pH-sensitive composite nanofibers of poly(-caprolactone) loaded with iron oxide nanoparticles/ammonium bicarbonate as a nanocarrier toward efficient doxorubicin release for postsurgical cancer treatment

The concurrent use of hyperthermia and chemotherapy has attracted considerable interest in the in situ treatment of cancer after surgical resection. In this study, poly(epsilon-caprolactone) (PCL) is embedded with iron oxide nanoparticles (IONPs) and ammonium bicarbonate pH-responsive moieties that conjugate with the DOX anticancer drug incorporated into the core of nanofibers. The synthesized composite nanofibers were characterized using FESEM, EDS, FTIR, and XRD analyses. The composite nanofibers display a temperature increase in a concentration dependant manner with IONPs using an FLIR camera under AMF excitation. The main advantage of our scaffold is that it can be directly implanted in the tumor site, thus ensuring high IONP loading and higher magnetic response. When exposed to the characteristic acidic pH of tumor tissues, the ammonium bicarbonate pH-responsive moieties dissociate, releasing the DOX, and intelligently convert the pH-triggered drug release into a tumor-triggered drug release. Simultaneously, the hyperthermal capability of the IONPs in the nanofibers, generated by applying an alternating magnetic field (AMF), results in localized heating of the tumor tissues and hence synergistic tumoricidal activities. In vitro cytotoxicity experiments further confirmed that PIAD composite nanofiber mats showed an enhanced inhibitory effect against MCF7 cells by the combination of hyperthermia and chemotherapy. Therefore, the magnetic polymeric nanofibers produced by electrospinning provide a promising controlled drug delivery nanosystem for postsurgical breast cancer treatment. We present pH-sensitive magnetic nanofibers for thermo-chemotherapy. This pH-sensitive approach may offer a versatile, chemo-selective method for targeted drug delivery in postsurgical breast cancer treatment.