Maintenance of Interstitial Cells of Cajal for Intestinal Smooth Muscle Engineering

Interstitial cells of Cajal (ICC) are the pacemakers that enable the oriented intestinal smooth muscle layers to contract rhythmically and autonomously. However, disruption of ICC networks has been reported in various intestinal motility disorders, which deteriorate the quality of life and life expectancy of a growing number of people in recent years. The key challenges in current intestinal smooth muscle engineering are the rapid loss of functional ICC and smooth muscle cells (SMC) in the culture. The objective of this study was to engineer functional intestinal smooth muscle with proper alignment and spontaneous rhythmic contraction by overcoming those obstacles. This was achieved by 1) developing orthogonally oriented scaffolds with aligned fibers for engineering intestinal smooth muscle in vivo; 2) identifying a reproducible culture system for in vitro maintenance of isolated ICC with pacemaker activity; and 3) engineering intestinal smooth muscle constructs with directional rhythmic contractions by implementing the functional ICC culture system into aligned scaffolds.In summary, this research yielded reproducible practices using a simple feeder cell system for in vitro expansion of isolated ICC, which enabled the development of structurally desirable intestinal smooth muscle constructs exhibiting spontaneous membrane potential oscillations and contractions over 10 weeks in vitro. The demonstrated work not only contributed to the progress of intestinal tissue engineering, but also may provide valuable information for research in intestinal motility disorders, and for other types of visceral smooth muscle engineering including the bladder and vascular system.