A shear-thinning hydrogel composition includes: a first polymer chain including: (i) a first plurality of units each having at least one of a monosaccharide and an amino acid; and (ii) a cross-linking group bound to the at least one of the monosaccharide and the amino acid of one of the first plurality of units via conversion of a carboxyl group of the unit to a peptide bond; a second polymer chain including a second plurality of the units; and a cross-linking additive connecting one of the second plurality of units to the first polymer chain via the cross-linking group.