Eggshell-derived nanoparticles accelerate wound healing.

Chronic wounds (a silent epidemic) and their adverse impacts are a serious global health problem. Normal wound healing is a complex process that occurs through a series of four interconnected, partially overlapping stages: hemostasis, inflammation, proliferation, and remodelling. Angiogenesis (new vasculatures produced from pre-existing blood vessels), the proliferative phase, serves a pivotal function in wound healing. In our earlier published literature, we reported the pro-angiogenic properties of eggshell-derived nanoparticles (ES-NP). Considering the central role of angiogenesis in regulating wound healing, the present study systematically demonstrates the therapeutic efficacy of ES-NP through several in vitro assays and in vivo experiments. Wound healing involves a highly regulated process of cellular events, in which keratinocytes serve as the key mediators by driving re-epithelialization and barrier restoration. Initially, several in vitro experiments, including MTT assay, thymidine incorporation assay, cell cycle and apoptosis assay, ROS generation, and immunocytochemical analysis, were performed in human keratinocytes (HaCaT cells) to support the wound healing properties of ES-NP. We then validated the wound healing activity of ES-NP in a pre-clinical mouse (C57BL/6) model, where treatment with ES-NP significantly accelerated wound closure compared with the untreated control. The results are supported by histopathology (H&E staining), immunohistochemistry (Ki-67 and CD31/PECAM), and Masson's trichome staining (collagen deposition) of mouse skin tissue. Altogether, our findings suggest that ES-NP could be potential candidate for the treatment of wounds (acute and chronic) and other diseases where angiogenesis plays an important role.