Application of AFM in understanding biomineral formation in diatoms

Hildebrand, Mark; Doktycz, Mitchel J.; Allison, David P.

doi:10.1007/s00424-007-0388-y

Cited by 48 publications

(32 citation statements)

References 43 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…S5). Similar observations were made in AFM studies of select diatom cell surfaces (41). In comparison, silica templated by single component protein hydrogel scaffolds was observed to be granular with a primary feature size of approximately 16 nm (35).…”

Section: Resultssupporting

confidence: 76%

Cellular complexity captured in durable silica biocomposites

Kaehr

Townson

Kalinich

et al. 2012

Proc. Natl. Acad. Sci. U.S.A.

103

View full text Add to dashboard Cite

Tissue-derived cultured cells exhibit a remarkable range of morphological features in vitro, depending on phenotypic expression and environmental interactions. Translation of these cellular architectures into inorganic materials would provide routes to generate hierarchical nanomaterials with stabilized structures and functions. Here, we describe the fabrication of cell/silica composites (CSCs) and their conversion to silica replicas using mammalian cells as scaffolds to direct complex structure formation. Under mildly acidic solution conditions, silica deposition is restricted to the molecularly crowded cellular template. Inter-and intracellular heterogeneity from the nano-to macroscale is captured and dimensionally preserved in CSCs following drying and subjection to extreme temperatures allowing, for instance, size and shape preserving pyrolysis of cellular architectures to form conductive carbon replicas. The structural and behavioral malleability of the starting material (cultured cells) provides opportunities to develop robust and economical biocomposites with programmed structures and functions.sol-gel | biomineralization | biopreservation | frustule T he synthesis of inorganic materials with controlled and complex forms has been facilitated through discoveries such as vesicle, micelle, and liquid crystalline templating of silicates (1-3), which provided inspiration to explore a range of templating strategies based on self-assembled molecular precursors (4-8), colloids (9-11), and biological templates and vessels (12)(13)(14). A driving force for these efforts is the many complex inorganic structures found in nature. An oft-cited example is the hierarchical composites built by silica condensing microorganisms such as diatoms, which have generated substantial scientific interest for over a century (15). Diatoms display complex three-dimensional (3D) architectures with great structural control over nano-to millimeter length scales. However, despite some success toward elucidating mechanisms of diatom biomineralization, the in vitro synthesis of 3D diatom-like forms has remained elusive. Diatom silica has found numerous applications including as a chemical stabilizer, absorbent, filter medium, and fine abrasive, and the lack of synthetic analogues has facilitated recent investigations to employ diatom frustules as starting materials for shape-preserving chemical transformations into functional nanomaterials (16)(17)(18). Given the potential of this biosilica, it would be desirable to be able to wield control over the silica structure to achieve broader applicability (19); however, strategies to direct diatom morphology using chemical (20) and genetic approaches (21) has proven challenging. Therefore, an ability to generate cell frustules from more malleable templates such as mammalian cells would provide greater access to natural and engineered cell heterogeneity-both structure and function-to be exploited in the design of complex materials.To these ends, biomineralization by silica condensing microorganisms...

show abstract

Section: Resultssupporting

confidence: 76%

Cellular complexity captured in durable silica biocomposites

Kaehr

Townson

Kalinich

et al. 2012

Proc. Natl. Acad. Sci. U.S.A.

103

View full text Add to dashboard Cite

show abstract

“…From the two taxa the diatoms and the siliceous sponges, the importance of the organic templates for the formation of their biomineralic skeletons has been well elucidated. The ornate and elaborated diatom frustules are formed onto organic templates (Kröger et al, 1994;Kröger et al, 1997;Kröger et al, 1999;Sumper and Brunner, 2008;Hildebrand et al, 2008), the biosilica-associated peptides (silaffins) and the long-chain polyamines (see Poulsen et al, 2003). Furthermore, it was found that those organic molecules accelerate silica formation from a silicic acid solution in vitro.…”

Section: Discussionmentioning

confidence: 99%

Biosilicification of loricate choanoflagellate: organic composition of the nanotubular siliceous costal strips of Stephanoeca diplocostata

Gong

Wiens

Schröder

et al. 2010

Journal of Experimental Biology

View full text Add to dashboard Cite

SUMMARYLoricate choanoflagellates (unicellular, eukaryotic flagellates; phylum Choanozoa) synthesize a basket-like siliceous lorica reinforced by costal strips (diameter of approximately 100nm and length of 3m). In the present study, the composition of these siliceous costal strips is described, using Stephanoeca diplocostata as a model. Analyses by energy-dispersive X-ray spectroscopy (EDX), coupled with transmission electron microscopy (TEM), indicate that the costal strips comprise inorganic and organic components. The organic, proteinaceous scaffold contained one major polypeptide of mass 14kDa that reacted with wheat germ agglutinin. Polyclonal antibodies were raised that allowed mapping of the proteinaceous scaffold, the (glyco)proteins, within the costal strips. Subsequent in vitro studies revealed that the organic scaffold of the costal strips stimulates polycondensation of ortho-silicic acid in a concentration-and pH-dependent way. Taken together, the data gathered indicate that the siliceous costal strips are formed around a proteinaceous scaffold that supports and maintains biosilicification. A scheme is given that outlines that the organic template guides both the axial and the lateral growth of the strips.

show abstract

“…[5,17,20c,21,22] Several nanostructural features, such as ridges around frustule pores, zig-zag channels, and hillock topography of the outer plate (cribellum), were also elucidated by AFM, but their function remains unknown. [17,21] …”

Section: Formation Of Biological Nanostructuresmentioning

confidence: 99%

Diatomaceous Lessons in Nanotechnology and Advanced Materials

2009

View full text Add to dashboard Cite

Silicon, in its various forms, finds widespread use in electronic, optical, and structural materials. Research on uses of silicon and silica has been intense for decades, raising the question of how much diversity is left for innovation with this element. Shape variation is particularly well examined. Here, we review the principles revealed by diatom frustules, the porous silica shells of diatoms, microscopic, unicellular algae. The frustules have nanometer‐scale detail, and the almost 100 000 species with unique frustule morphologies suggest nuanced structural and optical functions well beyond the current ranges used in advanced materials. The unique frustule morphologies have arisen through tens of millions of years of evolutionary selection, and so are likely to reflect optimized design and function. Performing the structural and optical equivalent of data mining, and understanding and adopting these designs, affords a new paradigm in materials science, an alternative to combinatorial materials synthesis approaches in spurring the development of new material and more nuanced materials.

show abstract

Application of AFM in understanding biomineral formation in diatoms

Cited by 48 publications

References 43 publications

Cellular complexity captured in durable silica biocomposites

Cellular complexity captured in durable silica biocomposites

Biosilicification of loricate choanoflagellate: organic composition of the nanotubular siliceous costal strips of Stephanoeca diplocostata

Diatomaceous Lessons in Nanotechnology and Advanced Materials

Contact Info

Product

Resources

About