Dual-photoresponsive elastomer nanofibres enhanced myofibre hybrid for skeletal muscle actuation

Light-responsive polymers offer promising opportunities for remote or
battery-free actuation in soft robotics. However, many existing systems
face limitations in responsiveness, processability, and
biocompatibility—challenges that remain particularly significant in the
context of muscle loss restoration. Here, we present a
dual-photoresponsive myofiber-nanofibre hybrid skeletal muscle system
(MyoHybrid) engineered from optogenetically modified myoblasts cultured on
a scalable, unidirectionally aligned polyurethane–azobenzene (PAzo)
nanofiber scaffold. This design enables synergistic photo-actuation
through the anisotropic integration of myotubes and nanofibers. Compared
to PAzo flat solid substrate, aligned PAzo nanofibers enhanced
unidirectional myotube fusion by 25.3 % and improved maturation by 37.7 %.
Furthermore, optogenetic stimulation of the resulting myofibers led to a
60 % increase in both contraction velocity and force. This MyoHybrid
actuator demonstrates a harmonious interface between synthetic nanofibers
and biological myofibers, offering a programmable platform for
muscle-on-chip models, biohybrid actuators, and lightdriven soft tissue
systems. Our work bridges mechanical bionics and cellular actuation,
paving the way for next-generation soft robotics and regenerative
technologies.