An ear punch model for studying the effect of radiation on wound healing

Abstract

Purpose: Radiation and wound combined injury represents a major clinical challenge because of the synergistic interactions that lead to higher morbidity and mortality than either insult would produce singly. The purpose of this study was to develop a mouse ear punch model to study the physiological mechanisms underlying radiation effects on healing wounds.

Materials and methods: Surgical wounds were induced by a 2 mm surgical punch in the ear pinnae of MRL/MpJ mice. Photographs of the wounds were taken and the sizes of the ear punch wounds were quantified by image analysis. Local radiation to the ear was delivered by orthovoltage X-ray irradiator using a specially constructed jig that shields the other parts of body.

Results: Using this model, we demonstrated that local radiation to the wound area significantly delayed the healing of ear punch wounds in a dose-dependent fashion. The addition of sublethal whole body irradiation (7 Gy) further delayed the healing of ear punch wounds. These results were replicated in C57BL/6 mice; however, wound healing in MRL/MpJ mice was accelerated.

Conclusions: These data indicate that the mouse ear punch model is a valuable model to study radiation and wound combined injury.

Keywords:

• radiation
• wound healing
• combined injury
• ear punch model
• MRL/MpJ mice
• in vivo imaging

Acknowledgements

This study was supported by grants from National Institute of Health (R21 AI080525 and U19 AI067798).

Declaration of interest:

The authors report no conflicts of interest. The authors alone are responsible for the content and writing of the paper.