الفهرس 
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Abstract
Biological hydroxyapatite is one of the most active bioceramics for bone implants, tissue
engineering, drug delivery, and other biomedical applications. The current goals in biomaterials
research focus on synthesis or develop HAp structures with improved characteristics to meet
biomedical applications. At present, HAp structures prepared by the commercially available
techniques depending on natural or chemical sources have some major drawbacks.
Biological hydroxyapatite powder was extracted from four different animal species: Buffalo
(Bubalus bubalis), Camel (Camelus dromedaries) and Sheep (Ovisaries) and bovine
(Bos Taurus) bones at 700 and 1000 oC via three-step thermal extraction approach.
Various analytical techniques were used for characterization of the structural and morphological
features of the extracted BHAp. XRD analysis confirmed that, no crystalline phases other than
biological hydroxyapatite were detected. It was observed that the calcination temperature had a
considerable effect on the structural and morphological characteristics of the extracted
hydroxyapatite such as, crystallinity, crystallite size, and particle size distribution. The results
indicated that the crystallite size and the degree of crystallinity increased with the increase of
calcination temperature up to 1000 0C. FTIR analysis showed well-defined vibrational bands
referring to the characteristic groups of the BHAp phase; Phosphate (PO4
3−), carbonate (CO3
2−),
hydroxide ions (OH−), and absorbed water H2O confirming the thermal stability of the BHAP up
to 1000 °C . Moreover the results confirmed that all the samples calcined at 700 0C had relatively
high quantity of carbonates .However samples calcined at 1000 0C had only traces amount of
carbonate ions. SEM analysis revealed that, the extracted biological hydroxyapatite at 700 0C
present different morphologies and particle sizes .As temperature increased up to 1000 0C, the
particles tend to increase in size and aggregate. The role of extracted biological hydroxyapatite in
bone regeneration was evaluated in vivo by testing its ability to repair critical femoral defects in a
rat model. The histological analysis, demonstrated that carbonated biological hydroxyapatite
promoted bone formation in the experimental induced bone defect rather than biological
hydroxyapatite devoid of carbonate, confirming its efficacy for usage in bone defects. The data
also showed that healing response was also dependent on the particle morphology. Spherical
biological hydroxyapatite particles of HAp (B700) and HAp (C700) samples, present faster and
more robust bone healing. Conversely, HAp (W1000) and HAp (S1000) samples had the lowest
bone formation response. Antibacterial abilities were tested against Escherichia
coli and Staphylococcus aureus. The multifunctional composite based on BHAp and ZnO
increased the inhibition against bacteria. The result showed that both 3wt% ZnO/BHAp and 2wt%
ZnO/BHAP enhance the antibacterial activity of the biological hydroxyapatite