Construction of curcumin-conjugated pH-responsive lignin-based nanoparticles for alleviating oxidative stress: Stability, antioxidant activity and biocompatibility.

Curcumin has a great effect on alleviating oxidative stress, but its poor stability and low biocompatibility limit its application in therapeutic field. In order to overcome these limitations of curcumin, in this study, curcumin was grafted to lignin by esterification, and then prepared into nanoparticles. The results showed that the photothermal stability of curcumin was effectively improved. Moreover, cytotoxicity test showed that Lig-Cur nanoparticles can significantly improve the biocompatibility of curcumin. The ester bonds formed from conjugate also help Lig-Cur nanoparticles have pH-sensitivity in stimulated inflammatory tissue and release curcumin. Finally, by reducing proinflammatory factors, Lig-Cur nanoparticles could effectively scavenge reactive oxygen species (ROS). In addition to alleviating oxidative stress, Lig-Cur nanoparticles were expected to be used as a carrier platform for the treatment of many other inflammatory diseases.