Degradation behavior of PGC/MgO composites for biodegradable ureteral stents

Abstract

Ureteral stents are widely used in urological surgery to maintain urinary drainage and facilitate postoperative recovery, yet for short-term biodegradable stents, achieving simultaneous control over degradation rate and mode remains a major challenge. Poly(glycolide-co-ε-caprolactone) (PGC) is an elastomeric copolymer with excellent mechanical flexibility but insufficiently rapid degradation for short-term indwelling use. In this study, nano magnesium oxide (MgO) was incorporated into PGC to regulate its degradation behavior and mechanical stability. The structural, thermal, and mechanical properties of PGC/MgO composites were characterized using FT-IR, SEM-EDS, DSC, and mechanical testing, while their in vitro degradation was systematically evaluated in simulated urine. PGC initially exhibited a bulk-degradation mode that gradually transitioned to a surface erosion-like pattern. The incorporation of MgO effectively accelerated degradation by promoting ester bond hydrolysis and facilitating molecular chain scission, whereas excessive MgO loading caused premature loss of mechanical integrity. The 5 wt% MgO formulation achieved the most balanced performance, maintaining sufficient mechanical support for approximately four weeks and enabling gradual, particulate-type degradation thereafter. Mg²⁺ release remained within physiologically safe limits, confirming good biocompatibility. These findings are based on experiments conducted on specimens, and further research is needed. This work can serve as a valuable reference for future stent designs and animal studies.