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International Journal of Bioprinting 3D bioprinting for musculoskeletal system

MSDs affect 1.7 billion people and have become the can effectively replicate desired mechanical characteristics
leading cause of morbidity worldwide according to the and structures. 3D bioprinting allows for the precise and
Global Burden of Disease Study. Moreover, the incidence controlled spatial arrangement of cells in 3D scaffold
1,2
of MSDs shows an increasing trend with the aging of the materials. The development of increasingly sophisticated
population. In the United States, for example, there are and biomimetic tissue-engineered analogues holds the
at least 70 million clinic visits and 130 million clinical promise for producing patient-derived functional grafts as
contacts for MSDs each year, resulting in more than $150 well as clinically predictive drug testing tools. Therefore,
billion in the national healthcare system costs. Mild it is an emerging strategy of constructing tissues for
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MSDs can be addressed with physical therapy or drug musculoskeletal regeneration, disease modeling, and drug
intervention. Severe MSDs, on the other hand, require development by 3D bioprinting.
surgical reconstruction. Autograft represents the gold In this review, we provide a concise review of 3D
standard for the treatment of severe MSDs, but is limited bioprinting, including several common 3D bioprinting
by donor site scarcity, morbidity, and pain. Allografts and techniques and bioinks. The application of these techniques
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xenografts are feasible alternatives, although concerns in musculoskeletal tissue regeneration is highlighted.
regarding immunological incompatibility, rejection risk, Following that, recent advances of 3D bioprinting for
and infectious agent transmission remain. Therefore, novel musculoskeletal disease modeling and drug screening are
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approaches to regenerating damaged musculoskeletal
tissues are urgently needed. summarized. Finally, we discuss the existing challenges and
future perspectives of 3D bioprinting for musculoskeletal
Tissue engineering enables the creation of viable regeneration and disease modeling.
scaffolds for the regeneration of damaged tissues. Since
the beginning, tissue engineering has the prospect of 2. Brief overview of 3D bioprinting
generating tissues for a variety of purposes, ranging from
in vitro disease modeling to in vivo tissue regeneration. 3D bioprinting is the process of patterning and assembling
Tissue-engineered scaffolds provide a hospitable bioactive materials, such as growth factors, cells, and
microenvironment for cell adhesion, spreading, biomaterials based on predefined 3D designs, leading to the
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proliferation, migration, and differentiation. Moreover, the creation of a functional tissue construct. 3D bioprinting
addition of bioactive molecules, such as drugs or growth technology is a subclass of 3D printing technology that
factors, can further enhance the ability of scaffolds to is primarily used in the biomedical field. Traditional 3D
promote cell differentiation and induce the formation of printing often uses plastic or alloy materials for printing,
target tissues. However, generating tissues that precisely whereas the materials used in 3D bioprinting are called
mimic the structural and functional features of native bioinks, which consist of living cells alone or together with
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tissues remain unattainable in musculoskeletal tissue supporting biomaterials such as hydrogels. The major
engineering, despite the promising translational potential advantage of 3D bioprinting over other approaches, such
of tissue engineering approaches. This is primarily due to as microengineering and cell sheet engineering, is its
the fact that conventional manufacturing technologies lack ability to create spatially complex and heterogeneous tissue
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the ability to accurately regulate the spatial arrangement of constructs consisting of cells and/or various biomaterials.
construction elements. Furthermore, while spontaneous Through 3D bioprinting, diverse cells and biomaterials
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cellular organization processes can build certain types of can be localized to replicate the structural complexity
fundamental biostructures, they are extremely difficult to of tissues. The 3D bioprinting process can be achieved
regulate and manage. Few technologies have so far been through different technologies and each technique is based
able to reconstruct the complex tissue architecture and on its own principles and has distinct requirements for the
cell spatial heterogeneity, which are required to mimic the materials to be used. Therefore, bioinks and bioprinting
physiologic function. techniques need to be attuned to each other. The following
is a brief introduction to several common 3D bioprinting
Recently, three-dimensional (3D) bioprinting is technologies and bioinks.
applied in a variety of biomedical scenes, such as tissue
engineering, disease modeling, and drug screening. 2.1. Bioprinting technologies
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Compared with traditional tissue engineering approaches, 3D bioprinting technologies create functional tissue
3D bioprinting has several advantages, such as determining constructs based on the principles of layer-by-layer
tissue form prior to printing, and acts as a bridge to clinical stacking and consistent self-assembly. According to
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application. The advancement of 3D bioprinting has the adopted bioprinting techniques, these layers can be
substantially expanded the field of musculoskeletal tissue integrated by different means, such as heat, light radiation,
engineering by allowing the development of scaffolds that and chemical crosslinking. The current mainstream 3D

Volume 10 Issue 1 (2024) 76 https://doi.org/10.36922/ijb.1037