title: The Anti-calcification Effect of Dithiobispropionimidate, Carbodiimide and Ultraviolet Irradiation Cross-linking Compared to Glutaraldehyde in Rabbit Implantation Models.
abstract: BACKGROUND
  Glutaraldehyde (GA) is a widely used cross-linking agent for improving mechanical properties and resistance to enzymatic degradation of collagenous tissue, but it has several drawbacks such as calcification and cytotoxicity. The aim of this study was to find the alternative effective cross-linking methods to GA.
  
  
  METHODS
  Bovine pericardium was processed with GA with ethanol+octanol and glycine detoxification, and polyethylene glycol (PG) space filler, dimethyl 3,3'-dithiobispropionimidate (DTBP), 1-ethyl-3-(3-dimethylaminopropyl) carbodiimide (EDC) treatment, and the physical fixation of ultraviolet irradiation were done. The biologic material properties of variously treated pericardial tissues were assessed by biochemical, mechanical and histological tests. Treated pericardial tissues were also implanted subcutaneously or intramuscularly into the rabbit for 10 weeks to assess the xenoreactive antibody response of immunoglobulin G and M, their anti-calcification effect.
  
  
  RESULTS
  The biochemical and mechanical properties of EDC fixed pericardial tissues were comparable to the GA fixed tissue. The cytotoxicity was lowest in space filler treated GA fixed group. In rabbit subcutaneous or intramuscular implantation models, decellularization, space filler, EDC treatment group showed significantly lower calcium content than GA only and DTBP treatment group (p<0.05, analysis of variance). The titer of anti Galα1-3Galβ1-4GlcNAc-R antibodies did not change in the postimplantation serial enzyme-linked immunosorbent assay. Hematoxylin and eosin and von Kossa staining showed that decellularization, space filler, EDC, and ultraviolet treatment had less inflammatory cell infiltration and calcium deposits.
  
  
  CONCLUSIONS
  The decellularization process, PG filler, and EDC treatments are good alternative cross-linking methods compared to GA only fixation and primary amine of DTBP treatment for cardiovascular xenograft preservation in terms of the collagen cross-linking stability and in vivo anti-calcification effects.
authors: Department of Thoracic and Cardiovascular Surgery, Seoul National University Hospital, Seoul National University College of Medicine, Korea.
authors: Samina
authors: S
authors: Park
authors: Soo Hwan
authors: SH
authors: Kim
authors: Hong-Gook
authors: HG
authors: Lim
authors: Cheong
authors: C
authors: Lim
authors: Yong Jin
authors: YJ
authors: Kim
keywords: Bioprosthesis; Glutaraldehyde; Pericardium; Polyethylene glycols; Ultraviolet