title: Comparison of two porcine-derived materials for repairing abdominal wall defects in rats.
abstract: OBJECTIVE
  The purpose of this study was to compare the mechanical properties, host responses and incorporation of porcine small intestine submucosa (PSIS) and porcine acellular dermal matrix (PADM) in a rat model of abdominal wall defect repair.
  
  
  METHODS
  Prior to implantation, PSIS and PADM were prepared and evaluated in terms of structure and mechanical properties. Full-thickness abdominal wall defects were created in 50 Sprague-Dawley rats, and were repaired using either PSIS or PADM. Rats were sacrificed 1, 2, 4, 8 and 12 weeks post-repair and examined for herniation, infection, adhesions, contraction, and changes in the thickness and strength of the tissues incorporated at the defect sites. Histopathology and immunohistochemistry were performed to analyze inflammatory responses, collagen deposition and vascularization.
  
  
  RESULTS
  PADM showed more dense collagen deposition and stronger mechanical properties than PSIS prior to implantation (P<0.01). However, the mechanical properties observed after integration with the surrounding native tissues was similar for PADM and PSIS. Both PADM and PSIS showed significant contraction by week 12. However, PADM tissue induced less adhesion and increased in thickness more slowly, and showed less infiltration by foreign giant cells, polymorphonuclear cells, and mononuclear cells. Improved remodeling of host tissue was observed after PSIS implantation, which was apparent from the orientation of bands of fibrous connective tissue, intermixed with newly formed blood vessels by Week 12.
  
  
  CONCLUSIONS
  PSIS showed weaker mechanical properties prior to implantation. However, after implantation PSIS induced more pronounced host responses and showed better incorporation into host tissues than PADM.
authors.affiliation: Department of General Surgery, Shanghai Ninth Hospital affiliated to Shanghai JiaoTong University School of Medicine, Shanghai, China.
authors.forename: Zhengni
authors.initials: Z
authors.lastname: Liu
authors.forename: Rui
authors.initials: R
authors.lastname: Tang
authors.forename: Zhiyuan
authors.initials: Z
authors.lastname: Zhou
authors.forename: Zhicheng
authors.initials: Z
authors.lastname: Song
authors.forename: Huichun
authors.initials: H
authors.lastname: Wang
authors.forename: Yan
authors.initials: Y
authors.lastname: Gu
mesh_terms: D034861:Abdominal Wall / Q000473:pathology*; D000818:Animals; D001672:Biocompatible Materials / Q000494:pharmacology*; D020405:Dermis / Q000378:metabolism; D005109:Extracellular Matrix / Q000187:drug effects / Q000648:ultrastructure; D007413:Intestinal Mucosa / Q000187:drug effects / Q000648:ultrastructure; D007421:Intestine, Small / Q000378:metabolism; D008297:Male; D008422:Materials Testing; D055595:Mechanical Phenomena / Q000187:drug effects; D019919:Prosthesis Implantation; D051381:Rats; D017207:Rats, Sprague-Dawley; D013499:Surface Properties / Q000187:drug effects; D034421:Sus scrofa; D000267:Tissue Adhesions / Q000473:pathology; D054457:Tissue Scaffolds / Q000737:chemistry; D014945:Wound Healing / Q000187:drug effects*
chemical_list: D001672:Biocompatible Materials