The functional regulation of protein composite nanofibers on human astrocyte for neural regeneration.

Collagen is an extracellular matrix molecule, and soy protein can potentially modulate neural immune activity. Nanofiber scaffolds fabricated from collagen and soy protein may enhance the neural repair process by conducting neural growth and regulating the immune response of neural tissue. Studies have reported that transplantation of fetal astrocytes may stimulate axonal regeneration and functional recover after spinal cord injury. Nanofibers may act as a matrix carrier for cell transplantation to enhance cell therapy. In this study, we fabricated nanofibers by collagen, soy protein isolate (SPI), and polycaprolactone (PCL) using electrospinning. The nanofibers were characterized by scanning electron microscopy (SEM), Fourier transform infrared (FTIR) spectroscopy, and contact angle assays. Human fetal astrocytes showed high viability on the nanofibers. Flow cytometry analysis showed that the SPI component in collagen/SPI/PCL nanofibers does not affect the cell cycle compared with the collagen/PCL nanofibers. The aligned fibers showed clear guidance for cell migration along the fibers. RNA-sequencing analysis revealed that the "neurodegeneration" and "antigen processing and presentation" pathways are enriched in down-regulated genes including IL1B, IL6, HLA-B, HLA-DMB, HLA-DPA1, and HLA-DRA for the cells on collagen/SPI/PCL fibers compared with collagen/PCL fibers. The "focal adhesion" pathway is enriched in up-regulated genes including COL4A1, COL4A2, FN1, LAMB1, LAMB2, AKT2, RAC1, RAC2, ROCK2, and PIP5K1A. These results suggest that SPI may regulate the cell immune response and cell adhesion and motility in the neural repair process.