Construction And Biomimetic Mineralization In Vitro Of SF/SA/HBG Fiber Composite Scaffold Material

Silk fibroin(SF)is extracted from silk degumming and has non-toxic,non-irritating odor,breathable and moisture permeable,excellent mechanical properties,biodegradability and good biocompatibility,natural polymer material.The silk fibroin is dissolved by calcium chloride to prepare regenerated silk fibroin,which can form a micro-nano sized fiber diameter,which helps to increase the specific surface area of the fiber scaffold material and form a larger pore structure;Proteins have broad application potential and development prospects in medical fields such as drug release,tissue engineering,bone repair materials,and wound dressings.In this paper,the silk fibroin formic acid spinning solution with suitable concentration is selected for electrospinning.In order to make up for the lack of performance of single material,we have added a certain proportion of non-toxic,harmless and biodegradable natural polymer materials.Sodium alginate(SA),and hollow bioactive glass(HBG),which can improve the osteoconductivity and healing ability of the scaffold material,finally construct fiber scaffold material with good biological activity.In addition,a series of tests and characterizations of fiber composites have been provided to provide an idea for the in-depth study of regenerated silk fibroin biomedical scaffold materials.The main content of this study included three aspects as follows:(1)Construction of silk fibroin fiber scaffold material and its spinnabilityUsing electrospinning technology,using formic acid as solvent and silk fibroin as raw materials,silk fibroin fiber scaffold materials were prepared.In order to obtain well-formed fiber scaffold materials,we designed experimental solutions for the concentration of spinning solution.The wire voltage and the spinning distance were explored.The morphology and diameter distribution of the fibers were analyzed by FE-SEM,and the optimal spinning conditions were finally obtained.The conclusions were as follows: the spinning solution concentration was 10 wt%,the spinning voltage was 14 kV,the spinning distance was 14 cm;the external environment adjustment setting: the temperature was controlled at 20 °C.the humidity was controlled at 55 %;fiber shape can be prepared A fiber scaffold material with a good appearance and an average diameter of 181 nm with minimal dispersion.(2)Preparation and in vitro bioactivity of SF/SA fiber composite scaffoldsThe SF/SA fiber composite scaffolds were prepared by using the optimal spinning parameters of silk fibroin fiber scaffold materials with different water-soluble sodium alginate as additives,and the optimal compounding ratio of the two was studied.Then,the SF/SA fiber composite scaffolds material were cross-linked and activity was studied in vitro biomineralization,followed by a series of tests and characterizations.The results shows that the optimal composite ratio of SF to SA is 5:1.The structure of the fiber composite scaffold after cross-linking with anhydrous ethanol was more stable,which makes the fiber diameter thicker and the interfiber pores increase.The video contact angle test results show that the hydrophilicity of the SF/SA fiber composite scaffold material was better with the increase of the SA composite content.After in vitro biomineralization,the results showed that with the increase of SA composite content,the formation capacity of hydroxyapatite on the surface of composite fiber also increased,and the amount of production per unit time also increased gradually,indicating that SF/SA fiber composite scaffold material it had good biological activity and had the potential as a fiber scaffold matrix material.(3)Preparation and in vitro bioactivity of SF/SA/HBG fiber composite scaffoldsUsing electrospinning technology,silk fibroin and sodium alginate were used as the organic part of the scaffold material,and the hollow bioactive glass was used as the inorganic part to successfully construct the SF/SA/HBG fiber composite scaffold material.In addition,we have carried out cross-linking treatment and in vitro biomineralization activity on fiber composite scaffolds,and carried out a series of tests and characterization.The results show that the optimum ratio of HBG was 10 wt%.Some of HBG were present in the fiber,and some were embedded on surface of the fiber,and local protrusions were formed on surface of the fiber to form a rough surface structure.With the increase of HBG content,the convex structure of the fiber surface is more obvious,and the agglomeration phenomenon becomes more and more serious.The molecular structure of the fiber composite scaffold after treatment with absolute ethanol tends to be stable,the fiber swells to make the diameter thicker,and the gap between the fiber and the fiber also becomes larger;the surface of the fiber after biomineralization had a large amount of calcium Phosphorus ion deposition,test analysis showed that when the amount of HBG added was 10 wt%,the surface morphology of the fiber was the best and its biological activity was the best in vitro,which was expected to provide excellent scaffold materials for bioengineering research.In summary,the successful construction of SF/SA/HBG fiber composite scaffold material and the in vitro biomineralization have the ability to deposit hydroxyapatite on the surface of the fiber,and have made a basic exploration for the field of bioscaffold materials,which is expected to be in subsequent cells,animal experiments provide good fiber composite scaffold materials.