• Poster Talk
  • RF 04

3D-bioprinting of microfiber-laden bioinks for the fabrication tissue precursors with anisotropic material properties

Termin

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Lecture hall 7

Themen

  • Biofabrication
  • Tissue regeneration/regenerated medicine

Abstract

Abstract text (incl. figure legends and references)

Introduction: The artificial cultivation of biological tissues and organs has been a research goal in the field of regenerative medicine for many years. To mimic the complex structure of natural tissues, 3D-bioprinting techniques are a promising new field. Despite recent progress, however, supplying cells with oxygen and nutrients in macroscopic tissue precursors remains a challenge.

Objective: The aim of this work is to provide a biomimetic solution for the unmet nutrient supply gap in macroscopic tissues. This is to be achieved by incorporating either electro-spun fibers made of poly-caprolactone (PCL) (diameter 5-10 µm) or wet spun collagen fibers (diameter 5-20 µm) to increase passive diffusion as well as endothelial cell alignment.

Methods: The bioinks comprising an agarose hydrogel with either PCL or collagen fibers, were thoroughly characterized regarding topographical, mechanical, diffusional and swelling properties. 3D-bioprinting was tested via drop-on-demand printing as well as microextrusion printing to achieve in-situ alignment of the printed fibers. Cytocompatibility of the composite bioinks was tested using human umbilical vein endothelial cells (HUVECs).

Results: Rheological measurements showed slight shear thinning properties of all bioinks. Swelling of the bioinks at 37 °C was roughly doubled compared to the hydrogel without PCL fibers. In line with these results, the diffusion rate of PCL-laden hydrogel was increased by 26 %. All bioinks exhibited a significant fiber, when being microextruded. Interestingly, collagen fibers supported guided growth of HUVECs in the aligned direction. All applied fiber types did not show cytotoxic side-effects.

Conclusion: The presented study reveals that the addition of microfibers is an exciting platform technology for the biofabrication of tissue precursors. In combination with the 3D-bioprinting process, the orientation of the fibers also enables the tuning of anisotropic material behavior.