PHOTODYNAMIC POTENTIAL OF POLYAMIDE 6 NANOFIBERS LOADED WITH METHYLENE BLUE VIA ELECTROSPINNING

Electrospinning is a widely used technique for manufacturing polymeric nanofibers due to its simplicity, versatility, and low cost. This method enables the incorporation of photosensitive molecules into the fibers, particularly for photodynamic therapy (PDT) of dermatological diseases. In this study, polyamide 6 (PA-6) fibers were used to incorporate the photosensitizer (PS) methylene blue (MB), aiming to evaluate the potential of these fibers in PDT after the incorporation of MB. Initially, a factorial screening design was performed to determine the optimal conditions regarding the concentration of PA-6 (m/v), PS concentration (mM), voltage (kV), working distance (cm), and flow rate (mg/min) to produce reactive oxygen species (ROS). The ability of MB-loaded fibers to generate ROS was tested using a spectrophotometric method based on 1,3-diphenylisobenzofuran (DPBF) reduction, and MTT assays assessed the efficacy of PDT. The results indicated that MB-loaded fibers efficiently produced singlet oxygen, as demonstrated by the reduction rate of DPBF after 15 minutes of light irradiation. In vitro analysis using a tumor cell line (SW480) and a non-tumor cell line (HEK293) revealed that PA-6/MB fibers promoted cell death in both models. A statistically significant photodynamic effect was observed for fibers containing 10 mM MB in the SW480 cell line. These findings highlight the potential of PA-6/MB fibers in photodynamic applications, offering a promising platform for future studies in phototherapeutic approaches.