A polymer composition can include an aqueous vehicle and a temperature-responsive degradable polymer having a polymer including a LCST-imparting unit and a lactone-bearing unit including a pendent lactone group. The number of LCST-imparting units is greater than the number of lactone-bearing units. The temperature-responsive degradable polymer has an initial lower critical solution temperature (LCST) of 37° C. or below. The polymer composition can have a pH lower than 7.
