Collagen and Chitosan hydrogels for 3D bioprinting: a rheological and printability approach

ANA CAROLINA HEIDENREICH; PÉREZ-RECALDE, MERCEDES; ANA GONZALEZ WUSENER; ÉLIDA B. HERMIDA

POLYMER TESTING

ELSEVIER SCI LTD

Lugar: Amsterdam; Año: 2020

0142-9418

Collagen and chitosan are widely employed as biomaterials, including for 3D-bioprinting. However the use of collagen and chitosan (col:chi) blends as bioinks is scarce. In this work, the rheology of different hydrogel precursors (0.5-1.50 % w/v chi: 0.18-0.54 % w/v col) was analyzed in oscillatory mode through frequency and strain sweeps, as well as at different shear rates. Col:chi blends showed a shear-thinning behavior, with viscosity values at low shear rates between 0.35 and 2.80 Pa.s. Considering the strain rate determined by the applied flow in a 3D-bioprinter, precursor viscosities during the extrusion were in the interval 0.5-0.8 Pa.s. Printability (Pr) was measured comparing images of the 3D-printed constructs and the corresponding CAD grid design, using photograph analysis. Col:chi 0.36:1.00 was chosen to print scaffolds for tissue engineering (TE) because of its suitable viscosity, printability and polymer ratio content. Hydrogels were obtained by NaHCO3 nebulization and 37º incubation, and NHS/EDC were added to obtain scaffolds with improved mechanical behavior. Scaffolds were stable after 44 h in PBS with collagenase at physiological level and showed no cytotoxic effect in NIH-3T3 fibroblasts.