Effect of Preservation Methods on the Performance of Bovine Pericardium Graft in a Rat Model

Abstract

This study investigates the effect of preservation methods on the performance of bovine parietal pericardium grafts in a rat model. Mid-ventral full thickness abdominal wall defects of 3 x 2.5 cm in size were created in 90 male Sprague-Dawley rats (300-400 g), which were divided into three groups of 30 rats each. The abdominal defects of group one and two were repaired with lyophilized and glycerolized bovine pericardium grafts, while the defects of group three were repaired with expanded polytetrafluoroethylene (ePTFE) Mycro Mesh as a positive control. Another group of 30 rats underwent sham operation and was used for comparison as negative control. Each group of rats (n = 30) was divided into five subgroups (n = 6) and killed at 1, 3, 6, 9 and 18 weeks post-surgery for gross and morphological evaluations. The rats tolerated the surgical procedure well with a total mortality of 0.05%. No serious post-operative clinical complications or signs of rejection were encountered. Adhesions between the grafts and the underlying visceral organs observed in the study were mostly results of post-surgical complications. Glycerol preservation delayed degradation and replacement of the grafts, whereas lyophilization caused early resorption and replacement of the grafts. The glycerolized grafts were replaced with thick dense fibrous tissue, and the lyophilized grafts were replaced with thin loose fibrous tissue. The healing characteristic of the bovine pericardium grafts was similar to those of the sham-operated group, and quite different from those of the ePTFE Mycro Mesh. The outcome of the present study confirmed the superiority of glycerolized bovine pericardium grafts over its lyophilized counter part.

Tissue Engineering for Tissue and Organ Regeneration

“…It was indeed an immediate response initiated by surgical trauma when the abdominal well defects were created which perhaps correlated with the inflammatory phase of defects. A similar observations was reported by many researchers (Singh et al, 2008;Zuki et al, 2007;Gangwar et al, 2006;Gamba et al, 2002;Tung et al, 2002). Moreover, the inflammatory process is a normal response to surgical injury and the presence of implant as foreign objects.…”

“…However, there was not even a single skeletal muscle fiber formation in the implant of control groups. This finding seems consistence with previous reports of biological biomaterials mediated wound repair (Singh et al, 2008;Zuki et al, 2007;Gangwar et al, 2006;Gamba et al, 2002;Tung et al, 2002). In contrast to the above cases, in both the treatment groups (I and II), skeletal muscle tissue regeneration were clearly observed.…”

“…These are bovine parietal pericardium and bovine tunica vaginalis parietalis which were collected from abattoir and processed by freezedrying preservation methods and sterilized using gamma irradiations system. In recent years, this preservation method in combination with sterilization using gamma irradiation has been reported in its good output (Zuki et al, 2007;Hafeez, 2005;Hafeez et al, 2005aHafeez et al, , 2005b. A reason for future use of collagen-based biomaterials seems functioning as temporary scaffolds which during resorption generate new permanent tissue.…”

Lyophilized glutaraldehyde-preserved bovine pericardium for experimental atrial septal defect closure

“…The bovine collagen part, which is biological in its origin, can be digested by inflammatory cells and collagenases, like other collagenous tissues, and with time suffers cartilaginous metaplasia (Wolley, 1984;Schlosser et al, 2005). The degradation of bovine pericardium is retarded by glutaraldehyde treatment, and it is not changed by lyophilization, (Laun et al, 1990;Maizato et al, 2003;Zuki et al, 2007;Maizato et al, 2008). They also found that lyophilization decreases the inflammatory response.…”

“…Lyophilization has been used to decrease aldehyde residues in GPBP, hence decreasing cytotoxicity and enhancing resistance to calcification (Maizato et al, 2003). The lyophilized glutaraldehyde preserved bovine pericardium (LGPBP) has been tested in vitro (Maizato et al, 2003), in non anatomical lung resection (OlmosZúñiga et al, 2001), as a dural substitute (Laun et al, 1990), abdominal wall repair (Olmos-Zúñiga et al, 1996, Zuki et al, 2007 and subcutaneous implantation (Maizato et al, 2008), with good results, nevertheless in all these works the LGPBP was implanted outside the cardiovascular system, and the main factor for GPBP degradation is the contact with host blood, as well as the site of implantation and function (Pires et al, 1999;Gabbay et al, 1984).…”