Fibroin Scaffold Repairs Critical-Size Bone Defects <i>In Vivo</i> Supported by Human Amniotic Fluid and Dental Pulp Stem Cells

TLDR

The study compared fibroin scaffolds seeded with dental pulp stem cells or amniotic fluid stem cells for repairing critical‑size cranial bone defects in immunocompromised rats. Rats received two full‑thickness parietal defects filled with silk fibroin scaffolds, with or without pre‑seeded stem cells directed toward osteogenesis, and after four weeks were euthanized for histology and confocal confirmation of human cells. The scaffolds promoted mature bone formation and defect closure, with hAFSC‑seeded constructs yielding more bone, demonstrating the strong potential of stem‑cell/fibroin bioengineered constructs for large cranial defect repair and suggesting promise for human craniofacial surgery.

Abstract

The main aim of this study was the comparative evaluation of fibroin scaffolds combined with human stem cells, such as dental pulp stem cells (hDPSCs) and amniotic fluid stem cells (hAFSCs), used to repair critical-size cranial bone defects in immunocompromised rats. Two symmetric full-thickness cranial defects on each parietal region of rats have been replenished with silk fibroin scaffolds with or without preseeded stem cells addressed toward osteogenic lineage in vitro. Animals were euthanized after 4 weeks postoperatively and cranial tissue samples were taken for histological analysis. The presence of human cells in the new-formed bone was confirmed by confocal analysis with an antibody directed to a human mitochondrial protein. Fibroin scaffolds induced mature bone formation and defect correction, with higher bone amount produced by hAFSC-seeded scaffolds. Our findings demonstrated the strong potential of stem cells/fibroin bioengineered constructs for correcting large cranial defects in animal model and is likely a promising approach for the reconstruction of human large skeletal defects in craniofacial surgery.