The effect of porosity on compressive,bending,and tensile properties of the porous tantalum scaffolds fabricated by electron beam powder bed fusion(EB-PBF)was investigated.The porous tantalum scaffolds with porosity f...The effect of porosity on compressive,bending,and tensile properties of the porous tantalum scaffolds fabricated by electron beam powder bed fusion(EB-PBF)was investigated.The porous tantalum scaffolds with porosity from 69%to 77.8%were obtained by varying the designed porosity and adjusting the processing parameters.It is found that the pores and unfused powder decrease with the increase of deposited energy density.The decrease of porosity leads to an improvement in mechanical properties.The relevancy between compressive/bending/tensile yield strength and relative density can be described appropriately by exponential model,while the relationship between elastic modulus and relative density is in good agreement with the Gibson-Ashby model.All the porous tantalum scaffolds exhibit good ductility in compressive,bending and tensile tests.No fragmentation of struts is observed during the compression process,but cracks are formed on the strut surface after 90°bending,mainly due to the high sensibility to defects caused by the oxide.展开更多
Objective： To develop a novel scaffolding method for the copolymers poly lactide-co-glycolide acid （PLGA） to construct a three-dimensional （3-D） scaffold and explore its biocompatibility through culturing Schwann...Objective： To develop a novel scaffolding method for the copolymers poly lactide-co-glycolide acid （PLGA） to construct a three-dimensional （3-D） scaffold and explore its biocompatibility through culturing Schwann cells （SCs） on it. Methods： The 3-D scaffolds were made by means of melt spinning, extension and weaving. The queueing discipline of the micro-channels were observed under a scanning electronic microscope （SEM）.The sizes of the micropores and the factors of porosity were also measured. Sciatic nerves were harvested from 3-day-old Sprague Dawley （SD） rats for culture of SCs. SCs were separated, purified, and then implanted on PLGA scaffolds, gelatin sponge and poly-L-lysine （PLL）-coated tissue culture poly-styrene （TCPS） were used as biomaterial and cell-supportive controls, respectively. The effect of PLGA on the adherence, proliferation and apoptosis of SCs were examined in vitro in comparison with gelatin sponge and TCPS. Results： The micro-channels arrayed in parallel manners, and the pore sizes of the channels were uniform. No significant difference was found in the activity of Schwann cells cultured on PLGA and those on TCPS （P〉0.05）, and the DNA of PLGA scaffolds was not damaged. Conclusion： The 3-D scaffolds developed in this study have excellent structure and biocompatibility, which may be taken as a novel scaffold candidate for nerve-tissue engineering.展开更多
基金supported by the Key R&D Program of Guangdong Province,China(Nos.2019B090904001,2018B090906003)。
文摘The effect of porosity on compressive,bending,and tensile properties of the porous tantalum scaffolds fabricated by electron beam powder bed fusion(EB-PBF)was investigated.The porous tantalum scaffolds with porosity from 69%to 77.8%were obtained by varying the designed porosity and adjusting the processing parameters.It is found that the pores and unfused powder decrease with the increase of deposited energy density.The decrease of porosity leads to an improvement in mechanical properties.The relevancy between compressive/bending/tensile yield strength and relative density can be described appropriately by exponential model,while the relationship between elastic modulus and relative density is in good agreement with the Gibson-Ashby model.All the porous tantalum scaffolds exhibit good ductility in compressive,bending and tensile tests.No fragmentation of struts is observed during the compression process,but cracks are formed on the strut surface after 90°bending,mainly due to the high sensibility to defects caused by the oxide.
文摘Objective： To develop a novel scaffolding method for the copolymers poly lactide-co-glycolide acid （PLGA） to construct a three-dimensional （3-D） scaffold and explore its biocompatibility through culturing Schwann cells （SCs） on it. Methods： The 3-D scaffolds were made by means of melt spinning, extension and weaving. The queueing discipline of the micro-channels were observed under a scanning electronic microscope （SEM）.The sizes of the micropores and the factors of porosity were also measured. Sciatic nerves were harvested from 3-day-old Sprague Dawley （SD） rats for culture of SCs. SCs were separated, purified, and then implanted on PLGA scaffolds, gelatin sponge and poly-L-lysine （PLL）-coated tissue culture poly-styrene （TCPS） were used as biomaterial and cell-supportive controls, respectively. The effect of PLGA on the adherence, proliferation and apoptosis of SCs were examined in vitro in comparison with gelatin sponge and TCPS. Results： The micro-channels arrayed in parallel manners, and the pore sizes of the channels were uniform. No significant difference was found in the activity of Schwann cells cultured on PLGA and those on TCPS （P〉0.05）, and the DNA of PLGA scaffolds was not damaged. Conclusion： The 3-D scaffolds developed in this study have excellent structure and biocompatibility, which may be taken as a novel scaffold candidate for nerve-tissue engineering.
