Multiphoton Microscopic Imaging Of Skin Injuries

Skin wounds refer to the damages of the integrity in structure and function or the lack of the components in tissues. Skin wound healing is the process of tissue repair by hyperplasia or regeneration, which always results in the formation of scars. It will cause both aesthetic and functional defects and affect the life level of patients. It is of critical importance to in-time diagnose and monitor the skin wound healing for prevention and treatment of scars. Multiphoton microscopy (MPM) based on second harmonic generation (SHG) and two-photon excited fluorescence (TPEF), with the advantages of reduced specimen photo-bleaching, enhanced penetration depth and high resolution, has been widely used in biomedical fields. In this study, we use the MPM technology to visualize and quantitatively analyze the process of cutaneous wound healing, demonstrating that this technology has the potential to diagnose scars and monitor wound healing in clinical application. Firstly, MPM was employed to examine the full-thickness skin in rabbit dorsal skin and the results showed that this technology can provide the detailed information of microstructure in normal skin tissues. And then, MPM was applied to characterize the morphology of uninjured skin, normal and pathological scars, providing the morphological reference for clinical diagnosis of skin scars and monitoring the process of wound healing. At last, MPM was employed to monitor the process of cutaneous wound healing in rat skin in vivo, via imaging the three main stages of wound healing. Meanwhile, the results from quantitative analysis of collagen contents and orientation showed significance between wounds at varied stages. Our results suggested that MPM has the ability to noninvasively diagnose and monitor wound healing, providing real-time information for clinicians and plastic surgeons to establish more effective treatment strategies.