Demond Handley, M.S.


Education: Bachelor of Science in mathematics (May 2018)

Master of Science in biomathematics, bioinformatics, and computational biology at Illinois State University

Currently pursuing a Doctor of Philosophy in biostatistics at Ohio State University

McNair Project: Parameter Estimation in the Mathematical Modeling of the Skin Absorption of 14 Natural Compounds (2017)

Mentor: Majid Jaberi-Douraki, Ph.D.

Natural compounds consisted of essential oils and plant extracts are often consumed in the pharmaceutical and cosmeceutical industries. For this purpose, a surge of interest in chemical compounds to the perception of natural origin has been observed for the past decade, but to take into consideration the effects of these compounds on the skin as absorbed over time, it requires developing novel mathematical models. Parameter estimation is an important part of mathematical modeling, especially in the case of dermal absorption where rates must be determined for measurement of the permeant as it penetrates from one layer of the next over a predetermined period. This study is concerned with the estimation of flux parameters using a physiologically based mathematical model. The model consisted of a system of ordinary differential equations designed to measure concentration of a permeant over time. We estimated the flux parameters for measuring the dermal absorption of fourteen natural compounds along with a control compound, ethanol. We also determined the percent flux as the permeant passed through the skin surface, stratum corneum and viable skin layers. Once the parameters were optimally estimated, Markov Chain Monte Carlo methods were employed to discover the distribution of each parameter. Sensitivity Analysis using the extended Fourier Amplitude Sensitivity Test method determined which parameters caused the most effect on the model output.