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

OBJECTIVETo investigate the effect and mechanism of FTY720 on acute graft versus host disease (GVHD) in rat small bowel transplantation (SBTx).

METHODSHeterotopic SBTx was performed using a parent (WF)-into-F1 (WFxACI) rat combination. Recipient rats were divided into experimental group (n=6) and control group (n=6). Rats in the experimental group were administered with FTY720 at 0.5 mg/kg for 14 days. Lymphocyte apoptosis in the liver and the mucosa of intestine and graft was detected by TUNEL and flow cytometry 15 days after transplantation. Recipient survival and lymphocyte apoptosis were compared between the two groups.

RESULTSRecipients in the control group died of GVHD after a mean survival time of (16+/-2.1) days. FTY720-treated recipients had a significantly longer survival (>100 days). After administration of FTY720, the percentage of apoptotic lymphocytes was significantly increased in the graft as compared to that in the control group by flow cytometry. The ratio of apoptotic lymphocyte in the liver and graft was also significantly higher in the experimental group by TUNEL.

CONCLUSIONFTY720 effectively induces the lymphocyte apoptosis, inhibits the lesion of target tissues by GVHD, and prolongs the recipient survival.

Animals ; Apoptosis ; drug effects ; Fingolimod Hydrochloride ; Graft vs Host Disease ; immunology ; prevention & control ; Immunosuppressive Agents ; pharmacology ; Intestine, Small ; transplantation ; Lymphocytes ; cytology ; drug effects ; Male ; Propylene Glycols ; pharmacology ; Rats ; Rats, Inbred WF ; Sphingosine ; analogs & derivatives ; pharmacology ; Transplantation, Heterotopic