Bioactivity of porous biphasic calcium phosphate enhanced by recombinant human bone morphogenetic protein 2/silk fibroin microsphere

J Mater Sci Mater Med. 2014 Jul;25(7):1709-19. doi: 10.1007/s10856-014-5194-4.

Abstract

To prepare a bioactive bone substitute, which integrates biphasic calcium phosphate (BCP) and rhBMP-2/silk fibroin (SF) microsphere, and to evaluate its characteristics. Hydroxyapatite and β-tricalcium phosphate were integrated with a ratio of 60–40%. RhBMP-2/SF (0.5 μg/1 mg) microsphere was prepared, and its rhBMP-2-release kinetics was assed. After joining pore-forming agent (Sodium chloride, NaCl), porous BCP/rhBMP-2/SF were manufactured, and its characteristics and bioactivity in vitro were evaluated. Mean diameter of rhBMP-2/SF microsphere was 398.7 ± 99.86 nm, with a loading rate of 4.53 ± 0.08%. RhBMP-2 was released in a dual-phase pattern, of which fast-release (nearly half of protein released) focused on the initial 3 days, and slow-release sustained more than 28 days. With the increase in concentration of NaCl, greater was porosity and pore size, but smaller mechanical strength of BCP/rhBMP-2/SF. Material with 150% (w/v) NaCl had an optimal performance, with a porosity of 78.83%, pore size of 293.25 ± 42.77μm and mechanical strength of 31.03 MPa. Proliferation of human placenta-derived mesenchymal stem cells (hPMSCs) on leaching extract medium was similar to the normal medium (P = 0.89), which was better than that on control group (P = 0.03). Activity of alkaline phosphatase on BCP/rhBMP-2/SF surface was higher than on pure BCP at each time point except at 1 day (P < 0.05). RhBMP-2 has a burst release on early times and a sustaining release on later times. BCP/rhBMP-2/SF with 150% (w/v) pore-forming agent has excellent porosity, pore size and mechanical strength. The biomaterial induces proliferation and differentiation hPMSCs effectively.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Animals
  • Biocompatible Materials / chemistry
  • Bombyx
  • Bone Morphogenetic Protein 2 / chemistry*
  • Bone and Bones / metabolism
  • Calcium Phosphates / chemistry*
  • Cell Adhesion
  • Cell Differentiation
  • Cell Proliferation
  • Cells, Cultured
  • Durapatite / chemistry
  • Female
  • Fibroins / chemistry*
  • Humans
  • Kinetics
  • Mesenchymal Stem Cells / cytology
  • Microscopy, Electron, Scanning
  • Microspheres*
  • Placenta / metabolism
  • Porosity
  • Pregnancy
  • Recombinant Proteins / chemistry
  • Sodium Chloride / chemistry
  • Stress, Mechanical
  • Time Factors
  • Transforming Growth Factor beta / chemistry*

Substances

  • Biocompatible Materials
  • Bone Morphogenetic Protein 2
  • Calcium Phosphates
  • Recombinant Proteins
  • Transforming Growth Factor beta
  • beta-tricalcium phosphate
  • recombinant human bone morphogenetic protein-2
  • Sodium Chloride
  • Fibroins
  • Durapatite
  • calcium phosphate