Porous Nanocellulose-Reinforced Polyacrylamide Hybrid Hydrogels for Tissue Engineering

Hydrogels emerge as promising scaffolds in tissue engineering due to their high water content and tunable mechanical and structural properties. However, balancing biocompatibility with mechanical strength remains a key challenge, especially when introducing porosity, which is crucial for cell population of the scaffold structure, subsequent proliferation and efficient mass transfer of nutrients and waste. Herein, a macroporous hydrogel scaffold composed of polyacrylamide (PAAM) and nanocellulose is presented, in which porosity is introduced via CO² generation from sodium bicarbonate decomposition during polymerization. This approach enables tunable pore architecture with minimal compromise to structural integrity, maintaining high resilience under mechanical deformation. Building on prior work demonstrating enhanced mechanical performance and cytocompatibility through nanocellulose reinforcement, this hydrogel system is now explored for cartilage tissue engineering. In vitro studies with human chondrocytes demonstrate enhanced cell adhesion, proliferation, and infiltration in scaffolds with intermediate porosity (≈300 μm), correlating with improved swelling dynamics. The hydrogel's resilience, tunable porosity, and cytocompatibility suggest its strong potential as a customizable scaffold for regenerating load-bearing, extracellular matrix-rich tissues such as cartilage.