Silk fibroin micro-particle scaffolds with superior compression modulus and slow bioresorption for effective bone regeneration

Sci Rep. 2018 May 8;8(1):7235. doi: 10.1038/s41598-018-25643-x.

Abstract

Silk fibroin (SF), a natural polymer produced by Bombyx mori silkworms, has been extensively explored to prepare porous scaffolds for tissue engineering applications. Here, we demonstrate, a scaffold made of SF, which exhibits compression modulus comparable to natural cancellous bone while retaining the appropriate porosities and interconnected pore architecture. The scaffolds also exhibit high resistance to in-vitro proteolytic degradation due to the dominant beta sheet conformation of the SF protein. Additionally, the scaffolds are prepared using a simple method of microparticle aggregation. We also demonstrate, for the first time, a method to prepare SF micro-particles using a Hexafluoroisopropanol-Methanol solvent-coagulant combination. SF microparticles obtained using this method are monodisperse, spherical, non-porous and extremely crystalline. These micro-particles have been further aggregated together to form a 3D scaffold. The aggregation is achieved by random packing of these microparticles and fusing them together using a dilute SF solution. Preliminary in-vitro cell culture and in-vivo implantation studies demonstrate that the scaffolds are biocompatible and they exhibit the appropriate early markers, making them promising candidates for bone regeneration.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Animals
  • Biocompatible Materials / chemistry
  • Biocompatible Materials / pharmacology*
  • Bombyx
  • Bone Regeneration / drug effects*
  • Bone Regeneration / physiology
  • Cell Line
  • Cell Line, Tumor
  • Compressive Strength
  • Femur / diagnostic imaging
  • Femur / surgery
  • Fibroblasts / cytology
  • Fibroblasts / drug effects
  • Fibroins / chemistry
  • Fibroins / pharmacology*
  • Fibroins / ultrastructure
  • Methanol / chemistry
  • Mice
  • Osteoblasts / cytology
  • Osteoblasts / drug effects*
  • Porosity
  • Propanols / chemistry
  • Rabbits
  • Solvents / chemistry
  • Tissue Engineering / methods
  • Tissue Scaffolds*
  • Tomography, X-Ray Computed

Substances

  • Biocompatible Materials
  • Propanols
  • Solvents
  • hexafluoroisopropanol
  • Fibroins
  • Methanol