Abstract
Structural biominerals are inorganic/organic composites that exhibit remarkable mechanical properties. However, the structure–property relationships of even the simplest building unit—mineral single crystals containing embedded macromolecules—remain poorly understood. Here, by means of a model biomineral made from calcite single crystals containing glycine (0–7 mol%) or aspartic acid (0–4 mol%), we elucidate the origin of the superior hardness of biogenic calcite. We analysed lattice distortions in these model crystals by using X-ray diffraction and molecular dynamics simulations, and by means of solid-state nuclear magnetic resonance show that the amino acids are incorporated as individual molecules. We also demonstrate that nanoindentation hardness increased with amino acid content, reaching values equivalent to their biogenic counterparts. A dislocation pinning model reveals that the enhanced hardness is determined by the force required to cut covalent bonds in the molecules.
This is a preview of subscription content, access via your institution
Access options
Subscribe to this journal
Receive 12 print issues and online access
$259.00 per year
only $21.58 per issue
Buy this article
- Purchase on Springer Link
- Instant access to full article PDF
Prices may be subject to local taxes which are calculated during checkout
Similar content being viewed by others
References
Wegst, U. G. K., Bai, H., Saiz, E., Tomsia, A. P. & Ritchie, R. O. Bioinspired structural materials. Nature Mater. 14, 23–36 (2015).
Fratzl, P. & Weinkamer, R. Nature’s hierarchical materials. Prog. Mater. Sci. 52, 1263–1334 (2007).
Weber, E. & Pokroy, B. Intracrystalline inclusions within single crystalline hosts: from biomineralization to bio-inspired crystal growth. Cryst. Eng. Comm. 17, 5873–5883 (2015).
Gries, K., Kroger, R., Kubel, C., Fritz, M. & Rosenauer, A. Investigations of voids in the aragonite platelets of nacre. Acta Biomater. 5, 3038–3044 (2009).
Li, H. Y. et al. Calcite prisms from mollusk shells (Atrina rigida): Swiss-cheese-like organic–inorganic single-crystal composites. Adv. Funct. Mater. 21, 2028–2034 (2011).
Davis, K. J., Dove, P. M. & De Yoreo, J. J. The role of Mg2+ as an impurity in calcite growth. Science 290, 1134–1137 (2000).
Stephenson, A. E. et al. Peptides enhance magnesium signature in calcite: insights into origins of vital effects. Science 322, 724–727 (2008).
Kim, Y. Y. et al. Bio-inspired synthesis and mechanical properties of calcite-polymer particle composites. Adv. Mater. 22, 2082–2086 (2010).
Kim, Y. Y. et al. An artificial biomineral formed by incorporation of copolymer micelles in calcite crystals. Nature Mater. 10, 890–896 (2011).
Kim, Y.-Y. et al. Structure and properties of nanocomposites formed by the occlusion of block copolymer worms and vesicles within calcite crystals. Adv. Funct. Mater. 26, 1382–1392 (2016).
Kunitake, M. E., Mangano, L. M., Peloquin, J. M., Baker, S. P. & Estroff, L. A. Evaluation of strengthening mechanisms in calcite single crystals from mollusk shells. Acta Biomater. 9, 5353–5359 (2013).
Li, L. & Ortiz, C. Pervasive nanoscale deformation twinning as a catalyst for efficient energy dissipation in a bioceramic armour. Nature Mater. 13, 501–507 (2014).
Courtney, T. H. Mechanical Behavior of Materials 2nd edn (Waveland Press, 2005).
Christian, J. W. & Mahajan, S. Deformation twinning. Prog. Mater. Sci. 39, 1–157 (1995).
Kunitake, M. E., Baker, S. P. & Estroff, L. A. The effect of magnesium substitution on the hardness of synthetic and biogenic calcite. MRS Commun. 2, 113–116 (2012).
Borukhin, S. et al. Screening the incorporation of amino acids into an inorganic crystalline host: the case of calcite. Adv. Funct. Mater. 22, 4216–4224 (2012).
Magnabosco, G. et al. Calcite single crystals as hosts for atomic-scale entrapment and slow release of drugs. Adv. Healthc. Mater. 4, 1510–1516 (2015).
Metzler, R. A., Tribello, G. A., Parrinello, M. & Gilbert, P. Asprich peptides are occluded in calcite and permanently disorder biomineral crystals. J. Am. Chem. Soc. 132, 11585–11591 (2010).
Albeck, S., Aizenberg, J., Addadi, L. & Weiner, S. Interactions of various skeletal intracrystalline components with calcite crystals. J. Am. Chem. Soc. 115, 11691–11697 (1993).
Aizenberg, J., Hanson, J., Koetzle, T. F., Weiner, S. & Addadi, L. Control of macromolecule distribution within synthetic and biogenic single calcite crystals. J. Am. Chem. Soc. 119, 881–886 (1997).
Kulak, A. N. et al. One-pot synthesis of an inorganic heterostructure: uniform occlusion of magnetite nanoparticles within calcite single crystals. Chem. Sci. 5, 738–743 (2014).
Kulak, A. N., Yang, P. C., Kim, Y. Y., Armes, S. P. & Meldrum, F. C. Colouring crystals with inorganic nanoparticles. Chem. Commun. 50, 67–69 (2014).
Li, H., Xin, H. L., Muller, D. A. & Estroff, L. A. Visualizing the 3D internal structure of calcite single crystals grown in agarose hydrogels. Science 326, 1244–1247 (2009).
Li, H. Y. & Estroff, L. A. Calcite growth in hydrogels: assessing the mechanism of polymer-network incorporation into single crystals. Adv. Mater. 21, 470–473 (2009).
Ihli, J., Bots, P., Kulak, A., Benning, L. G. & Meldrum, F. C. Elucidating mechanisms of diffusion-based calcium carbonate synthesis leads to controlled mesocrystal formation. Adv. Funct. Mater. 23, 1965–1973 (2013).
Chen, C. L., Qi, J. H., Tao, J. H., Zuckermann, R. N. & De Yoreo, J. J. Tuning calcite morphology and growth acceleration by a rational design of highly stable protein-mimetics. Sci. Rep. 4, 6266 (2014).
Penkman, K. E. H., Kaufman, D. S., Maddy, D. & Collins, M. J. Closed-system behaviour of the intra-crystalline fraction of amino acids in mollusc shells. Quat. Geochronol. 3, 2–25 (2008).
Tomiak, P. J. et al. Testing the limitations of artificial protein degradation kinetics using known-age massive Porites coral skeletons. Quat. Geochronol. 16, 87–109 (2013).
Elhadj, S., De Yoreo, J. J., Hoyer, J. R. & Dove, P. M. Role of molecular charge and hydrophilicity in regulating the kinetics of crystal growth. Proc. Natl Acad. Sci. USA 103, 19237–19242 (2006).
Hopp, T. P. & Woods, K. R. Prediction of protein antigenic determinants from amino acid sequences. Proc. Natl Acad. Sci. USA 78, 3824–3828 (1981).
De Yoreo, J. J. et al. Rethinking classical crystal growth models through molecular scale insights: consequences of kink-limited Kinetics. Cryst. Growth Des. 9, 5135–5144 (2009).
Nielsen, L. C., De Yoreo, J. J. & DePaolo, D. J. General model for calcite growth kinetics in the presence of impurity ions. Geochim. Cosmochim. Acta 115, 100–114 (2013).
Paquette, J. & Reeder, R. J. Relationship between surface-structure, growth-mechanism, and trace-element incorporation in calcite. Geochim. Cosmochim. Acta 59, 735–749 (1995).
Staudt, W. J., Reeder, R. J. & Schoonen, M. A. A. Surface structural controls on compositional oning of SO42− and SeO42− in synthetic calcite single crystals. Geochim. Cosmochim. Acta 58, 2087–2098 (1994).
Cho, K. R. et al. Direct observation of mineral-organic composite formation reveals occlusion mechanism. Nature Commun. 7, 10187 (2016).
Bass, J. D. Mineral Physics & Crystallography: A Handbook of Physical Constants 45–63 (American Geophysical Union, 2013).
Eshelby, J. D. The determination of the elastic field of an ellipsoidal inclusion, and related problems. Proc. R. Soc. Lond. A 241, 376–396 (1957).
Oliver, W. C. & Pharr, G. M. An improved technique for determining hardness and elastic-modulus using load and displacement sensing indentation experiments. J. Mater. Res. 7, 1564–1583 (1992).
Clayton, J. D. & Knap, J. Phase field modeling of twinning in indentation of transparent crystals. Modelling Simul. Mater. Sci. Eng. 19, 085005 (2011).
Foreman, A. J. E. & Makin, M. J. Dislocation movement through random arrays of obstacles. Philos. Mag. 14, 911–924 (1966).
Akbulatov, S., Tian, Y. C. & Boulatov, R. Force-reactivity property of a single monomer is sufficient to predict the micromechanical behavior of its polymer. J. Am. Chem. Soc. 134, 7620–7623 (2012).
Diesendruck, C. E. et al. Mechanically triggered heterolytic unzipping of a low-ceiling-temperature polymer. Nature Chem. 6, 624–629 (2014).
Grandbois, M., Beyer, M., Rief, M., Clausen-Schaumann, H. & Gaub, H. E. How strong is a covalent bond? Science 283, 1727–1730 (1999).
Spruijt, E., van den Berg, S. A., Stuart, M. A. C. & van der Gucht, J. Direct measurement of the strength of single ionic bonds between hydrated charges. ACS Nano 6, 5297–5303 (2012).
Demarchi, B. et al. Intra-crystalline protein diagenesis (IcPD) in Patella vulgata. Part I: isolation and testing of the closed system. Quat. Geochronol. 16, 144–157 (2013).
Kaufman, D. S. & Manley, W. F. A new procedure for determining DL amino acid ratios in fossils using reverse phase liquid chromatography. Quat. Sci. Rev. 17, 987–1000 (1998).
Demarchi, B. et al. New experimental evidence for in-chain amino acid racemization of serine in a model peptide. Anal. Chem. 85, 5835–5842 (2013).
Szeverenyi, N. M., Sullivan, M. J. & Maciel, G. E. Observation of spin exchange by two-dimensional Fourier-transform C-13 cross polarization-magic-angle spinning. J. Magn. Reson. 47, 462–475 (1982).
Thompson, S. P. et al. Beamline I11 at Diamond: a new instrument for high resolution powder diffraction. Rev. Sci. Instrum. 80, 075107 (2009).
Oliver, W. C. & Pharr, G. M. Measurement of hardness and elastic modulus by instrumented indentation: advances in understanding and refinements to methodology. J. Mater. Res. 19, 3–20 (2004).
Kim, Y.-Y. et al. Dataset for ‘Tuning hardness in calcite by incorporation of amino acids’. Research Data Leeds Repositoryhttp://doi.org/10.5518/46 (2016).
Acknowledgements
This work was supported by an Engineering and Physical Sciences Research Council (EPSRC) Leadership Fellowship (F.C.M. and Y.-Y.K., EP/H005374/1), by an EPSRC Materials World Network grant (EP/J018589/1, F.C.M. and Y.-Y.K.) and an EPSRC Programme Grant (grant EP/I001514/1) which funds the Materials Interface with Biology (MIB) consortium (F.C.M., J.H.H. and D.S.). We acknowledge Diamond Light Source for time on beamline I11 under commissioning time and proposal EE10137. L.A.E., J.D.C., M.E.K. and S.P.B. were supported by the US National Science Foundation (NSF) via a Materials World Network grant (DMR-1210304). B.P. acknowledges support from the European Research Council under the European Union’s Seventh Framework Program (FP/2007–2013)/ERC Grant Agreement no [336077]. B.D. and K.P. were supported by the Leverhulme Trust and the EU reintegration grant (PERG07-GA-2010-268429, FP7), project ‘mAARiTIME’. Ashely Coutu and Sheila Taylor are thanked for technical help for RP-HPLC analysis. This work made use of the Cornell Center for Materials Research Shared Facilities, which are supported through the NSF MRSEC Program (DMR-1120296). The authors also thank Matthew Collins for his intellectual contribution to the development of the study and for helpful discussions throughout.
Author information
Authors and Affiliations
Contributions
Y.-Y.K. led the experimental work, preparing samples and carrying out EM and XRD, and analysing the data; B.D. and K.P. performed HPLC measurements and analysed the occlusion data; J.D.C. and M.E.K. carried out nanoindentation measurements, J.D.C., S.P.B. and L.A.E. analysed and modelled mechanical data; S.P.B. and L.A.E. co-supervised J.D.C. and M.E.K.; D.S. carried out molecular dynamic simulations work and C.L.F. and J.H.H. supervised D.S. and analysed simulation data; C.C.T. assisted with the PXRD experiments; B.P. assisted with analysis and discussion of the PXRD data; D.G.R. and M.J.D. performed the NMR studies and analyses; F.C.M. originated and supervised the project. All authors contributed to the preparation of the manuscript.
Corresponding authors
Ethics declarations
Competing interests
The authors declare no competing financial interests.
Supplementary information
Supplementary Information
Supplementary Information (PDF 2604 kb)
Rights and permissions
About this article
Cite this article
Kim, YY., Carloni, J., Demarchi, B. et al. Tuning hardness in calcite by incorporation of amino acids. Nature Mater 15, 903–910 (2016). https://doi.org/10.1038/nmat4631
Received:
Accepted:
Published:
Issue Date:
DOI: https://doi.org/10.1038/nmat4631