Development of microbial transglutaminase-crosslinked gelatin hydrogel gratings with structural stability under high-stretching conditions for induction of muscle hypertrophy

Abstract

Lack of physical activity and aging can lead to the loss of skeletal muscle mass and function. Many efforts have been made to align and differentiate myoblasts into myotubes in hydrogel gratings supported by elastic substrates, and then induce muscle hypertrophy in the myotubes by applying repetitive stretching to the elastic substrate. However, muscle hypertrophy in vivo may require stretching at least 20%, which conventional hydrogel gratings cannot withstand. In this study, we developed a novel method for patterning structurally stable gelatin hydrogel gratings (GHG) on an elastic surface that can withstand high levels of cyclic stretching without detachment or tearing during cell culturing. We attached gelatin to the surface through aldehyde functionalization and crosslinking with microbial transglutaminase. GHG on the PDMS surface withstood stretching at high ratios (15% and 20%) for several days. Myoblasts cultured on GHG differentiated into myotubes that were aligned along the grooves. When subjected to cyclic stretching at a ratio of 20%, these myotubes showed a significant increase in width, up to 57%. This method represents a significant advance in the field, providing a valuable platform for studying the effects of resistance exercise on muscle hypertrophy in vitro.