Pacific Rim Symposium on Surfaces, Coatings and Interfaces (PacSurf 2018)
    Biomaterial Surfaces & Interfaces Tuesday Sessions
       Session BI-TuM

Paper BI-TuM12
In-Situ TEM Studies of Biomineralization

Tuesday, December 4, 2018, 11:40 am, Room Naupaka Salon 6-7

Session: Bioimaging and Bionanotechnology
Presenter: Tolou Shokuhfar, University of Illinois at Chicago
Authors: T. Shokuhfar, University of Illinois at Chicago
R. Shahbazian-Yassar, University of Illinois at Chicago
Correspondent: Click to Email
This talk will provide an overview of the PIs' efforts to understand the dynamics of biomineralization via in-situ transmission electron microscopy. First we demonstrate how to utilize graphene sheets to build a liquid-cell nanoreactor that fits the chamber of high-resolution TEM. Graphene is impermeable to liquids such as aqueous solutions and therefore can be used to seal liquid solutions from leaking to the high vacuum of TEM environment. In addition, the excellent electrical conductivity of graphene and its ability to scavenge the radicals produced by the interaction of electron beam and liquid solutions provide an excellent platform to perform imaging of biological or hydrated specimens. We then demonstrate our success to observe the biomineralization of calcium oxalate crystals that are the primary constituent of kidney stones. We show that the addition of citrate and other molecular inhibitors can affect the crystallization pathway of these minerals. In addition, we will showcase example of biomineralization of iron oxide core in ferritin proteins and demonstrate the ability to monitor the biomineralization of these crystals using graphene liquid cells in TEM. We will show that the ratio of L and H subunits in the ferritin protein shells can affect the nucleation and growth of iron oxide cores. We also will present our latest results on the biomineralization of magnetosomes in magnetotactic bacteria grown in iron-rich media using in situ GLC-TEM studies.