Preliminary Study On Prevention Of Postoperative Adhesions In SD Rats By PLGA Electrospun Sheets

Purpose:To study the effects of PLGA electrospun sheets with different thickness on SD rats’intra-abdominal adhesion (IAA) prevention by mouse fibroblast NIH3T3 cells strain and rat intra-abdominal adhesion model.Methods:(1) NIH3T3 cells were inoculated on PLGA electrospun sheets with different thickness and Ctrl+ sheets as a positive control. The cell viability, morphology and state of survival were determined by CCK-8 assay, rhodamine-phalloidin and calcein-PI staining respectively to identify the cell compatibility with PLGA electrospun sheets. (2) SD rats were randomly divided into 4 groups, and treated with 4 surgical methods. These rats were sacrificed two weeks later and the evaluation of their IAA severity was detemined by dissection observation and visceral organs weighing. The LDH in abdominal lavage, AKP in serum and blood routine examination were tested subsequently to evaluate the established rat IAA models. (3) SD rats were randomly divided into 5 groups, and 2 groups of them were ones as a normal control group and as a negtive control group respectively. Then the rats were treated with screened surgical methods and PLGA sheets with different thickness and Ctrl+ sheets were placed in areas adhesion. These rats were sacrificed 10 days later, and the effects of PLGA electrospun sheets on IAA prevention in the rat model were observed and analysed.Results:(1) The cell viability of mouse fibroblast NIH-3T3 cells inoculated on Ctrl+ sheets,160μm sheets and 60μm sheets were 32%,12% and 6% after 24 hrs and 15%,11% and 3% after 48 hrs respectively. Cells on PLGA sheets had irregular and unspreaded morphologies, and most cells were stayed in fibrous pores. In contrast, cells on Ctrl+ sheets were spreaded. However, cells on PLGA electrospun sheets were rarely died, and cells on Ctrl+ sheets is just the reverse. (2) The occurrences of severe postoperative adhesions in rat models established by 4 methods were 66%,28%,50% and 33%, and the corresponding death rates were 40%,30%,60% and 40% respectively. There were no significant differences in LDH activity in abdominal lavage, AKP activity in serum, results of Routine Blood Test and viscera weight among these models. (3) The adhesion incidences of Ctrl- group, Ctrl+ group,160μm group and 60μm group were 80%,14%, 25% and 71%, and the incidences of complications were 83%,62.5%,12.5% and 14% respectively.Conclusions:PLGA electrospun sheets have good cell compatibility, and can significantly reduce the incidence and severity of intra-abdominal adhesion complications in rat model, which greatly improved the rats’quality of life. The thickness has significant impact on curative effect of PLGA electrospun sheets, the thicker sheets can significantly reduce the incidence of postoperative adhesions.