ABSTRACT
Objective To explore the modification of bionic silk fibroin nerve conduits (SF-NCs) by silk sencin.Methods The innovative SS/SF blended-NCs was fabricated by a vertical sequential cooling thermal induced phase separation (TIPS) processing with SF solution added sericin in proportion,its morphology was observed by Scanning electron microscopy (SEM),X-ray diffraction (XRD) and infrared spectroscopy (FTIR) were used to detect its internal molecular structure.MTT assay was used to quantitatively analyzed the PC12 cells viability co-cultured with the innovative SS/SF-NCs,SEM was used to observe the adhesion and morphology of PC12 cells seeded into the innovative SS/SF,PC12 cells were used to assess the NGF bioactivity released from the SS/SF.Results The SEM results showed that the new fabricated SS/SF-NCs had linearly oriented lamellar-like multiple-channel which distributed evenly,got great changes on the channel microstructure and their mechanical properties had been greatly improved,compared to SF-NCs.The XRD and FTIR results showed that the SS/SF-NCs had the similar internal molecular structure with natural silk.The spaces between parallel lamellar-like channels,porosities and compressive strengths of the SS/SF-NCs decreased with decreasing Sequential freezing temperature.MTT assay results showed that the viability of PC12 cell was better than the control group (P ＜ 0.05).The SEM observation indicated that PC12 cells showed good adhesion and differentiation with neuritis outgrowth during the period of co-culture with the SS/SF-NCs.NGF release from the innovative SS/SF-NCs was prolonged over 4 weeks,and remained bioactive.Conclusion The new fabricated SS/SF-NCs modified though silk sericin,which was highly bionic the structure of peripheral nerve fasciculus,had excellent mechanical properties and could be used as another alternative of artificial nerve conduits.