Preparation and Characterization of Electrospun Colon-Specific Delivery System for Quercetin and Its Antiproliferative Effect on Cancer Cells.

To improve the oral bioavailability of quercetin (Q) and achieve colon-specific release, a core-sheath electrospun fiber mat containing Q-loaded chitosan nanoparticle (Q-loaded EFM) was developed in this study. The nanoparticle was first fabricated, and its antioxidant activity was as effective as free Q. Then the uniform Q-loaded EFM was obtained using response surface methodology optimization, and its core-sheath structure was characterized by confocal laser scanning microscopy. In vitro release kinetics confirmed the colon targeting profile, and the release rate of Q varied inversely with fiber diameter. The data of Cell Counting Kit-8 suggested Q-loaded EFM inhibited the proliferation of Caco-2 cells in a dose- and time-dependent manner with an IC50 of 4.36, 2.81, and 2.01 mg/mL after 24, 48, and 72 h, respectively, and it was caused by arresting cell cycle on G0 /G1 phase and triggering apoptotic cell death. This study suggests that the Q-loaded EFM represents a promising form in the oral therapy of colon disorders.