5-aminolevulinic acid-incorporated poly(vinyl alcohol) nanofiber-coated metal stent for application in photodynamic therapy

BACKGROUND The study investigated the use of combined photodynamic therapy (PDT) and stent placement for the treatment of cholangiocarcinoma (CC). For this purpose, 5-aminolevulinic acid (ALA) was incorporated into poly(vinyl alcohol) (PVA) nanofiber, and coated onto metal stents. Their efficacy was assessed in PDT towards HuCC-T1 CC cells. METHODS Fabrication of ALA-PVA nanofiber, and simultaneous coating onto metal stents, was performed through electrospinning. The dark-toxicity, generation of protoporphyrin IX (PpIX), and PDT effect of ALA and ALA-PVA nanofiber were studied in vitro, using HuCC-T1 CC cells. RESULTS The ALA-PVA nanofibers were coated onto metal stents less than 1000 nm in diameter. ALA-only displayed marginal cytotoxicity; ALA-PVA nanofiber showed less cytotoxicity. PpIX generation was not sigficantly different between ALA and ALA-PVA nanofiber treatments. PVA itself did not generate PpIX in tumor cells. ALA and ALA-PVA nanofiber displayed a similar PDT effect on tumor cells. Cell viability was decreased, dose-dependently, until ALA concentration reached 100 μg/mL. Necrosis and apoptosis of tumor cells occurred similarly for ALA and ALA- PVA nanofiber treatments. CONCLUSION The ALA-PVA nanofiber-coated stent is a promising candidate for therapeutic use with cholangiocarcinoma.