A Monolithic 3D-Printed Platform for Functional Maturation and In Situ Contractility Assessment of 3D Skeletal Muscle

Area of Science:

• Biomedical Engineering
• Tissue Engineering
• Regenerative Medicine

Background:

• Sarcopenia, the age-related loss of muscle mass and function, necessitates advanced in vitro models for assessing muscle contractility.
• Current microphysiological systems face challenges with tension loss and variable boundary conditions due to tissue compaction, limiting reliability.

Purpose of the Study:

• To develop a novel, reproducible microphysiological system for quantitative assessment of engineered muscle.
• To establish fixed-length boundary conditions for long-term culture and reliable evaluation of muscle function.

Main Methods:

• Development of a monolithic, 3D printed Fast-Optimizing and Regeneration/Contraction-Evaluating (FORCE) platform using stereolithography.
• Incorporation of a detachable polydimethylsiloxane spacer to maintain constant interpillar distance and fixed-length conditions.
• Long-term culture and electrical stimulation of engineered muscles within the FORCE platform.

Main Results:

• The FORCE platform demonstrated high architectural reproducibility and maintained fixed-length boundary conditions.
• Engineered muscles cultured on the platform showed improved cellular alignment, myogenic differentiation, and structural maturation.
• Markedly enhanced twitch and tetanic forces were observed upon electrical stimulation in muscles cultured under fixed-length conditions.

Conclusions:

• The FORCE platform provides a robust and reproducible muscle microphysiological system with fixed-length boundary conditions.
• This system enables reliable, long-term quantitative evaluation of morphological and functional changes in engineered muscle.
• The FORCE platform is suitable for applications in tissue engineering, drug screening, and modeling muscular diseases.