Functional PVA/VB2/TiO₂ Nanofiber Webs for Controlled Drug Delivery

Drug (vitamin B2, riboflavin, VB2)/nanoparticle (TiO₂, coated on drug surface) loaded poly(vinyl alcohol) (PVA) nanofiber webs were successfully produced by the electrospinning process. The characteristics of nanofiber structure, chemical composition, mechanical properties, and drug-release properties were investigated. The morphology and diameter of nanofibers were analyzed by atomic force microscopy and scanning electron microscopy. The chemical composition and mechanical properties of nanofiber webs were examined by Fourier transform infrared spectroscopy and Instron tensile tester. The drug-release properties of nanofiber webs were studied by liquid chromatography-mass spectrometry (LC-MS/MS). The influences of TiO₂:VB2 ratios (0, 18:1, 9:1, 4.5:1, 2.25:1, and 1:1) and releasing time on release behavior of PVA/VB2/TiO₂ nanofiber webs were also investigated, with the corresponding virgin PVA nanofibers and LC-MS grade water as control. Among all of the tested samples, PVA/VB2/TiO₂ nanofiber webs with TiO₂:VB2 ratios of 18:1 and 9:1 exhibited a steady release rate with 60% of VB2 released around 168 h and all VB2 released around 10 days. In addition, by coating VB2 with TiO₂, the burst release was effectively prevented due to three mechanisms: surface modification, polymer morphology, and coated surface. The results in this study indicate drug-loaded and nanoparticle-coated hydrophilic nanofiber webs are useful candidates for steady drug release in the drug delivery application field.