Release properties of tannic acid from hydrogen bond driven antioxidative cellulose nanofibrous films

• We fabricated a nanofibrous film with TA and PEG via LBL assembly driven by hydrogen bond.
• The nanofibrous film demonstrated sustained drug release.
• TA release rate could be adjusted by both temperature and pH.
• The nanofibrous mats possess good free radical scavenging activity.

Layer-by-layer (LBL) assembled films have been exploited for surface-mediated bioactive compound delivery. Here, an antioxidative hydrogen-bonded multilayer electrospun nanofibrous film was fabricated from tannic acid (TA), acting as a polyphenolic antioxidant, and poly(ethylene glycol) (PEG) via layer-by-layer assembly. It overcame the burst release behavior of nanofibrous carrier, due to the reversible/dynamic nature of hydrogen bond, which was responded to external stimuli. The PEG/TA nanofibrous films disassembled gradually and released TA to the media, when soaked in aqueous solutions. The release rate of TA increased with increasing bilayer number, pH and temperature, but decreased with enhancing ionic strength. The surface morphology of the nanofibrous mats was observed by scanning electron microscopy (SEM). The following antioxidant activity assay revealed that it could scavenge DPPH free radicals and ABTS+ cation radicals, a major biological activity of polyphenols. This technology can be used to fabricate other phenolic-containing slowly releasing antioxidative nanofibrous films.