91社区

3D imaging and quantification of synthetic and natural biomineralization systems: Growing and analyzing biorocks

Marc D McKee, 91社区
Tuesday November 5, 12-1pm
Zoom Link:听
In Person: 550 Sherbrooke, Room 189

Abstract:听Biomineralization is the formation of inorganic materials by living organisms. It is a highly abundant biological phenomenon that occurs in essentially all taxonomic groups, and is studied in many research areas ranging from ecology and geology to materials science and biomedicine. To date, more than 70 different types of biominerals are known, displaying species-specific architectures, as well as wide-ranging chemical compositions and biological functions. Biomineralization often occurs as mineral crystal growth within extracellular matrix fiber assemblies, where charged small molecules, peptides, and large intrinsically disordered proteins guide mineralization events. While small-molecule and protein inhibitors broadly prevent soft and compliant tissues from mineralizing, release from this inhibition in the skeleton (bone and enthesis fibrocartilage) occurs through local expression of enzymes that cleave these inhibitors. Mutations in these enzymes result in inhibitor accumulation leading to debilitating mineralization defects and losses of mechanical function in diseases of the skeleton and teeth.

I will present diverse biomineralizing systems and how we think they are regulated. Mechanical properties of mineralized fibrous biocomposites originate from nanoscale relations of their constituent parts, and often propagate across several hierarchical levels in 3D, all the way to the macroscale. Correlative, multi-scale 3D imaging approaches are now in common use in structural biology studies, and our work utilizes these approaches (including electron microscopy, particularly FIB-SEM serial-surface-view tomography combined with deep learning-assisted segmentation) to better understand at multiple levels how mineralization form organic-inorganic biocomposites having diverse properties and functions.