Injectable recombinant human collagen-derived material with high cell adhesion activity limits adverse remodelling and improves pelvic floor function in pelvic floor dysfunction rats

Female pelvic floor dysfunction (FPFD) is a life-changing condition that severely affects women's physical and mental health. Despite the effectiveness of current treatments for FPFD, there is a high rate of short-term recurrence. Here, we introduced an injectable recombinant human collagen (rhCOL)-derived material with high cell adhesion activity to achieve pelvic floor repair and extracellular matrix (ECM) assembly. In our study, rhCOL promoted human uterosacral ligament fibroblast (HULF) adhesion, migration, and collagen I and III expression and regulated the metabolism of HULFs in vitro. Subsequently, we established a rat model of FPFD. Then, rhCOL, including rhCOLI and rhCOLIII, was perivaginally injected into FPFD rats, resulting in a significant increase in abdominal urine leak point pressure (LPP) and maximum tensile strength compared to the FPFD model group. Better organization of the lamina propria and muscularis in FPFD rats was observed after 14 days of rhCOL treatment. Meanwhile, the expression of collagen I, collagen III, and TIMP1 was upregulated, and MMP2 was downregulated. Furthermore, rhCOL promoted HULF adhesion, migration, and ECM synthesis by upregulating the focal adhesion kinase (FAK)/RhoA/ROCK signalling pathway in vitro and in vivo. These findings suggest that the perivaginal injection of rhCOL is a promising treatment for FPFD with potential for future clinical use.