro and Nanotechnology, Turkey

Approval Date: 2020

Thesis Language: English


Principal Consultant (For Co-Consultant Theses): Alpan Bek

Co-Consultant: Çağdaş Devrim Son


Cells are known to interact with their physical environment and respond to cues such as substrate topography. Knowledge of the cell responses to topography may give information about cell behavior in health and disease, as well as be exploited in order to exert control on cells for various purposes. Cell responses to topography are dependent on cell type, substrate material and topographical features. In the present study, Neuro-2a cell line was used as a versatile and widely available neuronal cell model. The substrates consisted of polished or laser-structured silicon. Structuring was performed using an ultrafast infrared pulsed laser, which generated topographies such as laser induced periodic surface structures (LIPSS) and microcolumns. The substrates were characterized with scanning electron microscopy (SEM). Cells were grown on control substrates (glass or plastic), polished silicon and laser-structured silicon of different topographies for 3 hours or 24 hours to evaluate various cell behaviors. Initial cell adhesion and initial motility, as well as cell adhesion and shape after 24 hours were studied in different substrates using fluorescence microscopy and SEM. Initial cell adhesion was found to be strongest on the microcolumn topography, allowing for v selective cell patterning on microcolumn regions. After 24 hours, cell adhesion was found to be equal in all topographies. Moreover, cell motility was found to be fastest in polished silicon, and slowest in the microcolumn topography. On the other hand, cell area and perimeter was found to be larger on polished silicon and LIPSS, compared to microcolumn topography or glass. No difference was found in the average cell circularity for all substrates. Finally, cell preference for microcolumn stripes was found to be more prominent when LIPSS was found between the stripes, compared to when thee stripes were separated by flat regions. In conclusion, different cell behaviors related to spreading, migration and adhesion were found to be dependent on the substrate topography. Topography on silicon may be promising to control these behaviors in the Neuro-2A cell line.