Abstract: Objective To study the repair effect of PLGA-collagen I patch on inguinal hernia. Methods First, the PLGA-collagen I patch was prepared. Then, the rat bone marrow mesenchymal stem cells were extracted, and the rat model of abdominal wall defect was made. Bone marrow mesenchymal stem cells (BMSCs) bearing tissue engineering patches (experimental group) and cell-free tissue engineering patches (control group) were implanted into the groin respectively. The changes of pro-inflammatory factor IL-6 (interleukin -6) and IL-10 (interleukin -10) were detected by ELISA kit after operation. Immunohistochemistry was used to detect the change of macrophage surface antigen to analyze the inflammatory reaction. HE staining was used to observe the regeneration of tissue in the patch and the degradation state of the material. SEM was used to observe the integrity of peritoneum. The angiogenesis state was detected by immunohistochemistry. The formation of collagen fiber was detected by trichrome staining of Masson. Results After a week, the macrophages invasion in the patch of both the experimental group and the control group were significantly increased. For one month, the inflammatory reaction gradually subsided and the number of macrophages decreased. Long term tests showed that the BMSCs patch could promote the synthesis of collagen fibers, regeneration of blood vessels, and repair of abdominal wall injury. One month after surgery, there was no swelling in the abdominal wall of the experimental group and the control group. The rats were healthy. In one month, two months and six months after the operation, the tissue morphology and SEM electron microscope were observed. The PLGA-collagen I patch of BMSCs can promote cell infiltration, angiogenesis and tissue regeneration. The degradation rate of PLGA material was faster. In sixth months, the cell - based patch was almost completely degraded. However, PLGA-collagen I patches that were not planted cells were degraded, though. It degraded to pieces and remained in the body as a foreign body. Conclusions In this study, PLGA-collagen I tissue engineering materials planted with BMSCs can repair the defects more quickly and reliably, so as to achieve the purpose of treatment of hernia.

Key words: PLGA-Collagen I patch, inguinal hernia, macrophage, inflammatory response