The Pig as a Model for Human Wound Healing

Abstract

The medical literature describes numerous in vitro and in vivo wound-healing models. The selection of an animal model depends on a number of factors including availability, cost, ease of handling, investigator familiarity, and anatomical/functional similarity to humans. Small mammals are frequently used for wound healing studies, however, these mammals differ from humans in a number of anatomical and physiological ways. Anatomically and physiologically, pig skin is more similar to human skin. The many similarities between man and pig would lead one to believe that the pig should make an excellent animal model for human wound healing. The purpose of this paper is to review the existing literature for evidence of this supposition and determine how well the various models correlate to human wound healing. Studies of wound dressings, topical antimicrobials, and growth factors are examined. Over 180 articles were utilized for this comparative review. Our conclusion is that the porcine model is an excellent tool for the evaluation of therapeutic agents destined for use in human wounds.

A novel primate model of delayed wound healing in diabetes: dysregulation of connective tissue growth factor

“…More importantly, open wounds in different species heal in different ways. In humans and pigs this is mainly by the formation of granulation tissue followed by re-epithelialisation [29], whereas rodents and other mammals heal mainly by contraction of wound edges [30]. Therefore, the epithelial changes seen in open wound models in rodents do not necessarily translate to changes seen in human wounds.…”

The Limitations of In Vitro Experimentation in Understanding Biofilms and Chronic Infection

“…As with all models, some are deemed more applicable than others. For instance, porcine models lend themselves greatly to the study of chronic wound infections due to similarities of the immune response systems, spatial structuring within tissue, and wound healing processes (re-epithelialisation, scarring, and tissue granulation) [91,92]. The complexities within in vitro biofilms such as structure, gene regulation, and the production of virulence factors, has been elucidated for many problematic opportunistic pathogens.…”

Transcriptome-wide analysis of blood vessels laser captured from human skin and chronic wound-edge tissue

“…According to the National Institute of General Medical Sciences, a major sponsor of wound healing research in the United States, research to advance wound care is handicapped by the limitations of animal model systems in mimicking human wound healing (http://grants.nih.gov/grants/ guide/rfa-files/RFA-GM-06-002.html). Indeed, a vast majority of current wound healing research is based on rodent and in vitro studies, which have limited resemblance with the chronic human wound (2). Few studies use the preclinical porcine model, which has been estimated to agree with human studies 78% of the time (2).…”

“…Indeed, a vast majority of current wound healing research is based on rodent and in vitro studies, which have limited resemblance with the chronic human wound (2). Few studies use the preclinical porcine model, which has been estimated to agree with human studies 78% of the time (2). The study of experimental acute biopsy wounds in humans is valuable in many ways but does not resemble the chronic wounds that represent the most significant problem (3).…”