Limits...
Engineering Muscle Networks in 3D Gelatin Methacryloyl Hydrogels: Influence of Mechanical Stiffness and Geometrical Confinement

View Article: PubMed Central - PubMed

ABSTRACT

In this work, the influence of mechanical stiffness and geometrical confinement on the 3D culture of myoblast-laden gelatin methacryloyl (GelMA) photo-crosslinkable hydrogels was evaluated in terms of in vitro myogenesis. We formulated a set of cell-laden GelMA hydrogels with a compressive modulus in the range 1 ÷ 17 kPa, obtained by varying GelMA concentration and degree of cross-linking. C2C12 myoblasts were chosen as the cell model to investigate the supportiveness of different GelMA hydrogels toward myotube formation up to 2 weeks. Results showed that the hydrogels with a stiffness in the range 1 ÷ 3 kPa provided enhanced support to C2C12 differentiation in terms of myotube number, rate of formation, and space distribution. Finally, we studied the influence of geometrical confinement on myotube orientation by confining cells within thin hydrogel slabs having different cross sections: (i) 2,000 μm × 2,000 μm, (ii) 1,000 μm × 1,000 μm, and (iii) 500 μm × 500 μm. The obtained results showed that by reducing the cross section, i.e., by increasing the level of confinement—myotubes were more closely packed and formed aligned myostructures that better mimicked the native morphology of skeletal muscle.

No MeSH data available.


Related in: MedlinePlus

Scheme of the micromolding process for the fabrication of gelatin methacryloyl (GelMA) hydrogels: a U-shaped glass capillary is embedded within the hydrogel to act as a supporting frame for the hydrogel strings having different cross sections.
© Copyright Policy
Related In: Results  -  Collection

License
getmorefigures.php?uid=PMC5383707&req=5

Figure 4: Scheme of the micromolding process for the fabrication of gelatin methacryloyl (GelMA) hydrogels: a U-shaped glass capillary is embedded within the hydrogel to act as a supporting frame for the hydrogel strings having different cross sections.

Mentions: The first propaedeutic experiment evidenced a clear correlation between matrix stiffness and the ability of myoblasts to undergo efficiently myogenesis. Results showed that the best candidates were those at lower GelMA concentration (3 and 4%)—i.e., with lower compressive moduli. Despite the performances of 3% GelMA were slightly better, we decided to use 4% GelMA as these hydrogels were easier to handle. After determining the most suitable GelMA concentration for myogenic differentiation, a micromolding approach was established to investigate myotube organization under different confinement regimes, as sketched in Figure 4. The mold was designed to produce cell-laden thin hydrogel strings at different cross sections—namely 2,000 μm × 2,000 μm, 1,000 μm × 1,000 μm, and 500 μm × 500 μm—connected to a U-shaped supporting frame, further reinforced by a modeled glass capillary at its core. This solution endowed the structure with enhanced rigidity to support the ensuing myostructures and restraining hydrogel contraction due to myotube tensions.


Engineering Muscle Networks in 3D Gelatin Methacryloyl Hydrogels: Influence of Mechanical Stiffness and Geometrical Confinement
Scheme of the micromolding process for the fabrication of gelatin methacryloyl (GelMA) hydrogels: a U-shaped glass capillary is embedded within the hydrogel to act as a supporting frame for the hydrogel strings having different cross sections.
© Copyright Policy
Related In: Results  -  Collection

License
Show All Figures
getmorefigures.php?uid=PMC5383707&req=5

Figure 4: Scheme of the micromolding process for the fabrication of gelatin methacryloyl (GelMA) hydrogels: a U-shaped glass capillary is embedded within the hydrogel to act as a supporting frame for the hydrogel strings having different cross sections.
Mentions: The first propaedeutic experiment evidenced a clear correlation between matrix stiffness and the ability of myoblasts to undergo efficiently myogenesis. Results showed that the best candidates were those at lower GelMA concentration (3 and 4%)—i.e., with lower compressive moduli. Despite the performances of 3% GelMA were slightly better, we decided to use 4% GelMA as these hydrogels were easier to handle. After determining the most suitable GelMA concentration for myogenic differentiation, a micromolding approach was established to investigate myotube organization under different confinement regimes, as sketched in Figure 4. The mold was designed to produce cell-laden thin hydrogel strings at different cross sections—namely 2,000 μm × 2,000 μm, 1,000 μm × 1,000 μm, and 500 μm × 500 μm—connected to a U-shaped supporting frame, further reinforced by a modeled glass capillary at its core. This solution endowed the structure with enhanced rigidity to support the ensuing myostructures and restraining hydrogel contraction due to myotube tensions.

View Article: PubMed Central - PubMed

ABSTRACT

In this work, the influence of mechanical stiffness and geometrical confinement on the 3D culture of myoblast-laden gelatin methacryloyl (GelMA) photo-crosslinkable hydrogels was evaluated in terms of in vitro myogenesis. We formulated a set of cell-laden GelMA hydrogels with a compressive modulus in the range 1 ÷ 17 kPa, obtained by varying GelMA concentration and degree of cross-linking. C2C12 myoblasts were chosen as the cell model to investigate the supportiveness of different GelMA hydrogels toward myotube formation up to 2 weeks. Results showed that the hydrogels with a stiffness in the range 1 ÷ 3 kPa provided enhanced support to C2C12 differentiation in terms of myotube number, rate of formation, and space distribution. Finally, we studied the influence of geometrical confinement on myotube orientation by confining cells within thin hydrogel slabs having different cross sections: (i) 2,000 μm × 2,000 μm, (ii) 1,000 μm × 1,000 μm, and (iii) 500 μm × 500 μm. The obtained results showed that by reducing the cross section, i.e., by increasing the level of confinement—myotubes were more closely packed and formed aligned myostructures that better mimicked the native morphology of skeletal muscle.

No MeSH data available.


Related in: MedlinePlus