A bilayer swellable drug-eluting ureteric stent (BSDEUS) is engineered and implemented, as a sustained drug delivery platform technology that enhances localized drug delivery to the highly impermeable urothelium, for the treatment of urothelial diseases such as strictures and carcinomas. On deployment, the device swells to co-apt with the ureteric wall and ensure drug availability to these tissues.

BSDEUS consists of a stent spray-coated with a polymeric drug containing polylactic acid-co-caprolactone (PLC) layer which is overlaid by a swellable polyethylene glycol diacrylate (PEGDA) based hydrogel.

In-vitro quantification of released drug demonstrated a tunable time-profile, indicating sustained delivery over 1-month. The PEGDA hydrogel overlayer enhanced drug release and transport into explanted porcine ureteric tissues ex-vivo, under a simulated dynamic fluid flow. A preliminary pilot in-vivo feasibility study, in a porcine model, demonstrated that the swollen hydrogel co-apts with the urothelium and thus enables localized drug delivery to the target tissue section. Kidney functions remained unaffected and device did not result in either hydronephrosis or systemic toxicity.

This successful engineering of a bilayer coated stent prototype, demonstrates its feasibility, thus offering a unique solution for drug-based urological therapy.

设计并实施了双层可溶胀药物洗脱输尿管支架（BSDEUS），作为持续的药物输送平台技术，可增强局部药物向高度不可渗透的尿路上皮的输送，以治疗尿道上皮疾病（如狭窄和癌变）。部署后，该装置会膨胀以与输尿管壁配合，并确保这些组织的药物利用率。

BSDEUS包括一个支架，该支架上喷涂有包含聚乳酸-己内酯（PLC）层的聚合物药物，该药物层被可膨胀的聚乙二醇二丙烯酸酯（PEGDA）基水凝胶覆盖。

释放药物的体外定量显示了可调的时间曲线，表明持续交付超过1个月。在模拟的动态流体流下，PEGDA水凝胶覆盖层增强了药物的释放和离体进入离体猪输尿管组织的转运。在猪模型中的一项初步的体内初步可行性研究表明，溶胀的水凝胶与尿路上皮共同适应，因此能够将药物局部递送至目标组织部分。肾脏功能保持不受影响，装置不会导致肾积水或全身毒性。

双层涂层支架原型的成功设计证明了其可行性，从而为基于药物的泌尿科治疗提供了独特的解决方案。