scholarly journals Particle-Attachment-Mediated and Matrix/Lattice-Guided Enamel Apatite Crystal Growth

ACS Nano ◽  
2019 ◽  
Vol 13 (3) ◽  
pp. 3151-3161 ◽  
Author(s):  
Jacob R. Jokisaari ◽  
Canhui Wang ◽  
Qiao Qiao ◽  
Xuan Hu ◽  
David A. Reed ◽  
...  
Biomaterials ◽  
2005 ◽  
Vol 26 (13) ◽  
pp. 1595-1603 ◽  
Author(s):  
M. Iijima ◽  
J. Moradian-Oldak

1989 ◽  
Vol 68 (9) ◽  
pp. 1331-1336 ◽  
Author(s):  
T. Aoba ◽  
E.C. Moreno ◽  
M. Kresak ◽  
T. Tanabe

The purpose of this study was to assess the functional significance of homologous sequences of mammalian amelogenins at their N- and C-termini. A porcine 5-kDa fragment corresponding to the N-terminal 45 residues of amelogenins was purified from the secretory enamel. The decapeptide TDKTKREEVD corresponding to the C-terminal 10 residues of amelogenins was synthesized according to conventional solid-phase procedures. The inhibitory activity of both moieties on apatite crystal growth was determined in a supersaturated solution having an ionic composition similar to that of the fluid phase separated from porcine secretory enamel. The 5-kDa amelogenin fragment was sparingly soluble in neutral solutions and (in condensed forms because of aggregation) showed no significant inhibition of crystal growth, whereas the fragment molecules pre-adsorbed onto the seed crystals yielded modest inhibition of hydroxyapatite precipitation. However, their inhibitory activity was significantly lower than that of parent porcine amelogenin (25-kDa molecular mass). The high solubility of synthesized decapeptide allowed us to determine the adsorption isotherm onto hydroxyapatite at 37°C, at an ionic strength similar to that of the enamel fluid. The obtained adsorption isotherm was described by a Langmuir model; the adsorption affinity and the maximum adsorption sites were 6.2 mL/μmol and 0.53 μmol/m2, respectively. As expected from the low adsorption affinity, the peptide showed a much weaker inhibition of apatite crystal growth than the parent amelogenin. All the foregoing results suggest that the adsorption onto apatite crystals and any inhibition of crystal growth by the amelogenin macromolecules cannot be associated with either partial molecular sequence, but may be determined by the whole molecular structure, including both segments at the N- and C-termini.


2001 ◽  
Vol 13 (4) ◽  
pp. 1320-1325 ◽  
Author(s):  
Thomas Höche ◽  
Cornelia Moisescu ◽  
Issak Avramov ◽  
Christian Rüssel ◽  
Wolfgang D. Heerdegen ◽  
...  

Author(s):  
F.J.G. Cuisinier ◽  
P. Steuer ◽  
J.C. Voegel ◽  
R. M. Frank

The mineral component of human dental enamel is formed by nonstoichiometric carbonated hydroxyapatite crystals. The presence of relatively large amounts of impurities in mature enamel crystals as well as their external shape are related to their growing mechanism. Enamel crystal growth was investigated previously directly with low resolution electron microscopy or by comparison with synthetic apatite crystal growth. The growing process of enamel crystals is still unknown and the aim of this study was to investigate foetal enamel growth during secretory stage by high resolution transmission electron microscopy.Developing enamel from 5 month-old human foetuses was fixed for 3 hours in a 2% glutaraldehyde and 2% paraformaldehyde solution in 0.1 M sodium cacodylate buffer. After 2 hour postfixation in 1% OsO4 in the same buffer and embedding in Epon, non decalcified ultrathin sections were obtained with a Sorvall-Porter MT-2C microtome equipped with a diamond knife and floated on demineralized water saturated against hydroxyapatite (200mg/l). The sections were observed in a Philips EM 430 transmission electron microscope operating at 300 kV equipped with a double tilt specimen holder. This microscope possessed a Sherzer resolution of 0.19 nm and the absence of drift and astigmatism was checked for each micrograph by an optical diffraction.


2018 ◽  
Vol 82 (1) ◽  
pp. 171-180 ◽  
Author(s):  
Emilia García-Romero ◽  
Mercedes Suárez

ABSTRACTEvidence of crystallization by particle attachment in synthetic materials is described in numerous contributions. However, efforts to establish the contribution of the particle attachment mechanism to inorganic crystallization in natural environments have barely begun. Here, we show, for the first time, evidence that confirms oriented particle attachment as a crystal growth mechanism that is relevant in sedimentary environments. In these natural settings, oriented particle attachment operates during the formation of highly anisotropically structured clay minerals, which constitute one of the most extensively distributed groups of minerals in the Earth's crust. High-resolution transmission electron microscopy images show that the clay minerals aggregation process occurs in different manners. Smectites aggregate by semi-oriented attachment, while kaolinite, sepiolite and palygorskite aggregate by oriented attachment.


2006 ◽  
Vol 114 (s1) ◽  
pp. 304-307 ◽  
Author(s):  
Mayumi Iijima ◽  
Chang Du ◽  
Christopher Abbott ◽  
Yutaka Doi ◽  
Janet Moradian-Oldak

2005 ◽  
Vol 8 (4) ◽  
pp. 232-238 ◽  
Author(s):  
S Habelitz ◽  
PK DenBesten ◽  
SJ Marshall ◽  
GW Marshall ◽  
W Li

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