Periodic Nucleation of Calcium Phosphate in a Stirred Biocatalytic Reaction. Issue 7 (9th January 2020)

• Record Type: Journal Article
• Authors: Bohner, Bíborka; Bánsági, Tamás; Tóth, Ágota; Horváth, Dezső; Taylor, Annette F.
• Is Part Of: Angewandte Chemie international edition. Volume 59:Issue 7(2020)
• Page Start: 2823
• Page End: 2828
• Publication Date: 2020-01-09
• Subjects: biocatalysis -- biomineralization -- reaction networks -- self-organization -- systems chemistry; Chemistry -- Periodicals; 540
• DOI: 10.1002/anie.201911213
• Languages: English
• ISSNs: 1433-7851

Abstract

Abstract: Highly ordered superstructures composed of inorganic nanoparticles appear in natural and synthetic systems, however the mechanisms of non‐equilibrium self‐organization that may be involved are still poorly understood. Herein, we performed a kinetic investigation of the precipitation of calcium phosphate using a process widely found in microorganisms: the hydrolysis of urea by enzyme urease. With high initial ratio of calcium ion to phosphate, periodic precipitation was obtained accompanied by pH oscillations in a well‐stirred, closed reactor. We propose that an internal pH‐regulated change in the concentration of phosphate ion is the driving force for periodicity. A simple model involving the biocatalytic reaction network coupled with burst nucleation of nanoparticles above a critical supersaturation reproduced key features of the experiments. These findings may provide insight to the self‐organization of nanoparticles in biomineralization and improve design strategies of biomaterials for medical applications. Abstract : Periodic precipitation of calcium phosphate was obtained by using a biocatalytic reaction to maintain the system far from equilibrium. A simple model involving burst nucleation of nanoparticles above a critical supersaturation reproduced the results, suggesting a potential mechanism for self‐organization in biomineralization.