Dually optimized polycaprolactone/collagen I microfiber scaffolds with stem cell capture and differentiation-inducing abilities promote bone regeneration

J Mater Chem B. 2019 Nov 28;7(44):7052-7064. doi: 10.1039/c9tb01359h. Epub 2019 Oct 23.

Abstract

Micro-nano based fibrous scaffolds have been extensively studied in regenerative medicine. Bone marrow stem cells (BMSCs) and BMP2-derived peptides, two other important components for tissue engineering, have been successfully used for bone regeneration. However, a scaffold that specifically captures BMSCs and delivers BMP2-derived peptides to promote osteogenic differentiation of enriched BMSCs has not been reported. In this study, a microfiber scaffold was constructed by coaxial electrospinning technology using a polyvinylpyrrolidone/bovine serum albumin/BMP2-derived peptide compound as the core solution and a polycaprolactone/collagen I compound as the shell solution. The scaffolds were further functionalized by covalent grafting of a BMSC affinity peptide (E7) to develop a dual drug release system for the delivery of the BMP2-derived peptide and E7. Structural analysis indicated that the microfibers had a uniform diameter and homogeneous core-shell structure. Fourier transform infrared spectroscopy (FTIR) revealed that E7 was covalently bonded onto the surface of the fibers. In vitro, the E7-modified scaffolds promoted the initial adhesion of BMSCs and were more favorable for BMSC survival. Furthermore, the BMP2-derived peptide loaded in the E7-modified scaffolds was released in a sustained manner and retained bioactivity, significantly improving the osteogenic differentiation of BMSCs. In vivo, scaffolds loaded with the BMP2-derived peptide and E7 (PCME scaffolds) led to enhanced new bone formation and defect closure in a rat calvarial defect model. Overall, the PCME scaffold simultaneously facilitated all three of the essential elements needed for bone tissue engineering, providing a promising method for bone regeneration.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Animals
  • Apatites / chemistry
  • Bone Marrow Cells / physiology*
  • Bone Regeneration*
  • Cell Adhesion
  • Cell Differentiation
  • Cell Proliferation
  • Collagen Type I / chemistry*
  • Gene Expression Regulation
  • Male
  • Microscopy, Electron, Scanning
  • Osteogenesis / physiology*
  • Polyesters / chemistry*
  • Rats
  • Rats, Sprague-Dawley
  • Stem Cells / physiology*
  • Tissue Scaffolds

Substances

  • Apatites
  • Collagen Type I
  • Polyesters
  • polycaprolactone