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International Journal of Bioprinting dECM bioink for 3D musculoskeletal tissue reg.

Table 1. Advantages and disadvantages of different bioprinting techniques
3D bioprinting technique Advantages Disadvantages
Inkjet-based 46-49,63 Simple; low-cost; high throughput; high Low cell density; low-viscosity bioinks
resolution (10–100 μm); high cell viability (>90%) (3.5–12 mPa/s)
Extrusion-based 38,64,65 Printable with high-viscosity bioinks Low printing speed; low printing resolution
(6–30 × 10 mPa/s); applicable for multi-material (200–1000 μm)
7
bioprinting; simple
Laser-assisted 20,58,66,67 High cell viability (>95%); wide viscosity range High-cost; complex system
(1–300 mPa/s); high-throughput
Stereolithography apparatus (SLA) and High cell viability (>85%); wide variety of Bioink must be transparent; complex system
digital light processing (DLP)-based 68,69 bioinks; high resolution

bioinks to ensure uniform crosslinking. Furthermore, cell migration. Additionally, structural remodeling of
8
bioprinting accuracy and precision depend on factors ECM can form orientation or “highways” to facilitate
such as laser power, exposure time, scanning speed, and cell movement and subsequently affect cell migration.
laser wavelength. 62 In skeletal muscles, the ECM plays a crucial role by
providing a fundamental framework that supports
3. Extracellular matrix composition muscle fibers, capillaries, and nerve supplies. Likewise,
and function the ECM’s structural integrity is essential for the optimal
functioning of muscle tissue. 79
3.1. Components
The tissue’s cellular and noncellular components interlace to 3.2.2. Biochemical signals
form a durable composite structure. 70,71 The ECM is densely The ECM affects various cellular life activities, such as
concentrated with biomacromolecules synthesized and adhesion, proliferation, migration, differentiation, and
secreted by cells, including collagen, laminin (LN), elastin, homing, by binding and interacting with transmembrane
glycosaminoglycan, and a variety of cytokines. These ECM receptors. 80–82 ECM proteins, such as FN, collagen, and
components collectively or individually influence cellular proteoglycan (PG), can enhance the binding between
behavior. The ECM forms a 3D polymer network on cell cellular receptors and their growth factor ligands. 83,84 For
surfaces and between cells, facilitating cell interactions instance, myogenic cells multiply and remain undifferentiated
through membrane receptors like integrins. 72,13 ECM when exposed to FN. Conversely, these cells differentiate and
features high biodegradability, minimal immunogenicity, fuse to form myotubes when exposed to LN. 85
excellent biocompatibility, and a moderating effect on
inflammatory responses. Moreover, ECM is commonly 3.2.3. Biomechanical signals
Under different developmental and physiological
used as a scaffold material in regenerative medicine for conditions, the biomechanical properties of the ECM vary
its ability to support tissue regeneration and guide tissue greatly depending on its composition and topography.
repair effectively. 73–76
Elasticity of the ECM can vary widely, ranging from soft
3.2. Biological roles of the extracellular matrix and pliable to stiff and rigid. This variability significantly
impacts cell behavior and tissue function. For example,
3.2.1. Structural support adipose tissue is soft; muscles are relatively compliant;
The ECM provides cells with a porous 3D structure for and bones are stiff and rigid. The ECM can transmit
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cell adhesion, growth, and differentiation. Collagen mechanical signals by direct cellular binding or regulating
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and fibronectin (FN) in the ECM provide the necessary GFs and cytokines. 87,88 Likewise, an increase in matrix
physical strength and elasticity for cells to maintain their stiffness tends to enhance the osteogenic differentiation
morphology and facilitate migration. The stiffness, of mesenchymal stem cells (MSCs), whereas soft matrices
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porosity, and insolubility of ECM largely determine the tend to induce chondrogenesis and adipogenesis. Studies
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tissue structure and integrity and cell behavior within have demonstrated that applying cyclic uniaxial and
it. Studies have indicated that the ultrastructure and circumferential tensile strains to derivatives of human
mechanics of the ECM can affect cell behavior, migration, pluripotent stem cells-vascular smooth muscle cells
and differentiation. Tightly woven fibrin networks, such (hPSCs-vSMCs) can induce cell alignment and impact the
as basement membranes, form an apparent barrier for expression of ECM genes in vitro. 90

Volume 10 Issue 5 (2024) 72 doi: 10.36922/ijb.3418