3D-Printed CNT-Reinforced Bioresorbable Vascular Scaffold with Enhanced Mechanical Stability and Integrated Wireless Pressure Sensor for Continuous Hemodynamic Monitoring

Polymer-based bioresorbable vascular scaffolds (BVS) have garnered significant attention in biomedical applications. Among various BVS, polycaprolactone (PCL)-based scaffolds exhibit excellent biocompatibility, flexibility, chemical stability, and controlled degradation. However, their low radial strength limits practical applicability. Moreover, most reported BVS require periodic postimplantation monitoring to enable early detection of in-stent restenosis and thrombosis. To overcome these limitations, we fabricate a carbon nanotube (CNT)-reinforced PCL BVS using a 3D printing process, enabling patient-specific customization while significantly improving mechanical strength and durability. The proposed PCL/CNT-based stent not only serves as a structural scaffold but also facilitate real-time vascular pressure monitoring by integrating a wireless LC capacitive pressure sensor. The LC pressure sensor is microfabricated using microelectromechanical systems (MEMS) technology and exhibits highly stable resonance characteristics. A key innovation is the integration of a supporting micropillar within the capacitor cavity, which minimizes structural deformation and ensures a stable capacitance response. Mechanical testing demonstrates that PCL/CNT stents achieve significantly higher radial force (0.1 N/mm) compared to pristine PCL (0.013 N/mm). The wireless sensor exhibits high sensitivity (49 kHz/mmHg) with minimal capacitance variation (±5%). <i>In-vitro</i> studies in a phantom experiment confirm stable resonance frequency fluctuations that accurately correlate with hemodynamic changes. This smart stent integrates biodegradable nanocomposites, 3D printing, and wireless sensing, providing a noninvasive platform for restenosis and thrombosis monitoring. It marks a significant advancement in cardiovascular implants, paving the way for personalized and proactive patient care.