title: Defect induced asymmetric pit formation on hydroxyapatite.
abstract: Defect sites on bone minerals play a critical role in bone remodeling processes. We investigated single crystal hydroxyapatite (100) surfaces bearing crystal defects under acidic dissolution conditions using real-time in situ atomic force microscopy. At defect sites, surface structure-dependent asymmetric hexagonal etch pits were formed, which dominated the overall dissolution rate. Meanwhile, dissolution from the flat terraces proceeded by stochastic formation of flat bottom etch pits. The resulting pit shapes were intrinsically dictated by the HAP crystal structure. Computational modeling also predicted different step energies associated with different facets of the asymmetric etch pits. Our microscopic observations of HAP dissolution are significant for understanding the effects of local surface structure on the bone mineral remodeling process and provide useful insights for the design of novel therapies for treating osteoporosis and dental caries.
authors: Department of Bioengineering, University of California, Berkeley, California 94720, USA.
authors: Ki-Young
authors: KY
authors: Kwon
authors: Eddie
authors: E
authors: Wang
authors: Alice
authors: A
authors: Chung
authors: Neil
authors: N
authors: Chang
authors: Eduardo
authors: E
authors: Saiz
authors: Uh-Joo
authors: UJ
authors: Choe
authors: Maxwell
authors: M
authors: Koobatian
authors: Seung-Wuk
authors: SW
authors: Lee
mesh_terms: D017886:Durapatite / Q000737:chemistry*; D018625:Microscopy, Atomic Force; D008855:Microscopy, Electron, Scanning
chemical_list: D017886:Durapatite