Porcine urinary bladder matrix-polypropylene mesh: a novel scaffold material reduces immunorejection in rat pelvic surgery

The present study set out to modify polypropylene vaginal surgical material using porcine urinary bladder matrix (UBM) in order to improve biocompatibility. The aim was to develop a compound scaffold that induced less vaginal erosion and to evaluate host immunoreactivity to this material in vivo. Forty-eight Sprague-Dawley rats were randomly divided into four equal groups. One group underwent a sham operation, and the other groups underwent vaginal implantation with different materials: UBM (U); UBM + polypropylene (UP); or polypropylene (P). The host tissue response was determined by macro-observation, and by histological and immunohistochemical methods at 7, 14, 21, or 28 days after surgery. The inflammation reaction was strongest throughout the entire observation time in Group P, but was weaker and had a tendency to decrease with time in Groups U and UP. The presence of the UBM material in the compound scaffold allowed the polypropylene to fuse with newly proliferating surrounding tissue and resulted in less rejection of the material by the host, as indicated by the reduced appearance of CD4-, and CD8-positive cells. Porcine UBM allowed mechanical isolation of polypropylene, and also reduced the immune reaction to polypropylene. This study suggests that the UBM + polypropylene compound scaffold may be a promising material for clinical use in pelvic reconstruction surgery.