OBJECTIVETo explore the possibility of creating a rat new scar model by inserting gelatin sponge into rat excisional wounds.

METHODSTwo full-thickness wounds were created in each of total 49 SD rats. In the Experimental group (n = 19), a regular incisional wound (1 cm) was created on the left side, and an excisional wound of 1.0 cm x 0.2 cm was created on the right side with a gelatin sponge inserted. In control 1 group (n = 15), an excisional wound with sponge insertion was created on both sides of rats. In control 2 group (n = 15), two excisional wounds were created on both sides, and only one side wounds were inserted with a sponge. Animals were sacrificed at various time points for different examinations.

RESULTSThe wound/scar width increased 4 - 11 times in inserted wounds than in regular incisional wounds (P < 0.01), with an obvious delay of epithelialization. No difference in wound/scar width was found in both sides of wounds of control 1 group at various locations. In contrast to the linear scar of sponge-inserted wounds, contracted and irregular scar was found in non-inserted wounds of control 2 group.

CONCLUSIONSGelatin sponge insertion can create a thick linear scar in rat wounds, and thus provides a new model for scar research.