Cyclodextrin/caffeic acid nanofibers with enhanced antioxidant activity, fast-release and fast-disintegrating properties

Abstract

Cyclodextrin (CD)/caffeic acid inclusion complex nanofibers having fast-release and orally fast-disintegrating features were generated using the electrospinning technique. Here, two types of hydroxypropylated CD (HPβCD and HPγCD) were used to create electrospun nanofibers with two different molar ratios (1 : 1 and 2 : 1 CD : caffeic acid). Caffeic acid-incorporated pullulan nanofibers were also electrospun as a control sample. All nanofibrous webs exhibited homogeneous morphology with free-standing and foldable features. Caffeic acid is a phenolic bioactive compound with poor solubility. A phase solubility study confirmed a significant increase in the solubility of caffeic acid by ∼16 and 18-fold due to complex formation. Nanofibrous webs were successfully obtained with the initial caffeic acid contents (∼5–9% (w/w)) by protecting its chemical structure. The amorphized caffeic acid, combined with the unique features of nanofibers, enabled the achievement of faster disintegration, higher release rates, and better antioxidant activity for CD/caffeic acid nanofibers compared to the polymeric sample.