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Nanocrystalline biphasic calcium phosphate (BCP) powder was synthesized from natural bovine bone via a very economic process. The bovine bone was annealed at 900°C for 2 h and elemental compositions were qualitatively identified by energy dispersive X-ray spectroscopy (EDS) in the scanning electron microscope (SEM). The calcined bovine bone was powdered and mixed with calcium hydrogen phosphate dihydrate (CaHPO₄·2H₂O, DCPD). After that, the prepared powder was uniaxially pressed into pellets. The pellets were annealed at 900–1200°C and then crushed to obtain nanocrystalline BCP powder. The morphology and microstructure of the BCP powder were studied by SEM. The results showed that the prepared powder consisted of small size and highly agglomerated particles. X-ray diffraction method was utilized to characterize the phase formation and crystallite size of prepared powder. The crystallite sizes of BCP powder calculated by using XRD data were in the range of 20–60 nm.

Calcium silicate (CaSiO₃) is a promising material due to its favorable biological properties. However, it was difficult to fabricate ceramic scaffolds with interconnected porous structure via conventional technology. In present study, CaSiO₃ scaffolds with totally interconnected pores were fabricated via selective laser sintering (SLS). The microstructure, mechanical and biological properties were examined. The results revealed that the powder gradually fused together with the reduction of voids and the elimination of particle boundary as the laser power increased in the range of 3–15 W with scanning electron microscope. Meanwhile the low-temperature phase (β-CaSiO₃) transformed into high-temperature phase (α-CaSiO₃) gradually, which decreased the mechanical properties of the obtained scaffolds. Besides, the compressive strength increased from 12.9 ± 2.34 MPa to 18.19 ± 1.24 MPa (the laser power is 12 w) and then decreased gradually with increasing laser power. In vitro biological properties of CaSiO₃ scaffolds sintered under optimal conditions indicated that the distribution of apatite mineralization became uniform as the amount of them increased after being immersed in simulated body fluids. In the meantime, the thin cytoplasmic extensions of MG-63 cells increased until formed a dense cell layer after 1–5 days of cell culture. The results suggested that the CaSiO₃ scaffold fabricated via SLS has potential application for bone tissue engineering.

This research focuses on understanding the nature of the Fe ions substituted in hydroxyapatite ((HAP) Ca_10-xFe_x(PO₄)₆(OH)_2-xÿ_x: x = 0, 0.2 and 0.4) powder synthesized at temperatures between 500°C and 1000°C and their crystallization. The DSC scan indicates a solid state phase transition at about 757°C for the as-prepared powder HAP. The transformation of HAP to β-tricalcium phosphate (β-TCP, β-Ca₃(PO₄)₂) is seen when the powder were heated to 750°C. The sizes of the crystallites were determined to be about 46–51 nm, 33–40 nm and 33–59 nm for Fe content of 0, 0.2 and 0.4 mol%, respectively. The ESR parameters for the Fe³⁺ ions, g = 4.23 and 8.93 indicated that the ions were subjected to a rhombic ion crystal field within the HAP structures. The g values of ~2.01 indicated that the particles were super-paramagnetic and ferromagnetic iron nanoparticles, having an average size about 0.2–0.5 μm in length.

Nano-hydroxyapatite crystals of different morphologies were synthesized by adding two types of amino acids (glycine and arginine) under hydrothermal conditions. The XRD, FTIR, and TEM characterizations of samples showed that the final product was pure hydroxyapatite with high crystallinity. Organic small-molecule amino acids exhibited a significant inhibitory effect on crystal growth during the synthesis process. This regulatory effect is related to the side chains of amino acids. The results of co-culturing with bone mesenchymal stem cells showed that the cell compatibility of nanoparticles differs based on their morphologies. The results of this study are significant for the fabrication of nano-hydroxyapatite with tunable morphology, which can have applications in the fields of bone repair and drug loading.

A sampling of patients submitted in the past to a restoration of their auditory functionality in the framework of a planned experimental surgery, with use of different surgical techniques and materials, was recently checked to have a follow-up not lower than 5 years. A complete series of tests on their auditory functionality has allowed the formulation of statistical data on the behaviour of the different materials adopted over time. A wide comparison of the results is critically reported. Very interesting results come from the cases where alumina prostheses, with the brim covered with biological glass AP40, were adopted.

We have developed a new artificial intervertebral disc prosthesis consisting of a triaxial three-dimensional fabric (3-DF) woven by an ultra-high molecular weight polyethylene fiber and spray-coated bioactive ceramics on the disc surface. The arrangement of weave properties led to the mechanical behavior of 3-DF disc similar to the natural intervertebral disc. Using a sheep model, total intervertebral replacement using 3-DF disc either coated by hydroxyapatite or apatite-wollastonite glass ceramics was conducted with or without initial fixation. Without the use of initial fixation, interface bony union was detected, however, the segmental motion decreased at six months postoperatively. The use of temporary fixation provided a nearly physiological mobility as well as the increased fusion rate at six months. A scanning electron microscopy showed that each fiber of 3-DF disc had a direct contact to trabecula. This study first highlighted the in vivo effectiveness of artificial intervertebral disc experimentally, and clarified further problems in clinical application.

Tissue engineering utilizes the expertise in the fields of materials science, biology, chemistry, transplantation medicine, and engineering to design materials that can temporarily serve in a structural and/or functional capacity during regeneration of a defect. Hydroxyapatite (HAp) scaffolds are among the most extensively studied materials for this application. However, HAps have been reported to be too weak to treat such defects and, therefore, have been limited to non-load-bearing applications. Recent advancements in nanoscience and nanotechnology have reignited investigation of HAp formation in the nanorange to clearly define small-scale properties of HAp. It has been suggested that nano- HAp may be an ideal biomaterial due to its good biocompatibility and bone integration ability. In this chapter, a new view on nano-HAp particles highlights the importance of size, crystal morphology controls, and composites with other inorganic particles in the application of biomedical material development. We have also reviewed nanosized HAp-based highly porous composite materials used for bone tissue engineering, introduced various fabrication methods used to prepare nHAp/polymer composite scaffolds, and characterized these scaffolds on the basis of their biodegradability and biocompatibility through in vitro or in vivo tests. Finally, we provide a summary and our own perspectives on this active area of research.