Bioinspired Mineralization with Hydroxyapatite and Hierarchical Naturally Aligned Nanofibrillar Cellulose

We used cellulose and a nonclassical mineralization process to fabricate a bioinspired nanohybrid material that exhibited structural features and properties similar to those of human hard tissues. We made a hydrogel with highly compacted and aligned cellulose nanofibers. We thoroughly mineralized the cellulose hydrogel with hydroxyapatite nanocrystals, using poly(acrylic acid) as a soluble template for precursor minerals, which infiltrated the nanocompartments of the aligned cellulose nanofiber network. The ultrastructure and mechanical properties of the mineralized gels were strikingly similar to those of bone and dentin, which supports further use of cellulose-based fibrillary materials as affordable, biocompatible scaffolds for repair and regeneration of hard tissues. The versatility of the bioinspired mineralization processes used here can broaden the applications of these cellulosic nanohybrids.