Paper AS-ThM4
Degradation of Polypropylene Surgical Mesh: An XPS, FTIR, and SEM Study

Thursday, October 22, 2015, 9:00 am, Room 212D

Polypropylene mesh has been used to surgically treat stress urinary incontinence and has shown promising short-term results. However, serious complications have been associated with longer term implanted meshes. We hypothesize that these complications are due to oxidative degradation of the mesh brought about by reactive oxygen species that are released by adherent macrophages on the surface of the polypropylene.

Polypropylene is known to oxidize through a stable hydroperoxide (-COOH) intermediate, followed by chain scission and formation of a carbonyl (-C=O) end group. Oxidation of polypropylene leads to a reduction in molecular weight, embrittlement, cracking, and eventually fracture and fragmentation. An in vitro study was performed to study the oxidation of polypropylene surgical mesh in a model environment that simulates conditions the mesh would experiences in the body. Samples cut from three commercially available surgical devices produced by two manufacturers and polypropylene control samples were placed in an oxidizing medium consisting of 20% H₂O₂ and 0.1 M CoCl₂.

Samples were placed in the oxidizing medium and were incubated at 37 °C on a shaker for up to 6 weeks. The oxidizing medium was replaced every 3 to 4 days. Six samples were removed every week, washed in DI water, and dried. XPS and FTIR were used to analyze the samples for the presence of hydroperoxide and carbonyl species. SEM micrographs were acquired at 0, 4, and 5 weeks of oxidation.