A coaxial electrospun PLLA/PPDO/NAR mesh for abdominal wall hernia repair

This study aims to employ poly-L-lactic acid (PLLA) and poly(p-dioxanone) (PPDO), loaded with naringin (NAR) to fabricate a functionalized degradable mesh which can promote abdominal wall hernia (AWH) repair. Three meshes named PPDO, PLLA/PPDO, and PLLA/PPDO/NAR were fabricated by electrospinning. The physical and chemical properties of the meshes were evaluated from the aspects of morphology, wettability, chemical composition, mechanical properties, andin vitrodegradation. Then, the meshes were implanted into rats to evaluate their repair effects on abdominal wall defect models. The mechanical properties of PLLA/PPDO/NAR mesh were superior to the other two meshes, with a fixed tensile strength of 36.47 ± 2.40 N cm^-1and an elongation at break of 287.98% ± 51.67%, which adequately met the mechanical strength required for the human abdominal wall. The core-shell structure effectively delayed the degradation of PLLA/PPDO as well as PLLA/PPDO/NAR mesh, and drug release of PLLA/PPDO/NAR mesh. On the 7th, 14th, and 28th day after implantation, more neovascularization and tissue formation were observed in the PLLA/PPDO/NAR group and the newborn collagen was arranged in a regular and neat manner compared to the other two groups. The immunohistochemical results showed that the PLLA/PPDO/NAR mesh promoted abdominal wall repair by inhibiting the expression of matrix metalloproteinase2 as well as interleukin-6, and increasing the expression of vascular endothelial growth factor. The PLLA/PPDO/NAR mesh is promising for application in AWH repair.