Biomimetic three-dimensional anisotropic geometries by uniaxial stretch of poly(ɛ-caprolactone) films for mesenchymal stem cell proliferation, alignment, and myogenic differentiation
Teo, Erin Yiling
Chong, Mark Seow Khoon
Thian, Eng San
Chan, Jerry Kok Yen
Date of Issue2013
School of Chemical and Biomedical Engineering
Anisotropic geometries are critical for eliciting cell alignment to dictate tissue microarchitectures and biological functions. Current fabrication techniques are complex and utilize toxic solvents, hampering their applications for translational research. Here, we present a novel simple, solvent-free, and reproducible method via uniaxial stretching for incorporating anisotropic topographies on bioresorbable films with ambitions to realize stem cell alignment control. Uniaxial stretching of poly(ɛ-caprolactone) (PCL) films resulted in a three-dimensional micro-ridge/groove topography (inter-ridge-distance: 6 μm; ridge-length: 90 μm; ridge-depth: 200–900 nm) with uniform distribution and controllable orientation by the direction of stretch on the whole film surface. When stretch temperature (Ts) and draw ratio (DR) were increased, the inter-ridge-distance was reduced and ridge-length increased. Through modification of hydrolysis, increased surface hydrophilicity was achieved, while maintaining the morphology of PCL ridge/grooves. Upon seeding human mesenchymal stem cells (hMSCs) on uniaxial-stretched PCL (UX-PCL) films, aligned hMSC organization was obtained. Compared to unstretched films, hMSCs on UX-PCL had larger increase in cellular alignment (>85%) and elongation, without indication of cytotoxicity or reduction in cellular proliferation. This aligned hMSC organization was homogenous and stably maintained with controlled orientation along the ridges on the whole UX-PCL surface for over 2 weeks. Moreover, the hMSCs on UX-PCL had a higher level of myogenic genes' expression than that on the unstretched films. We conclude that uniaxial stretching has potential in patterning film topography with anisotropic structures. The UX-PCL in conjunction with hMSCs could be used as “basic units” to create tissue constructs with microscale control of cellular alignment and elongation for tissue engineering applications.
Chemical and Biomedical Engineering
Tissue engineering part C: methods
© 2013 Mary Ann Liebert, Inc. This paper was published in Tissue Engineering - Part C and is made available as an electronic reprint (preprint) with permission of Mary Ann Liebert, Inc. The paper can be found at the following official DOI: [http://dx.doi.org/10.1089/ten.tec.2012.0472]. One print or electronic copy may be made for personal use only. Systematic or multiple reproduction, distribution to multiple locations via electronic or other means, duplication of any material in this paper for a fee or for commercial purposes, or modification of the content of the paper is prohibited and is subject to penalties under law.