Ceramic hydroxyapatite

Dong M, Baggetto LG, Folson P, LeMaire M, Penin F. Complete removal and exchange of sodium dodecyl sulfate bound to soluble and membrane proteins and restoration of their activities, using ceramic hydroxyapatite chromatography. Anal Biochem 1997 247 333-341. 

More recently, it was demonstrated that the thermistor approach could be used to monitor specific interactions of fluoride ions with silica-packed columns in the flow injection mode. A thermometric method for detection of fluoride [56] was developed that relies on the specific interaction of fluoride with hydroxyapatite. The detection principle is based on the measurement of the enthalpy change upon adsorption of fluoride onto ceramic hydroxyapatite, by temperature monitoring with a thermistor-based flow injection calorimeter. The detection limit for fluoride was 0.1 ppm, which is in the same range as that of a commercial ion-selective electrode. The method could be applied to fluoride in aqueous solution as well as in cosmetic preparations. The system yielded highly reproducible results over at least 6 months, without the need of replacing or regenerating the ceramic hydroxyapatite column. The ease of operation of thermal sensing and the ability to couple the system to flow injection analysis provided a versatile, low-cost, and rapid detection method for fluoride. 

TG curves can also be used for quantifying compositions of composites containing thermally decomposable components. Figure 10.32 shows an example of using the TG curves to determine the weight fraction of ceramic content in a polymer matrix. It is quite often that the real content of particulates in a composite is not the same as the nominal content. Figure 10.32 demonstrates that the amount of ceramics (hydroxyapatite) in composites can be accurately... 

Ceramics Hydroxyapatite Bone cavity fillings, ear implants, vertebrae replacement, hip implant coatings, bone scaffolds Bioactive Cao and Hench (1996) and Lobel and Hench (1998)... 

T. (1996) Acceleration and deceleration of bone-like crystal growth on ceramic hydroxyapatite by electric poling. Chem. Mater., 8, 2697 - 2700. 

Vasilescu, C., Popa, M., Drob, S.I., Osiceanu, P., Anastasescu, M., and Calderon Moreno, J.M. (2014) Deposition and characterization of bioactive ceramic hydroxyapatite coating on surfaces of Ti-15Zr-5Nb alloy. Ceram. Int. 40 (9 Part B), 14973-14982. 

Apply the sample at 2 ml/min to a hydroxyapatite (Bio-Rad Macro-Prep Ceramic hydroxyapatite, Type I) HR 10/10 column (Pharmacia) equilibrated with buffer B. Wash the column with 80 ml of buffer B develop the column with a linear gradient from buffer B to buffer B - - 1 M K2HPO4/KH2PO4 pH 7.5 over 80 ml at a flow rate of 2 ml/min. saTBP elutes as the major peak centered at 440 mM K2HPO4/KH2PO4. 

Another application of dental composites is orthodontic archwires. One example is a unidirectional pultruded S2-glass-reinforced dimethacrylate thermoset resin. Depending on the yam of glass fiber used, the fiber volume fraction varied from 32 to 74 percent The strength and modulus were comparable with those of titanium wires. Orthodontic brackets were also made from composites with a polyethylene matrix reinforced with ceramic hydroxyapatite particles, resulting in isotropic properties and good adhesion to enamel. 

ASTM 1185 (1993) Standard specification for compositions of ceramic hydroxyapatite for surgical implants, 1988, reapproved 1993. 

The tropocollagen molecules themselves are aligned in parallel in bones and tendons, being shifted by 67 nm in adjacent layers. Within each layer, there are gaps between the molecules that serve as nucleation sites for the crystallisation of the ceramic hydroxyapatite crystals (see figure 9.16). 

Ceramic hydroxyapatite (CHT) is a spherical, macroporous form of hydroxyapatite. Compared to most other chromatography adsorbents, CHT is unusual in that it is both the ligand and the support matrix. Two types of CHT ceramic hydroxyapatite. Type 1 and Type 11, have elution characteristics similar to crystalline hydroxyapatite but also have some important differences. CHT Type 1 has a higher protein-binding capacity and better capacity for acidic proteins, while CHT Type 11 has a lower overall protein-binding capacity but has better resolution for nucleic acids and certain proteins. The Type 11 material also has a very low affinity for albumin and is especially suitable for the purification of many species and classes of antibodies. 

Jarcho, M Kay, JL Gumaer, RH Drobeck, HP. Tissue, cellular and subcellular events at bone-ceramic hydroxyapatite interface. J. Bioeng., 1997,1,79-92. 

Synthetic Ceramics Hydroxyapatite, tricalcium phosphate, bioactive glass, and calcinm silicate Resorbed materials, presenting conductive, and inductive properties Bachar et al. (2013), Tampieri et al. (2014), and Vimalnath et al. (2015)... 

---