Preparing and characterizing biodegradable materials for ureteral stents

Abstract

The development and application of biodegradable ureteral stents is of clinical significance for patients with ureteral stenosis and obstruction. We prepared five types of degradable monofilament, namely poly‐L‐lactide, poly(L‐lactide‐co‐ glycolide) (85% L‐lactide, 15% glycolide), poly(L‐lactide‐co‐glycolide‐co‐ε‐ caprolactone) (89% L‐lactide, 8% glycolide, and 3% ε‐caprolactone), poly(L‐lactide‐ co‐D,L‐lactide) (95% L‐lactide, 5% D,L‐lactide), and poly(lactide‐co‐ε‐caprolactone) (95% L‐lactide, 5% ε‐caprolactone), by melt extrusion and secondary drawing processes, after which degradation experiments were carried out in simulated urine at 37°C for 2 months. Because residues in the urinary systems of patients can cause complications, it is important that biodegradable ureteral stents are completely degraded after 6 weeks. Poly‐L‐lactide did not completely degrade under the abovementioned conditions and its molecular weight changed little. On the other hand, the poly(L‐lactide‐co‐glycolide) monofilament degraded slightly faster than that prepared from poly‐L‐lactide; however it maintained a certain mechanical strength after 8 weeks, which is not ideal for a woven ureteral stent. The poly(L‐lactide‐co‐D,L‐lactide), poly(L‐lactide‐co‐glycolide‐co‐ε‐caprolactone), and poly(lactide‐co‐ε‐caprolactone) monofilaments exhibited good tensile strengths and elongations at break in the first four weeks, which were reduced to almost zero in the eighth week. Ureteral stents made of these polymers can open narrow urethras at early stages and degrade completely at later stages. Based on its degradation rate, we conclude that the poly(lactide‐co‐ε‐caprolactone) monofilament is the best material for the preparation of ureteral stents.

Surface Modification of Zn–Cu Alloy with Heparin Nanoparticles for Urinary Implant Applications

“…Common ureteral stent materials, such as silicone, polyurethane, and stainless steel, led to complications. , What’s more, repeated inserting and removing could contribute to physical pain and psychological distress for the patient, as well as postoperative secondary infections . Lately, biodegradable polymers such as poly­( l -lactide- co -ε-caprolactone) PLCL, poly glycolic acid (PGA), poly lactide- co -glycolic acid (PLGA), poly­( l -lactide- co -ε-caprolactone) (PLACL), poly­( l -lactide- co -5-amino-1,3-dioxan-2-one) P­(LA- co -AC) have also been investigated as prospective materials for ureteral stents. Nonetheless, problems of extended degradation duration and insufficient support for the urinary system were observed .…”

Degradation behavior of polylactic‐co‐glycolic acid and polycaprolactone with nanosilver scaffolds

“…The implantation of ureteral scaffolds is a common clinical solution. [1][2][3][4][5][6] However, the use of ureteral scaffolds is often accompanied by some complications, such as scaffold displacement, biofilm, crusting, and vesicoureteral reflux. [7][8][9] These complications greatly affect the treatment effect and postoperative quality of life of patients.…”

“…Among them, the ureteral disease is particularly serious, which is a common and frequently occurring disease of the urinary system, accounting for 80% of patients in urology. The implantation of ureteral scaffolds is a common clinical solution 1–6 . However, the use of ureteral scaffolds is often accompanied by some complications, such as scaffold displacement, biofilm, crusting, and vesicoureteral reflux 7–9 .…”

Design and characterization of a novel braided biodegradable double‐J ureteral stent

“…The authors' previous research shows that among many degradable biomedical materials, poly(lactide-co-εcaprolactone) (PLCL) is an ideal material for braided ureteral stents. 32 To eliminate the disadvantages mentioned above, 8-, 12-, and 16-strand PLCL monofilament-braided degradable ureteral stents were designed, fabricated, and characterized in this study. The tensile performance, radial support performance, in vitro degradation, fixation performance, bending resistance performance, and drainage performance of the stents were evaluated.…”

“…To solve this, biodegradable ureteral stents have emerged as a new generation of endourological devices, overcoming the “forgotten stent syndrome” and reducing healthcare costs, 31 although research specifically focused on braided degradable ureteral stents is still scarce. The authors' previous research shows that among many degradable biomedical materials, poly(lactide‐co‐ε‐ caprolactone) (PLCL) is an ideal material for braided ureteral stents 32 …”