A hydrogel tissue adhesive formed by reacting an aldehyde-functionalized dextran containing pendant aldehyde groups with a multi-arm polyethylene glycol amine is described. The hydrogel exhibits little to no swell upon exposure to physiological conditions. The hydrogel may be useful as a tissue adhesive or sealant for medical applications that require a low swell hydrogel to inhibit complications, such as fibrosis, including scar formation or surgical adhesions.