Harmine-loaded PCL/PVA multilayer nanofibers for targeted pancreatic cancer therapy

Pancreatic cancer remains one of the deadliest malignancies because of late diagnosis, rapid metastasis, and poor response to conventional therapies. Localized drug delivery systems based on electrospun nanofibers may improve therapeutic outcomes by enabling sustained local drug release while minimizing systemic toxicity. This study developed harmine (HAR)-loaded multilayer nanofibers using polycaprolactone (PCL) and polyvinyl alcohol (PVA) and evaluated their physicochemical characteristics and anti-cancer effects against ASPC-1 pancreatic cancer cells. Bilayer and trilayer HAR-loaded nanofibers were successfully fabricated with uniform, bead-free morphology. Morphology was characterized by FE-SEM, and drug incorporation was confirmed by FTIR analysis. The multilayer architecture demonstrated favorable swelling behavior, controlled degradation, and regulated water vapor transmission. Drug release studies showed an initial burst release (~ 16% within 6 h), followed by sustained HAR release reaching approximately 68% over 72 h. Blank nanofibers exhibited high biocompatibility (> 97% cell viability). Compared with free HAR, HAR-loaded nanofibers (NFs) significantly enhanced anti-cancer efficacy and achieved nearly complete suppression of viability in ASPC-1 cells after 72 h. Functional analyses demonstrated substantial inhibition of cell migration and colony formation. Molecular evaluation revealed significant apoptosis induction through upregulation of BAX and CASP3 and downregulation of BCL-2, with the PCL/PVAHAR formulation showing the strongest response (BAX ≈ 4.8-fold, CASP3 ≈ 3.9-fold, BCL-2 ≈ 0.35-fold; BAX/BCL-2 ratio ≈ 13.7). STRING analysis further supported the involvement of apoptosis-associated signaling pathways. HAR-loaded PCL/PVA nanofibers provide an effective localized drug-delivery platform with sustained release and enhanced anti-pancreatic-cancer activity compared with free HAR. These findings support the further development of this system as a potential implantable therapeutic strategy for post-resection pancreatic cancer management.