Abstract
Engineered in vitro models of skeletal muscle are essential for efficiently screening drug safety and efficacy. However, conventional culture substrates poorly replicate physical features of native muscle and do not support long-term culture, which limits tissue maturity. Micromolded gelatin hydrogels cross-linked with microbial transglutaminase (gelatin-MTG hydrogels) have previously been shown to induce C21C2 myotube alignment and improve culture longevity. However, several properties of gelatin-MTG hydrogels have not been systematically characterized, such as changes in elastic modulus during incubation in culture-like conditions and their ability to support sarcomere maturation. In this study, various gelatin-MTG hydrogels were fabricated and incubated in ambient or culture-like conditions. Elastic modulus, mass, and transmittance were measured over a one- or two-week period. Compared to hydrogels in phosphate buffered saline (PBS) or ambient air, hydrogels in Dulbecco’s Modified Eagle Medium (DMEM) and 5% CO2 demonstrated the most stable elastic modulus. A subset of gelatin-MTG hydrogels was micromolded and seeded with C2C12 or primary chick myoblasts, which aligned and fused into multinucleated myotubes with relatively mature sarcomeres. These data are important for fabricating gelatin-MTG hydrogels with predictable and stable mechanical properties and highlight their advantages as culture substrates for engineering relatively mature and stable muscle tissues.
Highlights
Skeletal muscle is especially susceptible to adverse drug reactions because it occupies a large amount of body mass and is highly vascularized
We found that elastic modulus values of gelatin-microbial transglutaminase (MTG) hydrogels over time was highly sensitive to culture conditions, as hydrogels incubated in Dulbecco’s Modified Eagle Medium (DMEM) in a 5% CO2 incubator demonstrated the most stability compared to those incubated in phosphate buffered saline (PBS) or ambient air
In comparison to hydrogels incubated in PBS, hydrogels incubated in DMEM were generally more stable in terms of elastic modulus over two weeks (Figure 1b)
Summary
Skeletal muscle is especially susceptible to adverse drug reactions because it occupies a large amount of body mass and is highly vascularized. To evaluate drug safety at the pre-clinical stage, both in vivo and in vitro models of skeletal muscle are essential due to their tradeoffs in throughput, cost, complexity, and physiological relevance. In vitro models of skeletal muscle tissue generated from patient-derived myoblasts are especially powerful for correlating patient-specific genotypes and phenotypes and identifying personalized drug responses for inherited skeletal myopathies [4,5]. To generate in vitro models of skeletal muscle, myoblasts have conventionally been cultured on glass or polystyrene surfaces coated with extracellular matrix (ECM) [6]. Myoblasts are differentiated to fuse into multi-nucleated myotubes, which can be assessed
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callDisclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
