Standard Hydroxyapatite Research Articles

The effect of temperature on the synthesis and characterization of hydroxyapatite-polyethylene glycol composites by in-situ process

Hydroxyapatite (HAp) is a vital material in various biomaterials but has low flexibility. Because of that, research has been done to increase the efficiency of hydroxyapatite by combining it with polyethylene glycol (PEG). HAp-PEG composite synthesis using blood cockle shell waste (Anadara granosa) as Ca precursor. The HAp-PEG composite was synthesized by in-situ to avoid high agglomeration. It was carried out with various temperatures to study the effect of temperature on the formation of the HAp-PEG composite and to determine the effect of temperature on its morphology and degradation properties. Fourier-Transform infrared (FTIR) characterization showed the presence of HAp and PEG functional group vibrations. X-Ray Diffraction (XRD) analysis showed that the composite had HAp peaks that matched the standard HAp ICSD #97849 and corresponded to pure PEG peaks. Characterization of Scanning Electron Microscopy-Energy Dispersive Spectroscopy (SEM-EDS) It is known that the synthesis temperature affects the morphology and hydroxyapatite ratio. Thermogravimetric Analysis-Differential Thermal Analysis (TGA-DTA) analyzed weight reduction in HAp-PEG composite samples, showing that the composite experienced a significant decrease in mass at 176–306, indicating PEG decomposition. The HAp-PEG composite degradation behavior test confirmed that the optimum temperature for degradation occurred at 70 ​°C.

Wound healing efficacy of biocompatible hydroxyapatite from bovine bone waste for bone tissue engineering application

Extraction of biocompatible implantable biomaterials from bio-waste is a considerable strategy to protect environmental issues as well as human wellness. Hence, this work aimed to extract the hydroxyapatite (HAP) from beef bone (BB) by acid/alkali treatment, and calcination process. The hydrochloric acid (1 M), and sodium hydroxide (1 M) extraction followed by calcination at 600 °C for 5 h were facilitated to obtain the good quality of bovine bone-derived hydroxyapatite (BB-HAP). The characteristics of BB-HAP were demonstrated through XRD, FTIR, SEM, ICP-OES, and TGA analysis. The characteristics features of BB-HAP were compared with standard hydroxyapatite (Std-HAP). The FTIR spectrum confirmed the presence of carbonate and phosphate functional groups in BB-HAP, which is similar to Std-HAP. Further, XRD and SEM analysis confirmed the hexagonal crystalline structure of BB-HAP with size of 120 ± 12.5 nm. ICP-OES analysis evidenced the existence of Ca (40.42%), P (18.51%), Mg (0.55%), Na (0.22%), and Sr (0.05%) in BB-HAP. In vitro cytotoxicity assay confirmed that BB-HAP did not cause cytotoxicity to NIH3T3 cells, and augmented in vitro wound-healing activity. Hence, this study concluded that BB-HAP was biocompatible that would be used for the development of wound dressing and implantable material.

Correlation of heating profile with calcination temperature for the extraction of nano hydroxyapatite (Nano-HAp) derived from bone

Bone is one of the major sources of hydroxyapatite (HAp) in the form of calcium phosphate. The increasing demand for HAp has brought much interest in research line to find the best method for its production either synthetically or naturally. Calcination of natural bone is a common heat treatment method for production of HAp. However, the optimum temperature of calcination depends on source and heating profile of the bone. Therefore, this study aimed to determine heating profile and the optimum calcination temperature of Nano-hyroxyapatite (Nano-HAp) extracted from spotted sardinella (Amblygaster sirm) bone. Characterization of Nano-HAp was carried out using thermogravimetric analysis (TGA), chromameter and X-ray diffraction (XRD) spectroscopy. The composition of protein, ash, moisture and lipid content of raw bone (RB) were 1.08%, 50.98%, 10.47% and 3.78%, respectively. Results demonstrated that the optimum temperature for extracted nano-hydroxyapatite (HAp-1) was 700°C based on yield percentage (55%) and colour changes value (∆E=18). Heating profile of raw bone demonstrated the highest reduction of weight loss percentage (320°C to 610°C=36%); which determined the melting point of the bone that acted as a supporting analysis for calcination. XRD confirmed the crystallinity phase of HAp-1 particle similar to the standard peak of HAp, (PDF No: 1-1008) and comparable with the standard HAp. Based on the heating profile and colour changes value, the findings demonstrated that the calcination of HAp from bone of spotted sardinella (Amblygaster sirm) could be carried out at an optimum temperature of 700°C. Overall findings have suggested that the optimum calcination temperature obtainedmay contribute to the development of optimal method for the extraction of HAp via heat treatment process with different fish species.

Effect of Calcination Time on Bovine-Derived Hydroxyapatite as Bone Implant Material: An <em>In Vitro </em>Study

Bone fracture incidence has been increasing, according to recent studies. For a fracture to heal, orthopedic implants are usually employed. One of the bioceramics used is hydroxyapatite (HAp), which has a similar chemical structure with bone mineral and is biocompatible, bioactive as well as non-toxic to the human body. Current methods of HAp synthesis are mostly still toxic to the human body and expensive. Hydroxyapatite originated from natural resources can provide more favorable materials. The purpose of this study is to characterize HAp extracted from bovine bone calcination at 850°C for various holding times as bone implant material. The toxicity of the bovine-derived HAp is also assessed. Prepared bovine bones were subjected to calcination at 850°C over various holding times. The characterization was carried out with thermogravimetric analysis (TGA) instrument followed by X-ray diffraction (XRD), Scanning Electron Microscopy (SEM), Energy Dispersive X-ray Spectroscopy (EDX) and Fourier-Transform Infrared Spectroscopy (FT- IR). The toxicity of the bovine HAp was assessed using MTT (3-[4, 5-dimethyl-thiazol-2-yl-]-2, 5-diphenyltetrazolium bromide) assay. Each of the parameters was compared between the HAp extracted from bovine and the commercial HAp. Analysis of the phase, purity, and crystallinity showed that the bovine-derived HAp was similar to the standard HAp. Crystal agglomeration was observed at increased calcination time. The optimal holding time of 5 hours was demonstrated through the closest Ca/P ratio (1.679) to the stoichiometric HAp (Ca/P ratio = 1.67) in EDX analysis. The toxicity test using the MTT assay showed that the viabilities of CPAE cells treated with bovine HAp were well above 60% (non-toxic threshold). In conclusion, hydroxyapatite produced from bovine bone calcination at 850°C with 5 hours of holding time has the characteristics which are similar to the commercial HAp. This natural HAp has proven to be non-toxic and also cost-effective.

Structural and Magnetic Characterizations of Nano Sized Grain Zinc Ferrite/Hydroxyapatite Ceramic Prepared by Solid State Reaction Route.

A promising composite of bioactive hydroxyapatite (HAp) and zinc ferrite (ZnFe2O4) has potentials for future bone reinforcing formation. In present study, HAp and ZnFe2O4 composite ceramic was prepared by solid state reaction route for easier control of structural and magnetic characteristics and with low cost. HAp powder was synthesized by precipitation method from chicken eggshell. Mixed powders with varying ZnFe2O4/HAp weight ratios from 2-10 wt% were milled together and uniaxially pressed and then sintered at 1200 degrees C for 3 hours. The XRD results showing no other phases of composite ceramics with only HAp and ZnFe2O4 phases were identified, indicating high stability of HAp property. Phase fractions of ZnFe2O4 were found to increase from 10.8 to 18.73 wt% with increasing content of ZnFe2O4. FT-IR results were only revealed vibration bands of standard HAp phase. SEM results revealed primary grains sizes of the prepared ceramics in nano scale. The BET surface area and pore volume increased with increasing content of ZnFe2O4 in composite ceramics. The VSM results of composites with increasing ZnFe2O4 content had been shown with increasing magnetization from 0.05 to 1.85 emu/g while their coercivities were decreased from 44 to 24 Oe. Higher magnetization as well as higher super paramagnetic behavior could be achieved with increasing the studied ZnFe2O4 weight ratios in ZnFe2O4/HAp composite ceramics, which can be tailored for specific applications.

Effect of Calcination on the Properties of Hydroxyapatite from Tilapia Fish Bones

The present work focus on study of the effects of calcination temperatures (600, 800, 1000, and 1200°C) on derived natural hydroxyapatite from different parts of tilapia fish bones. The calcined samples were characterized regards to their chemical and structural properties. The XRD result revealed the presence hydroxyapatite (HAp) from the calcined samples and were identical to the standard HAp pattern. The FT-IR spectra confirmed that all organic materials and water molecule present in raw samples were completely eliminated during the calcination process at 600°C. SEM results show the surface morphology of calcined samples as compared to raw samples. The HAp was fully formed when samples were calcined at 800°C. The increasing temperature had led to the formation of mixtures of hydroxyapatite (Ca10(PO4)6(OH)2) and β-Tricalcium phosphate (Ca3(PO4)2, β-TCP). The degree of crystallinity and crystallite size gradually increased with the calcination temperature. Calcined Fin and head were found to have great potential in the extraction of biological HAp. The findings are the promising alternative to produce pure hydroxyapatite from marine wastes at a suitable temperature that beneficial to medical applications. The present work focus on a study of the effects of calcination temperatures (600, 800, 1000, and 1200°C) on derived natural hydroxyapatite from different parts of tilapia fish bones. The calcined samples were characterized regards to their chemical and structural properties. The XRD result revealed the presence hydroxyapatite (HAp) from the calcined samples and were identical to the standard HAp pattern. The FT-IR spectra confirmed that all organic materials and water molecule present in raw samples were completely eliminated during the calcination process at 600°C. SEM results show the surface morphology of calcined samples as compared to raw samples. The HAp was fully formed when samples were calcined at 800°C. The increasing temperature had led to the formation of mixtures of hydroxyapatite (Ca10(PO4)6(OH)2) and β-Tricalcium phosphate (Ca3(PO4)2, β-TCP). The degree of crystallinity and crystallite size gradually increased with the calcination temperature. Calcined Fin and head were found to have great potential in the extraction of biological HAp. The findings are the promising alternative to produce pure hydroxyapatite from marine wastes at a suitable temperature that beneficial to medical applications.

Ultrastructural Observation of Hydroxyapatite Ceramics with Preferred Orientation to a-plane Using High-resolution Transmission Electron Microscopy

The dense hydroxyapatite (HAp) ceramics with preferred orientation to a-plane were fabricated using composite powders of single-crystal apatite fibers (AF) and wet-synthesized apatite gels (AG). AF was synthesized by homogeneous precipitation method. The composites of AF and AG were prepared as the following process. Aqueous (NH4)2HPO4 solutions were added into the AF slurry with the amount of 1 mass%. In addition, aqueous Ca(NO3)2 solutions were added dropwise to the slurry to precipitate the AG on the AF at room temperature, and then aged at room temperature for 24h with stirring. The dried powders were uniaxially pressed at 200MPa of compaction pressure and then fired at 1300 ¼C for 5h. All the resulting ceramics were identified with HAp single phases. The (100), (200) and (300) reflections which correspond to a-plane were more intense than those of a standard HAp ceramics. With increasing the additive amount of AG, the orientation degree of a-plane decreased, and the relative density increased. Furthermore, the ultrastructure of the resulting ceramics was examined by high-resolution transmission electron microscopy. The selected area electron diffraction patterns showed clear spots corresponding to [110] zone axis direction of HAp crystal with high crystallinity. The lattice spacings of crystal grains were determined to be 0.34nm or 0.68nm which corresponds to the lattice constant of (002) or (001) plane of HAp crystal. Therefore, the resulting ceramics were HAp single phases with preferred orientation to a-plane.

Polymer assisted isolation of hydroxyapatite from Thunnus obesus bone

The combination of micro and nanostructured hydroxyapatite (HAp) was isolated from Thunnus obesus bone via thermal calcination method in the presence of polymers such as poly ethylene glycol (PEG), poly (ethylene glycol)-block-poly (propylene glycol)-block-poly (ethylene glycol) (PEG–PPG–PEG) and poly vinyl alcohol (PVA). The thermal stability, crystalline phase, chemical composition and morphology of the derived HAp were characterized by thermal gravimetric analysis, X-ray diffraction analysis, Fourier transform infrared spectroscopy and field emission scanning electron microscopy analysis. The physicochemical characteristic examination revealed that derived HAp was coherent with standard HAp data. Moreover, FE-SEM depicted significant difference in the crystal size of HAp derived with thermal calcination, with and without added polymers. The crystallinity of HAp isolated in the presence of polymer was lower than that obtained in the absence of polymers. The biocompatibility of the derived HAp crystals was checked with MC3T3-E1 osteoblastic cells by MTT assay and Hoechst-33342 staining. The biocompatibility of HAp derived by polymer assisted thermal calcination method revealed that it is less toxic as compared to HAp derived in the absence of polymer. As an inference, polymer assisted thermal calcination derived HAp is good in terms of the presence of combined micro and nanostructured HAp and its low toxicity will bring about new orthopaedic applications.