Fabrication of radiopaque, drug-loaded resorbable polymer for medical device development

Abstract

Resorbable medical devices provide temporary functionality before degrading into safe byproducts. One application is absorbable inferior vena cava filters (IVCFs), which prevent pulmonary embolism (PE) in high-risk patients with contraindications to anticoagulants. However, current absorbable IVCFs are limited by radiolucency and local clot formation risks. This study aimed to develop radiopaque, drug-loaded resorbable IVCFs with enhanced imaging and therapeutic capabilities. Poly-p-dioxanone (PPDO) sutures were infused with gadolinium nanoparticles (GdNPs) and dipyridamole (DPA), an anti-thrombotic agent. GdNPs were synthesized with an average diameter of 35.76 {+/-} 3.71 nm. Gd content was 371 {+/-} 1.6 mg/g (PPDO-Gd) and 280 {+/-} 0.3 mg/g (PPDO-Gd+DPA), while DPA content was 18.20 {+/-} 5.38 mg/g (PPDO-DPA) and 12.91 {+/-} 0.83 mg/g (PPDO-Gd+DPA). Suture thickness (0.39-0.49 cm, P = 0.0143) and melting temperature (103.61-105.90, P = 0.0002) statistically differed among the different groups, while load-at-break did not (4.39-5.38, P = 0.2367). Although suture thickness and melting temperatures differed significantly, load-at-break was preserved and did not alter the mechanical and degradation properties of the various IVCFs. Micro-CT imaging revealed enhanced radiopacity for Gd-containing IVCFs (2,713 {+/-} 105 HU for PPDO-Gd, 1,516 {+/-} 281 HU for PPDO-Gd+DPA). Radiopacity decreased gradually over 10-12 weeks. Clot-trapping efficacy was maintained, and no hemolysis or cellular toxicity was observed. In conclusion, the GdNP- and DPA-infused PPDO IVCFs demonstrated improved radiopacity, anti-thrombotic potential, and compatibility with routine imaging, without compromising mechanical strength or safety.