Functionally graded electrospun scaffolds with tunable mechanical properties for vascular tissue regeneration

Biomed Mater. 2007 Dec;2(4):224-32. doi: 10.1088/1748-6041/2/4/004. Epub 2007 Oct 8.

Abstract

Electrospun tubular scaffolds (4 mm inner diameter) based on bio-artificial blends of polyglyconate (Maxon) and proteins such as gelatin and elastin having a spatially designed multilayer structure were prepared for use as vascular tissue scaffolds. Scanning electron microscopy analysis of scaffolds showed a random nanofibrous morphology with fiber diameter in the range of 200-400 nm for protein-blended Maxon, which mimics the nanoscale dimensions of collagen (50-500 nm). The scaffolds have a well interconnected pore structure and porosity up to 82%, with protein blending and multi-layering in contrast to electrospun Maxon scaffolds (67%). Fourier-transform infrared spectroscopy, x-ray diffraction and differential scanning calorimetry results confirmed the blended composition and crystallinity of fibers. Uniaxial tensile testing revealed a strength of 14.46 +/- 0.42 MPa and a modulus of 15.44 +/- 2.53 MPa with a failure strain of 322.5 +/- 10% for a pure Maxon scaffold. The blending of polyglyconate with biopolymers decreased the tensile properties in general, with an exception of the tensile modulus (48.38 +/- 2 MPa) of gelatin/Maxon mesh, which was higher than that of the pure Maxon scaffold. Trilayered tubular scaffolds of gelatin/elastin, gelatin/elastin/Maxon and gelatin/Maxon (GE-GEM-GM) that mimic the complex trilayer matrix structure of natural artery have been prepared by sequential electrospinning. Tensile testing under dry conditions revealed a tensile strength of 2.71 +/- 0.2 MPa and a modulus of 20.4 +/- 3 MPa with a failure strain of 140 +/- 10%. However, GE-GEM-GM scaffolds tested under wet conditions after soaking in a phosphate buffered saline medium at 37 degrees C for 24 h exhibited mechanical properties (2.5 MPa tensile strength and 9 MPa tensile modulus) comparable to those of native femoral artery.

Publication types

  • Research Support, Non-U.S. Gov't
  • Research Support, U.S. Gov't, Non-P.H.S.

MeSH terms

  • Biocompatible Materials / chemistry*
  • Bioprosthesis*
  • Blood Vessel Prosthesis*
  • Blood Vessels / cytology
  • Blood Vessels / growth & development*
  • Crystallization / methods
  • Elasticity
  • Electrochemistry / methods
  • Extracellular Matrix Proteins / chemistry*
  • Materials Testing
  • Polymers / chemistry*
  • Regeneration / physiology*
  • Rotation
  • Stress, Mechanical
  • Tensile Strength

Substances

  • Biocompatible Materials
  • Extracellular Matrix Proteins
  • Polymers
  • polyglyconate