Animal Models of Wound Healing
For more than 20 years I have had the opportunity to work closely with many companies in the development of their products using animal models. Together with wound healing model pioneers William H. Eaglstein, MD and Prof. Patricia M. Mertz, we have evaluated numerous dressings, devices, and topical agents on healing1–11 and studied their effects on bacteria.12–18 Our objectives have been to develop both in-vitro and in-vivo models that can be used as a springboard to assess potential therapeutics prior to their clinical application. However, transitional research from the laboratory to the clinic is not always straightforward. Addressing complex issues in the clinic takes a team approach with both basic and clinical scientists. Most patients have multiple problems that may affect the healing course and preclinical evaluations can help focus on specific therapies or treatment regimens.
I always tell companies that negative results are just as important as positive results. When first developing a product for commercial use it is very unlikely that the optimal delivery system, dose, or treatment regimen has been established. A product that may be effective in vitro may take 1000x the concentration to work in vivo. It is always prudent to include a dose response study during preclinical evaluations to determine optimal concentrations before proceeding to the clinical trials. The number of applications, which are needed to achieve optimal efficacy, should also be evaluated (eg, twice daily application may be necessary for optimal healing and/or antimicrobial activity). Translational research needs to be taken in stepwise manner. These steps included in-vitro experiments, animal studies, and clinical evaluations, respectively.
It is my pleasure to be the editor of this WOUNDS section on Animal Models of Wound Healing. I have been able to gather some of the leading experts in the field who will illustrate the many ways in which animal models can be used in studying wound healing and infection. First, my colleague Roberto Perez and I discuss the general importance of preclinical models and the benefits and disadvantages of each. Myers and Gould discuss the use of ischemic models to evaluate the importance of oxygen in the wound environment. Scherer and colleagues review the use of diabetic models to allow a better understanding of the pathophysiology of wound healing and assess a variety of therapeutic modalities.
There is no doubt of the importance of pre-clinical testing and the immense contribution that animal models have had to our comprehension of the wound healing and infection process. The animal model is an essential tool in evaluating therapeutic agents that might eventually be used at the bedside to close wounds and/or treat infection.