Mistletoe- and Mussel-Inspired Fabrication of Hierarchically Structured Protein-Cellulose Scaffolds From Biomolecular Condensates.

Nature's ability to produce hierarchical materials via biomolecular self-assembly can inspire bioinspired avenues to advanced materials using biorenewable components and water as a solvent. Recent advances indicate that biomolecular condensates are important precursor phases for fabricating biological materials. Here, we leverage recent findings on the role of malleable biomolecular phases from both animal and plant systems to develop a synergistic mussel- and mistletoe-inspired approach for fabricating protein-cellulose composite scaffolds possessing tunable hierarchical structure. We demonstrate that recombinant mussel foot protein-1 (rMfp-1), undergoes controlled phase separation when mixed with surface-functionalized anionic cellulose nanorods, forming condensates with characteristic core-shell morphology. Using a facile approach based on freeze-drying of suspensions, we produce freestanding protein-cellulose composite scaffolds possessing tunable porous structures with potential as scaffolds for tissue engineering. Through a cross-disciplinary approach combining various spectroscopic and imaging modalities, we gain mechanistic insights into the role of intermolecular interactions and physical processes in guiding this process. These findings highlight that hierarchically structured materials can be fabricated simply via multi-component phase separation. This work establishes a framework for understanding and controlling bio-inspired material fabrication, offering a strategy to engineer materials with tunable structure and properties that bridge biomaterials research and emerging directions in synthetic biology.