The development of bioresorbable cardiovascular stents using micro-injection molding (μim) technology presents a cost-effective and scalable solution for addressing current limitations in stent manufacturing. μim is a state-of-the-art technique designed for the precise fabrication of micro-scale components with intricate geometries and high aspect ratios, making it well-suited for biomedical applications such as cardiovascular stents. however, the technology faces unique challenges, including high heat transfer rates due to the increased surface area-to-volume ratio, narrow gate openings, and the large flow length-to-thickness (l/t) ratio characteristic of stent geometries, often exceeding 200. these challenges necessitate strategic design, material optimization, and process parameter control to achieve reliable outcomes. this study explores a comprehensive approach to the design and development of bioresorbable stents using μim. initially, structural and melt flow analyses of multiple stent geometries were conducted to identify designs compatible with the technology's limitations, such as maximum injection pressure and clamping force. a precise mold was developed, incorporating strategically optimized gate locations to facilitate uniform material flow while minimizing defects like flash and incomplete filling. to overcome the material constraints associated with pure poly-lactic acid (pla), a bio-based plasticizer, was incorporated to enhance pla's melt flow index (mfi), enabling better filling behavior during the molding process, ensuring retention of critical mechanical and biological properties. fabrication trials confirmed the feasibility of producing high-quality stents using μim, while mechanical and biomedical characterizations validated their functional performance. the stents exhibited sufficient radial strength, flexibility, and bioresorbable behavior, demonstrating their potential for clinical applications. this research underscores the promise of μim as a transformative technology for manufacturing bioresorbable cardiovascular stents, offering a pathway to cost-effective mass production while addressing critical fabrication challenges. the findings provide valuable insights into the interplay of design, material properties, and process parameters, contributing to the advancement of next-generation biomedical implants.
Date :04-12-2024
The innovation presented in this research revolutionizes the manufacturing of stents by utilizing micro-injection molding (μIM) for high length-to-thickness ratio geometries. This breakthrough enhances precision, scalability, and cost-effectiveness, addressing key challenges in stent production. The study demonstrates the feasibility of fabricating complex stent structures with superior dimensional accuracy and minimal material wastage, ensuring high performance in cardiovascular applications. Through the strategic modification of materials and optimization of mold designs, this work paves the way for mass production of bioresorbable stents, providing a sustainable and accessible solution to meet the growing demand for advanced medical devices.