Fabrication and evaluation of a warp knitted polypropylene/polylactic acid composite mesh for pelvic floor repair

Abstract

Surgical mesh for repairing pelvic defects is expected to be stiff to improve surgical convenience, as well as be soft and flexible to relieve foreign body sensation. This paper aims to develop a new composite mesh (PA) consisted of polypropylene (PP) monofilaments and polylactic acid (PLA) monofilaments according to this expectation. The PA mesh was designed by the two-bar warp knitting technique to have a knitted structure with light weight (19.9 g/m2) and high porosity (porosity). A commercial lightweight PP mesh—Surgimesh® Prolapse mesh—was used as the control group. The mechanical property, in vitro degradation, and in vivo biocompatibility were then measured. The results revealed that the addition of stiffer, stronger PLA monofilaments did not significantly strengthen PA mesh, but made the mesh stiff. The warp knitted structure, porosity and pore size are vital factors affecting mesh mechanical properties. PLA monofilaments in PA mesh were degraded in 74 weeks, with a maximum weight loss reaching 62.4%. PA mesh was demonstrated to have better biocompatibility with evidences of lower shrinkage (13.1%) and faster tissue growth speed.