Organic acid cross-linked 3D printed cellulose nanocomposite bioscaffolds with controlled porosity, mechanical strength, and biocompatibility

Andreja Dobaj Štiglic; Fazilet Gürer; Florian Lackner; Doris Bračič; Armin Winter; Lidija Gradišnik; Damjan Makuc; Rupert Kargl; Isabel Duarte; Janez Plavec; Uros Maver; Marco Beaumont; Karin Stana Kleinschek; Tamilselvan Mohan

doi:10.1016/j.isci.2022.104263

Organic acid cross-linked 3D printed cellulose nanocomposite bioscaffolds with controlled porosity, mechanical strength, and biocompatibility

iScience. 2022 Apr 16;25(5):104263. doi: 10.1016/j.isci.2022.104263. eCollection 2022 May 20.

Authors

Andreja Dobaj Štiglic¹, Fazilet Gürer¹, Florian Lackner², Doris Bračič¹, Armin Winter³, Lidija Gradišnik⁴, Damjan Makuc⁵, Rupert Kargl^{1

2}, Isabel Duarte⁶, Janez Plavec^{5

7

8}, Uros Maver⁴, Marco Beaumont⁹, Karin Stana Kleinschek², Tamilselvan Mohan^{1

2}

Affiliations

¹ University of Maribor, Faculty of Mechanical Engineering, Laboratory for Characterization and Processing of Polymers, Smetanova Ulica 17, 2000 Maribor, Slovenia.
² Graz University of Technology, Institute for Chemistry and Technology of Biobased System (IBioSys), Stremayrgasse 9, 8010 Graz, Austria.
³ University of Natural Resources and Life Sciences (BOKU) Institute of Wood Technology and Renewable Materials, Konrad-Lorenz-Strasse 24, 3430 Tulln, Austria.
⁴ University of Maribor, Faculty of Medicine, Institute of Biomedical Sciences, Taborska Ulica 8, 2000 Maribor, Slovenia.
⁵ Slovenian NMR Center, National Institute of Chemistry, Hajdrihova 19, 1001 Ljubljana, Slovenia.
⁶ University of Aveiro, Department of Mechanical Engineering, Center for Mechanical Technology and Automation, Campus Universitário de Santiago, 3810-193 Aveiro, Portugal.
⁷ EN→FIST Center of Excellence, Trg OF 13, 1000 Ljubljana, Slovenia.
⁸ University of Ljubljana, Faculty of Chemistry and Chemical Technology, Večna pot 113, 1000 Ljubljana, Slovenia.
⁹ University of Natural Resources and Life Sciences (BOKU), Institute of Chemistry of Renewable Resources, Konrad-Lorenz-Strasse 24, 3430 Tulln, Austria.

Abstract

Herein, we fabricated chemically cross-linked polysaccharide-based three-dimensional (3D) porous scaffolds using an ink composed of nanofibrillated cellulose, carboxymethyl cellulose, and citric acid (CA), featuring strong shear thinning behavior and adequate printability. Scaffolds were produced by combining direct-ink-writing 3D printing, freeze-drying, and dehydrothermal heat-assisted cross-linking techniques. The last step induces a reaction of CA. Degree of cross-linking was controlled by varying the CA concentration (2.5-10.0 wt.%) to tune the structure, swelling, degradation, and surface properties (pores: 100-450 μm, porosity: 86%) of the scaffolds in the dry and hydrated states. Compressive strength, elastic modulus, and shape recovery of the cross-linked scaffolds increased significantly with increasing cross-linker concentration. Cross-linked scaffolds promoted clustered cell adhesion and showed no cytotoxic effects as determined by the viability assay and live/dead staining with human osteoblast cells. The proposed method can be extended to all polysaccharide-based materials to develop cell-friendly scaffolds suitable for tissue engineering applications.

Keywords: Biomaterials; Materials science; Tissue Engineering.

Grants and funding

J 4356/FWF_/Austrian Science Fund FWF/Austria