Influence of channel width on alignment of smooth muscle cells by high-aspect-ratio microfabricated elastomeric cell culture scaffolds.

Engineered smooth muscle tissue requires ordered configurations of cells to reproduce native function, and microtechnology offers possibilities for physically and chemically controlling cell organization with high spatial resolution. In this work, poly(dimethylsiloxane) microchannel scaffolds, modified by layer-by-layer self-assembly of polyelectrolytes to promote cell adhesion, were evaluated for use as substrates for the culture of aligned smooth muscle cells. The hypothesis that narrower channels would result in better alignment was tested using channel width dimensions of 20, 30, 40, 50, and 60 microm, in addition to flat (control) surfaces. Alignment of cells was assessed by two different methods, each sensitive to a different aspect of cell alignment from fluorescence micrographs. Two-dimensional fast Fourier transform analysis was performed to analyze the orientation distribution of actin filaments in cells. This was complemented by connectivity analysis of stained nuclei to obtain nuclear orientation distributions. Both methods produced consistent data that support the hypothesis that narrow microchannels promote a highly aligned culture of smooth muscle cells, and the degree of alignment is dependent on the microchannel width. Precise replication of in vivo cell alignment in engineered tissue, with the ability to tailor specific surface chemistries of the scaffold to the desired application, will potentially allow the production of artificial tissue that more closely duplicates the structure and function of native tissue.