Drug-Coated Balloon Surface Roughness Modulates Intraprocedural Contact Mechanics and Delivery Efficiency: An In-Silico Study

The global prevalence of peripheral artery disease (PAD) continues to rise, driving the increasing clinical use of drug-coated balloons (DCBs). These devices traditionally deliver the antiproliferative drug Paclitaxel (PTX) or its derivatives to the lesion site and have demonstrated superior effectiveness over plain old balloon angioplasty in mitigating post-interventional restenosis. Despite improved clinical outcomes, concerns with inefficient intraprocedural PTX transfer to the arterial wall and resultant off-target/systemic effects remain. This study utilizes DCB-arterial wall structural contact modeling to identify how the microstructural features of urea-based coatings modulate drug transfer efficiency, with consideration of both traditional PTX and recently proposed multi-drug payloads that also deliver the smooth muscle cell relaxant Valsartan (VAL). We incorporated experimentally-obtained measures of coating surface microstructures of PTX-urea and PTX-VAL-urea coatings into finite element models that simulate key physical processes in DCB deployment, namely device-tissue mechanical contact and diffusion-mediated drug transport. Model predictions enable the interrelation of coating surface microstructure to intraprocedural tissue-arterial wall contact area, mechanical load distribution, and drug-specific transfer to the arterial wall. Our findings suggest that coating microstructure modulates the transfer efficiency of PTX but not VAL, which is understood as a consequence of the procedural duration and relative molecular weights/mobilities of these drugs. Taken together, our study underscores the complexity of coating design/dosing for multi-drug payloads and supports the use of computational modeling in the device design process.