Bioinspired functionally graded composite assembled using cellulose nanocrystals and genetically engineered proteins with controlled biomineralization

Abstract

Nature provides unique insights into design strategies evolved by living organisms to construct robust materials with a combination of mechanical properties that are challenging to replicate synthetically. Hereby, inspired by the impact-resistant dactyl club of the stomatopod, we rationally designed and produced a mineralized biocomposite in the complex-shapes of dental implant crowns exhibiting high strength, stiffness, and fracture toughness. This material consists of an expanded helicoidal organization of cellulose nano-crystals (CNCs) mixed with genetically-engineered proteins that regulate both binding to CNCs, as well as in situ growth of reinforcing apatite crystals. Critically, the structural properties emerge from controlled self-assembly across multiple length scales regulated by rational engineering and phase separation of the protein components. This work replicates multiscale biomanufacturing of a model biological material and also offers an innovative platform to synthesize multi-functional biocomposites whose properties can be finely regulated by colloidal self-assembly and engineering of its constitutive protein building blocks.

Methylcellulose–Cellulose Nanocrystal Composites for Optomechanically Tunable Hydrogels and Fibers

“…Potential applications for advanced cellulosic materials include: biomedicine, tissue engineering, photonics, smart materials, emulsions, foaming, and sensors [ 13 , 14 , 15 , 16 , 17 ]. The rich history and applications of cellulose and various cellulose-based materials and nanocomposites are evident from several excellent reviews [ 4 , 5 , 18 , 19 , 20 , 21 , 22 , 23 , 24 ]. Yet, there are numerous properties and potential applications of celluloses, nanocelluloses, and their composites that remain unexplored.…”

Matrix-Directed Mineralization for Bulk Structural Materials

“…Examples include that the matrix with layered structures obtained by freeze-casting technique can template the growth of nacre-like MBSMs, 122 and that the matrix with liquidcrystalline helical structures can template the synthesis of MBSMs with Bouligand structures. 129,130 In addition, the matrixes should also facilitate the mass transfer from the surrounding environment into the matrixes. Otherwise, the in vitro mineralization of artificial matrixes and even matrixes obtained by biomineral demineralization would end up in a decreasing gradient of mineralization degree from the matrix surface to the core, and thus the mineral distribution is inhomogeneous and the overall mineral content is low.…”

“…Otherwise, the in vitro mineralization of artificial matrixes and even matrixes obtained by biomineral demineralization would end up in a decreasing gradient of mineralization degree from the matrix surface to the core, and thus the mineral distribution is inhomogeneous and the overall mineral content is low. 129,130,138,140,165 Therefore, it is suggested that abundant pores and channels as the path for mass transfer should be introduced into the matrixes.…”

“…129 In the second example, a liquidcrystalline cellulose matrix was mineralized in the presence of functional proteins (Figure 8c). 130 The mineral contents of the MBSMs obtained from such matrixes are limited because the prestructured liquid-crystalline matrixes are already very dense. Hydrogels, which comprise polymer networks and water, can resemble the environment in which biomineralization occurs.…”

Methylcellulose-Cellulose Nanocrystal Composites for Optomechanically Tunable Hydrogels and Fibers

“…[13][14][15][16][17] The rich history and applications of cellulose and various cellulose-based materials and nanocomposites are evident from several excellent reviews. [4,5,[18][19][20][21][22][23][24] Yet, there are numerous properties and potential applications of celluloses, nanocelluloses, and their composites that remain unexplored. Especially the trend towards sustainably produced optical and optoelectronic materials and devices has gained attraction recently, and therein cellulose derivatives and their composites appear as key components.…”