Bilayered silk/silk-nanoCaP scaffolds for osteochondral tissue engineering: In vitro and in vivo assessment of biological performance

Acta Biomater. 2015 Jan;12:227-241. doi: 10.1016/j.actbio.2014.10.021. Epub 2014 Oct 23.

Abstract

Novel porous bilayered scaffolds, fully integrating a silk fibroin (SF) layer and a silk-nano calcium phosphate (silk-nanoCaP) layer for osteochondral defect (OCD) regeneration, were developed. Homogeneous porosity distribution was achieved in the scaffolds, with calcium phosphate phase only retained in the silk-nanoCaP layer. The scaffold presented compressive moduli of 0.4MPa in the wet state. Rabbit bone marrow mesenchymal stromal cells (RBMSCs) were cultured on the scaffolds, and good adhesion and proliferation were observed. The silk-nanoCaP layer showed a higher alkaline phosphatase level than the silk layer in osteogenic conditions. Subcutaneous implantation in rabbits demonstrated weak inflammation. In a rabbit knee critical size OCD model, the scaffolds firmly integrated into the host tissue. Histological and immunohistochemical analysis showed that collagen II positive cartilage and glycosaminoglycan regeneration presented in the silk layer, and de novo bone ingrowths and vessel formation were observed in the silk-nanoCaP layer. These bilayered scaffolds can therefore be promising candidates for OCD regeneration.

Keywords: Bilayered scaffold; Calcium phosphate; Nanocomposite; Osteochondral regeneration; Silk fibroin.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Animals
  • Bone and Bones / physiology*
  • Calcium Phosphates / chemistry*
  • Cartilage / physiology*
  • In Vitro Techniques
  • Rabbits
  • Silk*
  • Tissue Engineering*
  • Tissue Scaffolds*
  • X-Ray Microtomography

Substances

  • Calcium Phosphates
  • Silk
  • calcium phosphate