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The production of porous ceramics for biomedical applications is widely available in the Ceramics industry. In bioceramic applications, interconnected pores are pertinent to increase osteoconductivity and cell proliferation. However, an increase in pore size and the pore amount decrease the mechanical properties. For this reason, pore properties must be precisely controlled. In this study, the effect of a natural pore-forming agent, corn starch addition, and sintering conditions on mechanical properties and biocompatibility was investigated. During mixing, four different starch amounts (1, 3, 5, and 10 wt%) were added to pure beta-tricalcium phosphate (β-TCP) ceramic powders and pressed. Pressed pellets were sintered at 1000, 1100, 1200, and 1300 °C. A scanning electron microscope (SEM) is used to investigate microstructure, texture, pore size, and cell adhesion. The mechanical properties of the β-TCP ceramic parts were further characterized by measuring the density and compressive strength. Cytotoxicity tests were carried out with MTT assays. The optimum mechanical properties were obtained at 1100 °C sintered biocomposites. Although starch starts to burn around 410 °C and analytical results show no presence of starch after the sintering process, biocomposites initially containing 10% starch showed improved cell proliferation. However, a reduction of 59% in compressive strength and a 16% reduction in the density were also recorded. It was observed that 10 wt% starch addition increases cell proliferation by 10% in sintered β-TCP samples. Starch powder additions can be used to increase the cell viability of the material by facilitating the creation of pores, as a low-cost pore-forming agent for porous bone graft and non-load-bearing material in both orthopaedics and maxillofacial applications. [ABSTRACT FROM AUTHOR]

The aim of this study was to systematically investigate the apatite layer formation and protein adsorption on the bioceramics, trying to reveal their relationship and the mechanisms of the process. Four different materials, hydroxyapatite (HA), apatite/wollastonite bioactive glass ceramics (BGC), biphasic calcium phosphate (BCP), and nano-hydroxyapatite (nHA), were prepared to meet the specific tissue engineering scaffold requirements. The porous samples in four groups were immersed into simulated body fluid (SBF) solution, and the structural and morphological changes for different times (maximum of 14 days) were analyzed. Then, the effect of their structure and chemical composition on protein adsorption capacity was systematically compared. [ABSTRACT FROM AUTHOR]

Multifunctional porous biological hydroxyapatite (b-Hap) tablets prepared from fine bone powder (FBP) are predicted to be useful as a calcium supplement and at the same time as low-dose drug carriers. FBP was hydrothermally extracted, then mechanically compressed and sintered without using chemical additives to prepare the porous b-Hap tablets. The properties of FBP and b-Hap tablets were characterized by XRD, FTIR, SEM, mechanical, and porosity tests. Moreover, an aqueous drug solution of atenolol was used to evaluate release behavior from porous b-Hap tablets. The prepared FBP exhibited microstructures with grain sizes of about 50 to 100 μm while b-Hap tablets sintered at 800 °C exhibited high porosity (55%) and compression strength of 8.5 MPa. When the atenolol-loaded b-Hap tablets were immersed in the acidic medium, the release of atenolol from the tablets continued for 120 min with complete dissolution of the b-Hap tablets. These results indicate that the porous b-Hap tablets are promised as an economic calcium supplement and as low-dose drug carriers. [ABSTRACT FROM AUTHOR]

Hydroxyapatite due to its good biocompatibility and similar chemical composition to the mineral part of bone has found various applications in tissue engineering. Porous hydroxyapatite has high surface area, which leads to excellent osteoconductivity and resorbability, providing fast bone ingrowth. In this study, highly porous body of nanostructure hydroxyapatite was successfully fabricated via gelcasting method. The pure phase of hydroxyapatite was confirmed by X-ray diffraction. The result of scanning electron microscopy analysis showed that the prepared scaffold has highly interconnected spherical pores with a size in the range 100-400 μm. The crystallite size of the hydroxyapatite scaffold was measured in the range 30-42 nm. The mean values of true (total) and apparent (interconnected) porosity were calculated in the range 84-91 and 70-78%, respectively. The maximum values of compressive strength and elastic modulus of the prepared scaffold were found to be about 1.5 MPa and 167 MPa, respectively, which were achieved after sintering at 1,000 °C for 4 h. Transmission electron microscopy analysis showed that the particle sizes are smaller than 80 nm. In vitro test showed good bioactivity of the prepared scaffold. The mentioned properties could make the hydroxyapatite scaffold a good candidate for tissue engineering applications, especially applications that did not need to stand any loading. [ABSTRACT FROM AUTHOR]