HAP Composites Research Articles

Preparation and Characterization of Biowaste Derived Zn, Sr Co‐substituted HAP/Lignin Biocomposite for Potential Biomedical Applications

AbstractThis present study deals with the facile synthesis of Zinc (Zn), Strontium (Sr) Co‐substituted hydroxyapatite (M‐HAP)/lignin composite for biomedical applications. For composite formation, HAP was isolated from egg shell through wet precipitation method, biopolymer of lignin was extracted from neem wood through organosolve technique then HAP composites (HAP, HAP/lignin, Zn‐HAP/lignin, Sr‐HAP/lignin, Zn, Sr‐HAP/lignin) were obtained using freeze drying performance. The synthesized HAP composites were characterized using X‐ray powder diffraction (XRD), Fourier transform infrared spectroscopy (FTIR), Scanning electron microscopy (SEM) and Energy‐dispersive X‐ray analysis (EDAX). The antibacterial behavior of the HAP composites was investigated against E. Coli, B. Subtilies, P. Aeruginosa and S. Aureus pathogens. Then the mechanical property of the HAP composites was carried out using Vicker's microhardness test which reveals a better improvement in mechanical hardness. The antibacterial activity confirms that the HAP composite exhibits enhanced antibacterial activity. Further, the cell viability analysis shows that the co‐substitution of Zn and Sr in HAP lattice improved cell viability analysis, which indicates that the obtained Zn, Sr co‐substituted HAP/lignin biocomposite acts as a potential biomaterial for better biomedical application.

Combinatorial anticancer effects of multi metal ion and drug substitute with hydroxyapatite coatings on surgical grade 316LSS stainless steel alloys towards biomedical applications

The present study highlights the metal ions and existing drug ampicillin-loaded nano-hydroxyapatite (nHAP) coated on 316 stainless steel alloy (316LSS) using the electrodeposition method. In addition, the sample phase purity and crystallinity of the HAp composite coatings on 316LSS were analyzed by X-ray diffraction analysis (XRD) and Fourier transform infrared (FT-IR) spectroscopy using the KBr pellet method. The coating microstructure/morphology was characterized using a scanning electron microscope, which showed a flower-like morphology with the attachment of energy-dispersive X-ray spectroscopy (EDX) to confirm the major element groups in the synthesized sample. The TGA results showed that weight loss occurred in the temperature range of up to 800 °C for oxidation and reduction reactions. Additionally, the beat-optimized nanomaterial showed promising in vitro bioactivity against disease-causing microorganisms, displaying a significant zone of inhibition. Furthermore, cytotoxicity assessment using the MTT assay demonstrated that the synthesized samples effectively inhibited cell proliferation in human osteosarcoma cell lines (Saos-2). AO/EB double staining performed under a fluorescence microscope indicated changes in the morphology of the apoptotic cell nuclei. In addition, the relationship between ROS and nanomaterial-induced apoptosis in Saos-2 cells was analyzed by flow cytometry. MMP (ΔѰmt) profiling showed that the HAp composite increased the effective mitochondrial membrane damage or depolarization in the human osteosarcoma cell line. Moreover, the TUNEL assay suggested that treated nanomaterial with Saos-2 cells showed enhanced green fluorescence intensity, indicating terminal DNA damage. The obtained results meet the recommended physiological standard for synthesized 316LSS HAp composites to guide bone tissue regeneration.

3D-Printed Filters for Efficient Heavy Metal Removal from Water Using PLA@CS/HAP Composites.

Chitosan/Hydroxyapatite composites, enriched with relatively active -NH2 and -OH groups, have emerged as promising adsorbents for heavy metal removal. In this study, we harnessed the potential of CS/HAP composites by developing monolithic PLA@CS/HAP filters utilizing 3D printing and freeze-drying techniques. These filters possess both macroscopic and microscopic porous structures, endowing them with exceptional capabilities for removing heavy metals from water. The adsorption properties of CS/HAP composites were explored by varying the dosage, duration, and initial concentrations of copper ions. The maximum adsorption capacity for Cu2+ was determined to be approximately 119+/-1 mg/g at the natural pH and 298 K. Notably, the monolithic PLA@CS/HAP filters demonstrated remarkable efficiency in the removal of copper ions, with 90% of copper ions effectively removed within a mere 2-h period in a cyclic adsorption experiment. Furthermore, the PLA@CS/HAP filters exhibited a robust dynamic Cu2+ removal capacity (80.8% or even better in less than 35 min) in a dynamic adsorption experiment. Importantly, all materials employed in this study were environmentally friendly. In summary, the PLA@CS/HAP filter offers advantages such as ease of preparation, eco-friendliness, versatility, and broad applicability in diverse wastewater treatment scenarios, thereby presenting a significant potential for practical implementation.

Efficient removal of heavy metal ions by diethylenetriaminepenta (methylene phosphonic) acid-doped hydroxyapatite

Diethylenetriaminepenta (methylene phosphonic) acid (DTPMP) was first used as a dopant to modify hydroxyapatite and applied to remove Pb2+. The adsorption capacity of modified hydroxyapatite for Pb2+ can reach 2185.92 mg/g, which was 10.4 times that of commercial nanohydroxyapatite. The characterizations after adsorption of Pb2+ indicated the existence of chelation and the formation of the low bioavailability Pb10(PO4)6(OH)2. Moreover, the interaction of different components containing DTPMP, HAP, and pollutant Pb2+ was investigated by molecular dynamics (MD) simulation, which indicated that the organic-phosphonic group of DTPMP (PO3H−) had a stronger complex effect with calcium ions or lead ions than that of the inorganic-phosphate group of HAP (PO43−) with the two metal ions, which affected the crystallinity of HAP, and greatly improved the removal effect of DTPMP doped HAP composites for Pb2+ contaminants, the existence of amino groups can further enhance the affinity between DTPMP and HAP or lead ions. The chelation mechanism of DTPMP and Pb2+ was probed in depth by combining basin analysis, topology analysis of atoms in molecules (AIM), electron localization function (ELF) analysis, bond order density (BOD) & natural adaptive orbital (NAdO)analysis and orbital component analysis.

Resultant effect of two different methods of incorporating metals in the hydroxyapatite structure on its mechanical properties

Metal deficiencies in synthetic hydroxyapatite (Hap), is one factor among others behind its poor mechanical reliability. Hence, compensating these deficiencies has been suggested as a possible way to improve these properties. Several studies have shown that the incorporation of metals or metal oxides appear to increase the fracture toughness and lower the brittleness of synthetic Hap. In this study, we examined the resultant effect of two different methods of incorporating metals into the Hap structure on its mechanical properties. The first method consisted of incorporating metals by replacing some calcium in the Hap structure via substitution. The second method consisted of modifying Hap by preparing (metal oxide)/Hap composites. Thus Nano powders of pure Hap, substituted Hap (Ca10-xMx(PO4)6(OH)2), and (MO)x /Hap composites (M = Mg, Zn) with x = 0.0, 0.1, and 0.3 were prepared by a simple low temperature technique. The (ZnO)x/Hap nanocomposites were prepared by precipitating Zinc oxide nanoparticles in a nano Hap slurry, while the (MgO)x/Hap composites were prepared by precipitating Hap nanoparticles in a diluted nano MgO slurry. XRD, FTIR, and SEM analysis of all prepared materials identified Hap as the only crystalline phase present, exhibiting a uniform morphology with particles in the 40–100 nm size range. EDAX analysis clearly shows the presence of Ca, P, and O in pure hydroxyapatite, Ca, P, O, Mg and Zn in both substituted Hap and (MO)x/Hap composites. The mechanical testing consisted of evaluating Breaking force, work of fracture, and brittleness/ductility of Hap, substituted Hap, and (MO)x/Hap composites. Our study clearly shows that the mechanical properties of Hap are much more improved by modifying Hap with metal oxides than by calcium substitution for the same quantity and type of incorporated metal. Optimum mechanical strength was obtained for the (MO)x/Hap composites with a 0.1:1.0 MO:Hap mole ratio (M = Mg, Zn).

Structural, physical, and mechanical properties of the TiO2 added hydroxyapatite composites

Abstract Composites are important as they have been used in a variety of different fields. Therefore, production and testing of composites have become one of the most popular topics for researchers. In this work, the physical, structural, and mechanical properties such as packing density (V t ), bond dissociation energy (G t ), Young’s (E), bulk (B), shear (S), longitudinal (L), indentation (E*) moduli, and Poisson’s ratio (σ) were obtained for (100 − x)HAP + xTiO2 composite, where x = 0, 3, 7.5, and 10 wt%. The variations in those properties with TiO2 rate in HAP composites were tested.

Fabrication of Novel Chitosan–Hydroxyapatite Nanostructured Thin Films for Biomedical Applications

In this study, we develop chitosan–hydroxyapatite (CS–HAp) composite layers that were deposited on Si substrates in radio frequency (RF) magnetron sputtering discharge in argon gas. The composition and structure of CS–HAp composite layers were investigated by analytical techniques, such as Fourier transform infrared spectroscopy (FT-IR), scanning electron microscopy (SEM), metallographic microscopy (MM), and atomic force microscopy (AFM). On the other hand, in the present study the second order derivative of FT-IR–ATR spectra, for compositional analyses of CS–HAp, were used. The SEM, MM, and AFM data have shown the formation of CS–HAp composite layers. The surface of CS–HAp composite layers showed uniform growth (at an Ar gas working pressure of p = 2 × 10−3 mbar). The surface of the CS–HAp composites coatings became more nanostructured, becoming granular as the gas pressure increased from 5 × 10−3 to 1.2 × 10−2 mbar. However, our studies revealed that the surface morphology of the CS–HAp composite layers varies with the Ar gas working pressure. At the same time, optical properties are slightly influenced by Ar pressure. Their unique physicochemical properties make them suitable for various applications in the biomedical field, if we consider the already proven antimicrobial properties of chitosan. The antifungal properties and the capacity of the CS–HAp composite layers to inhibit the development of fungal biofilms were also demonstrated using the Candida albicans ATCC 10231 (C. albicans) fungal strain.

Fast Neutrons Shielding Properties for HAP-Fe2O3 Composite Materials

Neutron has been one of the most interesting particle since its discovery. Being an uncharged particle it is more difficult to shield in comparison with the other radiation types. This may be due to the differences of its interaction with matter. The main interaction processes of neutron with a matter may be via (n,p) reaction and thus hydrogenous materials are generally preferred to shield neutron. In this study neutron shielding properties for HAP composites have been investigated. This is done using Phy-X/PSD software.

Wpływ naturalnych barwników na stabilność barwy kompozytów zawierających HAp, stosowanych w stomatologii zachowawczej

Wpływ naturalnych barwników na stabilność barwy kompozytów zawierających HAp, stosowanych w stomatologii zachowawczej

An Investigation on UHMWPE-HAp Composites Manufactured by Solution-Gelation Method

In this study, HAp reinforcement into UHMWPE matrix having 1.0 % wt. mass and its effects on microstructural and mechanical properties of the UHMWPE composites were investigated. UHMWPE composites reinforced with 0.5, 1 and 2.0 wt. % nano HAp powders, respectively were successfully produced by solution and gelation method. SEM studies showed that HAp nano particles were homogenously distributed into UHMWPE matrix and good cross-linked with the matrix. SEM-map EDS analysis confirmed SEM. FTIR results revealed that HAp incorporation into matrix was conducted and crystallization of UHMWPE increased by increment in amount of HAp results in deepening crystallization peaks at nearby 500 and 1500 cm-1. DSC results, which is useful technique to determine the variation of melting point and crystallization ratio of UHMWPE composites, indicated that there was no remarkable change in melting points of composites, while crystallinity of the samples generally showed slight increase by increasing amount of nano HAp particles. The tensile test instrument was utilized to determine elastic modulus of the samples and their elastic modulus were raised from 1050 to 1900 MPa with higher HAp reinforcement. It can be concluded that UHMWPE-2 % wt. HAp composites have promising results by being paired with crystallinity and elastic modulus.

HAp/TiO2 nanocomposites: Influence of TiO2 on microstructure and mechanical properties

Hydroxyapatite is a very attractive material for artificial implants and human tissue restorations because they accelerate bone growth around the implant. The hydroxyapatite nanocomposites (HAp/TiO2) were produced by using high energy ball milling. X-ray diffraction studies revealed the formation of HAp and TiO2 composites. Cubic-like crystals with boundary morphologies were observed; it was also found that the grain size gradually increased with the increase in TiO2 content. It was found that the mechanical properties (hardness, Young's modulus, fracture toughness, flexural strength, and compression strength)of the composites significantly improved with the addition of TiO2, which was sintered at 1200℃. These properties were then also correlated with the microstructure of the composites. This paper investigates the effect of titania (TiO2 = 0, 5, 10, 15, 20, and 25 wt%) addition on the microstructure and mechanical properties of hydroxyapatite (Ca10(PO4)6(OH)2) nanocomposites.

HYDROXYAPATITE - CARBON NANOTUBE COMPOSITES FOR DRUG DELIVERY APPLICATIONS

Abstract The aim of this study was the synthesis of composites containing hydroxyapatite (Hap) or silicon substituted hydroxyapatite (HapSi), carboxyl functionalized carbon nanotubes (fMWCNT) and gelatin (G) in different ratios. Ibuprofen (IBU) was chosen as a model drug for the formulation of extended-release dosage forms. The obtained composites were characterized using X-ray diffraction, laser diffraction particle size analyzer, Brunauer-Emmett-Teller surface area measurements, transmission electron microscopy and Fourier transformed infrared spectroscopy. IBU adsorption and desorption was monitored by UV-VIS spectroscopy. The obtained results revealed that composites containing three components exhibit higher adsorption efficiency (Hap-fMWCNT-20G - 82.7% and HapSi-fMWCNT-20G - 84.6%) and extended-release of IBU, due to the chemical bonds between the carboxyl groups of IBU and the functional groups on the composite surface. The adsorption capacity of Hap composites is important for dental or orthopedic implants, the anti-inflammatory substances being adsorbed on their surface; but the adsorption capacity also enhances new bone formation (osteosynthesis) around the implants. These composites are thus attractive materials to be used in bone tissue engineering and drug delivery systems.

Synthesis and characterization of hydroxyapatite/carboxylic acid functionalized MWCNTS composites and its triple layer coatings for biomedical applications

IntroductionAchievement of bioactive coatings on metallic implant surface with higher adhesive strength and corrosive resistance was one of the main challenges for the current biomaterial researchers. Hydroxyapatite was one of the promising bioactive ceramic which can be applied as a coating on the metallic substrate due to its similarity with the human bone. MethodsThe work describes the in-situ preparation of HAP/f-MWCNTs composite by sol-gel method. MWCNTs were functionalized by acid treatment. HAP composites have been prepared by varying the molar percentage of f-MWCNTs from 1% to 5%. The prepared composites with various concentrations of f-MWCNTs were characterized by FT-IR and XRD for its functional group analysis and phase purity. The morphology of the prepared powder was analyzed using SEM and TEM. In-vitro corrosive behavior on SBF was studied for the coating prepared HAP composite sol on 316L SS. The triple layer composite coating was obtained at the spin speed of 3000 rpm/min and subjected to sintering at 500 °C/2 h. ResultsX-ray diffraction results confirmed the formation of pure HAP up to the addition of 3% of f-MWCNTs without any secondary phases. The average crystallite size of the prepared particles was decreased from 40 ± 2.1 to 17 ± 2.5 nm with the addition f-MWCNTs. The morphological studies confirm the incorporation of f-MWCNTs in HAP matrix. The prepared HAP/f-MWCNTs composite efficiently inhibits the growth of the pathogens such as S. Aureus and E.coli. Improved hardness was observed with reinforcement of f-MWCNTs into the hydroxyapatite matrix. Electrochemical studies confirm the HAP/f-MWCNTs composites having increased corrosive resistance properties. The bonding strength of the composite coatings showed improved adhesion to the 316L surface. ConclusionIn this work we have fabricated sol-gel derived anti-microbial composite coating on the 316L substrate by means of spin coating at optimized conditions with higher adhesive strength and improved corrosion resistance.

Effect of ZrO2 content on the mechanical properties and microstructure of HAp/ZrO2 nanocomposites

This paper presents the effect of Zirconia (ZrO2 = 0, 5, 10, 15, 20 and 25 wt%) on the mechanical properties and micro structural studies of Hydroxyapatite (Ca10(PO4)6(OH)2) (HAp) nano composites. HAp and Zirconia nano composites of 20–40 nm were produced using High Energy Ball milling at 300 rpm for 1 h. X-ray diffraction studies showed that the crystallite and grain size gradually decreased with the increase in ZrO2 content till 20 wt%, after which there was a sudden raise in both parameters. A dominant ZrO2 phase was observed in X-ray diffraction studies of sintered samples. Mechanical properties were found to significantly improve on adding 20 wt% of ZrO2 at 1200 °C. However, the addition of 25 wt% of ZrO2 powder decreased the mechanical properties of HAp. The reduction could be due to the increase in grain size and dominant smaller particles of ZrO2. The improved mechanical properties were correlated with the observed micro structural features.

TiO2–Hydroxyapatite Composite as a New Support of Highly Active and Sintering-Resistant Gold Nanocatalysts for Catalytic Oxidation of CO and Photocatalytic Degradation of Methylene Blue

Supported gold catalysts have attracted intensive interest due to their unique catalytic properties. The easy sintering of gold particles, however, is still the major obstacle to the practical application of gold catalysts. Herein, a highly active and sintering-resistant TiO2–hydroxyapatite (HAP, Ca10(PO4)6(OH)2) composite supported gold catalyst was prepared by a deposition–precipitation method. TEM results manifested TiO2–HAP had smaller gold nanoparticles than TiO2 and HAP. Patterns of TG–DTG revealed that the presence of HAP inhibited the phase transformation from anatase to rutile. Based on UV–Vis and BET studies, HAP prevented the formation of large TiO2 agglomerates, leading to higher dispersion of TiO2 nanoparticles in TiO2–HAP composites. Au/TiO2–HAP had the higher activity and sintering-resistance compared with Au/TiO2 and Au/HAP for CO oxidation. TiO2–HAP and Au/TiO2–HAP exhibited the best photocatalytic activity among supports and gold nanocatalysts, respectively. Gold nanoparticles could further improve the photocatalytic performance. It was likely that the synergistic interaction among gold nanoparticles, TiO2 and HAP was responsible for the high activity and sintering-resistance of Au/TiO2–HAP.

Novel gamma irradiated agarose-gelatin-hydroxyapatite nanocomposite scaffolds for skin tissue regeneration

Agarose-gelatin-hydroxyapatite composites prepared by freeze-drying technique were gamma irradiated with various doses (25kGy, 50kGy and 100kGy). X-ray Diffraction (XRD) analysis revealed the pure phase of HAp and the intensity of prominent planes of hydroxyapatite (Ca10(PO4)6(OH)2, HAp) were found to decrease on irradiation. Fourier Transform Infrared spectra (FTIR) showed functional groups of HAp and polymer composites, and higher disorder of the polymer matrix on irradiation. In addition, gamma irradiation led to a drastic reduction in the wettability (62%) and the compressive modulus (76%) of the scaffolds. There was significant enhancement (113%) in pore size of the scaffolds at higher fluence (100kGy). The swelling and the dissolution studies of the gamma irradiated scaffolds showed that it had an appreciable change in the scaffold's mechanical and biological properties viz., compressive modulus, cell proliferation, hemolysis etc. The irradiated biomaterials exhibited enhanced hemocompatibility, antimicrobial activity and cell viability. The above results clearly reveal that the gamma irradiation is a suitable tool to tailor the multifunctional properties of the composites and could be used for various biomedical applications.

Concentrated gelatin/alginate composites for fabrication of predesigned scaffolds with a favorable cell response by 3D plotting

Developed concentrated gelatin/alginate with/without HAP composites were plotted into pre-designed scaffolds, which showed good cells attachments and penetration.

Mechanical properties and corrosion behavior of Mg–HAP composites

Mg and Mg–HAP composites containing 5, 10 and 15wt% of hydroxyapatite have been produced following a powder metallurgy route that consists of mixing raw powders and consolidation by extrusion. The microstructure, texture, mechanical behavior and resistance to corrosion under a PBS solution have been studied. Addition of HAP increases the microhardness of the composites, however the yield strength under compression slightly decreases. Texture analyses reveal a fiber texture for pure Mg that is weakened increasing the HAP fraction. This texture promotes twinning and softening of Mg and Mg–5HAP during the initial deformation stages. Mg–10HAP and Mg–15HAP present a strain-hardening dependence showing no softening. The volume fraction of HAP particles weakens the texture and favors the activation of secondary slip systems. Corrosion experiments in PBS solution have shown that Mg–5HAP exhibits the best resistance to corrosion. Texture and porosity appear to be the main material features controlling the corrosion rates of Mg–HAP composites under the present conditions.

Synthesis of multi-walled carbon nanotube–hydroxyapatite composites and its application in the sorption of Co(II) from aqueous solutions

In this paper, multi-walled carbon nanotube–hydroxyapatite (MWCNT–HAP) composites were synthesized and characterized by scanning electron microscopy (SEM), Fourier transform infrared (FT-IR) spectroscopy and X-ray diffraction (XRD) and used as an original adsorbent for Co(II) sorption from aqueous solutions. The sorption of Co(II) on MWCNT–HAP composites was investigated as a function of contact time, pH, foreign ions, fulvic acid (FA), humic acid (HA) and temperature. The results indicated that K+, Mg2+ and Ca2+ ions restrained Co(II) sorption on MWCNT–HAP composites at low pH. In the whole pH ranges, anions (i.e., ClO4−, NO3− and Br− herein) made no obvious effect on Co(II) sorption, while F− ions dramatically enhanced Co(II) sorption. The presence of FA and HA enhanced Co(II) sorption on MWCNT–HAP composites at low pH values, but suppressed Co(II) sorption at high pH values. The Freundlich and Langmuir models were used to imitate the Co(II) sorption isotherms at three different temperatures. The thermodynamic data (∆G0, ∆S0, and ∆H0) counted from the temperature dependent sorption isotherms suggested that the sorption of Co(II) on MWCNT–HAP composites was a spontaneous and endothermic process. The high sorption capacity of Co(II) on MWCNT–HAP composites suggested that the MWCNT–HAP composites were suitable materials in heavy metal pollution cleanup.

Influence of hydroxyapatite on maghemite-to-hematite phase transfer of FeO x -hydroxyapatite composite

FeO x -hydroxyapatite (FeO x -HAP) composites with different FeO x contents were prepared, and compared with pure FeOx, the FeO x -HAP composites exhibit strongly magnetic behavior in an external magnetic field even after 600 °C calcination. The combination of 57Fe Mossbauer and Fe K-edge XAFS indicates that HAP can stabilize the size and crystal phase of γ-Fe2O3 during heat treatment. Even after 600 °C calcination, the interaction imposed by HAP could produce large amounts of distorted octahedral coordination Fe sites in the interior lattice and then result in strong magnetism. The thermally stable γ-Fe2O3-HAP composites may provide a new opportunity for developing efficient supported crystal-dependent catalysts.