Natural tissues contain highly organized cellular architecture. One of the major challenges in tissue engineering is to develop engineered tissue constructs that promote cellular growth in physiological directionality. To address this issue, micro-patterned polydimethylsiloxane (PDMS) substrates have been widely used in cell sheet engineering due to their low microfabrication cost, higher stability, excellent biocompatibility, and most importantly, ability to guide cellular growth and patterning. However, the current methods for PDMS surface modification either require a complicated procedure or generate a non-uniform surface coating, leading to the production of poor-quality cell layers. A simple and efficient surface coating method is critically needed to improve the uniformity and quality of the generated cell layers. Herein, a fast, simple and inexpensive surface coating method was analyzed for its ability to uniformly coat polydopamine (PD) with or without collagen on micro-grated PDMS substrates without altering essential surface topographical features. Topographical feature, stiffness and cytotoxicity of these PD and/or collagen based surface coatings were further analyzed. Results showed that the PD-based coating method facilitated aligned and uniform cell growth, therefore holds great promise for cell sheet engineering as well as completely biological tissue biomanufacturing.
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Highlights • A simple and plasma etching-independent polydopamine (PD) based surface coatings were created on micro-grated polydimethylsiloxane (PDMS) substrates. • PD as well as PD and collagen (PD/collagen) coatings do not alter overall surface topography of micro-grated PDMS substrates. • PD and PD/collagen coatings significantly increased surface elastic modulus and hydrophilicity of micro-grated PDMS substrates compared to pristine PDMS, enabling better cell adhesion. • PD and PD/collagen coatings significantly enhanced human mesenchymal stem cell (hMSC) spreading on micro-grated PDMS substrates under physiological hypoxic environment, therefore are highly suitable for cell sheet culture.