Shape-dependent self-assembled peptides (EASPs) enhance radiofrequency ablation of lipid-rich atherosclerotic plaques
Background
Radiofrequency ablation (RFA) is a promising strategy for targeted lesion creation, but its effectiveness is severely limited in highly heterogeneous tissues like lipid-rich atherosclerotic plaques. The strong dependence on Joule heating means current electrosensitizers, which rely on passive diffusion and random distribution, often fall short. This creates a critical gap in treating atherosclerosis, a condition characterized by endothelial damage, lipid metabolism disorders, and progressive inflammation. A targeted approach that can precisely enhance RF energy deposition in diseased arteries is urgently needed to improve therapeutic outcomes and overcome the challenges of plaque heterogeneity.
Study Design
Inspired by Geobacter OmcZ nanowire networks, researchers designed electrosensitive atherosclerosis-targeting self-assembled peptides (EASPs) as novel RF sensitizers. These peptides feature a targeting motif and a self-assembling module, enabling them to accumulate in inflammatory regions of the aorta. Following systemic delivery, EASPs achieve recognition-induced self-assembly, forming in situ network aggregations. This process is rapidly amplified by the presence of vascular cell adhesion molecule-1 (VCAM-1), leveraging the unique shape-dependent electrical properties of the nanofiber networks to enhance local conductivity in diseased arteries.
Results
EASPs demonstrated a rapid and sustained increase in local conductivity following systemic delivery, exceeding 2.39-fold the initial level within 2 hours. This enhanced conductivity translated into a significant improvement in heat deposition during RFA. EASP-assisted RFA led to increased temperatures and expanded ablation zones within diseased arteries. The study compared accumulation times, finding a dose-response relationship:
The 4-hour accumulation group exhibited a 59.85% higher temperature increase and a 94.48% greater ablation area compared to the 2-hour group. This indicates that longer accumulation times for the self-assembled EASP networks further optimize the therapeutic effect, providing a substantial enhancement in both the intensity and spatial extent of ablation.
Key Findings
- EASPs increased local conductivity in diseased arteries by over 2.39-fold within 2 hours.
- EASP-assisted RFA significantly enhanced heat deposition, increasing temperatures and ablation zones.
- A 4-hour EASP accumulation led to a 59.85% higher temperature increase during RFA.
- The 4-hour EASP accumulation group achieved a 94.48% greater ablation area than the 2-hour group.
Why It Matters
This study introduces a groundbreaking approach to enhance radiofrequency ablation for atherosclerosis, particularly in challenging lipid-rich plaques. By leveraging targeted self-assembly and shape-dependent electrical properties, EASPs overcome the limitations of passive diffusion seen in conventional electrosensitizers. This could significantly improve the precision and therapeutic efficiency of RFA, making it a more viable and effective treatment option for advanced plaque removal. The concept of in situ network aggregation triggered by specific biomarkers like VCAM-1 opens new avenues for targeted nanomedicine, potentially leading to protocols where therapeutic agents are precisely delivered and activated only at the site of disease, minimizing off-target effects and maximizing localized treatment efficacy.
atherosclerosis
radiofrequency-ablation
self-assembled-peptides
nanomedicine
vcam-1
inflammation