02177nas a2200337   4500000000100000008004100001260001500042653001700057653002200074653002300096100002700119700001900146700002000165700001900185700001700204700002200221700001700243700001700260700001800277700001700295700001600312700001900328700002700347700002200374245014600396856007200542300001100614490000700625520119300632022001401825       2022                            d  c2022-05-2010abiomaterials10aMaterials science10aTissue engineering1 aAndreja Dobaj Štiglic1 aFazilet Gürer1 aFlorian Lackner1 aDoris Bračič1 aArmin Winter1 aLidija Gradišnik1 aDamjan Makuc1 aRupert Kargl1 aIsabel Duarte1 aJanez Plavec1 aUroš Maver1 aMarco Beaumont1 aKarin Stana Kleinschek1 aTamilselvan Mohan00aOrganic acid cross-linked 3D printed cellulose nanocomposite bioscaffolds with controlled porosity, mechanical strength, and biocompatibility  uhttps://www.sciencedirect.com/science/article/pii/S2589004222005338  a1042630 v253 aHerein, 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.  a2589-0042