Addition Of Hydroxyapatite Research Articles

Mechanical testing of cephalomedullary nail lag screws after the addition of hydroxyapatite substitutes.

Objective:To compare the effects of 3 implant designs, with and without hydroxyapatite reinforcement, on push/pull-out strength and rotational torque.Methods:Three implant designs (Gamma 3, INTERTAN, and PFNA-II) were selected for comparison. A hydroxyapatite cylinder (NEOBRACE) was used to reinforce the interface between the femoral head and the lag screw. Maximum push-out strength, maximum pull-out strength, and peak rotational torque were measured in cellular blocks mimicking osteoporotic cancellous bone, with and without NEOBRACE.Results:In the push-out test, INTERTAN produced a significantly higher push-out strength in osteoporotic bone density cellular blocks than the other lag screws and blades (P < .05). With the addition of NEOBRACE, push-out strength was significantly higher for INTERTAN and PFNA-II (P < .05) than for the non-NEOBRACE group. In the pull-out test, INTERTAN produced a significantly higher pull-out strength in the osteoporotic bone density cellular blocks than did the other lag screws and blades (P < .05). With the addition of NEOBRACE, the pull-out strengths of INTERTAN and Gamma 3 versus those of the non-NEOBRACE group significantly increased (P < .05). In the rotational torque test, INTERTAN produced significantly greater rotational torque in the osteoporotic cellular blocks than the other lag screws and blades (P < .05). The addition of NEOBRACE resulted in a significant increase in rotational torque only for INTERTAN (P < .05).Conclusion:The use of NEOBRACE supported an increase in push/pull-out strength and rotational torque, especially in systems with a relatively increased bone or implant interface area.Level of Evidence: Level V

Synthesis of Polycaprolactone-Hydroxyapatite (PCL-HA) Biodegradable Nanofibres Via an Electrospinning Technique for Tissue Engineering Scaffolds

The interest in biodegradable polymer nanofibres with tissue cell regeneration potential has increased in recent years. However, there are issues in the development of scaffolding to provide a favourable environment for cell proliferation and attachment. Such issues can be overcome by the addition of hydroxyapatite (HA), which is widely used in biomaterial applications. Biodegradable nanofibres of polycaprolactone (PCL) and hydroxyapatite (HA) have been produced by electrospinning. In this study, PCL was mixed with HA to synthesise nanofibres by single nozzle electrospinning. Furthermore, PCL-HA nanofibres were mixed with fibronectin to investigate the effect of adhesion of fibronectin to the surface of the PCL-HA nanofibres. The structure and morphology of nanofibres were determined by scanning electron microscopy (SEM), the chemical properties of nanofibres were analysed by Fourier transform infrared (FTIR), and the diameter and adhesive force of nanofibers and fibronectin were determined by an atomic force microscope (AFM). The SEM examination revealed the formation of cylindrical and smooth nanofibres with dense fibre networks when 10% HA was used, as HA can generate fibre. FTIR analysis indicated the presence of PCL and HA inside the nanofibres produced by electrospinning. The AFM examination showed that the PCL-HA nanofibres with 100 µg/ml of fibronectin gives the highest adhesion force which is important for the scaffold to resist the force from the external environment. This outcome resulted indicates that the PCL-HA nanofibers with fibronectin are promising for tissue engineering scaffold application. Hence, further investigations are needed to ensure the compatibility of living cells to survive and grow on the PCL-HA nanofibrous mats.

Performance and Mechanisms of PropS-SH/HA Coatings in the Inhibition of Pyrite Oxidation

Acid mine drainage (AMD) entering the environment will cause long-term environmental pollution and ecological damage, the treatment or remediation for which has become a difficult worldwide problem. To control AMD at the source, a novel composite coating, hydroxyapatite (HA) as the filler embedded in a γ-mercaptopropyltrimethoxysilane (PropS-SH) coating, was introduced in this study. The performance and mechanisms of PropS-SH/HA coatings in the inhibition of pyrite oxidation were investigated by chemical leaching testing and material structure characterization. The results of the investigations revealed that the addition of an appropriate amount of HA can enhance the passivation efficiency of the PropS-SH coating. The best coating was obtained from 3% (v/v) of PropS-SH solution with 16 wt % HA, as this coating decreased pyrite oxidation by 78.7% (based on total Fe release). The main mechanism of PropS-SH/HA for the inhibition of pyrite oxidation involved the generation of a PropS-SH network through a polycondensation reaction. The addition of HA increased the stability of the passivation film composed of PropS-SH as well as the combining capacity of PropS-SH/HA through the formation of Si–O–Si and Fe–O–Si bonds, respectively.

Graphene Oxide/Chitosan/Hydroxyapatite Composite Membranes Enhance Osteoblast Adhesion and Guided Bone Regeneration.

Two-dimensional materials provide a secluded space for bone formation and preserve the growth of surrounding tissues, thus playing a crucial role in guided bone regeneration (GBR). Graphene oxide (GO) has been widely employed in GBR due to its good mechanical and hydrophilic properties. A single GO membrane, however, does not provide a friendly environment for osteogenic cell adhesion. With their adjustable mechanical properties and excellent biocompatibility, composite membranes can simulate the multicomponent structure of an extracellular matrix for cell adhesion. To obtain two-dimensional membranes with appropriate mechanical strength and sufficient biocompatibility, GO-based composite membranes simultaneously containing chitosan (CS) and hydroxyapatite (HAP) were first prepared using one-step vacuum filtration and a biomimetic mineralization method. CS and HAP improved the mechanical strength and surface hydrophilicity of the membranes. In addition, moderate addition of HAP enhanced the adhesion, differentiation, and mineralization of osteoblasts. The prepared composite membranes were then implanted into a calvarial defect model to evaluate their osteogenic induction effects in vivo. Microcomputed tomography observation and histological analysis indicate that GO/CS/HAP composite membranes can accelerate bone regeneration without the contribution of endogenous cytokines. GO/CS/HAP composite membranes with unique biomimetic porous structures, superior mechanical properties, and excellent bone regeneration capacity are potential materials for application in GBR.

Effects of Different Particle Sizes of Hydroxyapatite on the Distribution and Migration of Trace Elements (Copper and Cadmium) in a Smelter-Impacted Soil.

To study the remediation effect of hydroxyapatite with different particle sizes, a field in situ experiment was carried out by adding conventional hydroxyapatite (0.25 mm) and microhydroxyapatite (3 μm) and nanohydroxyapatite (40 nm) to the contaminated soil and planting Elsholtzia splendens. The distribution and migration of copper (Cu) and cadmium (Cd) in soil were investigated after 4 years. The results show that the application of three different particle sizes of hydroxyapatite significantly raise the soil pH, total phosphorus, and soil organic carbon. Moreover, the addition of hydroxyapatite can reduce the EXC fraction of Cu and Cd by 73.7%–80.1% and 20.8%–35.2%, respectively. In addition, the concentrations of Cu and Cd in >2 mm, 0.25–2 mm, 0.053–0.25 mm, and <0.053 mm aggregate are significantly increased. This improvement indicates that there are risks which may cause the increasing of total Cu and Cd in the soil where the pollution sources still exist. Furthermore, the content of soil colloid is significantly increased, and the colloidal Cu and Cd distribution percentage have been significantly increased by 49.9%–120% and 30.3%–181%. This result illustrates that the application of hydroxyapatite may greatly increase the possibility of colloid and dust migration of Cu and Cd.

Combined application of ferrihydrite and hydroxyapatite to immobilize soil copper, cadmium, and phosphate under flooding-drainage alternations

Hydroxyapatite (HAP) can effectively immobilize soil heavy metals, but excess phosphate would be released to aquatic ecosystem, resulting in eutrophication. This study investigated the effects of ferrihydrite (FH) on the HAP immobilization of copper (Cu) and cadmium (Cd) and their reduction of phosphorus release under flooding-drainage alternation conditions. Results showed that the incorporation of HAP and FH significantly increased soil solution pH and decreased Cu2+ and Cd2+ concentrations. Applications of FH, HAP, and FH-HAP (FH and HAP combination) can all enhance soil pH and reduce CaCl2-extractable and exchangeable Cu and Cd, but HAP addition increased soluble phosphate by 6.60–7.77 times compared to control. However, FH-HAP application can significantly reduce phosphate release by 92.7–99.7% compared to HAP application. FH-HAP was the most effective to reduce exchangeable Cu and Cd by 49.8–93.4% and 50.9–88.8% and decreased labile and moderately labile phosphorus by 34.0–74.4% and 13.5–18.6%, respectively, while increased stable phosphorus by 22–45.1% than single HAP. All FH treatments significantly increased amorphous iron oxides by the factors of 4.66–20.8, but only 3% and 5% of FH applications slightly enhanced crystal iron oxides by the factors of 0.81–1.27. The major implication is that the combination of FH and HAP can not only immobilize of Cu and Cd, but also reduce the risk of phosphate release by HAP addition.

Extrusion‐based 3D printing of gelatin methacryloyl with nanocrystalline hydroxyapatite

AbstractThe particle shape and size distribution of inorganic fillers play a crucial role in the scaffold buildability when those are incorporated in the viscoelastic polymers. In order to address this issue, the phase pure rod‐shaped nanocrystalline hydroxyapatite (HAp) powders with varying particle sizes and shapes were synthesized by a one‐pot hydrothermal method without any regulatory surfactant at an initial solution pH of 9. As‐synthesized nanocrystalline HAp particles (0–5 wt%) were incorporated into 15 wt% pre‐cross‐linked gelatin methacryloyl (GelMA) hydrogel matrix to fabricate a predesigned scaffold architecture using a custom‐made 3D bioprinter. The printing parameters (nozzle diameter, extrusion pressure, and printing speed) were optimized for each composition. The biophysical properties (uniaxial compression behavior, swelling ratio, and in vitro degradation) of the composite hydrogel scaffolds were critically analyzed to unravel the role of nano‐sized HAp addition. The compression strength and modulus were substantially improved, while the rate of water uptake and bio‐enzymatic degradation significantly reduced with HAp content. We propose that the inorganic–organic nanocomposite hydrogel could be efficiently assembled to formulate a potential bioink for 3D bioprinting applications toward tissue regeneration.

Effect of hydroxyapatite content and particle size on the mechanical behaviors and osteogenesis in vitro of polyetheretherketone–hydroxyapatite composite

AbstractPoly‐ether‐ether‐ketone (PEEK) possesses excellent biocompatibility and similar elastic modulus as bones but suffers from poor osseointegration; usually, the addition of hydroxyapatite (HA) is considered as an effective way to improve the osseointegration of PEEK implant interface. To investigate the effect of HA content and particle size on the mechanical behaviors and osteogenesis in vitro of PEEK‐HA composites, the PEEK‐HA specimens with variable HA content and particle size have been fabricated by powder mixing‐heat press method and characterized by mechanical and biological tests. The results showed that the tensile/bending strength and elongation at break of PEEK‐HA are significantly impaired as the increasing HA amount, but the modulus improves. The compressive strength and modulus are improved as the increasing amount of HA. The PEEK‐HA with smaller HA particle size possesses higher‐performance tensile/bending and lower‐performance compressive properties. In osteogenesis tests in vitro, the results reveal that the cells amount attached on the substrate rises and the cells flatten more evenly with numerous cytoplasmic processes on greater area with the increasing HA content and decreasing particle size. The PEEK‐HA group that HA content is 20 wt% and particle size is 20 nm exhibits optimal‐performance osteogenesis in vitro, while maintaining sufficient mechanical properties.

Replacement of hydroxyapatite from chicken eggshell waste for ceramic properties improvement

AbstractThe chicken eggshell waste from food processing was synthesized as the hydroxyapatite for fluxing agent replacement in ceramic manufacturing. The main fluxing agents in Thailand ceramic manufacturing are natural potash feldspar (k‐feldspar) and animal bone ash. To overcome the problems of inconstant properties and the lack of k‐feldspar, the hydroxyapatite from chicken eggshell waste was selected as fluxing agent for the enhancement of the ceramic product. In this work, the hydroxyapatite with 0, 5, 10, and 15 wt% was replaced with the k‐feldspar in the ceramic samples. The results revealed the physical and mechanical properties of the ceramic samples with various hydroxyapatite contents were investigated after heat treatment in the temperature range of 1000–1200 °C. The ceramic samples added with hydroxyapatite have higher linear shrinkage and bulk density as compared with the ceramic sample without hydroxyapatite. The apparent porosity and water absorption decreased to near zero after the heat treatment at a temperature of 1200 °C. Moreover, the results showed that the physical properties affected the mechanical properties improvement after the hydroxyapatite addition and heat treatment process.

Composation of Polyaluminum Chloride with Hydroxyapatite and Its Application for Separation of Hexavalent Chromium Ions

Ch romium is the dominant heavy metal in liquid waste from the leather tanning industry, wood preservation and textile processing. Generally c h romium waste is found as trivalent and he x a v a l en t chromium ions. Hexavalent chromium ion is dangerous for humans because of its carcinogenic nature, which can lead to skin irritation, lung cancer, kidney and stomach disorders. Coagulation-flocculation (CF) is a method used to reduce hexavalent chromium ion levels. Polialuminum chloride (PAC) has been widely used in water treatm ent using the CF method. Unfortunately, however, the PAC stability is poor, the coagulation efficiency is low, and the floc formation time is slow. In addition, PAC can produce Al3+ which is toxic in processed water. But its toxicity can be overcome by adding donor ligands that contain oxygen such as hydroxides, carboxylic acids and phosphates, such as hydroxyapatite (HA). In addition, the addition of HA with the optimum composition and pH at PAC can increase the performance of PAC. This study aims to optimize the PAC/HA combination at various pH so as to reduce the concentration of hexavalent chromium ion, controlled by UV-VIS spectroscopy. The highest reduction in Cr (VI) ion content was obtained by PAC, but the highest stability was obtained by the composition of PAC/HA 4: 6.

Effect of hydroxyapatite nano rods on sinterability, hardness and bioactivity of Fe-14Mn-6Si alloy prepared by powder metallurgy

Recently, there is a great of industrial interest on the production of biodegradable metal/ceramic composites. The casted Fe-Mn-Si alloys prepared by casting tools have low biodegradable rate; so it is important to seek a method as powder metallurgy (PM) to prepare porous bodies with increased biodegradability. Moreover, the addition of hydroxyapatite (HA) nano rods to that alloy increases its bioactivity and forms composite with improved properties. In the present study, Fe-14Mn-6Si/HA composites were prepared by PM and sintered at different temperatures, i.e. 1100, 1150 and 1200oC. Also, the effect of HA nano-rods content on the composite properties (physical properties, microstructure and micro hardness) and bioactivity were studied. The results revealed that bulk density increased with increasing sintering temperature up to 1150oC; then decreased at 1200oC. Also, the bulk density increased with increasing the HA content. Moreover, the hardness of the sintered composites increased with increasing sintering temperature and HA amount. The maximum hardness values were 1293 & 1792 MPa for the specimens which contain 8 % HA and sintered at 1150 and 1200oC, respectively. The bioactivity of the prepared composites increased with increasing HA amount. The highest bioactivity was for the composite that contains 8 wt.% HA.

Understanding wear behavior of 3D-Printed calcium phosphate-reinforced CoCrMo in biologically relevant media

Recent advances in the processing of wear-resistant calcium-phosphate reinforced CoCrMo composites for articulating surface applications has necessitated further investigation of performance in biological conditions relevant to patient applications. To this end, CoCrMo composites containing calcium phosphate in the form of hydroxyapatite (HA) were manufactured to study the influence of the reinforcing phase on the tribofilm formation in biologically-relevant conditions. The CoCrMo-HA composites were processed using a laser engineered net shaping (LENS™) additive manufacturing (AM) system with three distinctive compositions: CoCrMo-0%HA, CoCrMo-1%HA, and CoCrMo-3%HA. Extensive wear testing of the CoCrMo-HA composites was carried out in DMEM (cell media) and DMEM + Hyaluronic acid (found naturally in synovial fluid). Wear tests were performed at loads ranging from 5N to 20N, and wear media was measured post-test using ICP-MS techniques to release Co and Cr ions. During testing, all coefficients of friction remained in the 0.15–0.25 range, which was lower than the previously reported 0.50–0.75 range in DI water, indicating that the DMEM + hyaluronic acid media plays a significant role in reducing frictional contact. At loads higher than 15N, the HA-tribofilm exhibited a breakdown resulting in higher wear rates but still lower overall ion release than the CoCrMo control composition. Our results indicate that CoCrMo alloys with HA addition can significantly reduce wear rates and ion release even in the presence of naturally-occurring synovial-fluid friction-reducing media.

Fabrication of Ca and P containing niobium oxide ceramic coatings on niobium by PEO coupled EPD process

Abstract Surface modification of niobium (Nb) to develop Ca and P containing niobium oxide (Nb2O5) ceramic coatings by plasma electrolytic oxidation (PEO) coupled with electrophoretic deposition (EPD) in a single step process is reported in the present study. Four coatings were obtained in silicate and phosphate electrolytes with and without the addition of hydroxyapatite (HA) nanoparticles. The phase composition, surface and cross-sectional morphology of the coatings were analysed. The corrosion resistance of the coated samples and niobium substrate was analysed using potentiodynamic polarisation (PDP) method in simulated body fluid (SBF) solution. The cell-viability and the live and dead cell morphology on the substrate and the coated samples were evaluated using L-929 cells. The adherence and growth of the L-929 cells were estimated by the direct contact assay. The surface modification by the PEO process enhanced the corrosion resistance of niobium in a fluid body environment. Among the coated samples, the PEO-EPD samples obtained in silicate electrolyte exhibited better corrosion resistance (6.02 × 10−7 mA/cm2), optimal surface properties, lower contact angle (47°), higher surface energy (50 mJ/m2), good adhesion strength (Lc = 18.1 N) and better cell viability.

Bioinspired mineral–organic hybridization strategy to produce a green high performance soybean meal based adhesive

Soybean meal-based adhesives have been applied in many fields due to the abundant source and eco-friendly property. However, the preparation of high-performance soybean meal-based adhesives was still challenging. Inspired by the mineral-organic hybridization structure of nacre, hydroxyapatite and tannic acid complex was used as rigid nanofiller and cross-linker to improve the properties of soybean meal adhesives. Tannic acid was bonded with hydroxyapatite through coordination bonds and could promote the hydrogen bond between soybean meal and hydroxyapatite. Owing to enhanced crosslinking density, the wet shear strength of the adhesive increased from 0.66 to 1.70 MPa and the toughness was also clearly improved. The residual ratio increased to 85.8% and the moisture absorption reduced to 16.5%, indicating better water resistance. The high chemical reactivity of catechol and pyrogallol groups on tannic acid endowed the adhesive with better mildew resistance and antibacterial ability. Besides, the addition of hydroxyapatite and tannic acid complex could restrict the heat transfer and quench the oxygen free radicals, which enhanced the flame resistance of the adhesives. This study provided a new strategy for the preparation of green soybean meal-based adhesives with high performance.

Alumina-Hydroxyapatite-Silver Spheres With Antibacterial Activity.

Researchers are currently looking for materials that are stable, functional, aesthetic, and biocompatible without infections. Therefore, there is a great interest in obtaining a material that has a balance between aesthetic, biological, mechanical, and functional factors, which can be used as an infection control material. The addition of hydroxyapatite to alumina make highly bioactive scaffolds with mechanical strength. Biomedical applications require antibacterial properties; therefore, this idea leads to great interest in the development of new synthetic routes of ceramic biomaterials that allow the release of nanoparticles or metal ions. This investigation presents the obtention of alumina-hydroxyapatite spheres doped with silver nanoparticles with antibacterial effect against various Gram-positive and negative bacteria related to drug-resistance infections. The microstructural and spectroscopic studies demonstrate that the spheres exhibit a homogeneous structure and crystal hydroxyapatite and silver nanoparticles are observed on the surface. The antimicrobial susceptibility was verified with the agar diffusion and turbidimetry methods in Gram-negative (Escherichia coli and Pseudomonas aeruginosa) and Gram-positive (Staphylococcus aureus and Bacillus subtilis) bacteria. All bacteria used were susceptible to the alumina-hydroxyapatite-silver spheres even at lower silver concentration. The composites have a higher possibility for medical applications focused on the control of drug-resistance microorganisms.

Development of ash condensation performance of paper materials via saccharides and Nano HAP application

Abstract The ash condensation ability of the cigarette paper is an important factor affecting the cigarette grades. In this study, we put forward an effective method of improving this ability. Xanthan gum was successfully synthesized, applied as an ash integrator in the dip-coating process of cigarette paper production, and showed good performance. Cationic guar gum, cellulose phosphate and Hydroxyapatite (HAP) have been added in the pulp and showed better performance of the ash condensation property. The ash become much whiter and the scatter of the ash have been suppressed. Moreover, the further addition of HAP would result in a worse combustion efficiency, leading to the burning out of the cigarette in early time.

Ameliorating quercetin constraints in cancer therapy with pH-responsive agarose-polyvinylpyrrolidone -hydroxyapatite nanocomposite encapsulated in double nanoemulsion

Despite quercetin (QC) promising features for cancer therapy, low solubility, poor permeability, and short biological half-life time significantly confine its application in cancer therapy. In this study, a novel approach is developed to improve loading efficiency and attain quercetin sustained-release concurrently. In this direction, hydrogel nanocomposite of agarose (AG)-polyvinylpyrrolidone (PVP)-hydroxyapatite (HAp) was loaded with QC. Incorporating HAp nanoparticles in the AG-PVP hydrogel improved the loading efficiency up to 61%. Also, the interactions between nanoparticle, drug, and hydrogel polymers rendered the nanocomposite pH-responsive at acidic conditions and controlled the burst release at neutral conditions. Then, QC-loaded hydrogel was encapsulated into the water in oil in water nanoemulsions to further sustain the drug release. As a result, the pH-responsive release of QC with prolonged-release over 96 h was observed. In more detail, according to the Korsmeyer-Peppas mathematical model, the mechanism of release was anomalous (diffusion-controlled) at pH 7.4 and anomalous transport (dissolution-controlled) at pH 5.4. The presence of all nanocomposite components was confirmed with FTIR analysis, and XRD results approved the incorporation of QC in the fabricated nanocomposite. The homogeneous surface of the nanocomposite in FESEM images showed good compatibility between components. The zeta potential analysis confirmed the good stability of the nanocarriers. Besides, the fabricated AG-PVP-HAp-QC platform showed significant cytotoxicity on MCF-7 cells compared to QC as a free drug (p < 0.001) and to quercetin-loaded AG-PVP (AG-PVP-QC) (p < 0.001) with enhanced apoptosis induction after the addition of HAp. Accordingly, this delivery platform ameliorated loading and sustained-release of QC, as well as its anticancer activity by releasing the drug at an effective therapeutic level over a long period to induce apoptosis. Thus, turning this drug delivery system into a potential candidate for further biomedical applications.

How to Improve Physico-Chemical Properties of Silk Fibroin Materials for Biomedical Applications?-Blending and Cross-Linking of Silk Fibroin-A Review.

This review supplies a report on fresh advances in the field of silk fibroin (SF) biopolymer and its blends with biopolymers as new biomaterials. The review also includes a subsection about silk fibroin mixtures with synthetic polymers. Silk fibroin is commonly used to receive biomaterials. However, the materials based on pure polymer present low mechanical parameters, and high enzymatic degradation rate. These properties can be problematic for tissue engineering applications. An increased interest in two- and three-component mixtures and chemically cross-linked materials has been observed due to their improved physico-chemical properties. These materials can be attractive and desirable for both academic, and, industrial attention because they expose improvements in properties required in the biomedical field. The structure, forms, methods of preparation, and some physico-chemical properties of silk fibroin are discussed in this review. Detailed examples are also given from scientific reports and practical experiments. The most common biopolymers: collagen (Coll), chitosan (CTS), alginate (AL), and hyaluronic acid (HA) are discussed as components of silk fibroin-based mixtures. Examples of binary and ternary mixtures, composites with the addition of magnetic particles, hydroxyapatite or titanium dioxide are also included and given. Additionally, the advantages and disadvantages of chemical, physical, and enzymatic cross-linking were demonstrated.

Effects of hydroxyapatite addition on the bioactivity of Ti-Nb alloy matrix composite fabricated via powder metallurgy process

This study investigates the bioactivity of titanium-niobium-hydroxyapatite (Ti-Nb-HA) composite prepared by mechanical alloying and powder metallurgy with variable HA content from 0 to 15 wt.%. Increasing the HA content weakened the X-ray diffraction intensity of β phase along with the noticeable presence of α phase and phases of TiO2, and Ti2P. The composite displayed good bioactivity in Hanks’ Balanced Salt Solution (HBSS) with the highest bioactivity exhibited by the 15 wt.% HA after a 30-day immersion with observed additional phases of CaTiO3 and CaO. Signs of HA decomposition, which led to an enhancement in the bioactivity, were remarked. The dispersion of HA particles in the Ti-Nb alloy matrix accelerated the apatite formation based on the accumulation of Ca, P and O elements on the composite surface. The presence of OH− and PO43- denoted the formation of calcium phosphate (apatite) with a hydrophilic surface. Based on the immersion test, only the 15 wt.% HA composite experienced a weight loss while the other composites gained weight.

Effect of hydroxyapatite (HA) addition on microstructure, corrosion resistance of AZ91D, AJ62 and AM60 alloys

In the present research work, the effect on Hydroxyapatite (HA) on the microstructure, corrosion and cytotoxicity of AZ91D, AJ62 and AM60 alloys has been studied. This research paper emphasized upon synthesis and characterization of commercial AZ91D, AJ62 and AM60 alloys after HA addition in terms of microstructure and corrosion resistance. To abstract it out, HA addition tends to refine the grain size which greatly improves the corrosion resistance by forming protective complex metal hydroxides over the material surface. This phenomenon has been experimentally proved from this research. In conclusion, AZ91D/3HA and AJ62/3HA were identified as potential biomaterials based on their finer grain structure, excellent corrosion resistance and exceptionally non-toxic behaviour applications.