An Improved Humanized Mouse Model for Excisional Wound Healing Using Double Transgenic Mice.

Splinting full-thickness cutaneous wounds in mice has allowed for a humanized model of wound healing. Delineating the epithelial edge and assessing time to closure of these healing wounds via macroscopic visualization have remained a challenge. Double transgenic mice were created by crossbreeding K14-Cre and ROSA reporter mice. Full-thickness excisional wounds were created in K14-Cre/ROSA mice ( = 5) and imaged using both normal and fluorescent light on the day of surgery, and every other postoperative day (POD) until wound healing was complete. Ten blinded observers analyzed a series of images from a single representative healing wound, taken using normal or fluorescent light, to decide the POD when healing was complete. K14-Cre/ROSA mice ( = 4) were subsequently sacrificed at the four potential days of rated wound closure to accurately determine the histological point of wound closure using microscopic fluorescence imaging. Average time to wound closure was rated significantly longer in the wound series images taken using normal light, compared with fluorescent light (mean POD 13.6 vs. 11.6, * = 0.008). Fluorescence imaging of histological samples indicated that reepithelialization was complete at 12 days postwounding. We describe a novel technique, using double transgenic mice K14-Cre/ROSA and fluorescence imaging, to more accurately determine the healing time of wounds in mice upon macroscopic evaluation. The accuracy by which wound healing can be macroscopically determined in mouse models of wound healing is significantly enhanced using K14-Cre/ROSA double transgenic mice and fluorescence imaging.