Catheter‐associated urinary tract infection (CAUTI) is the most common healthcare‐associated infection; however, current therapeutic strategies remain insufficient for standard clinical application. A novel urinary catheter featuring a dual‐layer nanoengineering approach using zinc (Zn) and silver nanoparticles (AgNPs) is successfully fabricated. This design targets microbial resistance, minimizes cytotoxicity, and maintains long‐term efficacy. The inner AgNPs layer provides immediate antibacterial effects against the UTI pathogens, while the outer porous Zn layer controls zero‐order Ag release and generates reactive oxygen species, thus enhancing long‐term bactericidal performance. Enhanced antibacterial properties of Zn/AgNPs‐coated catheters are observed, resulting in 99.9% of E. coli and 99.7% of S. aureus reduction, respectively. The Zn/AgNPs‐coated catheter significantly suppresses biofilm with sludge formation compared to AgNP‐coated and uncoated catheters (all, p < 0.05). The Zn/AgNP‐coated catheter in a rabbit model demonstrated a durable, effective barrier against bacterial colonization, maintaining antimicrobial properties during the catheter indwelling period with significantly reduced inflammation and epithelial disruption compared with AgNP and uncoated groups. This innovation has the potential to revolutionize the design of antimicrobial medical devices, particularly for applications requiring long‐term implantation. Although further preclinical studies are required to verify its efficacy and safety, this strategy seems to be a promising approach to preventing CAUTI‐related complications.

Intraductal radiofrequency (RF) ablation combined with placement of a self-expandable metal stent (SEMS) for malignant biliary obstruction has risks such as stent- and heat-induced biliary sludge and restenosis. Here, we investigated the efficacy of a silver nanoparticles (AgNPs)-coated SEMS to inhibit tissue hyperplasia and bacterial growth caused by RF ablation with stent placement in the rabbit bile duct. The release behavior and antibacterial effects of AgNPs-coated SEMSs were evaluated. Then, SEMSs were successfully placed in all rabbits immediately after RF ablation. Ag ions were rapidly released at the beginning and then showed a gradual release behavior. The AgNPs-coated SEMS significantly inhibited bacterial activity compared to the uncoated SEMS (p < 0.05). Cholangiography and histological examination confirmed that the level of tissue hyperplasia was significantly lower in the AgNPs group than in the control group (all p < 0.05). Immunohistochemistry analyses revealed that TUNEL-, HSP 70-, and α-SMA-positive areas were significantly lower in the AgNPs group than in the control group (all p < 0.05). Intraductal RF ablation combined with nanofunctionalized stent placement represents a promising new approach for suppressing thermal damage as well as stent-induced tissue hyperplasia and bacterial growth.

Conventional irreversible electroporation (IRE) with low-frequency pulsed electric field (LF-PEF) is used to induce cell death; however, it has several disadvantages including a long procedure time and severe muscle contraction due to high-voltage electric field. This study investigates a novel IRE protocol with high-frequency pulsed electric field (HF-PEF) of 500 Hz repetition to ablate the prostate tissue in beagles for treatment of prostate cancer. A finite element analysis was performed to validate optimal electrical field strength for the procedure. In total, 12 beagles received HF-PEF of 500 Hz and were sacrificed at 4 h, 4 days, and 28 days (3 each). The remaining three beagles underwent sham procedure. The outcomes of HF-PEF were assessed by histological responses. HF-PEF successfully decellularized the prostate tissues 4 h after the treatment. The prostate glands, duct, and urethra were well preserved after IRE with HF-PEF. The ablated prostatic tissues were gradually regenerated and appeared similar to the original tissues 28 d after IRE with HF-PEF. Moreover, electrocardiography and hematology demonstrated that IRE with HF-PEF did not seriously affect the cardiac tissue. HF-PEF was effective and safe in the beagle prostate and effectively induced the ablation and gradually recovered with cellular regeneration.

This study investigated whether interwoven self-expandable metallic stent (I-SEMS) placement suppresses stent-induced tissue hyperplasia compared with conventional knitted self-expandable metallic stent (K-SEMS) placement in a rat esophageal model. Twelve rats were randomly assigned to the I-SEMS (n = 6) and K-SEMS (n = 6) groups. All rats were sacrificed 4 weeks after the stent placement. The degree of stent-induced tissue hyperplasia on esophagography and histologic examination was compared between the groups. Stent placement was technically successful in all rats. Esophagography revealed significantly greater mean luminal diameter of the stented esophagus in the I-SEMS group than in the K-SEMS group (p < 0.001). Histologic examination revealed a significantly lower percentage of tissue hyperplasia area and a significantly thinner submucosal fibrosis in the I-SEMS group than in the K-SEMS group (all p < 0.001). There were no significant differences in the thickness of the epithelial layers (p = 0.290) and degree of inflammatory cell infiltration (p = 0.506). Formation of stent-induced tissue hyperplasia was evident with both I-SEMS and K-SEMS. Placement of I-SEMSs with a small cell size and high flexibility seems to be effective in suppressing stent-induced tissue hyperplasia compared with placement of K-SEMSs in rat esophageal models.

Malignant gastric outlet obstruction is a severe complication of gastrointestinal malignancies, often treated with self‐expandable metallic stents (SEMSs). However, conventional SEMSs are associated with in‐stent restenosis due to granulation tissue formation. This work aims to evaluate the efficacy and safety of everolimus‐coated laser‐cut SEMS in suppressing stent‐induced tissue hyperplasia in a rat gastric outlet model. Everolimus, a next‐generation antiproliferative drug, is applied to laser‐cut SEMS using ultrasonic spray coating. The mehcanical properties, drug release profiles, and surface morphology of the stents were analyzed. In vivo, 20 rats are divided into control (uncoated laser‐cut SEMS) and experimental (everolimus‐coated laser‐cut SEMS) groups. Endoscopic and histological analyzes reveal significantly reduced granulation tissue area, submucosal fibrosis thickness, and inflammatory cell infiltration in the everolimus group compared to controls ( p < 0.05). Immunohistochemical staining demonstrates decreased smooth muscle cell proliferation and increased apoptosis in the everolimus group. The drug‐coated stents exhibit drug release over 30 days and maintain structural integrity without stent‐related adverse events. These findings suggest that everolimus‐coated laser‐cut SEMS effectively suppress stent‐induced tissue hyperplasia while preserving mechanical properties, indicating its potential as a therapeutic strategy for improving stent patency in the early stage after stent placement.