To explore the modification of bionic silk fibroin nerve conduits (SF-NCs) by silk sericin.

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.

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.

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.

Nerve guidance conduits (NCs); Silk sericin/silk fibroin (SS/SF) blended; Bionic; Modification; Peripheral nerve