Fabrication And Properties Of Silk Fibroin/dopamine Medical Adhesive

Medical adhesives which are easy to apply,suitable for various tissues including soft tissues and bone and benefit for wound sealing have enormous potential to replace invasive mechanical fixations such as sutures and staples.In recent years,the medical adhesives used in clinical mainly include fibrin glue and cyanoacrylate adhesives.Despite their great development in the clinic,an adhesive that equipped the advantages of high stability,strong adhesion under wet condition,high biocompatibility and low cost is still required.Based on the above situation,silk fibroin was modified by dopamine through N-hydroxysuccinimide(NHS)and 1-ethyl-(3-dimethylaminopropyl)carbodiimide hydrochloride(EDC).On this basis,the adhesion strength of silk fibroin/dopamine medical adhesives were enhanced by using genipin and metal ions,respectively.The specific research contents and results are as follows:(1)Fabrication and properties study of genipin cross-linked silk fibroin/dopamine medical adhesiveFirstly,the preparation process of the adhesive was optimized through orthogonal experiment.The results showed that when the silk fibroin concentration was 12%,the molar ratio of grafted dopamine to silk fibroin was 1:6 and the molar ratio between the amino group and genipin was 1:0.5,the medical adhesives obtained the optimal adhesion strength.Under optimized situation,the tensile strength of the adhesive in the Lap-shear test can reach 122.62±7.32 kPa and 181.49±42.82 kPa after 12 h at 33.5 and 37?,respectively,which is 18 times higher than fibrin glue for clinical use.The results of cytotoxicity and migration experiments indicated the great biocompatibility of the adhesives.(2)Fabrication and properties study of metal ion modified silk fibroin/dopamine medical adhesiveMetal ions were also utilized to modify the adhesive properties in the early stage of the adhesives.The adhesives were prepared by Fe3+ and Cu2+.The results of the Lap-sheer test indicated that metal ions significantly promote rapid gelling speed.As the best,Fe3+ can reach 77.72±34.59 kPa after being treated at 37? for 1 h,which is 2.6 times higher than without Fe3+.The tensile strength also increased with time,and reached 248.35±28.74 kPa at 12 h,which is about 67 kPa higher than that without Fe3+.In the in vitro degradation experiment,the remaining weight of SFDG12/Fe after 30 d was 73.50±4.05%,showing advisable degradability.In cytotoxicity and migration experiments,SFDG12/Fe also indicated great biocompatibility.