Papers by Keyword: Hydroxyapatite (HA)

Abstract: Magnesium and its alloys are potential biodegradable implant materials. However, they are characterized by rapid degradation in the electrolytic environment of the body. This phenomenon might result a sudden implant failure before bone restoration was complete, or inflammation subsided. This research will explore ways to improve the corrosion resistance of AZ31 magnesium alloy by improving the coating layer of hydroxyapatite (HA) through multiple coating layers by an electrophoretic deposition (EPD) process. In this study, the quality of the coating layer was improved by multiple coating processes without using any binders. X-ray diffraction spectrometer (XRD) showed that an amorphous structure of HA was successfully deposited on the AZ31 alloy. Scanning electron microscopy (SEM) has been used to observe that the morphology of the AZ31 alloy coated with multiple layers of HA has a denser coating structure with improved adhesion at the interface as compared to the single coating layer. A denser coating structure with greater bonding between the coating layer and the substrate is expected to protect the substrate from a high corrosion rate, thus resulting in a longer period of biodegradation as in implant in the electrolytic environment.

Abstract: This work reports on the effect of shellac coated hydroxyapatite (HA) on the compression strength. The HA was processed from bovine bone. Shellac was derived from the resinous secretion of the lac insect. The aims of the addition of shellac solution is to improve the mechanical properties of the material, especially when this material is implanted as a bone filler in order to not easily broken.The four different of shellac solutions (2,5%; 5%; 7,5%; and 10% weight) coated HA scaffold and one ratio as a control. It was found that the compression strength is influenced by the shellac solution. The greater of shellac solution will increase the compression strength of HA. The highest compression strength ​​was obtained in a solution of 10%.The morphology of HA scaffold was analyzed by Scanning Electronic Microscopy (SEM).

Abstract: In this study, bovine bone waste obtained from meatballs sellers was utilized as novel alternative bioresource of hydroxyapatite (HA). The femur bovine bone waste in bulk form was initially deproteinized using HCl and NaOH and then followed by calcination at 500 °C and 800 °C for 5 h to obtained HA powder. The thermal stability of HA powder was monitored using simultaneous thermogravimetric analysis (TG) and differential thermal analysis (DTA). The TG/DTA result shows that the combustion of the organic component of bone, especially of collagen occured at temperature range of 174-550 °C. The phase content, type of bond present, and morphology of calcined HA powder were conducted using x-ray diffraction (XRD), Fourier Transform Infrared Spectroscopy (FTIR), and Scanning Electron Microscopy (SEM) respectively. The crystallinity of the HA sample shows increase with increasing of the temperature calcination. The characteristic of bands of HA and additionally peaks of carbonate ions were observed in the FTIR results and the morphologic characteristics of the HA particles shows the material is a homogeneous powder.

Abstract: A hydroxyapatite is known as one of vital materials and common use in biomedical field and concentrated in clinical area. In relation to the above, the development of hydroxyapatite powder becomes an attractive research lines due to simplify in produce it. Thus in this paper the researcher stress out about Hydroxyapatite powder gained from the natural sources or so called as the waste of Tilapia bone and scales. The raw bones of and scale were undergo to crushing process to form in powder size (0.2 mm) then analysed by X-ray Diffraction (XRD) to identified the mineralogy of raw bone. Moreover the powder of fish bone and scales also go through to Scanning Electron Microscope (SEM) machine to analyse the microstructure of the powder while EDS act as device to determine the chemical composition of the sample powder. Sample powder then forward calcination process at selected temperature range to as a cheaper method in obtained hydroxyapatite raw sources. The range of calcination temperatures are between 800°C to 1000 °C. The sample preparation were analysed in both condition before and after calcination process by using XRD, SEM and EDS. The HAP crystalline composition of tilapia bones for raw powder and at 800 °C are similar with HAP pattern (JDS 00-009-0432) and the chemical reaction is Ca₅(PO4)₃(OH) then at temperature 900 and 1000 similar to HAP pattern (JDS 00-055-0592) with chemical reaction equal to Ca₁₀(PO4)₆(OH)₂.

Abstract: The aim of this study was to find out the in-vivo radiography density changes of hydroxyapatite coated porous tantalum biomaterial implant after surgical implantation in rats. Ten adult male Sprague Dawley rats were divided into two groups: hydroxyapatite-coated porous tantalum (pTa-HAp) and uncoated porous tantalum (pTa). The implants with dimension of 5 x 2 x 0.5 mm³ was inserted into flatten bone defects drilled at the femur bone on latero-medial region. The implant density from right lateral view radiogram was analyzed at day 0, 7, 14 and 30 post-implantation. The results showed that the radiodensity of both pTa and pTa-HAp groups decreased in time of implantation. The radiodensity changes of pTa-HAp showed higher decrease compared to pTa.

Abstract: The bioactive glasses of SiO₂-CaO-P₂O₅-SrO system have been prepared by a quick alkali mediated sol-gel method. The prepared bioactive glass of 1, 3, 5 wt% of SrO (coded: SR1, SR3, SR5, respectively) were characterized by SEM, XRD and FTIR. XRD pattern of all glasses calcined at 700°C in air confirmed that the calcined bioactive glass generally existed in amorphous state. The samples were immersed in simulated body fluid (SBF) to investigate the presence of hydroxyapatite (HA). All bioactive glass samples can induce the formation of hydroxyapatite (HA) as verified by SEM and XRD.

Abstract: This study aims to create avirulent artificial bone scaffolds. Chitosan/gelatin mixture is blended with hydroxyapatite (HA) powder, followed by being processed with a free-dry method in order to form CGH artificial bone scaffolds. A stereomicroscope, an optical microscope and an MTT assay are used to evaluate the applications of the bone scaffolds. The combination of HA powders leads to isotropic pores in the bone scaffolds, while not inflicting their biocompatibility. In addition, the cell viability increases with the increasing content of HA powder. This study successfully produces biocompatible and non-toxic bone scaffolds.

Abstract: To calrify the combined effect of soft template and biominormolecule on the formation of hydroxyapatite (HAp), the study on the growth of HAp regulated by citrate and(or) hexadecyltrimethylammonium bromide (CTAB) solution was developed in a thermal aqueous. The as-obtained products were characterized by XRD, FT-IR and TEM, altogether with HRTEM and ED. Plate-like HAp crystals in nanosize with relative weak crystallinity were obtained in the presence of citrate. Nano-needle shape HAp crystals were produced in the presence of CTAB. Rod-like HAp crystals in a uniform nanosize were formed under the regulation of CTAB and citrate, which showed the same orientation as that of CTAB only. However, the possible mechanism of the growth of HAp was discussed in detail. CTAB micelles worked as a soft template modified by citrate, which guided to form HAp crystals in different morphology. The study is benefit to control the formation of HAp for its bioapplication.

Abstract: The properties of the interface between biomaterials and the host tissue play an important role for the process of successful adaptation of implants. Extensive research has focused on shortening the time of osseointegration by modifying the surface in adding a coating such as hydroxyapatite (HAp). We have developed a new type of biocompatible nanohydroxyapatite (n-HAp) coatings, which are characterized before and after deposit on a Ti-6Al-4V substrate using neutron diffraction and scanning electron microscopy. Three months after the implantation in the sheep tibias, high-energy synchrotron radiation (ID15B, ESRF, Grenoble, France) diffraction studies of the cortical bone identify that the c-axes of HAp are preferentially oriented in the direction of the stresses that bone usually withstands. This non destructive analysis of the bone-implant interface proves that bone maturation is achieved successfully with this novel n-HAp coating and demonstrates that the mineralization is completed without spatial organization. None of these findings are obtained with uncoated titanium alloys. The presence of this n-HAp coating on Ti-6Al-4V substrate is decisive in obtaining this mature bone at the interface.

Abstract: In Malaysia recently, it was found that cockle shell (Anadara granosa) is a potential source of biomaterial for bone repair. It is the most abundant sea species cultured in Malaysia. A possible advantage of using cockle shell as a biomaterial is that they may act as an antilog of calcium carbonate. Malaysian Nuclear Agency took this challenge to develop synthetic bone graft from natural cockle shell. To date, the artificial bone graft substitutes developed from hydroxyapatite (Ca₁₀(PO4)₆(OH)₂) a bio ceramic is similar to the mineral constituent of human bone. The structure and the composition of hydroxyapatite (HA) are similar to the mineral phase of bone and, its bioactivity and biocompatibility makes it a preferred bone graft.