3D printing is recognized as a powerful tool to develop complex geometries
for a variety of materials including nanocellulose. Herein, a one-pot synthesis
of 3D printable hydrogel ink containing zeolitic imidazolate frameworks
(ZIF-8) anchored on anionic 2,2,6,6-tetramethylpiperidine-1-oxylradicalmediated oxidized cellulose nanofibers (TOCNF) is presented. The synthesis
approach of ZIF-8@TOCNF (CelloZIF8) hybrid inks is simple, fast (≈30 min),
environmentally friendly, takes place at room temperature, and allows easy
encapsulation of guest molecules such as curcumin. Shear thinning properties of the hybrid hydrogel inks facilitate the 3D printing of porous scaffolds
with excellent shape fidelity. The scaffolds show pH controlled curcumin
release. The synthesis route offers a general approach for metal–organic
frameworks (MOF) processing and is successfully applied to other types of
MOFs such as MIL-100 (Fe) and other guest molecules as methylene blue.
This study may open new venues for MOFs processing and its large-scale
applications.