Rheology as a Mechanoscopic Method to Monitor Mineralization in Hydrogels

TitleRheology as a Mechanoscopic Method to Monitor Mineralization in Hydrogels
Publication TypeJournal Article
Year of Publication2017
AuthorsRegitsky, AU, Keshavarz, B, McKinley, GH, Holten-Andersen, N
JournalBiomacromolecules
Volume18
Issue12
Pagination4067 - 4074
Date Published2017/12//
ISBN Number1525-7797
Keywordsbiomineralization, caco3, calcium-carbonate, cryo-tem, crystal-growth, crystallization, fish gelatin, gelatin hydrogels, mammalian gelatin, viscoelastic properties
Abstract

Biominerals have been widely studied due to their unique mechanical properties, afforded by their inorganic-organic composite structure and well-controlled growth in macromolecular environments. However, a lack of suitable characterization techniques for inorganic minerals in organic-rich media has prevented a full understanding of biomineralization. Here, we applied rheometry to study mineral nucleation and growth dynamics by measuring viscoelastic material properties of a hydrogel system during mineralization. Our proof-of-concept system consists of a gelatin hydrogel matrix preloaded with calcium ions and a reservoir of carbonate ions, which diffuse through the gel to initiate mineralization. We found that gels with diffused carbonate show an increase in low frequency energy dissipation, which scales with carbonate concentration and gel pH. Using this signal, and recognizing that mineralization occurs simultaneously with carbonate diffusion in our system, we have mechanoscopically tracked mineral growth in situ, showcasing the potential of rheometry for studying mineralization kinetics in real time.

Short TitleBiomacromolecules