Polylactic acid nanosheets in prevention of postoperative intestinal adhesion and their effects on bacterial propagation in an experimental model.

BACKGROUND: Ultrathin films (nanosheets) adhere tightly to organ surfaces but prevent adhesion to other organs. The antiadhesive effect of nanosheets and their effect on bacterial propagation were investigated in a murine intestinal adhesion model.

METHODS: Polylactic acid nanosheets (approximately 80 nm thick) were produced. Serosal defects were created by peeling off the intestinal serosa; these were left open or covered with nanosheets or Seprafilm® and the formation of intestinal adhesions was analysed. To examine bacterial propagation, a nanosheet or Seprafilm® was placed on intact murine jejunum followed by Escherichia coli inoculation at the site.

RESULTS: Treatment both with nanosheets and with Seprafilm® reduced postoperative intestinal adhesion (mean adhesion score 0·67 for nanosheets, 0·43 for Seprafilm® and 2·87 for no antiadhesive treatment; P < 0·001 for nanosheets or Seprafilm® versus no adhesive treatment). Nanosheet treatment did not affect bacterial propagation in the peritoneal cavity, whereas Seprafilm®-treated mice showed bacterial propagation, leading to increased mortality.

CONCLUSION: Nanosheets may be effective novel antiadhesive agents even in the presence of bacterial contamination. Surgical relevance Intra-abdominal adhesions following surgical contamination can trigger postoperative complications and lead to deterioration in long-term quality of life. However, currently there are no effective antiadhesion materials to prevent the formation of adhesions. Treatment with ultrathin nanosheets effectively reduced postoperative intestinal adhesion in an experimental mouse model, and did not affect bacterial propagation in the peritoneal cavity. These nanosheets are potent novel antiadhesive materials that potentially can be applied even in contaminated conditions.