In vivo evaluation of adipose- and muscle-derived stem cells as a treatment for nonhealing diabetic wounds using multimodal microscopy.

Impaired skin wound healing is a significant comorbid condition of diabetes, which often results in nonhealing diabetic ulcers due to poor peripheral microcirculation, among other factors. The effectiveness of the regeneration of adipose-derived stem cells (ADSCs) and muscle-derived stem cells (MDSCs) was assessed using an integrated multimodal microscopy system equipped with two-photon fluorescence and second-harmonic generation imaging. These imaging modalities, integrated in a single platform for spatial and temporal coregistration, allowed us to monitor in vivo changes in the collagen network and cell dynamics in a skin wound. Fluorescently labeled ADSCs and MDSCs were applied topically to the wound bed of wild-type and diabetic (db/db) mice following punch biopsy. Longitudinal imaging demonstrated that ADSCs and MDSCs provided remarkable capacity for improved diabetic wound healing, and integrated microscopy revealed a more organized collagen remodeling in the wound bed of treated mice. The results from this study verify the regenerative capacity of stem cells toward healing and, with multimodal microscopy, provide insight regarding their impact on the skin microenvironment. The optical method outlined in this study, which has the potential for in vivo human use, may optimize the care and treatment of diabetic nonhealing wounds.