ETH team prints muscle tissue in weightlessness: Biofabrication via parabolic flight

The ETH Zurich reports a step forward in bioadditive manufacturing for space applications. A team led by Parth Chansoria printed complex muscle constructs during parabolic flights to investigate the fabrication of delicate tissue structures under microgravity. The background is the physiological loss of muscle mass in astronauts and the search for realistic tissue models for drug testing. On Earth, gravitational effects hinder the processing of bio-inks: cell-laden hydrogels can collapse before curing; in addition, sedimentation leads to inhomogeneous cell distribution and thus to models with limited informative value.

At the core of the work is a new biofabrication process called G-FLight (“Gravity-independent Filamented Light”). It combines a cell-laden bio-resin formulation with pressure- and light-based curing that produces precise filaments during the brief phases of weightlessness. In 30 parabolic cycles, muscle constructs were extruded and stabilized by photopolymerization. The researchers report cell viabilities and fiber counts comparable to samples manufactured under Earth’s gravity, while simultaneously achieving improved fiber alignment. Noteworthy is the ability to store the bioactive resins for longer periods, which is logistically relevant for deployments aboard the ISS or future platforms.

The motivation is application-oriented: microphysiological models with correctly aligned myofibers are intended to better reflect disease mechanisms such as muscular dystrophies or microgravity-induced atrophy and to serve as testbeds for therapeutics. Unlike rigid implants or complex bioreactor systems, the approach targets transportable, on-site–activatable printing processes that can be carried out within limited time windows. In the long term, the method could be extended to organoid-like structures to examine dose–response relationships and regeneration processes in a gravity-decoupled environment.

The project positions 3D bioprinting as a tool of space medicine and provides data points for transferring laboratory protocols into orbital operations. The crucial next steps will be to validate scaling, reproducibility, and interfaces with measurement and stimulation systems.