Co-Assembled Binary\nPolyphenol Natural Products for the Prevention and Treatment of Radiation-Induced\nSkin Injury

Radiation therapy, a fundamental treatment for tumors,\nis often accompanied by radiation-induced skin injury (RISI). Excessive\nproduction of reactive oxygen species (ROS) and subsequent inflammation\nare two key factors in RISI development that will cause skin injury\nand affect radiotherapy. Herein, the co-assembled binary polyphenol\nnatural products inspired the development of a dual-functional cascade\nmicroneedle system for prevention and treatment of RISI. Specifically,\nepigallocatechin gallate (EGCG) and curcumin (CUR) were co-assembled\ninto nanoparticles (CEPG) by intermolecular interactions and then\nincorporated with catalase (CAT) to achieve a cascade system in the\nmicroneedles (this microneedle system was conducive to penetrate into\nthe epidermal keratinocytes where RISI had the greatest impact). When\nusing microneedles, the tip dissolved rapidly and delivered CEPG and\nCAT into the dermis, where CEPG NPs were able to respond to ROS and\ndecompose into EGCG and CUR. More importantly, EGCG and CAT formed\na cascade that converts superoxide anions into water step-by-step,\nwhich can reduce cell damage caused by free radicals in the early\nstages of radiation for prevention; meanwhile, CUR inhibited inflammatory\npathways, achieving the treatment of skin inflammation in the post-radiotherapy\nperiod. These explorations broaden the strategy for the application\nof natural products in RISI.