Linking the Geosciences to Emerging Bio-Engineering Technologies

Abstract

Is application of Geosciences research at Sandia National Laboratories to biological and human health systems beneficial to the lab's biotechnology efforts? This LDRD project was funded to answer that question for three application areas: biochemistry, bioengineering, and human health. The biochemistry section includes modeling for protein folding and improved drug delivery substrates. For those molecular simulations, a hybrid energy forcefield was developed to model the conformation of an oligopeptide within the clay interlayer. Results demonstrate that the nonbonded interactions are especially important in understanding the control of the structure and function of proteins as modified by inorganic substrates, and that the protein structure may be denatured by the clay surface. More sophisticated molecular simulations involving waters of solvation for the protein, hydrated clay interlayers, and different charged distributions in the clay substrates are recommended for future research. The bioengineering section focuses on drug delivery and hazardous chemical absorption through the skin. Percutaneous absorption of chemicals was developed using a probabilistic, multiphase, heterogeneous model of the skin. Penetration routes through the skin included intercellular diffusion through the stratum corneum, diffusion through aqueous-phase sweat ducts, and diffusion through oil-phase hair follicles. Mass fluxes were calculated for varying lengths of time, and sensitivity analyses showed that the aqueous solubility limit, thickness of the stratum corneum, and aqueous molecular diffusion coefficient were important input parameters. Complex flow and transport models used for enhanced oil recovery, geothermal energy production, and subsurface contaminant migration could be used to further model percutaneous absorption. The human health section includes a review of the geophysical imaging methods that have been used for imaging the interior of the human body, including electrical impedance tomography and magnetic induction tomography.Accurate 3D interpretations of surface or near surface voltage/current or electromagnetic field measurements are dependent upon the inversion algorithms used. EIT impedance inversion is computationally less challenging than EM induction inversion, but rapid and resource-efficient solutions are being developed for geophysical applications. Details of this report can be found at

Aspect‐related microclimatic influences on slope forms and processes, northeastern Arizona

“…X‐ray diffraction analysis of Morrison sandstones reveals that the major clays are smectite and kaolinite [ Tillery , 2003]. Swelling of smectites is directly related to the mass water content in soils [ Fu et al , 1990; Cygan , 2002]. Since volumetric and mass water contents in sandy materials change only slightly below −100 kPa [ Brady and Weil , 2000], we assume that only fluctuations in moisture potential above this limit are important for smectite hydration.…”

A comparative study of passive drug diffusion through human skin via intercellular and sweat duct route: effect of aging

“…Hence, based on above discussion, we can conclude that a drug diffusion through skin encounters mainly four routes (as depicted in Fig. 2), namely the intercellular route (ICR), transcellular route, and appendage route, which includes the hair follicle route (pilosebaceous unit) and sweat duct route (SDR) (Cygan et al, 2002). From the literature survey, it is found that most of the studies have been focused on diffusion through the overall skin and hair follicle route.…”

Bentonite, Bandaids, and Borborygmi

“…The transport of chemicals from the clay to the body is a complex process that involves absorption and diffusion through skin, sweat ducts, and hair follicles (Cygan et al 2002). There are no blood vessels in the epidermis (upper skin layer), so chemical transport to the blood occurs through sweat glands and hair follicles anchored in the vascular part of the dermis (lower skin layer).…”