Title: Fiber filled hybrid hydrogel for bio-manufacturing

Bio-printing has the potential to regenerate 3D functional living tissue through the controlled layer-by-layer allocation of biomaterials along with high precision positioning of cells. The extrusion based three-dimensional (3D) bio-printing deposits cell-laden bio-ink with high spatial resolution and may offer living tissue regeneration. Due to the biocompatibility, less cytotoxicity and high water content, natural hydrogels are commonly considered as the bio-ink for scaffold fabrication. However, due to the low mechanical integrity, a large scale scaffold (> 10 layers) with intricate architecture is a challenge. In this paper, Cellulose-based nano-fiber and CMC are added with alginate material to improve the rheological behavior of the hybrid hydrogel.

Tempo nano-fibrillated cellulose (TO-NFC 1% solid content, 0.2-2.0 mmol/g carboxylate level) is mixed with alginate and carboxymethyl cellulose-CMC. The length and diameter of the nanofibers are measured as 35 ± 4.5 μm and 82 ± 11 nm respectively. The addition of CMC and TO-NFC will increase the overall viscosity of the material, which will assist in achieving better printability and shape fidelity. All sample compositions prepared under continuous stirring until the solution turns into viscous and homogeneous. As an ionic cross-linker, 4% (w/v) calcium chloride (CaCl2) (Sigma-Aldrich) is prepared with 0.2 µm filtered deionized (DI) water.

Shear-thinning behavior, shape fidelity, printability of the composition are investigated and evaluated for various compositions. This hybrid hydrogel can be a potential biomaterial to fabricate a large-scale functional tissue scaffold. Finally, both regular and freeform 3D scaffolds are fabricated with the proposed hybrid hydrogel to validate its printability and shape fidelity. The illustrated characterization techniques can direct the 3D bio-fabrication of the tailored anisotropic scaffolds, which will assist the fabrication of functional tissue in the future. The required properties of bio-ink are highly dependent upon the percentage composition and the solid content.

Keywords: 3D bioprinting, TEMPO nano fibrillated cellulose, rheology and shape fidelity.

Tempo nano-fibrillated cellulose (TO-NFC 1% solid content, 0.2-2.0 mmol/g carboxylate level) is mixed with alginate and carboxymethyl cellulose-CMC. The length and diameter of the nanofibers are measured as 35 ± 4.5 μm and 82 ± 11 nm respectively. The addition of CMC and TO-NFC will increase the overall viscosity of the material, which will assist in achieving better printability and shape fidelity. All sample compositions prepared under continuous stirring until the solution turns into viscous and homogeneous. As an ionic cross-linker, 4% (w/v) calcium chloride (CaCl2) (Sigma-Aldrich) is prepared with 0.2 µm filtered deionized (DI) water.


Fiber Filled Hybrid Hydrogel for Bio-Manufacturing

Division / Sponsor: 
Manufacturing Engineering Division (MED)

International Manufacturing Science and Engineering Conference - Paper Proceedings: https://asmedigitalcollection.asme.org/MSEC/MSEC2020/volume/84256

JSME 2020 Conference on Leading Edge Manufacturing/Materials and Processing - Paper Proceedings: https://asmedigitalcollection.asme.org/lemp/LEMP2020/volume/83624

MSEC2020 - Virtual Conference, LEMP2020 - Virtual Conference

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