The Preparation Of Silk Fibroin Scaffolds With Designable Properties And The Study Of Cell-scaffolds Interaction

The types of tissues include bone,muscle,nervous tissues,and etc.The optimal properties of scaffolds depend on the targeted tissues.Silk fibroin(SF)is widely applied widely in tissue engineering due to its good biocompatibility and superior mechanical properties.There are many types of SF scaffolds such as hydrogels,sponges,films and non-woven fabrics,and the features of SF scaffolds(conformation,mechanical properties,degradation rate,etc.)are also highly controllable.Hence,SF was utilized to fabricate scaffolds with designable properties in this study,and the cell-scaffolds interaction was also investigated.In the research of fabricating SF film with designable morphology,lithography technique was used to prepare silicon wafer with grating patterns and circular pillars/holes array patterns.The patterns were transferred onto polydimethylsiloxane(PDMS)followed by casting process to form patterned SF films.Human umbilical vein endothelial cells(HUVEC)were cultured onto the grating patterned films,and we found that cells were oriented along the grating and the shape of cells were"stretched".The degree of cells orientation and stretching was decreasing with the increasing width of "ridges" and "grooves".Cells cultured on circular pillars/holes array patterns appeared flat shape and the cell-attachment degree was related to the sizes and space of feature structure.In the fabrication of scaffolds with physical properties,we developed a simple method to fabricate lyophilized silk/agarose scaffolds with tunable features(mechanical property and pore structure)via controlling the gelation degree of silk fibroin and freezing-drying gels from different gelation degree.Sodium dodecyl sulfate(SDS)was utilized to accelerate the gelling process of silk with controllable rate.Agarose helped retain the shape of scaffolds after hydration and sterilization.Moreover,the scaffolds could be easily realized to desired shape for specific applications by shaping corresponding gels.The compressive modulus of scaffolds was tunable within a range of 18.6-58.8 kPa,and inner pore sizes could be tuned from 52.3 to 426.5 ?m.In vitro MC3T3-E1 cells proliferation indicated good biocompatibility of silk/agarose scaffolds.Alkaline phosphatase(ALP)activity assay and mineralization analysis indicated scaffolds with higher mechanical properties were more beneficial for bone tissue engineering.