Biocompatible and soft micro/nanoporous 3D-printed scaffolds with superoleophilic/superadsorption capabilities

Tuning materials' micro/nanoporous architecture is pivotal in maintaining microenvironmental homeostasis. Bioinspired micro/nanoporous scaffolds, based on triply periodic minimal surface (TPMS), present promising avenues for restoring microenvironmental equilibrium in tissue regeneration. Moreover, micro/nanoporous TPMS holds potential for applications in wastewater treatment and pollutant removal to restore microenvironmental homeostasis. 3D printing provides high flexibility in fabricating these multifunctional scaffolds with precise pore geometry and permeability control. However, printing micro/nanoscale pores using material extrusion (MEX) is still challenging. To address this issue, this study presents a novel approach to print soft micro/nanoporous scaffolds. A polymer blend of thermoplastic polyurethane elastomer (TPE) and polyvinyl alcohol (PVA) filament is selected to print gyroid-based scaffolds. Then, the water-soluble PVA molecules are removed, allowing for the creation of scaffolds with controllable porosity at the nanometer scales. The link between non-porosity, nanoporosity, mechanical behavior, and structure topology is investigated, and its impact on cell viability evaluated. Findings demonstrate that these 3D-printed scaffolds with multiscale porosity exhibit exceptional pollutant adsorption capabilities and enhance oil/water separation efficiency. These outcomes underscore the MEX potential in supporting the fabrication of biocompatible, soft micro/nanoporous structures, offering promising applications across diverse domains, including adsorption, separation, and tissue engineering, and, therefore in developing multifunctional materials and solutions.