'American Association for the Advancement of Science (AAAS)'
Doi
Abstract
Avian (and formerly dinosaur) eggshells form a hard, protective biomineralized chamber for embryonic growth—an
evolutionary strategy that has existed for hundreds of millions of years. We show in the calcitic chicken eggshell how
the mineral and organic phases organize hierarchically across different length scales and how variation in nanostructure
across the shell thicknessmodifies its hardness, elastic modulus, and dissolution properties.We also show that the
nanostructure changes during egg incubation, weakening the shell for chick hatching. Nanostructure and increased
hardness were reproduced in synthetic calcite crystals grown in the presence of the prominent eggshell protein osteopontin.
These results demonstrate the contribution of nanostructure to avian eggshell formation, mechanical properties,
and dissolution.This work was supported by a grant from the Canadian Institutes of Health Research
(no. MOP-142330) and the Natural Sciences and Engineering Research Council of Canada
(NSERC; no. RGPIN-2016-05031) to M.D.M., an NSERC (no. RGPIN-2016-04410) Discovery grant
to M.T.H., a Spanish Government grant (CGL2015-64683-P) to A.B.R.-N., an Emmy Noether
research grant from the German Research Foundation (no. WO1712/3-1) to S.E.W., and an NSF
grant (NSF BMAT; no. 1507736) to J.J.G. M.D.M. is a member of the Fonds de Recherche
Quebec–Sante Network for Oral and Bone Health Research and the McGill Centre for Bone
and Periodontal Researc