In situ gelling poly(aspartic acid) thiomers are investigated to demonstrate their potential application in the development of injectable formulations. The chemical stability of the thiomer solutions is measured against air to determine the maximum storage time of the solution before injection. Hydrogels exhibit considerably large storage moduli after the chemical oxidation of the low-viscosity thiomer solution. The gelation time can be controlled within 2-6 min, which is advantageous for injection because the thiomer solution and the oxidising agent can be mixed safely in a two-chamber system before injection into the desired site of the body. (C) 2014 Elsevier B.V. All rights reserved.