Silicon-substituted hydroxyapatite (Ca10(PO4)6-x(SiO4)x(OH)2-x, Si-HA) composite coatings on a bioactive titanium substrate were prepared by electrophoretic deposition technique with the addition of triethanolamine (T...Silicon-substituted hydroxyapatite (Ca10(PO4)6-x(SiO4)x(OH)2-x, Si-HA) composite coatings on a bioactive titanium substrate were prepared by electrophoretic deposition technique with the addition of triethanolamine (TEA) to enhance the ionization degree of Si-HA suspension. The surface structure was characterized by XRD, SEM, XRF, EDS and FTIR. The bond strength of the coating was investigated. The results show that the depositing thickness and the images of Si-HA coating can be changed with the variation of deposition time. The XRD spectra of Ti/Si-HA coatings show the characteristic diffraction peaks of HA, and the incorporation of silicon changes the lattice parameter of the crystal. The FTIR spectra shows that the most notable effect of silicon substitution is the decrease of intensities of —OH and PO43- groups with the silicon contents increasing. XRD and EDS element analyses present that the content of silicon in the coating increases with increasing silicon concentration in the suspension. The bioactive TiO2 coating formed may improve the bond strength of the coatings. The interaction of Ti/Si-HA coating with BSA is much greater than that of Ti/HA coating, suggesting that the incorporation of silicon in HA is significant to improve the bioactive performance of HA.展开更多
In previous study, dense and homogenous 20wt% HAP/Ti composite coatings were successfully deposited on Ti substrates by cold gas dynamic spray technique. The results revealed that the phase composition of the HAP in t...In previous study, dense and homogenous 20wt% HAP/Ti composite coatings were successfully deposited on Ti substrates by cold gas dynamic spray technique. The results revealed that the phase composition of the HAP in the deposit is identical to that of the precursor powder and the bonding strength of the deposit is comparable/better to that of the plasma sprayed HAP. A relatively higher corrosion current of HAP/Ti composite than that of pure Ti coating in simulated body fluid indicates a good bioactivity for composite coating. In the present study, in vitro immersion test is carried out for various period of time and the formation of apatite layer on surface of composite coating proves the good bioactivity of the composite coating further. The cold sprayed HAP/Ti composite can be anticipated to be a promising load-bearing implant material for biomedical applications.展开更多
The composite films constituted of hydroxyapatite (HAP) submicron particles embedded in the gel composed of the titania nanoparticles were prepared on commercial Ti6Al4V plates with titania buffer layer obtained by a ...The composite films constituted of hydroxyapatite (HAP) submicron particles embedded in the gel composed of the titania nanoparticles were prepared on commercial Ti6Al4V plates with titania buffer layer obtained by a spin-coating technique. The films were annealed in air at 450 ℃, 550 ℃ and 650 ℃, respectively. The phase formation, surface morphology, andinterfacial microstructure of the films were investigated by X-ray diffraction(XRD),Fourier transform infrared spectroscopy (FT-IR), field emission-scanning electron microscopy(FE-SEM) and energy dispersive X-ray (EDS) analysis. The results show that the as-prepared films are all well-crystallized, dense,homogeneous, and there was a close interfacial bond between the film and the substrate. The results of adhesion test indicate that there is a good bonding strength between the film and the substrate. The bone-like apatite formation on the surface of the films after immersion in acellular simulatedbody fluid(SBF) validated their bioactivities.展开更多
TiO2-hydroxyapatite （HA） nanostructured coatings were produced by atmospheric plasma spray method. The effects of starting powder composition and grain size on their mechanical properties were investigated. The micr...TiO2-hydroxyapatite （HA） nanostructured coatings were produced by atmospheric plasma spray method. The effects of starting powder composition and grain size on their mechanical properties were investigated. The microstructure and morphology were characterized by X-ray diffraction and scanning electron microscopy （SEM）. It is found that the coating with 10% HA has the best mechanical properties. Based on Rietveld refinement method, the mean grain size of the as-received powder （212 nm） extensively decreases to 66.4 nm after 20 h of high-energy ball milling. In spite of grain growth, the deposited coatings maintain their nanostructures with the mean grain size of 112 nm. SEM images show that there is a lower porosity in the coating with a higher HA content. Optical microscopy images show that uniform thickness is obtained for all the coatings.展开更多
The in-vitro biological behavior of a newly-developed iron-containing hydroxyapatite/titanium（HA/Ti） composite was investigated by immersing the composites in the simulated body fluid（SBF） for up to 5 weeks.The ad...The in-vitro biological behavior of a newly-developed iron-containing hydroxyapatite/titanium（HA/Ti） composite was investigated by immersing the composites in the simulated body fluid（SBF） for up to 5 weeks.The addition of iron was observed to have a significant influence on the in-vitro biological behavior of the composites.The obtained results revealed that the stability of the composites in the physiological solution was markedly improved.The solubility decreased in the order of pure HA,HA/5（Ti-33Fe）,and HA/15（Ti33Fe）.Precipitation occurred on the surface of HA/5（Ti-33Fe） composite,showing a good combination of physiostability with bioactivity,while HA/15（Ti-33Fe） composite exhibited superior physiostability since there was no obvious change on the surface of HA/15（Ti-33Fe）.展开更多
The aim of this work was to study the influence of the different synthesis processes on microstructural and morphological characteristics and distribution of hydroxyapatite-bioactive glass(HAp-BG)composite nanopowders...The aim of this work was to study the influence of the different synthesis processes on microstructural and morphological characteristics and distribution of hydroxyapatite-bioactive glass(HAp-BG)composite nanopowders obtained by sol-gel method.HAp-BG composite nanopowders with 20 wt%bioactive glass were prepared using a sol-gel method via four routes:(I)mixing the prepared HAp solution with BG solution before aging time;(II)mixing the prepared BG solution with the prepared HAp gel after gelation;(III)mixing the calcined BG nanopowders with the prepared HAp solution;and(IV)mixing the two prepared calcined nanopowders by mechanochemical activation.The prepared nanopowders were evaluated and studied by X-ray diffraction(XRD),scanning electron microscopy(SEM),energy dispersive X-ray spectrometer(EDS),Fourier transform infrared(FTIR),transmission electron diffraction(TEM)and Brunauer-Emmet-Teller(BET)method to investigate the phase structure,microstructure and morphology,functional groups,and the size and distribution of nanopowders.Results indicated that morphology,crystallinity,crystallite size and specific surface area(SSA)of the powders are highly correspondent to the process and type of synthesis method.These findings suggest that the modified sol-gel derived HAp-BG composite nanopowders are expected to efficiently provide a possibility to produce a good candidate to use for fabrication of a bulk nanostructured HAp-BG composite for bone tissue engineering.展开更多
Various surface bioactivation technology has been confirmed to improve the osteogenic ability of porous titanium(pTi)implants effectively.In this study,a three-layered composite coating,i.e.outer layer of hydroxyapati...Various surface bioactivation technology has been confirmed to improve the osteogenic ability of porous titanium(pTi)implants effectively.In this study,a three-layered composite coating,i.e.outer layer of hydroxyapatite(HA),middle layer of loose titanium dioxide(L-TiO2)and inner layer of dense TiO2(D-TiO2),was fabricated on pTi by a combined processing procedure of pickling,alkali heat(AH),anodic oxidation(AO),electrochemical deposition(ED)and hydrothermal treatment(HT).After soaking in simulated body fluid for 48 h,the surface of the AHAOEDHT-treated pTi was completely covered by a homogeneous apatite layer.Using MC3T3-E1 pro-osteoblasts as cell model,the cell culture revealed that both the pTi without surface treatment and the AHAOEDHT sample could support the attachment,growth and proliferation of the cells.Compared to the pTi sample,the AHAOEDHT one induced higher expressions of osteogenesis-related genes in the cells,including alkaline phosphatase,Type I collagen,osteopontin,osteoclast inhibitor,osteocalcin and zinc finger structure transcription factor.As thus,besides the good corrosion resistance,the HA/L-TiO2/D-TiO2-coated pTi had good osteogenic activity,showing good potential in practical application for bone defect repair.展开更多
Stable tissue integration is important to keratoprosthesis （KPro）. The aim of this study was to evaluate the tissue bonding ability of hydroxyapatite （HAp）-coated titanium KPro. The samples were divided into three...Stable tissue integration is important to keratoprosthesis （KPro）. The aim of this study was to evaluate the tissue bonding ability of hydroxyapatite （HAp）-coated titanium KPro. The samples were divided into three groups： test groups （IBAD group and AD group） and Ti control. The coated samples had a HAp layer created by ion beam assisted deposition （IBAD） or aerosol deposition （AD）. The surface characteristics were analyzed with SEM, AFM, and XRD. The samples were surgically inserted into the muscles of rabbits. Eight weeks after healing, the attachment to the tissue was tested with a universal test device. The three samples exhibited distinctive surface morphology. The force to remove the HAp implants from the muscles was significantly greater than that of Ti group （P〈0.01）, with the AD samples requiring the greatest force （P〈0.01）. After removal, SEM showed that the tissue was firmly attached to the surface of AD samples. Photomicrographs of the peri-implant muscles showed a layer of aligned fibrous tissue without severe inflammation. The AD samples had more fibroblasts. Results indicate that because of enhanced mechanical adhesion of soft tissue to the implants, HAp-coated Ti by AD is a suitable KPro skirt material.展开更多
Titanium and its alloys are often used as substrates for dental implants due to their excellent mechanical properties and good biocompatibility.However,their ability to bind to neighboring bone is limited due to the l...Titanium and its alloys are often used as substrates for dental implants due to their excellent mechanical properties and good biocompatibility.However,their ability to bind to neighboring bone is limited due to the lack of biological activity.At the same time,they show poor antibacterial ability which can easily cause bacterial infection and chronic inflammation,eventually resulting in implant failure.The preparation of composite hydroxyapatite coatings with antibacterial ability can effectively figure out these concerns.In this review,the research status and development trends of antibacterial hydroxyapatite coatings constructed on titanium and its alloys are analyzed and reviewed.This review may provide valuable reference for the preparation and application of high-performance and multi-functional dental implant coatings in the future.展开更多
基金Project(39931702) supported by the National Natural Science Foundation of ChinaProject(041223) supported by the Natural Science Foundation of Hebei Province, China
文摘Silicon-substituted hydroxyapatite (Ca10(PO4)6-x(SiO4)x(OH)2-x, Si-HA) composite coatings on a bioactive titanium substrate were prepared by electrophoretic deposition technique with the addition of triethanolamine (TEA) to enhance the ionization degree of Si-HA suspension. The surface structure was characterized by XRD, SEM, XRF, EDS and FTIR. The bond strength of the coating was investigated. The results show that the depositing thickness and the images of Si-HA coating can be changed with the variation of deposition time. The XRD spectra of Ti/Si-HA coatings show the characteristic diffraction peaks of HA, and the incorporation of silicon changes the lattice parameter of the crystal. The FTIR spectra shows that the most notable effect of silicon substitution is the decrease of intensities of —OH and PO43- groups with the silicon contents increasing. XRD and EDS element analyses present that the content of silicon in the coating increases with increasing silicon concentration in the suspension. The bioactive TiO2 coating formed may improve the bond strength of the coatings. The interaction of Ti/Si-HA coating with BSA is much greater than that of Ti/HA coating, suggesting that the incorporation of silicon in HA is significant to improve the bioactive performance of HA.
文摘In previous study, dense and homogenous 20wt% HAP/Ti composite coatings were successfully deposited on Ti substrates by cold gas dynamic spray technique. The results revealed that the phase composition of the HAP in the deposit is identical to that of the precursor powder and the bonding strength of the deposit is comparable/better to that of the plasma sprayed HAP. A relatively higher corrosion current of HAP/Ti composite than that of pure Ti coating in simulated body fluid indicates a good bioactivity for composite coating. In the present study, in vitro immersion test is carried out for various period of time and the formation of apatite layer on surface of composite coating proves the good bioactivity of the composite coating further. The cold sprayed HAP/Ti composite can be anticipated to be a promising load-bearing implant material for biomedical applications.
基金Projects(50235020 30300078)supported by the National Natural Science Foundation of China
文摘The composite films constituted of hydroxyapatite (HAP) submicron particles embedded in the gel composed of the titania nanoparticles were prepared on commercial Ti6Al4V plates with titania buffer layer obtained by a spin-coating technique. The films were annealed in air at 450 ℃, 550 ℃ and 650 ℃, respectively. The phase formation, surface morphology, andinterfacial microstructure of the films were investigated by X-ray diffraction(XRD),Fourier transform infrared spectroscopy (FT-IR), field emission-scanning electron microscopy(FE-SEM) and energy dispersive X-ray (EDS) analysis. The results show that the as-prepared films are all well-crystallized, dense,homogeneous, and there was a close interfacial bond between the film and the substrate. The results of adhesion test indicate that there is a good bonding strength between the film and the substrate. The bone-like apatite formation on the surface of the films after immersion in acellular simulatedbody fluid(SBF) validated their bioactivities.
文摘TiO2-hydroxyapatite （HA） nanostructured coatings were produced by atmospheric plasma spray method. The effects of starting powder composition and grain size on their mechanical properties were investigated. The microstructure and morphology were characterized by X-ray diffraction and scanning electron microscopy （SEM）. It is found that the coating with 10% HA has the best mechanical properties. Based on Rietveld refinement method, the mean grain size of the as-received powder （212 nm） extensively decreases to 66.4 nm after 20 h of high-energy ball milling. In spite of grain growth, the deposited coatings maintain their nanostructures with the mean grain size of 112 nm. SEM images show that there is a lower porosity in the coating with a higher HA content. Optical microscopy images show that uniform thickness is obtained for all the coatings.
基金supported by the Fundamental Research Funds for the Central Universities (N090602001)the Natural Sciences and Engineering Research Council of Canada (NSERC)
文摘The in-vitro biological behavior of a newly-developed iron-containing hydroxyapatite/titanium（HA/Ti） composite was investigated by immersing the composites in the simulated body fluid（SBF） for up to 5 weeks.The addition of iron was observed to have a significant influence on the in-vitro biological behavior of the composites.The obtained results revealed that the stability of the composites in the physiological solution was markedly improved.The solubility decreased in the order of pure HA,HA/5（Ti-33Fe）,and HA/15（Ti33Fe）.Precipitation occurred on the surface of HA/5（Ti-33Fe） composite,showing a good combination of physiostability with bioactivity,while HA/15（Ti-33Fe） composite exhibited superior physiostability since there was no obvious change on the surface of HA/15（Ti-33Fe）.
文摘The aim of this work was to study the influence of the different synthesis processes on microstructural and morphological characteristics and distribution of hydroxyapatite-bioactive glass(HAp-BG)composite nanopowders obtained by sol-gel method.HAp-BG composite nanopowders with 20 wt%bioactive glass were prepared using a sol-gel method via four routes:(I)mixing the prepared HAp solution with BG solution before aging time;(II)mixing the prepared BG solution with the prepared HAp gel after gelation;(III)mixing the calcined BG nanopowders with the prepared HAp solution;and(IV)mixing the two prepared calcined nanopowders by mechanochemical activation.The prepared nanopowders were evaluated and studied by X-ray diffraction(XRD),scanning electron microscopy(SEM),energy dispersive X-ray spectrometer(EDS),Fourier transform infrared(FTIR),transmission electron diffraction(TEM)and Brunauer-Emmet-Teller(BET)method to investigate the phase structure,microstructure and morphology,functional groups,and the size and distribution of nanopowders.Results indicated that morphology,crystallinity,crystallite size and specific surface area(SSA)of the powders are highly correspondent to the process and type of synthesis method.These findings suggest that the modified sol-gel derived HAp-BG composite nanopowders are expected to efficiently provide a possibility to produce a good candidate to use for fabrication of a bulk nanostructured HAp-BG composite for bone tissue engineering.
基金financially supported by the National Natural Science Foundation of China(81671825)the Sichuan Science and Technology Innovation Team of China(2019JDTD0008).
文摘Various surface bioactivation technology has been confirmed to improve the osteogenic ability of porous titanium(pTi)implants effectively.In this study,a three-layered composite coating,i.e.outer layer of hydroxyapatite(HA),middle layer of loose titanium dioxide(L-TiO2)and inner layer of dense TiO2(D-TiO2),was fabricated on pTi by a combined processing procedure of pickling,alkali heat(AH),anodic oxidation(AO),electrochemical deposition(ED)and hydrothermal treatment(HT).After soaking in simulated body fluid for 48 h,the surface of the AHAOEDHT-treated pTi was completely covered by a homogeneous apatite layer.Using MC3T3-E1 pro-osteoblasts as cell model,the cell culture revealed that both the pTi without surface treatment and the AHAOEDHT sample could support the attachment,growth and proliferation of the cells.Compared to the pTi sample,the AHAOEDHT one induced higher expressions of osteogenesis-related genes in the cells,including alkaline phosphatase,Type I collagen,osteopontin,osteoclast inhibitor,osteocalcin and zinc finger structure transcription factor.As thus,besides the good corrosion resistance,the HA/L-TiO2/D-TiO2-coated pTi had good osteogenic activity,showing good potential in practical application for bone defect repair.
文摘Stable tissue integration is important to keratoprosthesis （KPro）. The aim of this study was to evaluate the tissue bonding ability of hydroxyapatite （HAp）-coated titanium KPro. The samples were divided into three groups： test groups （IBAD group and AD group） and Ti control. The coated samples had a HAp layer created by ion beam assisted deposition （IBAD） or aerosol deposition （AD）. The surface characteristics were analyzed with SEM, AFM, and XRD. The samples were surgically inserted into the muscles of rabbits. Eight weeks after healing, the attachment to the tissue was tested with a universal test device. The three samples exhibited distinctive surface morphology. The force to remove the HAp implants from the muscles was significantly greater than that of Ti group （P〈0.01）, with the AD samples requiring the greatest force （P〈0.01）. After removal, SEM showed that the tissue was firmly attached to the surface of AD samples. Photomicrographs of the peri-implant muscles showed a layer of aligned fibrous tissue without severe inflammation. The AD samples had more fibroblasts. Results indicate that because of enhanced mechanical adhesion of soft tissue to the implants, HAp-coated Ti by AD is a suitable KPro skirt material.
基金This work was supported by the National Natural Science Foundation of China(Grant Nos.12272253,11632013,and 11902214)the Shanxi-Zheda Institute of Advanced Materials and Chemical Engineering(Grant Nos.2021SX-AT008 and 2021SX-AT009)The support of the Fund Program for the Scientific Activities of Selected Returned Overseas Professionals in Shanxi Province(Grant No.20220006)is also acknowledged with gratitude.
文摘Titanium and its alloys are often used as substrates for dental implants due to their excellent mechanical properties and good biocompatibility.However,their ability to bind to neighboring bone is limited due to the lack of biological activity.At the same time,they show poor antibacterial ability which can easily cause bacterial infection and chronic inflammation,eventually resulting in implant failure.The preparation of composite hydroxyapatite coatings with antibacterial ability can effectively figure out these concerns.In this review,the research status and development trends of antibacterial hydroxyapatite coatings constructed on titanium and its alloys are analyzed and reviewed.This review may provide valuable reference for the preparation and application of high-performance and multi-functional dental implant coatings in the future.
