Nanoscale amorphous precursors and their phase transitions in diverse biominerals

Crystallization by particle attachment (CPA)1 of amorphous precursors has been demonstrated in
biominerals formed by several animals. Precisely the same precursors phases, hydrated (ACCH2O)
and anhydrous calcium carbonate (ACC), have been observed spectromicroscopically in 3
diverse phyla: echinoderms2, molluscs3, and cnidarians4 (Figure 1). This is surprising because
these groups diverged from one another long before they evolved their characteristic body plans
and capacity for skeletal biomineralization. How far back in time does this biomineralization
strategy go, and why? Can we harness it for 3D printing or other useful materials synthesis?
1 JJ De Yoreo, PUPA Gilbert, NAJM Sommerdijk, RL Penn, S Whitelam, D Joester, H Zhang, JD Rimer, A
Navrotsky, JF Banfield, AF Wallace, FM Michel, FC Meldrum, H Cölfen, PM Dove. Crystallization by
particle attachment in synthetic, biogenic, and geologic environments. Science 349, aaa6760 (2015).
2 YUT Gong, CE Killian, IC Olson, NP Appathurai, AL Amasino, MC Martin, LJ Holt, FH Wilt, PUPA Gilbert.
Phase transitions in biogenic amorphous calcium carbonate. Proc Natl Acad Sci 109, 6088-6093
(2012).
3 RT DeVol, C-Y Sun, MA Marcus, SN Coppersmith, SCB Myneni, PUPA Gilbert. Nanoscale Transforming
Mineral Phases in Fresh Nacre. J Am Chem Soc 137, 13325-13333 (2015).
4 T Mass, AJ Giuffre, C-Y Sun, CA Stifler, MJ Frazier, M Neder, N Tamura, CV Stan, MA Marcus, PUPA
Gilbert. Amorphous calcium carbonate particles form coral skeletons. Procs Natl Acad Sci 114, E7670-
E7678 (2017).
Bio: Pupa Gilbert got her doctoral degree in Physics in 1987 in Rome, Italy. She was a staff scientist at the Italian CNR and the EPFL before going to the US as a professor of physics at UW-Madison in 1999. She is a physicist with a burning passion for biology and materials science, and she studies biominerals, their structure, and formation mechanisms with the synchrotron spectromicroscopy methods she developed.