A hydrogel tissue adhesive having decreased degradation time is described. The hydrogel tissue adhesive is formed by reacting an oxidized polysaccharide with a water-dispersible, multi-arm polyether amine in the presence of an oligomer additive, which promotes the degradation of the hydrogel. The hydrogel may be useful as a tissue adhesive or sealant for medical applications, such as a hemostat sealant or to prevent undesired tissue-to-tissue adhesions resulting from trauma or surgery.