Molten stringing 3D printed microfibrous net-integrated mineralized hydrogels with tunable micromechanical and cell-responsive properties

Micro/nanofibrous materials play an increasingly important role in tissue regeneration due to their ECM-mimicking properties and mechanical regulation capabilities. This study developed a microfiber fabrication method based on molten stringing of fused deposition modeling (FDM), successfully creating an ordered microfiber network with spatial structures. It surpasses the size limits of FDM filaments, enabling the precise fabrication of microfibers with diameters of 15-150 μm. The customizable PLA microfiberous-net was then encapsulated in GelMA hydrogel and mineralized in situ, effectively producing biomimetic bone repair materials with customization of surface microstructures and control of micromechanics, which in turn influences and regulates cell behavior. By adjusting the structure and density of the microfiber network, it is possible to control the compressive modulus, viscoelasticity, and tensile strength to match the micromechanical environment for cell spreading and proliferation. Additionally, the network structure can guide cell alignment and aggregation, influencing cell morphology and enabling controlled guidance of cellular behavior. Our simple and convenient microfibrous printing method holds great potential for the preparation of various fibrous materials for tissue regeneration.