Galvanic microparticles increase migration of human dermal fibroblasts in a wound-healing model via reactive oxygen species pathway.

Electrical signals have been implied in many biological mechanisms, including wound healing, which has been associated with transient electrical currents not present in intact skin. One method to generate electrical signals similar to those naturally occurring in wounds is by supplementation of galvanic particles dispersed in a cream or gel. We constructed a three-layered model of skin consisting of human dermal fibroblasts in hydrogel (mimic of dermis), a hydrogel barrier layer (mimic of epidermis) and galvanic microparticles in hydrogel (mimic of a cream containing galvanic particles applied to skin). Using this model, we investigated the effects of the properties and amounts of Cu/Zn galvanic particles on adult human dermal fibroblasts in terms of the speed of wound closing and gene expression. The collected data suggest that the effects on wound closing are due to the ROS-mediated enhancement of fibroblast migration, which is in turn mediated by the BMP/SMAD signaling pathway. These results imply that topical low-grade electric currents via microparticles could enhance wound healing.

Biomimetic electrical stimulation platform for neural differentiation of retinal progenitor cells.

Electrical activity is abundant in early retinal development, and electrical stimulation has been shown to modulate embryonic stem cell differentiation towards a neuronal fate. The goal of this study was to simulate in vitro retinal developmental electrical activity to drive changes in mouse retinal progenitor cell (mRPC) gene expression and morphology. We designed a biomimetic electrical stimulation protocol based on spontaneous waves present during retinal development, and applied it to retinal progenitor cells (RPCs) over 3 days of culture. Analysis of protein localization and calcium dynamics, indicate that mRPCs undergo functional neuronal maturation. Our findings suggest that this type of electrical stimulation may be utilized for application in neural tissue engineering and open possibilities for understanding mechanisms guiding active electric membrane development and functional organization during early retinogenesis.