| Research background and purpose:Biodegradable metals(BMS)have been widely studied in the last decade and are expected to replace temporary implants,Iron and iron-based scaffolds are gradually becoming at the research forefront of degradable metal scaffolds,Iron is the basic element needed by the human body,With both good biocompatibility and mechanical properties,However,since its slow degradation rate is still a major obstacle to clinical application,To address this issue,Using the template method and the electrodeposition process,Use the porous iron foam as the base,Alloying iron with zinc to produce a double-layer porous Fe / Fe-Zn alloy scaffold,And investigated the microstructure,mechanical properties,degradation properties,cytotoxicity,and in vitro osteogenic properties of the material,In order to achieve the purpose of human cancellous bone bionic.Research technique(1)Preparation and characterization of the physical and chemical properties of the porous Fe / Fe-Zn alloyA double-layer porous Fe / Fe-Zn alloy scaffold was prepared in this experiment.The inner layer of the stent is porous iron,and the outer layer of the stent is iron-zinc alloy.The electrodeposition time was all 1h,and the current density was 0.3A,0.5A,1A.According to the mass fraction ratio of iron to zinc,they were divided into porous pure iron group,porous Fe-9 Zn group,porous Fe-14 Zn group and porous Fe-19 Zn group and blank control group.According to the characteristics of the material,the physical and chemical properties of the material are detected by scanning electron microscope(SEM),measuring the porosity and pore size,energy spectrometer(EDS)elements analysis,mechanical properties test,and in vitro degradation properties measurement.Experimental results were drawn and statistically analyzed using Graph Pad Prism,Image J and other software.(2)Biological evaluation of the porous Fe / Fe-Zn alloyMC3T3-E1 cells were routinely resuscitated,subcultured and the cells were seeded in well plates for 24 hours.The extract of each group was co-cultured with MC3T3-E1 cells and tested by CCK-8 experiments,cell live death staining,cell migration experiment,ghost pen cyclic peptide staining,ALP staining and quantitative analysis,Alizarin red staining and semi-quantitative analysis,QPCR and other techniques.Experimental results were drawn and statistically analyzed using Graph Pad Prism,Image J and other software.Results:(1)By observing the surface morphology of the material through SEM,it was found that when the iron-zinc ratio is Fe-14 Zn,the material shape is good and uniform and smooth,the surface of the material skeleton is clear,and the interior is a hollow structure.Elemental analysis of the energy spectrometer(EDS)shows that the inner layer of the material is composed of iron and a small amount of oxygen,and the outer layer is composed of iron and zinc.By testing the mechanical properties,the material is similar to cancellous bone,and the degradation experiments show that the material has a good degradation rate.(2)CCK-8 results showed that the cells in all groups grew well at 10-fold dilution and without cytotoxicity,which could promote cell proliferation.Ghost pen cyclopeptide confirmed good actin expression in the cells cultured with the material extract,where the Fe-14 Zn group had more microfilaments and tailfeet.ALP,Alizarin red,and QPCR results proved that the material showed good bone growth promotion properties.Research conclusion:(1)A bilayer porous Fe / Fe-Zn alloy scaffold was successfully fabricated,which showed an excellent surface microtopography,unique mechanical properties,and proper degradation rate.The Fe-14 Zn group was superior to the other groups.(2)The MC3T3-E1 cells grown with the material extract grew well,demonstrating the excellent biocompatibility of this material.It is found that the higher the proportion of zinc ions in the overall mass fraction of the material,the higher the concentration release of zinc ions,the higher the Ph value of zinc ions,the more the loss of the material,and the decrease of biological activity.(3)Porous Fe / Fe-Zn alloy has a good ability to promote bone proliferation and mineralization,and the Fe-14 Zn group is more significant.This material better meets the basic requirement of degradable bone implantation materials,and is expected to become a new choice for bone implantation materials. |
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