Complementarity and Uncertainty in Intrafibrillar Mineralization of Collagen

Abstract

Biomineralization in vertebrates is a ubiquitous and tightly regulated process which creates hierarchical structures for the skeleton. Because of the lack of understanding and applicability of cell‐based or biological systems to achieve intrafibrillar mineralization, scientists adopted various in vitro methods to elucidate the mechanism of intrafibrillar mineralization. In this article, biomimetic intrafibrillar mineralization of collagen in its wide ramifications is reviewed. It is intriguing how prevailing intrafibrillar mineralization mechanisms derived from two potentially discordant crystallization philosophies were equally adept, depending on the experimental context, at theorizing the formation of calcium phosphate within a fibrillar template. This complementarity is not unique to biomineralization and has precedence in other fundamental physical interpretations. A new intrafibrillar mineralization process based on the use of polycationic process‐directing agent added uncertainty to the use of existing mechanisms in accounting for the observations.

Short-Range Structure of Amorphous Calcium Hydrogen Phosphate

“…[7][8][9][10][11][12][13][14] Today, there is mounting evidence that in animal bones and teeth, ACP is a precursor to apatites (or an important component of the complex structures), [15][16][17][18][19][20][21][22] and liquid precursors may also play a role in CaP biomineralization. [23][24][25] ions were shown to be present within an "acidic" ACP, which is thought to be essential for CaP biomineralization. 21 Generally, the term "acidic" ACP implies that HPO4 2-ions are present in the material, yielding Ca/P atomic ratios between ~1.0-1.5 even though it is obtained at near-neutral, slightly basic pH values.…”

Biomacromolecules enabled dendrite-free lithium metal battery and its origin revealed by cryo-electron microscopy

“…Biomineralization is a widespread phenomenon in nature leading to the formation of hierarchically structured minerals by living organisms [31][32][33] . It has been revealed that biomolecules, particularly the stereochemical side chains within them, can guide the nucleation and growth of mineral crystals [34][35][36][37] . As a well-known example in biomineralization, the eggshell has attracted much attention, because its calcified crystallization ( Fig.…”

Biomineralization‐Inspired Material Design for Bone Regeneration

“…Other polymer additives include poly(glutamic acid) (pGlu), poly(amidoamine) dendrimers, poly(acrylic acid) (PAA), typically used in combination with poly(vinylphosphonic acid) (PVPA), sodium trimethaphosphate (STMP), poly(glutamic acid), or phosphorylated collagen . The only example of a cationic polymer able to induce intrafibrillar mineralization of collagen is the one of poly(allylamine) hydrochloride (PAH) …”

“…For example, collagen substrates have been used as reconstituted fibrils or sponges (sometimes called membranes) from acid‐ or enzyme‐extracted collagen (that can be prepared in‐house or purchased). They can originate from rat‐tail tendon, bovine or equine tendon, or bovine skin . Substrates have also been prepared directly from biological tissue, such as turkey tendon, demineralized sections from mouse periodontium, and bone from manatee, or fish origin, as well as demineralized dentin from mouse, or human origin …”

“…Carbonate has also been hypothesized to have a role in the formation of first mineral domains, but at the moment only limited in vitro evidence exists . Therefore, much is still to be discovered about the mechanisms of mineralization regulated by organic components …”