Page 71 - IJB-9-1

International Journal of Bioprinting

RESEARCH ARTICLE
Osteoconductivity of bone substitutes with

filament-based microarchitectures: Influence of
directionality, filament dimension, and distance

Julien Guerrero , Chafik Ghayor , Indranil Bhattacharya , Franz E. Weber *
1,2
1
1
1
1 Center of Dental Medicine, Oral Biotechnology & Bioengineering, University of Zurich, 8032 Zurich,
Switzerland
2 CABMM, Center for Applied Biotechnology and Molecular Medicine, University of Zurich, 8057
Zurich, Switzerland
(This article belongs to the Special Issue: 3D Printing in Tissue Engineering)

Abstract

Additive manufacturing can be applied to produce personalized bone substitutes.
At present, the major three-dimensional (3D) printing methodology relies on fila-
ment extrusion. In bioprinting, the extruded filament consists mainly of hydrogels,
in which growth factors and cells are embedded. In this study, we used a lithogra-
phy-based 3D printing methodology to mimic filament-based microarchitectures
by varying the filament dimension and the distance between the filaments. In the
first set of scaffolds, all filaments were aligned toward bone ingrowth direction. In a
second set of scaffolds, which were derived from the identical microarchitecture but
tilted by 90°, only 50% of the filaments were in line with the bone ingrowth direction.
Testing of all tricalcium phosphate-based constructs for osteoconduction and bone
*Corresponding author:
Franz E. Weber regeneration was performed in a rabbit calvarial defect model. The results revealed
(franz.weber@zzm.uzh.ch) that if all filaments are in line with the direction of bone ingrowth, filament size and
distance (0.40–1.25 mm) had no significant influence on defect bridging. Howev-
Citation: Guerrero J, Ghayor C,
Bhattacharya I, et al., 2023, er, with 50% of filaments aligned, osteoconductivity declined significantly with an
Osteoconductivity of bone increase in filament dimension and distance. Therefore, for filament-based 3D- or
substitutes with filament-based bio-printed bone substitutes, the distance between the filaments should be 0.40 to
microarchitectures: Influence of
directionality, filament dimension, and 0.50 mm irrespective of the direction of bone ingrowth or up to 0.83 mm if perfectly
distance. Int J Bioprint, 9(1): 626. aligned to it.
https://doi.org/10.18063/ijb.v9i1.626
Received: June 01, 2022
Accepted: September 21, 2022 Keywords: Cranioplasty; Three-dimensional printing; Additive manufacturing; Poly-
Published Online: October 27, ether-ether-ketone; Fused filament fabrication
2022
Copyright: © 2022 Author(s).
This is an Open Access article
distributed under the terms of the 1. Introduction
Creative Commons Attribution
License, permitting distribution Additive manufacturing, in contrast to subtractive methodologies, creates object
and reproduction in any medium,
provided the original work is layer-by-layer and allows the production of objects with so far unreached designs,
properly cited. particularly their microarchitecture. Microarchitecture describes the distribution of
Publisher’s Note: Whioce the material in the macroarchitecture. The latter is the overall shape of the object and
Publishing remains neutral with in context of personalized bone substitutes, it matches exactly the missing piece of the
regard to jurisdictional claims in patient’s bone . Nanoarchitecture, as third level of architecture, is characterized by
[1]
published maps and institutional
affiliations. the surface morphology and microporosity in the material phase, both mainly but not

Volume 9 Issue 1 (2023) 63 https://doi.org/10.18063/ijb.v9i1.626