Dual-Crosslinked Alginate Hydrogels with Shear-Thinning Property for ۳D Bio-Printing Applications

Objective: Calcium-alginate hydrogel is often used for differentbiomedical applications, but its use as bio-ink in three-dimensional(۳D) printing applications is somewhat limited dueto its low mechanical properties. In this s tudy, we synthesize ashear-thinning alginate hydrogel through dynamic imine chemistry and then use ionic crosslinking for pos t-printing s tabilizationusing CaCl۲ solution.Materials and Methods: Poly(ethylene glycol), sodium alginate,ethylene glycol, ammonium chloride, calcium chloride,and sodium hydroxide Alginate were oxidized to form alginatedialdehyde (ADA) and then mixed with ۴-arm PEG-NH۲ andpure alginate to form Schiff-base hydrogels. The pos t-printingreinforcement through the addition of CaCl۲ solution and secondionic crosslinking resulted in the printable hydrogel withs tability and shape fidelity.Results: Due to shear-thinning property and doul crosslinking,the hydrogels could be extruded for ۳D printing of s tructureswith high shape fidelity and s tability to relaxation. Doulcrosslinked hydrogels were degraded much more slowly thanthe single Schiff’s base hydrogels. Additionally, the hydrogelsshowed very low cytotoxicity and hence can be used as a scaffoldfor cell encapsulation.Conclusion: The s table tubes and grid s tructures were printedusing these procedures with s tructural s tiffness and shape fidelity.Double crosslinked hydrogels were s table for up to a monthof incubation. The hydrogel also showed very low cytotoxicityand hence can be suitable for cell encapsulation. The doublecovalent-ionic crosslinked hydrogel could facilitate the printingof alginate hydrogel and address the challenges of mechanicals tability upon printing.

کلیدواژه ها:

Schiff’s Base ، Shear-Thinning Hydrogel ، Three-Dimensional(۳D) Printing