Leucocyte accumulation and leukotriene B4 release in response to polyglactin 910 and expanded polytetrafluoroethylene in hollow chambers in the rat

The acute inflammatory reaction elicited after implantation of polymer membranes used clinically to promote bone healing and augmentation was studied in a soft tissue titanium chamber model. The two materials compared were non-degradable expanded polytetrafluoroethylene (ePTFE) and degradable polyglactin 910, a copolymer of 90% polyglycolic acid and 10% polylactic acid. The membranes were implanted in the titanium chamber for 24 h and 6d. The number of leucocytes increased for both materials, whereas the leukotriene B4 (LTB4) content decreased over time. In both groups polymorphonuclear granulocytes predominated. The number of leucocytes was significantly higher in chambers with polyglactin 910 than ePTFE. In contrast, the LTB4 content was higher in chambers with ePTFE than polyglactin 910. No differences in cell viability were observed between the materials tested. This study shows that both degradable and non-degradable polymers elicit a marked influx and activation of inflammatory cells during early healing in soft tissues.