| Objective:The purpose of this study is to design and synthesize a new type of graphene oxide/chitosan/silk fibroin composite bone tissue engineering scaffold containing graphene oxide-nanosilver composites(GO-Ag NPs),with a view to the scaffold with good antibacterial ability.Our research group has designed and synthesized a new type of graphene oxide/chitosan/silk fibroin composite scaffold in the preliminary experiment.The experimental results show that its microstructure,porosity,hydrophilicity and swelling rate are all good,so this experiment is Based on the previous research,silver-loaded antibacterial materials are introduced,and the composite stent is expected to have antibacterial ability under the premise of good biocompatibility.Methods:First,GO-Ag NPs nanocomposite was synthesized,and then added to a graphene oxide/chitosan/silk fibroin mixed solution containing 1% GO,and a new type of composite scaffold system was prepared by freeze dryer technology.According to the different amount of GO-Ag NPs added,the experiment was divided into four groups:0?g/m L group(control group),20?g/m L group,40?g/m L group,and 60?g/m L group.After the preparation of the scaffold is completed,the physical properties,biocompatibility and antibacterial ability of each group of specimens are tested.Observe the microstructure of the scaffold by scanning electron microscope,and perform elemental analysis on the scaffold surface;detect the porosity,swelling rate and other physical parameters of the scaffold;co-culture the extracts of each group of scaffolds with mouse fibroblasts(L929),The CCK-8 method was used to detect the cytotoxicity of the scaffold;Staphylococcus aureus and Escherichia coli were cultured,and the anti-bacterial adhesion ability of the scaffold was evaluated by counting the bacterial colony on the plate.Results:1.The experiment uses freeze dryer technology to prepare loose and porous composite scaffolds.The microscopic appearance of the scaffolds is observed by scanning electron microscope to meet the requirements of bone tissue engineering.EDS analysis results show that each experimental group shows Ag elements at a binding energy of 3.0ke V.The peaks of the experimental groups have successfully introduced nano-silver particles,and with the increase of the proportion of GO-Ag NPs,the peak of the silver element gradually increased;2.The porosity and swelling rate of each group of scaffolds did not change significantly.It proved that adding a small amount of GO-Ag NPs did not change the physical properties of the stent;3.The results of CCK-8 showed that the toxicity grades of the 0?g/m L group(control group),20?g/m L group,40?g/m L group and 60?g/m L group were Grade 0 or1 meets the requirements of safety standards;4.The results of bacterial adhesion plate colony count show that the number of bacteria attached to the surface of the experimental group with GO-Ag NPs is significantly less than that of the control group,of which the 40?g/m L group The antibacterial rate is high,the antibacterial rate for Staphylococcus aureus is >90%,and the antibacterial rate for Escherichia coli is close to 90%.The antibacterial rate of 60?g/m L group against Staphylococcus aureus and Escherichia coli were both >90%.Conclusion:The composite scaffold after adding GO-Ag NPs has a porous structure and stable physical and chemical properties.The graphene oxide/chitosan/silk fibroin composite scaffold containing 40?g/m LGO-Ag NPs has good performance in biocompatibility and antibacterial properties,and can be used as a bone tissue engineering scaffold material with antibacterial ability to carry out further experiments the study. |
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