Thin microporous polydimethylsiloxane membrane prepared by phase separation and its applications for cell culture

Animal experiments are often required for biological studies. However, in vitro cell culture models, such as cell-culture inserts and microphysiological systems, can provide a suitable alternative, making them essential tools in cell biology research, including the simulation of an organ environments closely related to the human body. Cell-culture inserts with porous membranes assist in recreating in vivo cell culture environments to study and process cell-culture assays. However, conventional cell culture membranes typically made of polyethylene terephthalate or polycarbonate cannot accommodate cell types that require deformable substrates. As such, this paper introduced a novel approach using spin-casting-assisted polymer-blend phase separation to create thin, flexible, and highly porous membranes for cell culture applications. Polydimethylsiloxane (PDMS) was selected as the material for the porous membrane, and polystyrene (PS) was used as a counter pair to induce phase separation with PDMS. PDMS facilitated the necessary reversible deformations during cell culture owing to its low elastic modulus. The thickness of the membrane and connectivity of the phase-separated PS domains can be adjusted, facilitating the fine-tuning of the pore size and density to improve the membrane performance. Therefore, this study successfully fabricated thin microporous PDMS membranes with improved performance over standard membranes for cell-culture inserts, namely a higher porosity, flexibility, and softness. The results of this study can enhance cell culture methodologies and contribute to a deeper understanding of cellular processes.