Cystic Fibrosis Transmembrane Conductance Regulator: A Possible New Target for Photodynamic Therapy Enhances Wound Healing

Objective: Cell migration is an essential process in skin wound healing. Photodynamic therapy (PDT) enhances wound healing by photoactivating a photosensitizer with a specific wavelength of light. Cystic fibrosis transmembrane conductance regulator (CFTR) is an ion channel expressed in multiple layers of keratinocytes. Recent studies showed that the activation of CFTR-related downstream signaling affects skin wound healing. We examined whether indocyanine green (ICG)-mediated PDT-enhanced cell migration is related to CFTR activation. Approach: The spatial and temporal expression levels of CFTR and proteins involved in focal adhesion, including focal adhesion kinase (FAK) and paxillin, were evaluated during cell migration in vitro and in vivo for wound healing. Results: ICG-PDT-conditioned medium collected from cells exposed to 5 J/cm² near-infrared light in the presence of 100 μg/mL ICG activated CFTR and enhanced HaCaT cell migration. The expression of phosphorylated FAK Tyr861 and phosphorylated paxillin in focal adhesions was spatially and temporally regulated in parallel by ICG-PDT-conditioned medium. Curcumin, a nonspecific activator of CFTR, further increased PDT-enhanced cell migration, whereas inhibition of CFTR and FAK delayed cell migration. The involvement of CFTR in ICG-PDT-enhanced skin wound healing was confirmed in a mouse back skin wound model. Innovation: CFTR is a potential new therapeutic target in ICG-PDT to enhance wound healing. Conclusion: ICG-PDT-enhanced cell migration may be related to activation of the CFTR and FAK pathway. Conditioned medium collected from ICG-PDT may be useful for treating patients with chronic skin ulcer by regulating CFTR expression in keratinocytes.

CO2 Delivery To Accelerate Incisional Wound Healing Following Single Irradiation of Near-Infrared Lamp on the Coordinated Colloids

Traditional wound care methods include wound infection control, adequate nutritional supplements, education of changing position every 2-3 h to avoid tissue hypoxia, vacuum assistant closure, debridement, skin graft, and tissue flap. Electric current stimulation, ultrasound, laser, and hydrotherapy have emerged as adjuvant therapies. However, most, if not all, of these therapies are expensive, and the treatment results are variable. The development of the active methods to improve wound healing is mandatory. CO₂ administration has been known to improve microcirculation and local oxygen supply that are beneficial to wound healing. Here, the metal ion-ligand coordination nanoarchitecture was designed to reveal NIR light-induced CO₂ generation for wound healing. The administration simply topically dropped the colloidal solution on the incisional wound, followed by exposure of near-infrared (NIR) lamp to yield CO₂, resulting in the observation of the accelerated wound healing.