Athanasia Kasouni

Wound healing is a great challenge in many health conditions, especially in non-healing conditions. The search for new wound healing agents continues unabated, as the use of growth factors is accompanied by several limitations. Medicinal plants have been used for a long time in would healing, despite the lack of scientific evidence veryfying their efficacy. Up to now, the number of reports about medicinal plants with wound healing properties is limited. Urtica dioica L. is a well-known plant, widely used in many applications. Reports regarding its wound healing potential are scant and sparse. In this study, the effect of an Urtica dioica L. extract (containing fewer antioxidant compounds compared to methanolic or hydroalcoholic extracts) on cell proliferation, the cell cycle, and migration were examined. Additionally, antioxidant and anti-inflammatory properties were examined. Finally, in vivo experiments were carried out on full-thickness wounds on Wistar rats. It was found that the extract increases the proliferation rate of HEK-293 and HaCaT cells up to 39% and 30% after 24 h, respectively, compared to control cells. The extract was found to increase the population of cells in the G₂/M phase by almost 10%. Additionally, the extract caused a two-fold increase in the cell migration rate of both cell lines compared to control cells. Moreover, the extract was found to have anti-inflammatory properties and moderate antioxidant properties that augment its overall wound healing potential. Results from the in vivo experiments showed that wounds treated with an ointment of the extract healed in 9 days, while wounds not treated with the extract healed in 13 days. Histopathological examination of the wound tissue revealed, among other findings, that inflammation was significantly reduced compared to the control. Urtica dioica L. extract application results in faster wound healing, making the extract ideal for wound healing applications and a novel drug candidate for wound healing.

Carbon nanodots (CNDs) are more and more being exploited for various applications including biological ones. To this end, they have been thoroughly studied for their potential as antibacterial, wound healing, and bioimaging agents. In this study, we examined the sun protection properties of CNDs. Dunaliella salina was selected as a promising precursor for the synthesis of CNDs which were compared with those produced by citric acid, a widely used precursor for such materials. The CNDs were examined spectrophotometrically, and the sun protection factors were calculated. Additionally, in vitro experiments were carried out to evaluate their UV protection properties and to obtain better insight into whether CNDs are suitable to be used as filters for the development of new sunscreens. The results were conclusive that both CNDs possess favorable properties that potentiate their use for the development of sunscreens. However, the CNDs from Dunaliella salina were found to be superior to those derived from citric acid. Therefore, they can further be exploited as sun protection filters.

Carbon nanodots (CNDs) is the newest member of carbon-based nanomaterials and one of the most promising for the development of new, advanced applications. Owing to their unique and unparalleled physicochemical and photoluminescent properties, they are considered to be a rising star among nanomaterials. During the last decade, many applications have been developed based on CNDs. Among others, they have been used as bioimaging agents to label cells and tissues. In this review, we will discuss the advancements in the applications of CNDs in in the field of imaging, in all types of organisms (i.e., prokaryotes, eukaryotes, and animals). Selective imaging of one type of cells over another, imaging of (bio)molecules inside cells and tumor-targeting imaging are some of the studies that will be discussed hereafter. We hope that this review will assist researchers with obtaining a holistic view of the developed applications and hit on new ideas so that more advanced applications can be developed in the near future.