Carbon‐Nanogold Hierarchical Micro/Nano Topographies for Cell Guidance

Abstract Here it is reported on the fabrication of a carbon‐gold micro/nano hierarchical platform using a stimuli‐responsive wrinkling technology. The approach exploits the generation of depth wise photo‐crosslinking gradient in SU8 thin films doped with a UV light absorbing gold precursor. Wrinkled films are then pyrolyzed at 900 °C, resulting in well preserved carbonized wrinkle patterns along with the growth of GNPs. The wrinkling phenomenon is explained using a theoretical model that includes the influence of the film thickness, the gold precursor concentration, and the exposure gradient that sets the theoretical intermolecular distance of free monomers along the film's depth direction. The predicted evolution of the wrinkle patterns is supported by experimental results. Surface roughness and wetting properties of the resulting topographies are studied in detail. GNPs act as potential anchor points for cell adhesion whereas mechanical topographies controls the cellular alignment as a result of contact guidance. Fibronectin functionalization significantly improves cell attachment, biocompatibility, and provides highly aligned cell cultures. This whole strategy of fabricating non‐planar carbon/gold‐based cell culture platform has great potential for their use in lab on a chip and tissue engineering based applications.