Abstract: Cross-linked shear-thinning fluids of pectic acid demonstrating increased viscosity with decreasing shear, as well as methods of producing and using the same. A shear-thinning fluid includes an aqueous solution of pectic acid cross-linked by a divalent cation is disclosed. The pectic acid may be present in an amount ranging from about 0.5 to about 3.0% (w/v), the divalent cation may be present at a concentration of from about 0.5 mM to about 7.0 mM, and the viscosity of the shear-thinning fluid increases with decreasing shear. These cross-linked shear-thinning fluids of pectic acid can be utilized for controlled release formulations, cell encapsulation, and 3D printing, and provide for an improved balance between structure fidelity/mechanical stability and cell viability.