3D Printed Magneto‐Active Microfiber Scaffolds for Remote Stimulation and Guided Organization of 3D In Vitro Skeletal Muscle Models

Abstract

This work reports the rational design and fabrication of magneto‐active microfiber meshes with controlled hexagonal microstructures via melt electrowriting (MEW) of a magnetized polycaprolactone‐based composite. In situ iron oxide nanoparticle deposition on oxidized graphene yields homogeneously dispersed magnetic particles with sizes above 0.5 µm and low aspect ratio, preventing cellular internalization and toxicity. With these fillers, homogeneous magnetic composites with high magnetic content (up to 20 weight %) are obtained and processed in a solvent‐free manner for the first time. MEW of magnetic composites enabled the creation of skeletal muscle‐inspired design of hexagonal scaffolds with tunable fiber diameter, reconfigurable modularity, and zonal distribution of magneto‐active and nonactive material, with elastic tensile deformability. External magnetic fields below 300 mT are sufficient to trigger out‐of‐plane reversible deformation. In vitro culture of C2C12 myoblasts on three‐dimensional (3D) Matrigel/collagen/MEW scaffolds showed that microfibers guided the formation of 3D myotube architectures, and the presence of magnetic particles does not significantly affect viability or differentiation rates after 8 days. Centimeter‐sized skeletal muscle constructs allowed for reversible, continued, and dynamic magneto‐mechanical stimulation. Overall, these innovative microfiber scaffolds provide magnetically deformable platforms suitable for dynamic culture of skeletal muscle, offering potential for in vitro disease modeling.

Rectification for Stitched Images with Deformable Meshes and Residual Networks

“…Simultaneously, the hexagonal mesh can more compactly cover the image area, reducing redundancy. It can decrease edge effects when handling image boundaries, reducing the likelihood of extensive deformation at the image edges and thereby improving repre-sentation efficiency [60]. In contrast, rectangular meshes may require more mesh points to represent the same image area, resulting in larger input dimensions [61].…”

Degradable biomedical elastomers: paving the future of tissue repair and regenerative medicine

“…Castilho and colleagues investigated magnetically active microfiber networks with controllable hexagonal microstructures based on iron-deposited oxidized graphene/poly(e-caprolactone) through melt extrusion. 380 Singlefiber elastic moduli reached 369 AE 20 MPa. Under cyclic magnetic fields with magnetic flux density B = 100 mT or higher, these skeletal muscle constructs immersed in culture medium successfully underwent reversible bending while maintaining the loaded cells, creating a three-dimensional cell culture environment.…”