Nanoformulations of quercetin and cellulose nanofibers as healthcare supplements with sustained antioxidant activity.

Given its health benefits to the human body, quercetin (QT) offers promising applications in the healthcare food and pharmaceutical industries. However, the instability, low water solubility and low bioavailability of QT remain to be solved. In this paper, cellulose nanofiber (CNF) was used as an effective nanoscale carrier to alleviate these problems. By adjusting the solvent composition ratio and processing method, QT was optimally immobilized on CNF surfaces and was eventually encapsulated in the CNF matrices, forming a CNF/QT nanoformulation. A high loading capacity of 78.91% and encapsulation efficiency of 88.77% were achieved simultaneously. The nanoformulation exhibited better dietary performance and antioxidant activity than raw QT. Moreover, sustained release of QT was demonstrated in vitro. These results reveal that CNF is an ideal natural nanoscale dietary carrier and offers high encapsulation efficiency for healthcare supplementation. This work also provides a promising nanoformulation candidate for managing sustained antioxidant requirements.