Fabrication of zein/modified cyclodextrin nanofibers for the stability enhancement and delivery of curcumin

Poor aqueous solubility and low stability are major problems hindering curcumin exerting potent physiological activity. To overcome these challenges, this study fabricated zein-succinic acid modified cyclodextrin (SACD) nanofibers using the electrospinning technology. By optimising the proportion of SACD in the nanofibers, homogenous cylindrical fibers with a uniform size distribution could be observed. The maximum loading capacity of the optimized nanofibers for curcumin was ca. 35.7 mg/g, as demonstrated by X-ray diffraction and differential scanning. No cytotoxicity was observed for any of the Zein/SACD and curcumin-loaded Zein/SACD (Cur-Zein/SACD) nanofibers. The stability of curcumin in the Cur-Zein/SACD nanofibers was significantly improved under conditions mimicking gastrointestinal environments and common heat sterilization processes. In a digestion study, less than 18% of the curcumin loading was released simulated upper digestive tract conditions, suggesting most of the drug cargo is able to reach the lower digestive tract and be utilized by the gut microbiota. This study suggests that Zein/SACD nanofibers could be a highly effective strategy promoting the encapsulation, stabilization and delivery of bioactive compounds, showing potential for food, pharmaceutical, and cosmetic products.