The lipophilic hydroxyapatite(HA)nanorods were firstly synthesized by the solvothermal method using calcium oleate as the precursor.As-synthesized HA nanorods had an average aspect ratio of 11.4 with 18.4 wt%oleic aci...The lipophilic hydroxyapatite(HA)nanorods were firstly synthesized by the solvothermal method using calcium oleate as the precursor.As-synthesized HA nanorods had an average aspect ratio of 11.4 with 18.4 wt%oleic acid attached on the surface.Then the hydroxyapatite/polylactic acid(HA/PLA)nanocomposites were prepared by dispersing the HA nanorods in PLA using dichloromethane(CH_(2)Cl_(2))as the volatile solvent.The influence of the HA content on the properties of the HA/PLA nanocomposites was investigated.It is found that the nanocomposite with 2 wt%HA exhibits the optimal mechanical properties.The tensile strength and elongation at break are 59.4 MPa and 18.19%,respectively.The values are enhanced by 13%and 184.2%compared with that of the pure PLA.The higher HA addition results in the decrease in the mechanical properties due to the aggregation of HA nanorods.The thermal properties of the HA/PLA nanocomposites were also examined.It is found that the thermal stability and crystallization transition temperature are decreased while the glass transition temperature and melting temperature remain basically unchanged with the increasing HA content up to 10 wt%.展开更多
Nonporous and porous C/PLA/nano-HA composites were fabricated by the process of solvent blending and freeze-drying technique, and the effect of porous structure on the mechanical properties of C/PLA/nano-HA composites...Nonporous and porous C/PLA/nano-HA composites were fabricated by the process of solvent blending and freeze-drying technique, and the effect of porous structure on the mechanical properties of C/PLA/nano-HA composites scaffold was investigated and analyzed. The results show that the effects of porous structure on the bending strength, modulus and curves of stress and strain were obvious. Compared with nonporous sample, the curves of stress and strain of porous sample show more rough, and alternative phenomenon of stress increase and stress relaxation appears. It is strongly suggested that the fracture model of C/PLA/nano-HA composites scaffold transforms from the local to global load due to the porous structure.展开更多
PLA/MWNT/HA hybrid nanofibers were prepared via electrospinning technology.Multi walled carbon nanotube (MWNT) were first treated by anodic oxidation,which resulted in various functional groups such as C—O,CO and O—...PLA/MWNT/HA hybrid nanofibers were prepared via electrospinning technology.Multi walled carbon nanotube (MWNT) were first treated by anodic oxidation,which resulted in various functional groups such as C—O,CO and O—CO on the surface of oxidized MWNT.Then the MWNT/hydroxyapatite (HA) nano composites (MWNT content 3?wt%) were in situ synthesized by wet method with the help of ultrasonic treatment.Because of the strong interaction between the functional groups on the surface of MWNT and Ca 2+ in HA,the obtained HA nano particles were deposited onto the surface of oxidized MWNT.The as received MWNT/HA nano composites with excellent biocompatibility and osteoinduction were introduced into a bioabsorbable polymer,polylactide (PLA),and the PLA/MWNT/HA hybrid nanofibers were electrospun through a double solvent method under the voltage of 18 kV and the capillary to target distance was 4?cm.The structure and morphology of hybrid nanofibers were characterized by SEM.Because of the nanoscaled diameters,microscaled interconnected pores and suitable surface chemistry,the hybrid nanofibers would match the requirements of ideal bone tissue engineering scaffold and may be a potential material for preparing bone tissue engineering scaffold.展开更多
In the field of bone defect repair,critical requirements for favorable cytocompatibility and optimal mechanical properties have propelled research efforts towards the development of composite materials.In this study,c...In the field of bone defect repair,critical requirements for favorable cytocompatibility and optimal mechanical properties have propelled research efforts towards the development of composite materials.In this study,carbon nanotubes/polylactic acid/hydroxyapatite(CNTs/PLA/HA)scaffolds with different contents(0.5,1,1.5 and 2 wt.%)of CNTs were prepared by the thermally induced phase separation(TIPS)method.The results revealed that the composite scaffolds had uniform pores with high porosities over 68%and high through performances.The addition of CNTs significantly enhanced the mechanical properties of resulted PLA/HA,in which the 1.5 wt.%CNTs/PLA/HA composite scaffold demonstrated the optimum mechanical behaviors with the bending elastic modulus of(868.5±12.34)MPa,the tensile elastic modulus of(209.51±12.73)MPa,and the tensile strength of(3.26±0.61)MPa.Furthermore,L929 cells on the 1.5 wt.%CNTs/PLA/HA scaffold displayed good spreading performance and favorable cytocompatibility.Therefore,it is expected that the 1.5 wt.%CNTs/PLA/HA scaffold has potential applications in bone tissue engineering.展开更多
基金the Foundation of Hubei Province Key Laboratory of Green Materials for Light Industry,Hubei University of Technology。
文摘The lipophilic hydroxyapatite(HA)nanorods were firstly synthesized by the solvothermal method using calcium oleate as the precursor.As-synthesized HA nanorods had an average aspect ratio of 11.4 with 18.4 wt%oleic acid attached on the surface.Then the hydroxyapatite/polylactic acid(HA/PLA)nanocomposites were prepared by dispersing the HA nanorods in PLA using dichloromethane(CH_(2)Cl_(2))as the volatile solvent.The influence of the HA content on the properties of the HA/PLA nanocomposites was investigated.It is found that the nanocomposite with 2 wt%HA exhibits the optimal mechanical properties.The tensile strength and elongation at break are 59.4 MPa and 18.19%,respectively.The values are enhanced by 13%and 184.2%compared with that of the pure PLA.The higher HA addition results in the decrease in the mechanical properties due to the aggregation of HA nanorods.The thermal properties of the HA/PLA nanocomposites were also examined.It is found that the thermal stability and crystallization transition temperature are decreased while the glass transition temperature and melting temperature remain basically unchanged with the increasing HA content up to 10 wt%.
基金Project(30870609) supported by the National Natural Science Foundation of ChinaProjects(KJ081205 KJ091213) supported by the Natural Science Foundation of Chongqing Education Committee, China
文摘Nonporous and porous C/PLA/nano-HA composites were fabricated by the process of solvent blending and freeze-drying technique, and the effect of porous structure on the mechanical properties of C/PLA/nano-HA composites scaffold was investigated and analyzed. The results show that the effects of porous structure on the bending strength, modulus and curves of stress and strain were obvious. Compared with nonporous sample, the curves of stress and strain of porous sample show more rough, and alternative phenomenon of stress increase and stress relaxation appears. It is strongly suggested that the fracture model of C/PLA/nano-HA composites scaffold transforms from the local to global load due to the porous structure.
文摘PLA/MWNT/HA hybrid nanofibers were prepared via electrospinning technology.Multi walled carbon nanotube (MWNT) were first treated by anodic oxidation,which resulted in various functional groups such as C—O,CO and O—CO on the surface of oxidized MWNT.Then the MWNT/hydroxyapatite (HA) nano composites (MWNT content 3?wt%) were in situ synthesized by wet method with the help of ultrasonic treatment.Because of the strong interaction between the functional groups on the surface of MWNT and Ca 2+ in HA,the obtained HA nano particles were deposited onto the surface of oxidized MWNT.The as received MWNT/HA nano composites with excellent biocompatibility and osteoinduction were introduced into a bioabsorbable polymer,polylactide (PLA),and the PLA/MWNT/HA hybrid nanofibers were electrospun through a double solvent method under the voltage of 18 kV and the capillary to target distance was 4?cm.The structure and morphology of hybrid nanofibers were characterized by SEM.Because of the nanoscaled diameters,microscaled interconnected pores and suitable surface chemistry,the hybrid nanofibers would match the requirements of ideal bone tissue engineering scaffold and may be a potential material for preparing bone tissue engineering scaffold.
基金supported by the National Natural Science Foundation of China(Grant Nos.12202302,12272253,and 82103147)The support of the Fund Program for the Scientific Activities of Selected Returned Overseas Professionals in Shanxi Province(Grant No.20220006)was also acknowledged with gratitude.
文摘In the field of bone defect repair,critical requirements for favorable cytocompatibility and optimal mechanical properties have propelled research efforts towards the development of composite materials.In this study,carbon nanotubes/polylactic acid/hydroxyapatite(CNTs/PLA/HA)scaffolds with different contents(0.5,1,1.5 and 2 wt.%)of CNTs were prepared by the thermally induced phase separation(TIPS)method.The results revealed that the composite scaffolds had uniform pores with high porosities over 68%and high through performances.The addition of CNTs significantly enhanced the mechanical properties of resulted PLA/HA,in which the 1.5 wt.%CNTs/PLA/HA composite scaffold demonstrated the optimum mechanical behaviors with the bending elastic modulus of(868.5±12.34)MPa,the tensile elastic modulus of(209.51±12.73)MPa,and the tensile strength of(3.26±0.61)MPa.Furthermore,L929 cells on the 1.5 wt.%CNTs/PLA/HA scaffold displayed good spreading performance and favorable cytocompatibility.Therefore,it is expected that the 1.5 wt.%CNTs/PLA/HA scaffold has potential applications in bone tissue engineering.
