Despite the fact that numerous attempts have been made to recreate the complex extracellular matrix (ECM) that regulates cell fate, most of them have focused on three-dimensional (3D) culture models. Nevertheless, these models are not suitable for high-throughput screening and quantification of intracellular mechanics due to their structurally undefined surface characteristics. On the other hand, highly structured surfaces (2 1/2D) comprising various micro- and nano-patterns (created by physical patterning as well as chemical treatment), hold great promise as they can induce a crossover from 2D to 3D cell behavior, simulate the cellular natural microenvironment without compromising reproducibility, and facilitate the characterization of inter- and intra- cellular interactions.
In this work, we present the results obtained from culturing MDA-MB-231 breast cancer cells on various laser-patterned and biochemically-modified silicon as well as PDMS surfaces. Silicon wafers were patterned by a nanosecond Q- switched Nd:YAG laser system (355 nm, 532 nm, and 1064 nm wavelength) to introduce a variety of surface morphologies, including microspikes, ripples, and craters. In parallel, PDMS surfaces of different Young’s moduli were treated both with plasma as well as acid solutions to render them hydrophilic, but also to induce the formation of rippled nanostructures. Both types of substrates were then incubated with different proteins of the ECM. Collectively, the obtained substrates allowed for a great plethora of variables (stiffness, morphology, biochemical cues) and their effect on cell cultures was studied.
Our preliminary data have shown that certain morphologies promote increased cell survival, as revealed by cell proliferation assays (cell counting kit 8 (CCK8)). In addition, the metastatic ability of the MDA-MB-231 cells was enhanced or inhibited at specific surfaces, as it was demonstrated by the rearrangement of cytoskeletal filaments (phalloidin staining), a marker of their migratory potential.
Τhe obtained results could be used to establish a pipeline towards the identification of the most appropriate structural modifications for a cell line or co-culture system and the creation of an application-specific pattern library, which could be exploited in drug screening and personalized medicine as well as in tissue engineering and regeneration.
Acknowledgements: This research is co-financed by Greece and the European Union (European Social Fund – ESF) through the Operational Programme “Human Resources Development, Education and Lifelong Learning 2014 – 2020 in the context of the project “Novel studies of cell interactions on nanostructured surfaces (MIS 5048213)”.