Background Stroke and traumatic injury to the nerve system may trigger axonal destruction and the formation of scar tissue, cystic cavitations and physical gaps. Olfactory ensheathing cells （OECs） can secrete neurot...Background Stroke and traumatic injury to the nerve system may trigger axonal destruction and the formation of scar tissue, cystic cavitations and physical gaps. Olfactory ensheathing cells （OECs） can secrete neurotrophic factors to promote neurite growth and thus act as a prime candidate for autologous transplantation. Biological scaffolds can provide a robust delivery vehicle to injured nerve tissue for neural cell transplantation strategies, owing to the porous three-dimensional structures （3D）. So transplantation of the purposeful cells seeded scaffolds may be a promising method for nerve tissue repair. This study aimed to evaluate the compatibility of a novel collagen-heparan sulfate biological scaffold with olfactory ensheathing cells in vitro. Methods Collagen-heparan sulfate （CHS） biological scaffolds were made, and then the scaffolds and OECs were co-cultured in vitro. The viability of OECs was tested by 3-（4,5-dimethylthiazol-2-yl）-2,5-diphenyl tetrazolium （MTT） assay at days 1, 3, 5 and 7. Statistical analysis was evaluated by student＇s ttest. Significance was accepted at P 〈0.05. OECs were labeled with carboxyfluorescein diacetate succinimidyl ester （CFSE）, and the CFSE-labeled OECs were seeded into CHS scaffolds. The attachment and growth of OECs in CHS scaffolds were observed and traced directly by fluorescent microscopy and environmental scanning electron microscope （ESEM）. Results CHS biological scaffolds had steady porous 3D structures and no cytotoxicity to OECs （F=-0.14, P=-0.9330）. CHS biological scaffolds were good bridging materials for OECs attachment and proliferation, and they promoted the axonal growth. Conclusion The compatibility of CHS biological scaffolds with OECs is pretty good and CHS biological scaffold is a promising cell carrier for the implantation of OECs in nerve tissue bioengineering.展开更多
Bio-inspired porous metallic scaffolds have tremendous potential to be used as artificial bone substitutes.In this work,a radially graded lattice structure (RGLS),which mimics the structures of natural human bones,was...Bio-inspired porous metallic scaffolds have tremendous potential to be used as artificial bone substitutes.In this work,a radially graded lattice structure (RGLS),which mimics the structures of natural human bones,was designed and processed by laser powder bed fusion of martensitic Ti-rich TiNi powder.The asymmetric tension-compression behaviour,where the compressive strength is significantly higher than the tensile strength,is observed in this Ti-rich TiNi material,which echoes the mechanical behaviour of bones.The morphologies,mechanical properties,deformation behaviour,and biological compatibility of RGLS samples were characterised and compared with those in the uniform lattice structure.Both the uniform and RGLS samples achieve a relative density higher than 99%.The graded porosities and pore sizes in the RGLS range from 40%-80% and 330-805 µm,respectively,from the centre to the edge.The chemical etching has significantly removed the harmful partially-melted residual powder particles on the lattice struts.The compressive yield strength of RGLS is 71.5 MPa,much higher than that of the uniform sample (46.5 MPa),despite having a similar relative density of about 46%.The calculated Gibson-Ashby equation and the deformation behaviour simulation by finite element suggest that the dense outer regions with high load-bearing capability could sustain high applied stress,improving the overall strength of RGLS significantly.The cell proliferation study suggests better biological compatibility of the RGLS than the uniform structures.The findings highlight a novel strategy to improve the performance of additively manufactured artificial implants by bio-inspiration.展开更多
基金This study was supported by grants from the National Natural Science Foundation of China （No. 30570628 and No. 30770751）.
文摘Background Stroke and traumatic injury to the nerve system may trigger axonal destruction and the formation of scar tissue, cystic cavitations and physical gaps. Olfactory ensheathing cells （OECs） can secrete neurotrophic factors to promote neurite growth and thus act as a prime candidate for autologous transplantation. Biological scaffolds can provide a robust delivery vehicle to injured nerve tissue for neural cell transplantation strategies, owing to the porous three-dimensional structures （3D）. So transplantation of the purposeful cells seeded scaffolds may be a promising method for nerve tissue repair. This study aimed to evaluate the compatibility of a novel collagen-heparan sulfate biological scaffold with olfactory ensheathing cells in vitro. Methods Collagen-heparan sulfate （CHS） biological scaffolds were made, and then the scaffolds and OECs were co-cultured in vitro. The viability of OECs was tested by 3-（4,5-dimethylthiazol-2-yl）-2,5-diphenyl tetrazolium （MTT） assay at days 1, 3, 5 and 7. Statistical analysis was evaluated by student＇s ttest. Significance was accepted at P 〈0.05. OECs were labeled with carboxyfluorescein diacetate succinimidyl ester （CFSE）, and the CFSE-labeled OECs were seeded into CHS scaffolds. The attachment and growth of OECs in CHS scaffolds were observed and traced directly by fluorescent microscopy and environmental scanning electron microscope （ESEM）. Results CHS biological scaffolds had steady porous 3D structures and no cytotoxicity to OECs （F=-0.14, P=-0.9330）. CHS biological scaffolds were good bridging materials for OECs attachment and proliferation, and they promoted the axonal growth. Conclusion The compatibility of CHS biological scaffolds with OECs is pretty good and CHS biological scaffold is a promising cell carrier for the implantation of OECs in nerve tissue bioengineering.
基金financially supported by the National Natural Science Foundation of China(52005189)Guangdong Basic and Applied Basic Research Foundation(2019A1515110542 and 2020A1515110699)+1 种基金Guangzhou Foreign Cooperation Projects(2020B1212060049 and 201704030067)Guangdong Academy of Sciences and the University of Birmingham(Contract 17-0551).
文摘Bio-inspired porous metallic scaffolds have tremendous potential to be used as artificial bone substitutes.In this work,a radially graded lattice structure (RGLS),which mimics the structures of natural human bones,was designed and processed by laser powder bed fusion of martensitic Ti-rich TiNi powder.The asymmetric tension-compression behaviour,where the compressive strength is significantly higher than the tensile strength,is observed in this Ti-rich TiNi material,which echoes the mechanical behaviour of bones.The morphologies,mechanical properties,deformation behaviour,and biological compatibility of RGLS samples were characterised and compared with those in the uniform lattice structure.Both the uniform and RGLS samples achieve a relative density higher than 99%.The graded porosities and pore sizes in the RGLS range from 40%-80% and 330-805 µm,respectively,from the centre to the edge.The chemical etching has significantly removed the harmful partially-melted residual powder particles on the lattice struts.The compressive yield strength of RGLS is 71.5 MPa,much higher than that of the uniform sample (46.5 MPa),despite having a similar relative density of about 46%.The calculated Gibson-Ashby equation and the deformation behaviour simulation by finite element suggest that the dense outer regions with high load-bearing capability could sustain high applied stress,improving the overall strength of RGLS significantly.The cell proliferation study suggests better biological compatibility of the RGLS than the uniform structures.The findings highlight a novel strategy to improve the performance of additively manufactured artificial implants by bio-inspiration.
