Non-mulberry silk fibroin grafted poly (Є-caprolactone)/nano hydroxyapatite nanofibrous scaffold for dual growth factor delivery to promote bone regeneration

J Colloid Interface Sci. 2016 Jun 15:472:16-33. doi: 10.1016/j.jcis.2016.03.020. Epub 2016 Mar 12.

Abstract

Hypothesis: This study aims at developing biodegradable, mineralized, nanofibrous scaffolds for use in bone regeneration. Scaffolds are loaded with combinations of bone morphogenic protein-2 (rhBMP-2) and transforming growth factor beta (TGF-β) and evaluated in vitro for enhancement in osteoinductivity.

Experiments: Poly(Є-caprolactone) (PCL) doped with different portions of nano-hydroxyapatite is electrospun into nanofibrous scaffolds. Non-mulberry silk fibroin (NSF) obtained from Antheraea mylitta is grafted by aminolysis onto them. Scaffolds prepared have three concentrations of nano-hydroxyapatite: 0% (NSF-PCL), 25% (NSF-PCL/n25), and 50% (NSF-PCL/n50). Growth factor loading is carried out in three different combinations, solely rhBMP-2 (BN25), solely TGF-β (TN25) and rhBMP-2+TGF-β (T/B N25) via carbodiimide coupling.

Findings: NSF-PCL/n25 showed the best results in examination of mechanical properties, bioactivity, and cell viability. Hence only NSF-PCL/n25 is selected for loading growth factors and subsequent detailed in vitro experiments using MG-63 cell-line. Both growth factors show sustain release kinetics from the matrix. The T/B N25 scaffolds support cellular activity, proliferation, and triggering of bone-associated genes' expression better and promote earlier cell differentiation. Dual growth factor loaded NSF grafted electrospun PCL/nHAp scaffolds show promise for further development into a suitable scaffold for bone tissue engineering.

Keywords: Aminolysis; Bone tissue engineering; Growth factor; Nonmulberry silk fibroin; Poly (Є-caprolactone).

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Animals
  • Bombyx / chemistry
  • Bone Morphogenetic Protein 2 / administration & dosage*
  • Bone Morphogenetic Protein 2 / pharmacology
  • Bone Regeneration / drug effects
  • Cell Line
  • Delayed-Action Preparations / chemistry
  • Drug Delivery Systems
  • Durapatite / chemistry*
  • Fibroins / chemistry*
  • Humans
  • Nanofibers / chemistry*
  • Nanofibers / ultrastructure
  • Osteoblasts / cytology
  • Osteoblasts / drug effects
  • Osteoblasts / metabolism
  • Osteogenesis / drug effects
  • Polyesters / chemistry*
  • Tissue Engineering
  • Tissue Scaffolds / chemistry*
  • Transforming Growth Factor beta / administration & dosage*
  • Transforming Growth Factor beta / pharmacology

Substances

  • BMP2 protein, human
  • Bone Morphogenetic Protein 2
  • Delayed-Action Preparations
  • Polyesters
  • Transforming Growth Factor beta
  • polycaprolactone
  • Fibroins
  • Durapatite