Silver Nanofunctionalized Stent after Radiofrequency Ablation Suppresses Tissue Hyperplasia and Bacterial Growth.

Yubeen Park,Wooram Park,Ga-Hyun Bae,Sang Soo Lee,Jung-Hoon Park,Jeon Min Kang,Dong-Sung Won,Dae Sung Ryu,Ji Won Kim,Song Hee Kim,Chu Hui Zeng

doi:10.3390/pharmaceutics14020412

Abstract

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.

Highlights

Introduction iationsMalignant biliary obstruction (MBO) is caused by various factors, including cholangiocarcinoma, pancreatic cancer, extrinsic compression, and adjacent inflammation
AgNPs-coated self-expandable metal stent (SEMS) were successfully fabricated through a two-step simple synthesis process
Elemental analysis through energy-dispersive X-ray spectroscopy revealed that the atomic percentage of Ag was 0% in uncoated SEMS and 11.8% in AgNPs-coated SEMS (Figure 2a–c)

Summary

Introduction

Malignant biliary obstruction (MBO) is caused by various factors, including cholangiocarcinoma, pancreatic cancer, extrinsic compression, and adjacent inflammation. As. MBO is often diagnosed at a later stage, the proportion of patients who undergo surgical resection is limited to only 30%, resulting in a high mortality rate [1–4]. Placement of a selfexpandable metal stent (SEMS) is the current standard treatment for palliation in patients with unresectable MBO [5–8]. SEMSs are susceptible to recurrent symptoms due to tumor ingrowth, tissue hyperplasia, biofilm deposition, and biliary sludge formation with restenosis, which occur within 6 to 8 months [5,8–10]. Ablation has been presented as a novel option for the palliative management of unresectable. RF ablation generates high-frequency alternating currents to create localized heating and induce coagulative necrosis in tumor tissues, maintaining patency

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