In recent years, biopolymers have been attracting the attention of researchers from different fields including biotechnology, material science, engineering and medicine. The combination of biodegradable and resorbable polymers with bio-based building blocks such as cellulose nanocrystals (CNCs) allows to create new materials, which on the one hand have enhanced functional properties that can be tailored, and at the same time contribute to the development of a more sustainable circular economy.<br/>In this work, we developed biodegradable composites using Poly(3-hydroxybutyrate-<i>co</i>-3-hydroxyhexanoate) (PHBH), a bio-based and biodegradable aliphatic polyester synthesized by bacteria, as a matrix and CNCs as reinforcing elements. The thermal and mechanical properties of the matrix were enhanced by melt-compounding PHBH with acetylated cellulose nanocrystals at varied concentrations from 5 up to 20 wt%. The biocomposites were further processed with a filamentary 3D printing approach, named Fused Filament Fabrication (FFF). We demonstrated the printability of the bio-based composites by preparing simple grid shapes, samples for characterization of rheological and thermo-mechanical properties, and more complex architectures with vertical development and axis inclination. The enhanced thermal stability and thermomechanical properties of the composites were attributed to the optimized affinity between the biodegradable PHBH matrix and the functionalized CNCs. Our results showed that CNCs also offer a way to tailor the degree of disintegration of the composite materials, in line with the nanocellulose content.<br/>This novel grade of printable customized materials with tuneable properties opens great opportunities for creating bio-based, sustainable and biodegradable objects, combining the advantages of eco-friendly materials with the advantages of additive manufacturing. Particularly promising is their application in a field where the high level of customization is needed, such as in the area of biomedical engineering, for creating customized medical devices and scaffolds for tissue engineering. To demonstrate the potential of our materials in this field we have evaluated the growth and proliferation of normal human dermal fibroblast (NHDF) cells in the 3D printed scaffolds.

3D printing nanocellulose-PHBH composites for biomedical applications

ACS Spring 2022

The official archive and repository for all ACS Meetings & Expositions abstracts and select posters or presentations.