Biology subjects

Winkelbauer, M.

Publications and source records attributed to Winkelbauer, M..

3 recordsLinked to original sources

bioRxiv2025

Prolonged cell encapsulation and rapid filamented light biofabrication of muscle constructs in microgravity

The prospects of fabricating human tissue grafts or models using cell-laden bioresins in space has garnered significant interest in recent years. While there has been tremendous progress in extrusion or light-based bioprinting in microgravity conditions, printing of aligned tissues, such as those featuring anisotropic organization of cells and extracellular matrices (e.g., muscle, tendon, cardiac, etc.), remains a challenge. Furthermore, current photoresin formulations do not allow long-term cell encapsulation and are difficult to perform in microgravity. In this study, we demonstrate a new gravity-independent filamented light (G-FLight) biofabrication system with in-built refrigeration and heating units, which can create viable muscle constructs within seconds. We developed new photoresin formulations based on gelatin methacrylate (GelMA) for encapsulation of primary cells (murine myoblasts) and storage in printing cuvettes for at least a week at 4{degrees}C or -80{degrees}C. The tissues printed in microgravity based on the new formulations exhibited higher cell viability, number of proliferating cells and after maturation higher numbers of myotubes and fusion index compared to control formulations (i.e., GelMA dissolved in phosphate buffered saline). The microgravity-printed tissues also featured similar myotube density and fusion index to those printed using the same resins on-ground. The G-Flight printing concept, together with the new resins enabling refrigeration or cryopreservation with encapsulated cells, offers a promising solution for biofabrication in space.

bioengineering↗

bioRxiv2025

Filamented Light (FLight) Bioprinting of Mini-Muscles with Self-Renewal Potential

The plasticity and regenerative capacity of skeletal muscle arise from quiescent stem cells activated upon overload, injury, or inflammation. Developing in vitro muscle models to study these properties could advance muscle disease modeling and pre-clinical evaluation. Here, we leverage Filamented Light (FLight) bioprinting as a high-throughput approach for producing mini-muscle tissues. Using Pax7-nGFP myoblasts, we bioprinted mini-muscles from pristine collagen-fibrinogen. The FLight hydrogel consisted of aligned microstructures which guided the formation of aligned myotubes. Mini-muscles demonstrated in vivo-like tissue organization, including highly aligned myotubes and a Pax7+ cell pool embedded in newly deposited laminin. Both spontaneous and electrically stimulated contractions were observed. Collagen-fibrinogen matrix was promising for maintenance of the Pax7+ cell pool. Damage from cardiotoxin-induced injury of the mini-muscles led to a massive proliferation of Pax7+ cells and restoration of the contractile properties. Notably, small molecules such as Repsox could enhance regeneration. FLight printed mini-muscles have potential for applications in muscle biology, exercise/atrophy, disease models, and drug screening.

bioengineering↗

bioRxiv2024

Structured light projection using image guide fibers for in situ photo-biofabrication

Light-based biofabrication techniques have revolutionized the field of tissue engineering and regenerative medicine. Specifically, the projection of structured light, where the spatial distribution of light is controlled at both macro- and micro-scale, has enabled precise fabrication of complex three-dimensional structures with high resolution and speed. However, despite almost two decades of progress, biofabrication processes have been mostly limited to benchtop devices which limit the flexibility in terms of where the fabrication can occur. Here, we demonstrate a Fiber-assisted Structured Light (FaSt-Light) projection apparatus for rapid in situ crosslinking of photoresins. This approach uses image-guide fiber bundles which can project bespoke images at multiple wavelengths, enabling flexibility and spatial control of different photoinitiation systems and crosslinking chemistries and also the location of fabrication. We demonstrate coupling of different sizes of fibers and different lenses attached to the fibers to be able to project small (several mm) or large (several cm) images for material crosslinking. FaSt-Light allows control over the cross-section of the crosslinked resins and enables the introduction of microfilaments which can further guide cellular infiltration, differentiation and anisotropic matrix production. The proposed approach could lead to a new range of in situ biofabrication techniques which improve the translational potential of photo-fabricated tissues and grafts.

bioengineering↗