Novel nano-electrospuns with superparamagnetic and NIR photo-responsive behaviors as smart drug delivery systems and biomedical applications

Smart Drug Delivery Systems (SDDSs) are advanced platforms enabling controlled and stimuli-responsive drug release. Among external stimuli, near-infrared (NIR) light and magnetic fields are particularly attractive due to their non-invasive activation and tunable energy conversion. Multifunctional electrospun scaffolds (PCI) based on poly(butylene succinate) (PBS), ciprofloxacin (CPX), and iron oxide nanopowder (INPs, d < 50 nm) as a low-cost superparamagnetic component has been exhaustively explored, reporting the use of INP as photothermal agent in electrospun scaffolds, enabling high nanoparticle loading and NIR-triggered drug release, a strategy still scarcely explored in electrospun systems. This powder-based strategy simplifies formulation compared to stabilized SPION dispersions while preserving magnetic and photothermal functionalities. The resulting mats exhibited uniform, defect-free fibers with tunable mechanical properties and sustained CPX release (≈40% over 11 days), which increased to ≈60% under NIR irradiation. INPs imparted superparamagnetic behavior, NIR responsiveness, and MRI and X-ray detectability, while CPX improved fiber morphology and surface wettability. High cell viability (>85%) confirmed the cytocompatibility of the scaffolds. Comprehensive characterization included morphology, wettability, thermal and mechanical properties, NIR response, and drug release. Magnetic properties were evaluated using a cost-effective sensor-based approach (Hall sensors and fluxgate magnetometer), confirming superparamagnetic behavior. By coupling NIR-triggered drug release with MRI detectability, PCI scaffolds provide a compact theranostic platform for localized biomedical applications. Overall, PCI scaffolds represent a scalable and cost-effective multifunctional platform integrating controlled drug delivery, photothermal responsiveness, and imaging capability, showing strong potential for advanced biomedical applications.