TITLE:
Engineered Hydrophobin for Biomimetic Mineralization of Functional Calcium Carbonate Microparticles
AUTHORS:
Hanna Heinonen, Päivi Laaksonen, Markus B. Linder, Hans-Peter Hentze
KEYWORDS:
Biomimetic Mineralization; Engineered Proteins; Hydrophobin; Calcium Carbonate; Functional Microparticles
JOURNAL NAME:
Journal of Biomaterials and Nanobiotechnology,
Vol.5 No.1,
January
8,
2014
ABSTRACT:
In this study, the modified hydrophobin, engineered for biomimetic
mineralization, has been employed as a structure-directing agent for
mineralization of calcium carbonate. For the first time amphiphilic calcium carbonate particles have been obtained, using engineered
proteins. The mineral microparticles have been characterized by optical microscopy, scanning electron
microscopy (SEM) and X-ray diffraction (XRD). While mineralization in the presence of non-modified
hydrophobin results in polymorph mineral structures, uniform microspheres with an average particle diameter of one
micron are obtained by employing hydrophobin which has been modified with an
additional ceramophilic protein sequence. Owing to the tri-functionality of the
modified hydrophobin (hydrophilic,
hydrophobic and ceramophilic), the obtained mineral microparticles exhibit
amphiphilic properties.
Potential applications are in the areas of functional fillers and pigments,
like biomedical and composite materials. Pickering emulsions have been prepared
as a demonstration of the emulsion-stabilizing properties of the obtained
amphiphilic mineral microspheres. The structure-directing effects of the
studied engineered hydrophobins are
compared with those of synthetic polymers (i.e. polycarboxylates) used as crystallization and
scaling inhibitors in industrial applications.