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

Abstract

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.

The Blending of Poly(glycolic acid) with Polycaprolactone and Poly(l-lactide): Promising Combinations

“…Although the aforementioned PGA characteristics make the polymer suitable for high-end applications, such as packaging, electronics, and automobile, so far, it has been mainly used in the biomedical field [ 18 , 19 , 20 ]. The main challenge of the application of PGA is related to its high production cost.…”

Development of Hybrid Materials Based on Polymers for Biomedical Applications: A Short Introduction

“…Kim et al reported the fabrication of silk fibroin (SF) nanofiber membranes and PGA hybrid scaffolds by electrospinning and 3D printing for their use as guided bone tissue regeneration. SF-PGA scaffolds exhibited superior bone volume regeneration compared to scaffolds without nanofiber membranes [88].…”

Poly(glycolic acid) (PGA): a versatile building block expanding high performance and sustainable bioplastic applications

“… Scaffolds exhibited co-continuous morphologies with the porosity of ~50 %. Silk fibroin and PGA 121 Bone regeneration  Silk fibroin membranes and PGA based scaffolds prepared by combining electrospinning and hot-melt additive manufacturing.  Within eight weeks, in-vivo rabbit calvarial defect regeneration was achieved.…”