Sviluppo di siringhe in plastica pre-riempite senza olio di silicone mediante stampaggio a iniezione di superfici microstrutturate

This thesis presents the development of silicone oil-free prefilled plastic syringes by integrating low-friction microstructured surfaces. Prefilled syringes, widely used for drug delivery, often rely on silicone oil as a lubricant to reduce friction between the rubber plunger and syringe barrel. However, silicone oil poses challenges such as protein aggregation, immunogenicity risks, and variability in drug performance. To address these issues, this research explored microtextured surfaces as a viable alternative. The study employed a multidisciplinary approach, integrating machine learning, advanced fabrication techniques, and experimental validation. Key geometrical factors influencing friction reduction, including pitch, aspect ratio, and contact pressure, were identified through data-driven analysis. Two-photon polymerization (TPP) was used to fabricate precise microstructures, demonstrating submicron accuracy and significant friction reduction in experimental tests. Microinjection molding was utilized to replicate the optimized microstructures on syringe barrels, achieving high replication fidelity and scalability. Prototypes exhibited up to a 36% reduction in friction forces compared to untextured, unsiliconized references, validating the functionality of microtexturing as a silicone oil-free alternative. While the performance was slightly higher than silicone-oiled syringes, it remained within acceptable commercial ranges. This work highlights the potential of microtexturing to enhance syringe performance, improve patient safety, and address environmental concerns associated with silicone oil. The findings provide a framework for integrating advanced manufacturing techniques and surface optimization into biomedical device development, paving the way for sustainable and innovative syringe designs.