Isolation of calcium-phosphate crystals of bone by non-aqueous methods at low temperature

Abstract

We have developed low temperature nonaqueous solution methods as well as low power plasma ashing for the degradation of the organic matrix of bone power which have permitted us to obtain bone crystals essentially free of organic matrix constituents without any significant change in their composition, overall structure, or internal short-range order. We have also been able to disperse the crystals, which has made it possible to examine the isolated crystals by X-ray diffraction and resolution-enhanced Fourier transform infrared (FTIR) spectroscopy and isolated single crystals by high resolution transmission electron microscopy (TEM) and electron diffraction. TEM of isolated single crystals of fish, chicken, mouse and bovine bone have clearly demonstrated that the crystals are very thin plates. No rod or needle-like crystals were observed in any of the bone samples in the four species studied including the earliest crystals deposited. Although there were variations in the size distribution of the crystals in the different species studied, in general the average crystal dimensions were very similar.

FT-IR imaging of native and tissue-engineered bone and cartilage

“…Similar changes are seen in trabecular bone going from the outer surface to the center of the trabeculae [27]. These age related changes have been reported in FT-IR images and point-by-point microscopic data from rats [28,29], chicks [30], fish and cows [31], dogs [32,33], monkeys [34,35], and mice and humans.…”

Dentine bonding agents comprising calcium-silicates to support proactive dental care: Origins, development and future

“…This mineral-reinforced composite was described by Weiner and Wagner as containing oriented plate-like crystals with their c-axis aligned with the long axis of each collagen fibril 11) . Their sizes, ranging in length from 20 Å to 1100 Å 12) , is not arbitrary; rather, it seems to give them remarkable physical characteristics 13,14) , exposing a very large surface area to the extracellular fluids, which is critically important for rapid ion exchange. Minerals start to nucleate within or immediately adjacent to the holes and pores present in the collagen fibrils 15) .…”

Hydrothermal synthesis and characterization of hydroxyapatite from octacalcium phosphate

“…The calciumdeficiency of this HA ceramic was thought to be important because the Ca/P molar ratio of HA in the bone was reported to be lower than the stoichiometric Ca/P ratio, 1.67. 4), 18) In the previous study, we synthesized plate-shaped HA particles by hydrothermal treatment of octacalcium phosphate [OCP, Ca 8 (HPO 4 ) 2 (PO 4 ) 4 ·5H 2 O]. 19) OCP is regarded as a precursor of HA in bones and teeth, 20) and tends to have plateshaped morphology.…”