Bio-mimicked Leaf-Imprinted Topographies: Pattern Characterization and Cell Response

Proper alignment of cells is crucial for functioning of various tissues such as skeletal muscle tissues, neural cells, adipose-derived stem cells, etc. Current in-vitro fabrication methods to replicate the cellular environment, e.g., photolithography and 3D printing, are not cost-effective and cannot capture the complexity of the surfaces to which these cells are exposed to. In this work, we used bio-mimicked leaf templates to closely resemble the in-vivo environment the muscle cells and cultured C2C12 cells, myoblast cell lines, on modified PDMS substrates fabricated using these leaf templates. Using image analysis software, we analyzed the degree of alignment of cells, aspect ratio and the area projected by individual cells cultured on these surfaces. The C2C12 cells cultured on the PDMS substrates formed utilizing the front and back sides of the leaves of Musaceae Banana were found to have an Aspect Ratio of 6.3 and 8.3, the highest among the surfaces studied in this paper. C2C12 cells cultured had the highest degree of alignment on the negative replica of the back side of Dracaena Sanderiana. Due to the availability of a wide range of leaf templates and bio-mimicked surface structures to measure cell response, it is difficult to find the optimal design. Hence, we have also tried to create a catalog using 15 different leaf surfaces and characterized these surfaces into various categories based on the grooves on the surfaces to provide a more comprehensive set of surface designs for studying cell behavior. To quantitatively analyze the groove pattern, 2D FFT analysis was also performed to find the dominant wavelength of the grooves. In surface characterization, hydrophobicity is also a parameter that needs to be considered; hence, the water contact angle of these surfaces was also measured. Our findings highlight the importance of surface topography and hydrophobicity in influencing cell alignment and can contribute to developing biomimetic surfaces for tissue engineering applications.