Is there an ideal animal model to study hypertrophic scarring?

Wound healing in hypertrophic scarring and keloid animal models presents significant differences when compared with humans. A brief review is presented about hypertrophic scarring in animal models during the last 5 years. Models were described by animals and scientific artifices to cause hypertrophic scarring. They were divided into 1) heterologous hypertrophic scarring or keloid implants in immunodeficient animals (athymic mice and rats); 2) heterologous hypertrophic scarring or keloid implant in immune privileged site (hamster cheek pouch); 3) hypertrophic scarring or keloid induction via chemically mediated injury (guinea pigs); 4) hypertrophic scarring or keloid induction in anatomic specific site (rabbit ear); and the 5) porcine model. The ideal model would allow to research pathophysiology, histology, and molecular events during time and to test prophylactic and therapeutic treatments for humans. Some of these animals were useful to study specific steps of the scarring process and better understand abnormal wound healing, but none of them have a widespread use. Most recently, the female red Duroc pigs were validated as a new model, demonstrating its similarity to human conditions in different ways. Full-thickness human skin grafts in nude mice also represent improvement in the search of an ideal hypertrophic scarring animal model.