We evaluated the biological scaffold properties of canine small intestinal submucosa (SIS) compared to a those of polypropylene mesh in growing rats with full-thickness abdominal defects. SIS is used to repair musculoskeletal tissue while promoting cell migration and supporting tissue regeneration. Polypropylene mesh is a non-resorbable synthetic material that can endure mechanical tension. Canine SIS was obtained from donor German shepherds, and its porous collagen fiber structure was identified using scanning electron microscopy (SEM). A 2.50-cm2 section of canine SIS (SIS group) or mesh (mesh group) was implanted in Sprague-Dawley rats. At 1, 2, 4, 12, and 24 weeks after surgery, the implants were histopathologically examined and tensile load was tested. One month after surgery, CD68+ macrophage numbers in the SIS group were increased, but the number of CD8+ T cells in this group declined more rapidly than that in rats treated with the mesh. In the SIS group, few adhesions and well-developed autologous abdominal muscle infiltration into the SIS collagen fibers were observed. No significant differences in the tensile load test results were found between the SIS and mesh groups at 24 weeks. Canine SIS may therefore be a suitable replacement for artificial biological scaffolds in small animals.
Abdominal Wall/*surgery ; Animals ; Biocompatible Materials/*therapeutic use ; Dogs ; Female ; Intestinal Mucosa/cytology/transplantation ; Intestine, Small/cytology/*transplantation ; Polypropylenes/*therapeutic use ; Rats ; Rats, Sprague-Dawley ; Tensile Strength ; Tissue Adhesions ; *Tissue Scaffolds ; Transplantation, Heterologous/*methods ; *Wound Healing

BACKGROUND/AIMS: Bone marrow-derived cells (BMDC) contribute to tissue maintenance under many kinds of pathologic conditions. We carried out a study to see how BMDC play a role in the treatment of experimental murine colitis. METHODS: We divided the animals into 3 groups and treated them with 50% ethanol (control group), 2,4,6-trinitrobenzene sulfinic acid colitis (TNBS group), and TNBS+bone marrow transplant (BMT group). To induce colitis, TNBS (5.0 mg/mouse) dissolved in 50% ethanol was injected into anus weekly for two weeks. Bone marrow transplantations were performed using bone marrow of male transgenic mouse (donor) with green fluoresence protein (GFP) into female wild type mouse (recipient) three weeks before TNBS instillation. All animals were sacrificed, and colons were extracted one week after the last TNBS instillation. We measured microscopic scores of mucosal injury and investigated the GFP expression for bone marrow engraftment. The immunostaining of vimentin and alpha-smooth muscle actin (alpha-SMA) for myofibroblasts was performed. RESULTS: The score of mucosal injury in the TNBS group was much more severe than those in control, and reduced significantly by BMT (p<0.05). GFP-positive cells were almost deposited in pericryptal niche of BMT group but not at all in both control and TNBS group. Most of myofibroblasts stained with both vimentin and SMA also infiltrated into pericryptal niche. But, the number of myofibroblasts stained with vimentin and SMA in both control and TNBS group was smaller than that in BMT group. CONCLUSIONS: BMDC deposited on pericryptal niche might have a significant role in repairing acute experimental murine colitis.
Actins/metabolism ; Acute Disease ; Animals ; *Bone Marrow Transplantation ; Colitis/chemically induced/pathology/*surgery ; Female ; Fibroblasts/cytology ; Intestinal Mucosa/cytology ; Male ; Mice ; Mice, Inbred C57BL ; Mice, Transgenic ; Transplantation, Homologous ; Trinitrobenzenesulfonic Acid/*toxicity ; Vimentin/metabolism