Page 110 - IJB-6-4

ORIGINAL ARTICLE

3D Printing of Anisotropic Bone-Mimetic Structure with

Controlled Fluid Flow Stimuli for Osteocytes: Flow

Orientation Determines the Elongation of Dendrites

Aira Matsugaki , Tadaaki Matsuzaka , Ami Murakami , Pan Wang , Takayoshi Nakano *
1
2
1
1
1
1 Division of Materials and Manufacturing Science, Graduate School of Engineering, Osaka University, 2-1 Yamada-oka,
Suita, Osaka 565-0871, Japan
2 Singapore Institute of Manufacturing Technology, 73 Nanyang Drive, 637662, Singapore
Abstract: Although three-dimensional (3D) bioprinting techniques enable the construction of various living tissues and
organs, the generation of bone-like oriented microstructures with anisotropic texture remains a challenge. Inside the
mineralized bone matrix, osteocytes play mechanosensing roles in an ordered manner with a well-developed lacunar-
canaliculi system. Therefore, control of cellular arrangement and dendritic processes is indispensable for construction
of artificially controlled 3D bone-mimetic architecture. Herein, we propose an innovative methodology to induce
controlled arrangement of osteocyte dendritic processes using the laminated layer method of oriented collagen sheets,
combined with a custom-made fluid flow stimuli system. Osteocyte dendritic processes showed elongation depending on
the competitive directional relationship between flow and substrate. To the best of our knowledge, this study is the first
to report the successful construction of the anisotropic bone-mimetic microstructure and further demonstrate that the
dendritic process formation in osteocytes can be controlled with selective fluid flow stimuli, specifically by regulating
focal adhesion. Our results demonstrate how osteocytes adapt to mechanical stimuli by optimizing the anisotropic
maturation of dendritic cell processes.
Keywords: Bioprinting, Collagen substrate, Mineralization, Osteocyte, 3D arrangement of bone matrix

*Corresponding Author: Takayoshi Nakano, Graduate School of Engineering, Osaka University, Osaka, Japan; nakano@mat.eng.osaka-u.ac.jp
Received: June 03, 2020; Accepted: June 25, 2020; Published Online: July 27, 2020

Citation: Matsugaki A, Matsuzaka T, Murakami A, et al., 2020, 3D Printing of Anisotropic Bone-Mimetic Structure with
Controlled Fluid Flow Stimuli for Osteocytes: Flow Orientation Determines the Elongation of Dendrites, Int J Bioprint, 6(4):
293. DOI: 10.18063/ijb.v6i4.293

1 Introduction two-dimensional (2D) cultures have limitations
in approaching the crosstalk among multiple
The highly ordered three-dimensional (3D) cell types in biomimetic niches. Development
microstructured bone matrix determines the of an appropriate 3D platform is critical for
specialized anisotropic bone function ; for the manufacturing of a functional bone tissue
[1]
example, the collagen/apatite bone matrix shows equivalent since a 3D environment is necessary
anisotropic texture depending on the anatomical for bone cell functionalization. In particular,
position, which realizes the mechanoadaptation of osteocytes are embedded in the mineralized matrix
bone tissue [2-4] . Although several approaches have with an ordered cell arrangement, surrounded
been made for the development of bone-mimetic by a networked lacunar-canaliculi system .
[8]
structures in vitro [5-7] , conventional monolayered Increasing evidence shows that osteocytes play

© 2020 Matsugaki, et al. This is an Open Access article distributed under the terms of the Creative Commons Attribution-NonCommercial 4.0 International
License (http://creativecommons.org/licenses/by-nc/4.0/), permitting all non-commercial use, distribution, and reproduction in any medium, provided the
original work is properly cited.
106