Guided Regeneration of Rabbit Calvarial Defects Using Silk Fibroin Nanofiber-Poly(glycolic acid) Hybrid Scaffolds.

Bone tissue engineering aims to regenerate defected bones by combining cells, scaffolds, and growth factors. In general, defected bone tissues are treated with barrier membranes or guiding scaffolds to achieve bone restoration. However, the growth rate of bone tissue is slower than that of adjacent soft tissue. Therefore, we propose patient-customizable guided bone regeneration (GBR) and membrane-guided tissue regeneration (GTR) scaffold hybrid constructs for precise bone tissue restoration without dimensional collapse beyond the critical bone defect size. Silk fibroin (SF) nanofiber membranes and poly(glycolic acid) (PGA) scaffolds were fabricated using electrospinning and hot-melt additive manufacturing methods based on a computer-generated scaffold design. Their manipulation parameters, microstructures, compressive moduli, and biodegradability were investigated. The initial attachment and proliferation of preosteoblasts on a PGA scaffold were analyzed based on seeding efficiency and a 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide assay. The regenerated bone volumes of control and SF-PGA hybrid scaffolds were 14.8 and 21.4%, respectively, after 8 weeks of in vivo rabbit calvarial defect regeneration. The SF-PGA hybrid scaffold group exhibits greater regeneration of bone tissue than the control and PGA scaffold groups, indicating that this is a promising material combination as a GBR-GTR agent.