Abstract

Surface engineering of polydimethylsiloxane for stem cell based on-chip tissue regeneration

Yuejun Kang, Assistant Professor of Bioengineering, Nanyang Technological University

Polydimethylsiloxane (PDMS) has been extensively exploited to study stem cell physiology in the field of mechanobiology and lab-on-a-chip devices due to their transparency, low cost and ease of fabrication. Maintenance of stem cell adhesion on the substrate surface is crucial in determining the cell viability, proliferation and differentiation. However, the intrinsic hydrophobicity of PDMS renders a surface incompatible for prolonged cell adhesion and proliferation. Plasma-treated or protein-coated PDMS shows some improvement but these strategies are often short-lived with either cell aggregates formation or cell sheet dissociation from the substrate. Recently, chemical silanization of PDMS surfaces using (3-aminopropyl)triethoxy silane (APTES) and cross-linker glutaraldehyde (GA) has proved to be able to immobilize matrix proteins such as fibronectin and collagen, thereby stabilizing long-term stem cell culture and maintaining their multi-potency. Meanwhile, the chemicals and tedious procedures involved in this surface treatment are not user- and eco-friendly. To address this critical issue, we have tailored greener and biocompatible PDMS surfaces by developing a one-step bio-inspired polydopamine coating strategy to stabilize long-term mesenchymal stem cell (MSC) culture on PDMS substrates. Characterization of the polydopamine-coated PDMS surfaces has revealed changes in surface wettability and presence of hydroxyl and secondary amines as compared to uncoated surfaces. These changes in PDMS surface profile contribute to the stability in MSC adhesion, proliferation, cell sheet integrity and multipotency. This simple methodology can significantly enhance the biocompatibility of PDMS-based lab-on-a-chip devices for long-term stem cell mediated tissue regeneration or mechanobiological studies.