Dual-stimuli-responsive poly(vinyl alcohol) nanofibers for localized cancer treatment: Magnetic hyperthermia and drug release studies

Smart materials are a promising option for a more personalized cancer treatment approach. In particular, materials that can respond to an external stimulus may be manipulated to provide a tailored response when and where it is needed. This work confined thermoresponsive poly (N-isopropyl acrylamide) microgels and superparamagnetic iron oxide nanoparticles into poly (vinyl alcohol) nanofibrous membranes. Physical and chemical crosslinking methods were tested to obtain membranes stable in physiological environments for long-term applications, and their effect on the membranes' morphology, swelling, and mechanical properties was evaluated. The results demonstrated that thermal crosslinking for 10 min is enough to obtain a robust membrane for biomedical applications that retain their components' magnetic and thermal responses. The swelling degree decreases with the increase of crosslinking time and is even smaller for chemically crosslinked membranes. Similarly, a high crosslinking degree is associated with more brittle membranes than ductile membranes with thermal crosslinking. Drug delivery assays using doxorubicin as a model drug demonstrated that only membranes with a smaller crosslinking degree are suitable for drug delivery purposes, with about 10 % of doxorubicin released for 15 days. Additionally, magnetic hyperthermia assays showed that composite membranes can increase the surrounding temperature by 10 °C in only 10 min of applying an alternating magnetic field. This work demonstrates the potential of combining stimuli-responsive materials using a simple, low-cost, and easily scalable technique (electrospinning) to produce smart materials for biomedical applications.