Previous studies aimed to regenerate small intestine with material of autologous origin and using collagen sponge as a scaffolds, but the regenerated intestine lacked a smooth muscle layer. To accomplish regeneration of a smooth muscle layer, this study presently used collagen scaffolds seeded with the smooth muscle cells (SMC) in a canine model.
Material and methods:
Autologous SMC were isolated from stomach wall and cultured. Two types of scaffolds were fabricated: in SMC (+), cultured SMC were mixed with collagen solution and poured into a collagen sponge; in SMC (-), SMC were omitted. Both scaffolds were implanted into defects of isolated ileum as a patch graft. Animals were killed at 4, 8, and 12 weeks; for the last time point, the ileal loop had been reanastomosed at 8 weeks.
At 4 weeks, the graft site was infiltrated by numerous myofibroblasts in both groups. In the SMC (+) group, the SMC were sparsely distributed among myofibroblasts in the graft site. At 12 weeks the SMC (-) group showed a luminal surface covered by a regenerated epithelial cell layer with very short villi, however only a thin smooth muscle layer was observed, representing the muscularis mucosae. In the SMC (+) group, the luminal surface was covered completely by a relatively well-developed epithelial layer with numerous villi. Implanted SMC were seen in the lamina propria and formed a smooth muscle layer.
Collagen scaffolds seeded with autologous SMC were concluded to have a potential for small intestine regeneration.