Light-Responsive Bilayer Cell Culture Platform for Reversible Cell Guidance.

In vivo, cells are surrounded by a constantly changing microenvironment, which regulates many cell functions such as differentiation, migration, and cell death. Stimuli-responsive biomaterials aim to mimic this interaction between cells and extracellular matrix in vitro. However, reproducing dynamic signaling noninvasively without affecting the cell viability remains a challenge. Herein, a dynamic cell culturing platform consisting of a light-responsive azobenzene molecular glass film and a protective polydimethylsiloxane (PDMS) coating is developed. By tuning the PDMS layer thickness, surface relief gratings (SRGs) can be efficiently photoinscribed on the platform surface. The SRGs can also be erased with light in the presence of PDMS, i.e., the topography can be reversibly photomodulated. The inscribed SRGs can guide epithelial cell orientation along the topography. The erasure parameters are targeted toward cell culturing environment, enabling experiments with live cells. Finally, the photoresponsive platform is patterned with proteins by microcontact printing, allowing its biofunctionalization and the combination of microtopography and protein patterns. This study paves the way for using reconfigurable cell culture platforms for the dynamic control of cell-material interactions. The PDMS coating has potential to protect underneath material, broadening the spectrum of possible materials for dynamic cell culture platforms.