269 Agent-based computational modeling of the human epidermis and applications

Abstract

The ontogenesis and maintenance of human epidermis is well documented in the scientific literature. Under physiological conditions, processes such as epidermal cell proliferation, differentiation and eventual desquamation from the skin surface are coordinated to support epidermal homeostasis. We have developed an agent-based computational model of the human epidermis that recapitulates the biochemical and biomechanical aspects of the tissue physiology. Modeling is performed at the individual cell (“agent”) level and multiple agents are then allowed to follow their programming and interact with their neighbors. Although all programing is done at the cellular level, emerging properties of the system are manifested at the tissue level, such as dynamic steady state of the stratified epidermis, barrier to water loss as well as to external penetration of topical substances, steady state water and calcium profiles qualitative similar to the ones in the literature, etc. By appropriately adjusting the rate constants of the processes at the cellular level we have been able to achieve distinct tissue architectures corresponding to adult and infant epidermis. This approach allows us to perform experiments in silico by perturbing the system and monitoring its behavior, such as following complete removal of the Stratum Corneum. Moreover, the model was able to recapitulate clinical data of: a) the effects of a topical moisturizer, b) the dynamics of tissue penetration of a topically applied agent, c) skin barrier-related effects of topical treatment with a surfactant, and d) effects of a barrier-enhancing topical agent. In conclusion, computational modeling is a valuable tool for studying epidermal behavior and demonstrating product effects, which can be used to provide design guidelines for topical product development.