FeCrAl fiber-reinforced hydroxyapatite（HA） biocomposites（FeCrAl（f）/HA） were fabricated by the hot pressing technique.The metallographic microscopy,X-ray diffractometry,scanning electron microscopy（SEM） and ene...FeCrAl fiber-reinforced hydroxyapatite（HA） biocomposites（FeCrAl（f）/HA） were fabricated by the hot pressing technique.The metallographic microscopy,X-ray diffractometry,scanning electron microscopy（SEM） and energy dispersive spectroscopy（EDS） were used to observe and analyze the microstructure and composition of FeCrAl（f）/HA composites,respectively.The mechanical properties of FeCrAl（f）/HA composites were measured by the three-point-bending test.The results show that the composite can be reinforced by FeCrAl fiber and enhanced gradually,and then declined with the increase of the content of FeCrAl fiber（0-11%,volume fraction） in the whole range of experiments.Both the HA matrix and FeCrAl fiber integrate very tightly and bit into each other very deeply and counter-diffusion takes place to some extent at two-phase interface.The optimum parameters of FeCrAl（f）/HA composite are diameter of 22 μm,length of 1-2 mm and of volume faction of about 7% for FeCrAl fibers.展开更多
The in vitro degradation characteristic of the poly D, L-lactic acid （ PDLIA ）/ hydroxyapatite （ HA ） compound were investigated. The compoundfibers were immersed in static phosphate buffer at 37℃ to degrade fo...The in vitro degradation characteristic of the poly D, L-lactic acid （ PDLIA ）/ hydroxyapatite （ HA ） compound were investigated. The compoundfibers were immersed in static phosphate buffer at 37℃ to degrade for 22 weeks. The changes in pH value of the buffer solution, the mechanical strength and morphological of inside and outside of composite fibers with degrurlation characteristic were observed. Results show that pH value of the buffer solution stabilized to aboat 7.0 before 12 weeks, however after 20 weeks that pH value quick declined. After 7 weeks that composite fibers of mechanical strength cannot mensuration. SEM observation revealed ttua bimodal degradation occurred in composite fibers.展开更多
The co-continuous(HA+β-TCP)/Zn−3Sn composite was fabricated via vacuum casting-infiltration method.The microstructure,mechanical properties,corrosion behaviors,and hemolysis ratio of the composite were studied by sca...The co-continuous(HA+β-TCP)/Zn−3Sn composite was fabricated via vacuum casting-infiltration method.The microstructure,mechanical properties,corrosion behaviors,and hemolysis ratio of the composite were studied by scanning electron microscope,X-ray diffractometer,mechanical testing,electrochemical test,immersion test,and ultraviolet spectrophotometry.The results indicate that Zn−3Sn alloy infiltrated into porous HA+β-TCP scaffold,which resulted in the formation of a compact(HA+β-TCP)/Zn−3Sn co-continuous composite,without any reaction layer between the Zn−3Sn alloy and the HA+β-TCP scaffold.The compressive strength of the composite was equal to about 3/4 that of Zn−3Sn alloy bulk.The corrosion rate of composite in simulated body fluid solution was slightly higher than that of Zn−3Sn alloy bulk.The main corrosion product on the composite surface was Zn(OH)2.The hemolysis rate of the composite was lower than that of Zn–3Sn alloy bulk and exhibited superior blood compatibility.展开更多
3D printed polyether-ether-ketone(PEEK)implant has become a popular clinical alternative to implants made of titanium alloy for cranial bone substitutes due to its bone-match properties,however its biological inert hi...3D printed polyether-ether-ketone(PEEK)implant has become a popular clinical alternative to implants made of titanium alloy for cranial bone substitutes due to its bone-match properties,however its biological inert hin-dered the progress of clinical applications of such material.To enhance the tissue integration capability of PEEK implants and promote their long-term stability,cranial implants of gradient porous structures were designed and manufactured via fused filament fabrication(FFF)3D printing technology in both PEEK and PEEK/HA com-posites materials,then functionally evaluation of the implants on the tissue in-growth and the osteointegration mechanisms was conducted via animal tests.The 3D printed PEEK scaffold was found to have 2-5 folds of the compressive strength to those of the natural cranial bone.The in vivo studies verified that the porous PEEK/HA scaffold could effectively induce the bone ingrowth to form a stable biointegration boundary surrounding the host bone tissue after 4 weeks of implantation.Moreover,the PEEK/HA scaffold showed no significant advantages in improving the soft tissue in-growth,only making its distribution more evenly.It is also interestingly to find out that the vertically connective pores throughout the implant did not enhance the tissue binding force even though it did promote the nutrient transportation.In conclusion,the use of PEEK/HA composite material and a well-designed porous structure was proved to be an effective approach to improve the biointegration between the implant and host tissues.展开更多
AZ91/HA composite was prepared by AZ91 magnesium alloy and porous HA using squeeze casting method. The microstructure and mechanical property of the AZ91/HA composite were studied. The results show that the molten AZ9...AZ91/HA composite was prepared by AZ91 magnesium alloy and porous HA using squeeze casting method. The microstructure and mechanical property of the AZ91/HA composite were studied. The results show that the molten AZ91 alloy completely infiltrated the preform without destroying the porous structure of the HA preform. The compressive strength of AZ91/HA composite increased significantly compared with that of the porous HA. The immersion test indicated that AzgI ahoy shows a lower corrosion resistance and is easier to be corroded in comparison with HA.展开更多
This study investigates the in vitro degradation of calcium-deficient hydroxyapatite powder after heat treatment at different temperatures and analyzes the calculated phase composition,particle size distribution,degra...This study investigates the in vitro degradation of calcium-deficient hydroxyapatite powder after heat treatment at different temperatures and analyzes the calculated phase composition,particle size distribution,degradation rate,and bioactivity of the powder after heat treatment.A mixture of hydroxyapatite and𝛽-tricalcium phosphate(BCP)coatings was prepared on the surface of a 3D-printed hydroxyapatite-whisker-strengthened hydroxyapatite scaf-fold(HAw/HA)by vacuum impregnation and ultraviolet light curing combined with an optimized heat treatment process.The performance of the coatings under different methods was characterized.The composite scaffolds with highly interconnected pores and excellent mechanical properties were prepared,and their biodegradation performance,bioactivity,osteoconductivity,and osteoinductivity of the scaffolds were improved.The results showed that calcium-deficient hydroxyapatite began to transform into BCP between 600℃and 800℃,and the powder treated at 800℃has better bioactivity.The BCP coating prepared by light curing was more uniform,resulting in a higher interfacial bonding strength,and has better osteoconductivity and osteoinductivity than that prepared by vacuum impregnation.展开更多
基金Project(50774096) supported by the National Natural Science Foundation of ChinaProject(2011QNZT046) supported by the Fundamental Research Funds of the Central South University,ChinaProject supported by the Postdoctoral Science Foundation of Central South University,China
文摘FeCrAl fiber-reinforced hydroxyapatite（HA） biocomposites（FeCrAl（f）/HA） were fabricated by the hot pressing technique.The metallographic microscopy,X-ray diffractometry,scanning electron microscopy（SEM） and energy dispersive spectroscopy（EDS） were used to observe and analyze the microstructure and composition of FeCrAl（f）/HA composites,respectively.The mechanical properties of FeCrAl（f）/HA composites were measured by the three-point-bending test.The results show that the composite can be reinforced by FeCrAl fiber and enhanced gradually,and then declined with the increase of the content of FeCrAl fiber（0-11%,volume fraction） in the whole range of experiments.Both the HA matrix and FeCrAl fiber integrate very tightly and bit into each other very deeply and counter-diffusion takes place to some extent at two-phase interface.The optimum parameters of FeCrAl（f）/HA composite are diameter of 22 μm,length of 1-2 mm and of volume faction of about 7% for FeCrAl fibers.
文摘The in vitro degradation characteristic of the poly D, L-lactic acid （ PDLIA ）/ hydroxyapatite （ HA ） compound were investigated. The compoundfibers were immersed in static phosphate buffer at 37℃ to degrade for 22 weeks. The changes in pH value of the buffer solution, the mechanical strength and morphological of inside and outside of composite fibers with degrurlation characteristic were observed. Results show that pH value of the buffer solution stabilized to aboat 7.0 before 12 weeks, however after 20 weeks that pH value quick declined. After 7 weeks that composite fibers of mechanical strength cannot mensuration. SEM observation revealed ttua bimodal degradation occurred in composite fibers.
基金the National Natural Science Foundation of China(No.51101039)the Fundamental Research Funds for the Central Universities,China(No.3072020CFT0702).
文摘The co-continuous(HA+β-TCP)/Zn−3Sn composite was fabricated via vacuum casting-infiltration method.The microstructure,mechanical properties,corrosion behaviors,and hemolysis ratio of the composite were studied by scanning electron microscope,X-ray diffractometer,mechanical testing,electrochemical test,immersion test,and ultraviolet spectrophotometry.The results indicate that Zn−3Sn alloy infiltrated into porous HA+β-TCP scaffold,which resulted in the formation of a compact(HA+β-TCP)/Zn−3Sn co-continuous composite,without any reaction layer between the Zn−3Sn alloy and the HA+β-TCP scaffold.The compressive strength of the composite was equal to about 3/4 that of Zn−3Sn alloy bulk.The corrosion rate of composite in simulated body fluid solution was slightly higher than that of Zn−3Sn alloy bulk.The main corrosion product on the composite surface was Zn(OH)2.The hemolysis rate of the composite was lower than that of Zn–3Sn alloy bulk and exhibited superior blood compatibility.
基金supported by National Natural Science Foundation of China(Grant.Nos.51835010,12202347)Natural Science Basic Research Program of Shaanxi Province of China(Grant.No.2022JQ-378)+1 种基金Fundamental Research Funds for the Central Universities and the Program for Innovation Team of Shaanxi Province of China(Grant.No.2023-CX-TD-17)Natural Science Foundation of Guangdong Province of China(Grant.No.2022A1515012552).
文摘3D printed polyether-ether-ketone(PEEK)implant has become a popular clinical alternative to implants made of titanium alloy for cranial bone substitutes due to its bone-match properties,however its biological inert hin-dered the progress of clinical applications of such material.To enhance the tissue integration capability of PEEK implants and promote their long-term stability,cranial implants of gradient porous structures were designed and manufactured via fused filament fabrication(FFF)3D printing technology in both PEEK and PEEK/HA com-posites materials,then functionally evaluation of the implants on the tissue in-growth and the osteointegration mechanisms was conducted via animal tests.The 3D printed PEEK scaffold was found to have 2-5 folds of the compressive strength to those of the natural cranial bone.The in vivo studies verified that the porous PEEK/HA scaffold could effectively induce the bone ingrowth to form a stable biointegration boundary surrounding the host bone tissue after 4 weeks of implantation.Moreover,the PEEK/HA scaffold showed no significant advantages in improving the soft tissue in-growth,only making its distribution more evenly.It is also interestingly to find out that the vertically connective pores throughout the implant did not enhance the tissue binding force even though it did promote the nutrient transportation.In conclusion,the use of PEEK/HA composite material and a well-designed porous structure was proved to be an effective approach to improve the biointegration between the implant and host tissues.
基金supported by the Medicine-Engineering Cross Research Foundation of Shanghai Jiao Tong University(Grants No.YG2014MS41)
文摘AZ91/HA composite was prepared by AZ91 magnesium alloy and porous HA using squeeze casting method. The microstructure and mechanical property of the AZ91/HA composite were studied. The results show that the molten AZ91 alloy completely infiltrated the preform without destroying the porous structure of the HA preform. The compressive strength of AZ91/HA composite increased significantly compared with that of the porous HA. The immersion test indicated that AzgI ahoy shows a lower corrosion resistance and is easier to be corroded in comparison with HA.
基金supported by Natural Science Foundation of China(Grant Nos.51972268 and 81860384).
文摘This study investigates the in vitro degradation of calcium-deficient hydroxyapatite powder after heat treatment at different temperatures and analyzes the calculated phase composition,particle size distribution,degradation rate,and bioactivity of the powder after heat treatment.A mixture of hydroxyapatite and𝛽-tricalcium phosphate(BCP)coatings was prepared on the surface of a 3D-printed hydroxyapatite-whisker-strengthened hydroxyapatite scaf-fold(HAw/HA)by vacuum impregnation and ultraviolet light curing combined with an optimized heat treatment process.The performance of the coatings under different methods was characterized.The composite scaffolds with highly interconnected pores and excellent mechanical properties were prepared,and their biodegradation performance,bioactivity,osteoconductivity,and osteoinductivity of the scaffolds were improved.The results showed that calcium-deficient hydroxyapatite began to transform into BCP between 600℃and 800℃,and the powder treated at 800℃has better bioactivity.The BCP coating prepared by light curing was more uniform,resulting in a higher interfacial bonding strength,and has better osteoconductivity and osteoinductivity than that prepared by vacuum impregnation.
