Rapid 3D printing of anatomically accurate and mechanically heterogeneous aortic valve hydrogel scaffolds

Biofabrication. 2012 Sep;4(3):035005. doi: 10.1088/1758-5082/4/3/035005. Epub 2012 Aug 23.

Abstract

The aortic valve exhibits complex three-dimensional (3D) anatomy and heterogeneity essential for the long-term efficient biomechanical function. These are, however, challenging to mimic in de novo engineered living tissue valve strategies. We present a novel simultaneous 3D printing/photocrosslinking technique for rapidly engineering complex, heterogeneous aortic valve scaffolds. Native anatomic and axisymmetric aortic valve geometries (root wall and tri-leaflets) with 12-22 mm inner diameters (ID) were 3D printed with poly-ethylene glycol-diacrylate (PEG-DA) hydrogels (700 or 8000 MW) supplemented with alginate. 3D printing geometric accuracy was quantified and compared using Micro-CT. Porcine aortic valve interstitial cells (PAVIC) seeded scaffolds were cultured for up to 21 days. Results showed that blended PEG-DA scaffolds could achieve over tenfold range in elastic modulus (5.3±0.9 to 74.6±1.5 kPa). 3D printing times for valve conduits with mechanically contrasting hydrogels were optimized to 14 to 45 min, increasing linearly with conduit diameter. Larger printed valves had greater shape fidelity (93.3±2.6, 85.1±2.0 and 73.3±5.2% for 22, 17 and 12 mm ID porcine valves; 89.1±4.0, 84.1±5.6 and 66.6±5.2% for simplified valves). PAVIC seeded scaffolds maintained near 100% viability over 21 days. These results demonstrate that 3D hydrogel printing with controlled photocrosslinking can rapidly fabricate anatomical heterogeneous valve conduits that support cell engraftment.

Publication types

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

MeSH terms

  • Alginates / chemistry
  • Animals
  • Aortic Valve / anatomy & histology*
  • Aortic Valve / cytology
  • Biocompatible Materials / chemistry
  • Cell Survival
  • Cells, Cultured
  • Elastic Modulus
  • Glucuronic Acid / chemistry
  • Hexuronic Acids / chemistry
  • Hydrogel, Polyethylene Glycol Dimethacrylate / chemistry*
  • Polyethylene Glycols / chemistry
  • Swine
  • Tissue Engineering
  • Tissue Scaffolds / veterinary*

Substances

  • Alginates
  • Biocompatible Materials
  • Hexuronic Acids
  • poly(ethylene glycol)diacrylate
  • Hydrogel, Polyethylene Glycol Dimethacrylate
  • Polyethylene Glycols
  • Glucuronic Acid