Chemical analyses of hydroxyapatite formation on SAM surfaces modified with COOH, NH(2), CH(3), and OH functions.
Hydroxyapatite formation was examined at the surface of self-assembled monolayers (SAMs) modified with four functional groups, -COOH, -NH(2), -CH(3), and -OH. For COOH-SAM and NH(2)-SAM, scanning electron spectroscopic observation showed that flake-like sheet crystals covered the whole wafer and small broccoli-like crystals were observed occasionally on the flake-like crystal base layer. For CH(3)-SAM and OH-SAM, no flake-like sheet crystals were observed; broccoli-like crystals were observed in a dispersed manner for CH(3)-SAM, but in localized spots for OH-SAM. X-ray diffraction patterns showed a strong apatite pattern oriented toward the c-axis direction for COOH-SAM. ESCA analysis revealed distinct Ca, P, O peaks for COOH-, NH(2)-, CH(3)-, and OH-SAM. Surface plasmon resonance (SPR) analysis indicated that during the supply of supersaturated calcium phosphate solution, the deposition of precipitates increased monotonically with time for COOH-SAM, increased slightly for NH(2)-SAM, but little increase in deposition was detected for CH(3)-SAM and OH-SAM.
Hirata
Isao
I
Department of Biomaterials Science, Graduate School of Biomedical Sciences, Hiroshima University, Minami-ku, Hiroshima, Japan.
Akamatsu
Mai
M
Fujii
Eri
E
Poolthong
Suchit
S
Okazaki
Masayuki
M
D001031:Apatites / Q000032:analysis / Q000737:chemistry; D002130:Calcium Phosphates / Q000032:analysis / Q000737:chemistry*; D002264:Carboxylic Acids / Q000032:analysis / Q000737:chemistry*; D011232:Chemical Precipitation; D003461:Crystallography; D017886:Durapatite / Q000032:analysis / Q000737:chemistry*; D006047:Gold Alloys / Q000737:chemistry; D006801:Humans; D006878:Hydroxides / Q000032:analysis / Q000737:chemistry*; D008567:Membranes, Artificial; D008697:Methane / Q000031:analogs & derivatives* / Q000032:analysis / Q000737:chemistry; D008855:Microscopy, Electron, Scanning; D009584:Nitrogen / Q000032:analysis / Q000737:chemistry*; D056951:Photoelectron Spectroscopy; D020349:Surface Plasmon Resonance; D017155:Wettability; D014961:X-Ray Diffraction
D001031:Apatites; D002130:Calcium Phosphates; D002264:Carboxylic Acids; D006047:Gold Alloys; D006878:Hydroxides; D008567:Membranes, Artificial; C051224:methyl radical; C031356:hydroxide ion; D017886:Durapatite; C020243:calcium phosphate; D009584:Nitrogen; D008697:Methane