Surface coated zein-pectin nanoparticles for the specific delivery of resveratrol

Resveratrol is a naturally occurring polyphenolic phytoalexin produced by a wide range of different plants. Among its several beneficial effects on human health, resveratrol includes the treatment and prevention of ulcerative colitis and cancer. Despite the potential benefits that may be gained from ingestion of this natural molecule, it is often difficult to incorporate it into commercial pharmaceutical, supplement, and functional food products because of its poor water solubility, chemical instability, and low bioavailability. In addition, the resveratrol is highly degraded in the upper gastrointestinal tract, with consequent inability to reach the colon with amount enough for the therapeutic effects. With this aim, this work proposes the formulation and characterization of zein (Z) nanoparticles coated by a hydrophilic pectin (P) shell, in which resveratrol (Rsw) is encapsulated to be specifically delivered to the colon, thanks to a newly proposed additional protective coating, based on Eudragit S 100. The work describes the formulation and morphological characterization of the zein-pectin (ZP) nanoparticles (NPs) with SEM and centrifugal field flow fractionation (CF3), whose combined information allow to state that the particles have a spherical morphology with a diameter in the range of 100-200 nm. The dissolution experiments prove that the ZP nanoparticles are able to significantly increase the dissolution rate of Rsw in aqueous environments and that the dissolved drug is strongly degraded in a simulated gastrointestinal (GI)tract. The new coating of the ZP NPs with Eudragit S 100 here proposed, induced the aggregation among the particles, but the release studies of resveratrol from the ZP coated NPs allowed to evidence their potential ability to induce a specific colon delivery of this drug. This formulation can be therefore proposed for the enrichment of natural food products in order to strength of their preventive and therapeutic effects in the lower GI tract.