Ureteral Stent Drug-Eluting Coating Patents 2026
Ureteral Stent Drug-Eluting Coating & Encrustation Prevention
Encrustation affects 56% of ureteral stents between weeks 6–12 of dwell time. Drug-eluting coatings, biodegradable polymer matrices, and nanoparticle surfaces represent the primary patent-active response strategies across this dataset.
Encrustation Cascade and the Engineering Response
Encrustation on ureteral stents follows a multistep cascade: urinary proteins and ions form a conditioning film, which attracts bacteria into a biofilm, which then catalyzes mineral crystal deposition — predominantly calcium oxalate, struvite, and calcium phosphate — progressing to functional stent failure and clinical complications including sepsis and renal failure.
Encrustation rates climb steeply with dwell time, reaching 18.33% within the first 5 weeks, 56% between weeks 6 and 12, and 75% thereafter in a cohort of 134 stents in 83 patients. High-resolution micro-CT analysis confirms that 91.5% of stents show inner luminal encrustation as early as postoperative day 14.
Four primary technology clusters have emerged across retrieved patent records: drug-eluting polymer coating systems, antimicrobial surface coatings targeting biofilm formation, hydrophilic and lubricious barrier coatings reducing crystal nucleation, and biodegradable stent bodies with integrated drug matrices that eliminate secondary retrieval procedures.
In this dataset, Boston Scientific Scimed holds the largest single-assignee share of drug-delivering stent patents with at least 8 distinct records across US, EP, and WO jurisdictions. The most recent filings (2022–2025) in retrieved records show increasing geographic diversification, with Indian, Chinese, and Spanish-foundation entities entering the space alongside established US assignees.
Filing Patterns Across Technology Clusters and Jurisdictions
Patent activity in this dataset spans three distinct eras from 1997 to 2025, with the most recent cluster (2019–2025) characterized by biodegradable drug matrices, nanoparticle coatings, and photocuring manufacturing methods — reflecting a shift from structural stent design toward surface-level therapeutic engineering.
Patent Records by Technology Cluster — Ureteral Stent Encrustation Prevention (Dataset Snapshot)
Drug-eluting polymer coatings account for the largest share of patent records in this dataset, followed by antimicrobial surface coatings and hydrophilic barrier coatings, with biodegradable stent bodies representing the most recent and fastest-growing cluster.
↗ Click bars to explorePatent Filing Activity by Era — Ureteral Stent Encrustation Prevention (Dataset Snapshot)
Filing activity in this dataset increased markedly in the 2019–2025 acceleration era, with biodegradable and nanoparticle-based coating patents emerging for the first time, compared to foundational structural patents in the 1990–2005 period.
↗ Click bars to exploreKey Clinical Indication Areas for Encrustation Prevention Technologies
Retrieved patent and literature records map to five distinct clinical indication domains, each with differing encrustation risk profiles, dwell-time expectations, and engineering requirements that drive differentiated coating and drug-delivery strategies.
Post-Ureteroscopy Urolithiasis Management
The dominant clinical indication across retrieved records, with encrustation rates correlated directly to stent dwell time — reaching 56% between weeks 6 and 12 in a 134-stent cohort. The Tria (PercuShield) and Polaris Ultra (HydroPlus) stents were compared in a randomized clinical trial, with HydroPlus hydrophilic coating evaluated as a marketed anti-encrustation approach. Micro-CT confirmed 91.5% of stents show inner luminal encrustation by postoperative day 14.
Urolithiasis IndicationMalignant Ureteral Obstruction Long-Term Stenting
Patients with extrinsic ureteral compression from malignancy or retroperitoneal fibrosis require long-term stenting where encrustation and infection risks are amplified with extended dwell times. The Resonance metallic stent (Cook Medical) offers inherent encrustation resistance with longer dwell durations versus polymer stents. The Allium nitinol stent, coated with a co-polymer specifically to reduce encrustation, addresses this domain.
Oncology / Long-Term StentingUpper Tract Urothelial Carcinoma
An emerging niche: biodegradable stents serve as local adjuvant chemotherapy delivery vehicles following endoscopic tumor ablation. The silk fibroin-coated mitomycin C-releasing biodegradable stent (BraidStent® platform) targets this indication, with controlled drug release demonstrated over 6–12 hours and significant delay of stent degradation rate assessed in a 2022 study. This platform demonstrates the breadth of the biodegradable coated-stent approach beyond encrustation prevention alone.
Oncology / Drug DeliveryPediatric Urology Encrustation Risk
Surface analysis of double-J stents in pediatric patients shows both proximal (renal pelvis) and distal (bladder) ends are maximally susceptible to crystal and biofilm deposition within 7 days of implantation. Studies document a 27–30% reduction in Young’s modulus after 31 days of encrustation in pediatric-sized stents, highlighting the specific biomechanical consequence of encrustation in smaller-caliber devices. This defines a distinct engineering requirement for anti-encrustation coatings in pediatric urology applications.
Pediatric UrologyKey Patent Assignees in Ureteral Stent Encrustation Prevention (Retrieved Records)
In this dataset, Boston Scientific Scimed holds the largest single-assignee share of drug-releasing stent patents with at least 8 records across US, EP, and WO jurisdictions filed between 2003 and 2019. Gyrus ACMI follows with 6 records in retrieved records, while recent 2022–2025 filings show new entrants from India and China gaining ground in coating-specific innovation.
Top Assignees by Filing Count — Ureteral Stent Encrustation Prevention in Retrieved Records (Dataset Snapshot)
↗ Click bars to exploreBoston Scientific Scimed, Inc.
Boston Scientific Scimed holds at least 8 distinct patent records in this dataset spanning US, EP, and WO jurisdictions, with priority dates from 2003 to 2019, representing the most developed commercial-grade portfolio in retrieved records. Key patents include drug-releasing structural stent features with salinity-responsive hydrogel outlets (US 2016, active), a pressurized balloon drug-delivery reservoir at the proximal retention structure (US 2016), and a comprehensive EP grant for urologically beneficial agent delivery (EP 2019, active). Multiple records remain in active status, covering local analgesia, infection prevention, and anti-spasm indications.
United StatesSree Balaji Medical College and Hospital
Sree Balaji Medical College and Hospital holds 2 active Indian patent records filed in 2023 and 2024, focusing on ionotropic gelation-prepared biopolymeric nanoparticle coatings for ureteral stent surfaces. The 2023 filing describes cephalexin-glyoxal and sulfamethoxazole-chitosan nanoparticle coatings targeting bacterial adhesion inhibition, biofilm prevention, and calcium carbonate crystal deposition reduction. The 2024 continuation adds explicit encrustation prevention claims alongside biocompatibility and sustained-release assertions, representing the first use of this nanoparticle platform in this dataset for dual infection and encrustation control.
India — INFive Directional Signals from 2022–2025 Filings
The most recent filing cluster in this dataset (2022–2025) reveals five distinct directional signals, each representing a materially different technical approach from the foundational stent architecture patents of the 2003–2019 era.
Biodegradable Stents Eliminating Secondary Retrieval
The 2024–2025 filings from NIMS University Rajasthan (IN, 2025) and Fundación Jesus Uson (WO, 2024) converge on fully biodegradable stents incorporating pH-sensitive linkages and enzymatically cleavable bonds — mechanisms claimed for the first time in this dataset. These designs target elimination of the secondary retrieval procedure, which represents the clinical event exposing encrusted patients to the greatest procedural morbidity. Clinical translation remains a high-risk path given the challenge of controlling degradation kinetics in the urinary environment.
Nanoparticle-Functionalized Dual Antibiotic Coatings
The Sree Balaji chitosan nanoparticle platform (IN, 2023–2024) introduces ionotropic gelation-prepared biopolymeric nanoparticles as a stent surface coating, using dual antibiotics — cephalexin and sulfamethoxazole — to simultaneously inhibit biofilm formation and reduce calcium carbonate crystal deposition. This is the first application of this nanoparticle preparation method in the ureteral stent encrustation prevention space within this dataset. The 2024 continuation expands claims for biocompatibility and cost-effectiveness, indicating a pathway toward volume-manufacture application.
Drug-Eluting Polymer Coatings vs. Biodegradable Drug-Matrix Stents
Click any row to explore further.
| Dimension | Drug-Eluting Polymer Coating | Biodegradable Drug-Matrix Stent |
|---|---|---|
| Representative Assignees | Boston Scientific Scimed (US); Jiangsu Biosurf Biotech (CN→US); Sree Balaji Medical College (IN) | NIMS University Rajasthan (IN, 2025); Fundación Jesus Uson (WO, 2024); Jin Jiahao (US, 2024) |
| Stent Base Material | Polyurethane or silicone base with drug-loaded polymer overcoat (e.g. PLGA + papaverine hydrochloride via dip-coating) | Biodegradable polymer body throughout (e.g. silk fibroin, polycaprolactone lactide, heparin-coated biodegradable matrix) |
| Retrieval Requirement | Standard cystoscopic retrieval required; encrusted stent removal carries procedural morbidity risk | Designed for retrieval-free degradation; Jin Jiahao 2024 patent claims removal without anesthesia or cystoscopy |
| Drug Release Mechanism | Controlled release from polymer matrix; salinity-responsive hydrogel outlet variants (Boston Scientific Scimed 2016 US); sustained release demonstrated for PLGA-papaverine | pH-sensitive linkages, enzymatically cleavable bonds, and hydrolytically labile components (NIMS University 2025 IN patent); silk fibroin release over 6–12 hours (2022 literature) |
| Patent Status (Dataset) | Multiple active US and EP grants; Boston Scientific Scimed records active through 2019 priority; Jiangsu Biosurf 2022 and 2024 US patents active | Predominantly pending (IN 2025, US 2024); WO 2024 filed; earlier biodegradable records include active heparin-coated stent animal studies (2021 literature) |
| Encrustation Prevention Mechanism | Local pharmacological inhibition of biofilm and crystal nucleation; hydrophilic coating reduces protein conditioning film; contact angle reduction confirmed to reduce mineral deposition mass | Eliminates long-term indwelling surface entirely through degradation; active antimicrobial, anti-inflammatory, and anti-proliferative agents distributed throughout polymer matrix |
| Key Technical Risk | Coating adhesion failure under urinary flow is the primary unresolved barrier identified across multiple retrieved review articles (2017–2022); coating durability limits clinical efficacy | Degradation kinetics in urine difficult to control; clinical translation for biodegradable ureteral stents historically slow; in vivo degradation rate validation identified as primary technical risk |
| Clinical Validation Stage | Randomized clinical trial data available (Tria vs. Polaris Ultra, 2021; pH-modulation RCT in 105 patients across 9 hospitals, Spain, 2020) | Preclinical and early-stage; silk fibroin mitomycin C stent assessed in 2022 study; polycaprolactone lactide degradation studied 2021; no large RCT data in this dataset |
Frequently Asked Questions: Ureteral Stent Drug-Eluting Coatings and Encrustation Prevention
Encrustation follows a multistep cascade: urinary proteins and ions first form a conditioning film on the stent surface, which attracts bacteria to form a biofilm, which then catalyzes mineral crystal deposition — predominantly calcium oxalate, struvite, and calcium phosphate. Encrustation rates reach 18.33% within the first 5 weeks, 56% between weeks 6 and 12, and 75% thereafter, based on a cohort of 134 stents in 83 patients.
Based on retrieved patent records in this dataset, drug-eluting polymer coating systems represent the most active cluster, led by Boston Scientific Scimed with at least 8 patent records. Antimicrobial surface coatings (including chitosan nanoparticle approaches from Sree Balaji Medical College), hydrophilic and lubricious barrier coatings (Jiangsu Biosurf Biotech), and biodegradable stent bodies with integrated drug matrices (NIMS University Rajasthan, Fundación Jesus Uson) are the three other primary clusters.
Biodegradable stents aim to eliminate the need for secondary retrieval — the clinical procedure that exposes encrusted patients to the greatest morbidity. The 2024–2025 filings from NIMS University Rajasthan and Fundación Jesus Uson claim pH-sensitive linkages and enzymatically cleavable bonds for site-specific, time-controlled degradation. Clinical translation has historically been slow due to the difficulty of controlling degradation kinetics in the urinary environment.
In vitro comparative studies indicate that contact angle and surface charge are the critical surface parameters predicting mineral deposition quantity. Materials with lower contact angles consistently show reduced encrustation mass. These findings are reported in a 2020 literature study specifically investigating which surface parameters provide guidance for novel stent material development.
Sree Balaji Medical College and Hospital’s 2023–2024 Indian patents describe ionotropic gelation-prepared biopolymeric nanoparticle coatings using cephalexin-glyoxal and sulfamethoxazole-chitosan nanoparticles. These coatings target bacterial adhesion inhibition, biofilm prevention, and calcium carbonate crystal deposition reduction simultaneously — representing the first application of this preparation method for ureteral stent surfaces in this dataset.
Boston Scientific Scimed holds the foundational drug-releasing stent architecture IP in this dataset, with multiple active US and EP grants dating to 2013–2019 priority dates across at least 8 distinct patent records covering drug-delivery reservoirs, salinity-responsive hydrogel outlets, and end-effector controlled-release systems. New entrants designing drug-eluting stents must design around this portfolio or seek licensing; freedom-to-operate analysis is identified as essential before clinical development investment.
Data and insights on this page are based on a limited patent and literature dataset and are for reference only. Figures may not represent the complete technology landscape.