Original Article Engineering of aligned skeletal muscle by micropatterning
Ngan F. Huang, Randall J. Lee, Song Li,
Joint Graduate Program in Bioengineering, University of California Berkeley/University of California San Francisco, Berkeley/San Francisco, CA, 94720, USA; Department of Medicine and the Cardiovascular Research Institute, University of California San Francisco, San Francisco, CA; Department of Bioengineering, University of California Berkeley, Berkeley, CA
Received August 7, 2009; accepted September 19, 2009; available online January 1, 2010
Abstract: Tissue engineered skeletal muscle has tremendous potential for the treatment of muscular injury or muscular dysfunction. However, in vitro methods to generate skeletal muscle with physiologically aligned myofiber structure remains limited. To develop a robust in vitro model that resembles the physiologically aligned structure of muscle fibers, we fabricated micropatterned polymer membranes of poly(dimethylsiloxane) (PDMS) with parallel microgrooves, and then examined the effect of micropatterning on myoblast cellular organization and the cell fusion process. In comparison to the myoblasts on non-patterned PDMS films, myoblasts on micropatterned PDMS films had well-organized F-actin assembly in close proximity to the direction of microgrooves, along with enhanced levels of myotube formation at early time points. However, expression of contractile proteins was not significantly affected by micropatterned substrates at the transcriptional and protein levels. Similar results of cellular alignment was observed when myoblasts were cultured on microfluidically patterned poly(2-hydroxyethyl methacrylate) (pHEMA) microgrooves. To apply this technology for generating aligned tissue-like muscle constructs, we developed a methodology to transfer the aligned myotubes into biodegradable collagen gels. Histological analysis revealed the persistence of aligned cellular organization in the collagen gels. Together, these results demonstrate that topographically micropatterned PDMS or pHEMA can promote cell alignment and fusion along the direction of the microgrooves, and this platform can be utilized to transfer aligned myotubes on biodegradable hydrogels. This study highlights the importance of spatial cues in creating aligned skeletal muscle for tissue engineering and muscular regeneration applications. (AJTR908001).
Address all correspondence to: Song Li, Ph.D. University of California Berkeley Department of Bioengineering Berkeley, CA 94720-1762 Tel: (510) 666-2799, Fax: (510) 666-3381 Email: song_li@berkeley.edu