Grayson W. Marshall D.D.S., M.P.H., Ph.D.
Structure-mechanical property relationships of calcified tissues
We study structure-mechanical property relationships of calcified tissues (bone, cementum, dentin, enamel). The main functions of these biological materials are mechanical, but much work is needed to understand how their unique and versatile properties are derived based on combinations of protein and mineral. We seek insight into biomineralization processes associated with these tissues during development, resulting from disease, or repair and regeneration from clinical treatments. We also focus on natural interfaces between various calcified tissues and artificial interfaces between the tissues and artificial, e.g., dental restorations, implants, bioactive substrates. We use a wide variety of approaches including atomic force microscopy (AFM); and AFM-based nano-indentation) as well as other complimentary methods including wet SEM and x-ray microanalysis, and participate in wide ranging collaborations in the Bay Area. This work helps define alteration in properties and structure with hydration state, mineral level, and variations induced by disease and physiological processes. This information is needed to develop a composite structural model of calcified tissues and can assist in the development of bio-inspired materials and tissue engineering.
H Mankani MH, Afghani S, Franco J, Launey M, Marshall S, Marshall GW, Nissenson R, Lee J, Tomsia AP, Saiz E. Lamellar spacing in cuboid HA scaffolds regulates bone formation by human bone marrow stromal cells. Tissue Eng A 2011 17:1615-1623. PMCID: PMC3098957 [
Burwell AK, Thula-Mata T, Gower LB, Habelitz S, Kurylo M, Ho SP, Chien Y-C, Cheng J, Cheng NF, Gansky SA, Marshall SJ, Marshall GW. Functional Remineralization of Dentin Lesions using Polymer-Induced Liquid-Precursor Process. PLOS ONE 2012 7(6): e38852 doi: 10.1371/journal.pone.0038852. PMCID: PMC3374775
Tousi NS, Velten MF, Bishop TJ, Leong KK, Barkhordar NS, Marshall GW, Loomer PM, Aswath PB, Varanasi VG. Combinatorial effect of Si4+, Ca2+, and Mg2+ released from bioactive glasses on osteoblast osteocalcin expression and biomineralization Mater Sci Engr C 2013 33: 2757–2765.
Chien Y-C, Burwell AK, Saeki K, Fernandez-Martinez A, Pugach MK, Nonomura G, Habelitz S, Ho SP, Rapozo-Hilo M, Featherstone JD, Marshall SJ, Marshall GW Distinct decalcification process of dentin by different cariogenic organic acids: Kinetics, ultrastructure and mechanical properties. .Archives of Oral Biology 2016 63: 93-105.. PMCID: PMC4851108