Speaker
Description
Introduction:
Biofabrication in space enables the production of patient-specific, structurally complex tissue constructs with customized properties (e.g., cell density, material composition, architecture), essential for future long-duration missions. Although substantial progress has been made in evaluating biofabrication strategies for space applications, the fabrication of anisotropic, highly aligned tissues remains a significant challenge. Additionally, the maintenance and handling of living cells under microgravity conditions require specialized protocols and equipment. Notably, traditional layer-by-layer printing techniques typically rely on gravity, while light-based approaches require specialized resins with active leveling mechanisms to redistribute the material between sequential material depositions during layer shifts. In contrast, the herein developed G-Flight platform employs ready to use resin cuvettes and a single, rapid light projection to fabricate tissue constructs within seconds, entirely independent of gravitational effects.
Methods:
In this study, we developed gelatin methacrylate (GelMA)-based bioresin formulations capable of storage under refrigerated and cryogenic conditions for up to one week. For storage at refrigeration temperatures (“CoolResin”), a commercially available hypothermic preservation medium, Hypothermosol® FRS, was incorporated into the reformulation. For cryopreservation at –80°C (“CryoResin”), additional supplementation with trisaccharide melezitose hydrate and dimethyl sulfoxide was employed.
Figure 1. A. Schematic illustration of the light-engine developed for parabolic flight experiments, during which an approximately 22-second microgravity window was available for biofabrication. B. Light-sheet images of printed constructs, alongside confocal micrographs showing the filamented microstructur. C. On-ground viability assays after seven days of culture, using previously encapsulated Pax7⁺-nGFP primary myoblasts in various resin formulations. D. Representative immunofluorescence images showing myotube fusion and sarcomere maturation within the printed constructs. E. Constructs fabricated from CoolResin_4C and CryoResin_4C displayed spontaneous contractility which synchronized contractions after electrical stimulation at 1 Hz and 5 H.
Results:
We engineered a custom, small-form-factor FLight biofabrication engine (Figure 1A) equipped with refrigerated resin storage and a 37°C warming block for resin liquefaction. This system was deployed during the 43rd Deutsches Zentrum für Luft- und Raumfahrt parabolic flight campaign (Bordeaux, September 2024) to demonstrate its functionality under repeated microgravity conditions. Across 90 parabolic maneuvers, aligned, filamented hydrogel constructs were successfully fabricated (Figure 1B). Cell viability assays demonstrated excellent survival (>90%) after seven days of culture in constructs fabricated from CoolResin and CryoResin formulations (Figure 1C). Upon induction of differentiation, myoblasts fused into contractile myotubes. Notably, constructs derived from CoolResin4C and CryoResin4C formulations exhibited higher cell densities and significantly increased fusion indices compared to controls. Furthermore, functionality testing via electrical stimulation confirmed synchronized contractility of the tissue constructs (Figure 1D).
Discussion:
This work demonstrates that tailored resin formulations can preserve cell viability of encapsulated primary muscle cells during prolonged refrigerated or cryogenic storage and our custom printer design enables successful fabrication of functional tissue constructs in microgravity. Our optimized resins resulted in high post-printing viability, significantly enhanced myotube formation, and consequently improved contractility compared to controls, highlighting their potential for future biofabrication applications in space environments.
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