Biomechanical evaluation of biodegradable PCL cog threads for prolapse rehabilitation

Pelvic organ prolapse (POP) is a prevalent pelvic floor dysfunction (PFD) that significantly impacts women's quality of life, driving the need for innovative and less invasive treatment options. Surgical intervention remains the primary treatment for POP; however, it is often associated with high invasiveness, substantial risks, and a notable rate of failure. In this study, we investigate the potential of biodegradable cog threads, commonly used in cosmetic facial lifting, as an alternative surgical solution for reinforcing vaginal wall defects. Specifically, we evaluate the performance of commercially available 360° 4D barb threads made of polycaprolactone (PCL) under simulated physiological conditions. The degradation and mechanical properties of the threads were analyzed after immersion in Phosphate Buffer Solution (PBS) and Potassium Hydrogen Phthalate (KHP) for periods of 90 and 180 days, with comparisons to a control group. Fourier-transform infrared (FTIR) spectroscopy revealed mild to moderate degradation of the threads over 180 days in both mediums. Tensile strength tests indicated a reduction in maximum load-bearing capacity, with declines of 13% to 19%, more pronounced in the PBS medium. Despite this, cyclic tests demonstrated that the threads retained sufficient mechanical integrity to endure 100 loading cycles across all conditions, suggesting their durability under repetitive stress. These preliminary in vitro findings highlight the potential of biodegradable cog threads as a promising material for developing a novel, minimally invasive technique for POP correction. The threads' ability to maintain mechanical strength despite degradation supports their viability for long-term pelvic floor reinforcement.