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REVIEW ARTICLE

Bio-assembling and Bioprinting for Engineering

Microvessels from the Bottom Up

Xiaoming Liu *, Tao Yue , Masaru Kojima , Qiang Huang *, Tatsuo Arai 1,5
1
2,3
1
4
1 Key Laboratory of Biomimetic Robots and Systems, Ministry of Education, State Key Laboratory of Intelligent Control
and Decision of Complex System, Beijing Advanced Innovation Center for Intelligent Robots and Systems, and School of
Mechatronical Engineering, Beijing Institute of Technology, Beijing 100081, China
2 School of Mechatronic Engineering and Automation, Shanghai University, Shanghai 200444, China
3 Shanghai Institute of Intelligent Science and Technology, Tongji University, Shanghai 200092, China
4 Department of Materials Engineering Science, Osaka University, Osaka 5608531, Japan
5 Center for Neuroscience and Biomedical Engineering, the University of Electro-Communications, Tokyo 1828585, Japan.

Abstract: Blood vessels are essential in transporting nutrients, oxygen, metabolic wastes, and maintaining the homeostasis of
the whole human body. Mass of engineered microvessels is required to deliver nutrients to the cells included in the constructed
large three-dimensional (3D) functional tissues by diffusion. It is a formidable challenge to regenerate microvessels and build
a microvascular network, mimicking the cellular viabilities and activities in the engineered organs with traditional or existing
manufacturing techniques. Modular tissue engineering adopting the “bottom-up” approach builds one-dimensional (1D) or
two-dimensional (2D) modular tissues in micro scale first and then uses these modules as building blocks to generate large
tissues and organs with complex but indispensable microstructural features. Building the microvascular network utilizing this
approach could be appropriate and adequate. In this review, we introduced existing methods using the “bottom-up” concept
developed to fabricate microvessels including bio-assembling powered by different micromanipulation techniques and
bioprinting utilizing varied solidification mechanisms. We compared and discussed the features of the artificial microvessels
engineered by these two strategies from multiple aspects. Regarding the future development of engineering the microvessels
from the bottom up, potential directions were also concluded.
Keywords: Microvessels; Bio-assembling; Bioprinting; Bottom-up; Tissue engineering

*Correspondence to: Xiaoming Liu, School of Mechatronical Engineering, Beijing Institute of Technology, Beijing 100081, China; liuxiaoming555@
bit.edu.cn; Qinag Huang, School of Mechatronical Engineering, Beijing Institute of Technology, Beijing 100081;qhuang@bit.edu.cn
Received: April 7, 2021; Accepted: May 7, 2021; Published Online: June 11, 2021
(This article belongs to the Special Section: Bioprinting of 3D Functional Tissue Constructs)

Citation: Liu, X, Yue, T, Kojima, M, et al., 2021, Bioassembling and Bioprinting for Engineering Microvessels from the
Bottom Up. Int J Bioprint. 7(3):366. http://doi.org/10.18063/ijb.v7i3.366

1. Introduction molecules, and organic materials . In the past two
[4]
decades, significant advances have been achieved in
Tissues such as bone and skin have the ability to repair tissue engineering. Many different kinds of tissues have
slight injuries by themselves [1-3] . However, many serious
tissue injuries and multiple organ failures can hardly been fabricated, but most of these engineered tissues
[9,10]
be effectively cured by conventional interventional, feature thin slices and simple architectures . The main
pharmacological, and surgical therapies, except organ reason is the challenges in including the microvascular
[11]
transplantation [4-6] . Unfortunately, organ transplantation networks in the large functional regenerated tissues .
in the clinic is greatly limited by the shortage of Blood vessels are essential in transporting
donors [7,8] . Tissue engineering was introduced by Langer nutrients, oxygen, metabolic wastes, and maintaining the
30 years before targeting to build artificial functional homeostasis of the whole human body. Mass of engineered
tissue substitutes through combining specific cell lines, microvessels is required to deliver nutrients to the cells
© 2021 Liu, et al. This is an Open Access article distributed under the terms of the Creative Commons Attribution License (https://creativecommons. org/
licenses/by/4.0/), permitting distribution and reproduction in any medium, provided the original work is cited.
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