Direct ink writing of multifunctional nanocellulose and allyl-modified gelatin biomaterial inks for the fabrication of mechanically and functionally graded constructs

Alessandro Cianciosi; Jonas Simon; Michael Bartolf-Kopp; Heinrich Grausgruber; Tim R Dargaville; Aurélien Forget; Jürgen Groll; Tomasz Jungst; Marco Beaumont

doi:10.1016/j.carbpol.2023.121145

Direct ink writing of multifunctional nanocellulose and allyl-modified gelatin biomaterial inks for the fabrication of mechanically and functionally graded constructs

Carbohydr Polym. 2023 Nov 1:319:121145. doi: 10.1016/j.carbpol.2023.121145. Epub 2023 Jun 24.

Authors

Alessandro Cianciosi¹, Jonas Simon², Michael Bartolf-Kopp¹, Heinrich Grausgruber³, Tim R Dargaville⁴, Aurélien Forget⁵, Jürgen Groll¹, Tomasz Jungst⁶, Marco Beaumont⁷

Affiliations

¹ Department for Functional Materials in Medicine and Dentistry, Institute of Functional Materials and Biofabrication, University of Würzburg, Pleicherwall 2, Würzburg 97070, Germany.
² Department of Chemistry, Institute of Chemistry of Renewable Resources, University of Natural Resources and Life Sciences (BOKU), Konrad-Lorenz-Str. 24, A-3430 Tulln, Austria.
³ Department of Crop Sciences, University of Natural Resources and Life Sciences (BOKU), Konrad-Lorenz-Str. 24, A-3430 Tulln, Austria.
⁴ ARC Centre for Cell & Tissue Engineering Technologies, Max Planck Queensland Centre for the Materials Science of Extracellular Matrices, QUT Centre for Materials Science, School of Chemistry and Physics, Faculty of Science, Queensland University of Technology (QUT), Brisbane, Australia.
⁵ Institute for Macromolecular Chemistry, University of Freiburg, Freiburg 79104, Germany.
⁶ Department for Functional Materials in Medicine and Dentistry, Institute of Functional Materials and Biofabrication, University of Würzburg, Pleicherwall 2, Würzburg 97070, Germany. Electronic address: tomasz.juengst@uni-wuerzburg.de.
⁷ Department of Chemistry, Institute of Chemistry of Renewable Resources, University of Natural Resources and Life Sciences (BOKU), Konrad-Lorenz-Str. 24, A-3430 Tulln, Austria. Electronic address: marco.beaumont@boku.ac.at.

PMID: 37567703
DOI: 10.1016/j.carbpol.2023.121145

Abstract

Recreating the intricate mechanical and functional gradients found in natural tissues through additive manufacturing poses significant challenges, including the need for precise control over time and space and the availability of versatile biomaterial inks. In this proof-of-concept study, we developed a new biomaterial ink for direct ink writing, allowing the creation of 3D structures with tailorable functional and mechanical gradients. Our ink formulation combined multifunctional cellulose nanofibrils (CNFs), allyl-functionalized gelatin (0.8-2.0 wt%), and polyethylene glycol dithiol (3.0-7.5 wt%). The CNF served as a rheology modifier, whereas a concentration of 1.8 w/v % in the inks was chosen for optimal printability and shape fidelity. In addition, CNFs were functionalized with azido groups, enabling the spatial distribution of functional moieties within a 3D structure. These functional groups were further modified using a spontaneous click chemistry reaction. Through additive manufacturing and a readily available static mixer, we successfully demonstrated the fabrication of mechanical gradients - ranging from 3 to 6 kPa in indentation strength - and functional gradients. Additionally, we introduced dual gradients by combining gradient printing with an anisotropic photocrosslinking step. The developed biomaterial ink opens up possibilities for printing intricate multigradient structures, resembling the complex hierarchical organization seen in living tissues.

Keywords: 3D printing; Cellulose nanofibers; Periodate oxidation; Regioselective succinylation; Tissue engineering.